Posts Tagged ‘antihistamines’

Generic Name
Deferasirox (deh-fur-ASS-sih-rox)
Brand Name Exjade
Type of Drug
Iron chelating agent. Prescribed For
Chronic iron overload. General Information
Deferasirox binds with iron in stored in the liver. It can also bind small amounts of zinc and copper but the importance of these effects are not known. Almost 3/4 of every dose is absorbed into the bloodstream. Most of the drug is broken down in the liver and passes out of the body in the feces. Women clear this drug from their bodies 17.5% slower than men, but this has not affected how it is used or the doses given.
Cautions and Warnings
Do not take deferasirox if you are allergic or sensitive to any of its ingredients. Most reactions occur within the first month of treatment.
People with liver disease should have monthly blood tests while taking deferasirox.
Kidney failure has developed in people taking deferasirox with fatal results in some cases. People with or those who are at risk of kidney failure should have routine kidney monitoring while taking this medication. People who are at risk for kidney failure in-ciudes seniors, those with kidney disease, and people taking medicines that affect kidney function. Dose adjustment may be needed.
Deferasirox has been associated with potentially severe reduced white-blood-cell and platelet counts, usually in people with preexisting blood disorders.
Rarely, deferasirox has caused hearing loss and eye problems. You should have a full hearing and eye exam before starting on this drug and once a year thereafter.
Skin rash can occur with this medicine. If it is severe, the drug may have to be temporarily stopped. It may be restarted at a lower dosage.
Possible Side Effects
♦    Most common: fever, headache, abdominal pain, cough, sore throat, nasal irritation, diarrhea, flu symptoms, nausea, and vomiting.
✓    Common: respiratory infections, bronchitis, runny nose, rash, upper abdominal pain, joint pain, back pain, tonsillitis, and ear infection.
✓    Less common: itching.
✓    Rare: stomach pain, swelling in the arms or legs, sleep disorder, skin color changes, dizziness, anxiety, gallstones, fatigue, early cataract and hearing loss, some visual haziness, and other eye disorders. Contact your doctor if you experience anything unusual.
Drug Interactions
•    Do not mix antacids containing aluminum with deferasirox. They can prevent it from being absorbed.
Food Interactions
This drug should be taken at the same time every day on an empAq stomach, 30 minutes before eating.
Ustlak 13bSe
Adult and Child (age 2 and over): 9-13.6 mg per lb. of body weight once a day. Dose adjustments will be made according to your response. See “Special Information” for a specific instructions on how to take these tablets.
Overdosage
Large doses of 2-3 times the prescribed amount taken for several weeks with no adverse effects have occurred. Overdose symptoms include hepatitis (mild fever, muscle or joint aches, nausea, vomiting, appetite loss, slight abdominal pain, diarrhea, and fatigue) and some drug side effects. Take the victim to a hospital emergency room for treatment because the heart may be affected. ALWAYS bring the prescription bottle or container.
Special Information
Call your doctor at once if you develop a severe skin rash.
You must have regular vision and hearing tests while taking deferasirox.
Deferasirox tablets should not be chewed or swallowed whole. They must first be mixed completely in 1/2-1 glass of water, orange juice, or apple juice. The tablet will not dissolve but tablet particles will become suspended in the liquid. Drink the resulting sus-Pension immediately. If there is anything left in the glass after drinking the suspension, add a small amount of liquid, mix it with the remaining tablet particles and drink it.
This drug can cause dizziness. Be cautious while driving, operating machinery, or doing anything that requires intense concentration.
If you forget a dose, take it as soon as you remember. If it is almost time for the next dose, skip the one you forgot and continue with your regular schedule. Do not take a double dose.
Special Populations
Pregnancy/Breast-feeding: There are no studies of ranolazine in pregnant women or of its effect on the developing fetus. Pregnant women should take this drug only if its potential benefits outweigh the risks.
This drug may pass into breast milk. Nursing mothers should consider using infant formula.
Seniors: Seniors may experience more drug side effects than younger adults due to greater chances of reduced kidney, liver, and heart function; other diseases; or drug side effects.

Generic Name
Desmopressin (dez-moe-PRES-in)
Brand Names
DDAVP Minirin
Type of Drug
Pituitary hormone replacement.
Stimate
Prescribed For
Nighttime bed-wetting and diabetes insipidus (central or cranial diabetes); also used to control bleeding in certain forms of hemophilia A and von Willebrand’s disease.
General Information
Desmopressin acetate is a synthetic version of antidiuretic hormone (ADH). When ADH is lacking, the body has difficulty retaining fluid. People lacking ADH experience excessive thirst, increased urination, and dehydration; desmopressin controls these symptoms. When used for nighttime bed-wetting, desmopressin should be used in conjunction with behavioral or other non-drug therapies.
Cautions and Warnings
Do not take desmopressin if you are allergic or sensitive to any of its ingredients.
People, especially children and seniors and people with cystic fibrosis and electrolyte imbalances, should only drink enough fluid to satisfy their thirst while taking desmopressin because of the risk of water intoxication, which can result in seizures that could lead to coma. People with coronary artery disease, heart disease, or high blood pressure should use this drug with caution.
Heart attacks and St&D’KeS after treatment with desmopressin MV~bEbn reported in people at risk for them, but there is no definite link to desmopressin use.
People using desmopressin should have their urine checked regularly by their doctor. Your doctor should also check for nasal swelling, congestion, and scarring.
Drug Interactions
experience in blood pressure, loss of sodium, symptoms include coma, confusion, ng headache, decreased urination, rapid
zures), edema, stomach or abdominal dness or flushing of the skin, passing ain, and stuffy or runny nose. Contact perience any side effect not listed above.
Possible Side Effects
V Rare: slight increase
intoxication (
drowsiness, continuin
gain, and seizures)
nausea, rednes
vulvar pain
doctor if you
•    Desmopressin may increase the effects of other drugs that raise blood pressure. This only happens with large dosages.
•    Chlorpropamide and carbamazepine may increase the effects of desmopressin.
Food Interactions None known.
Usual Dose
Nasal Solution—Nighttime Bed-Wetting
Adult and Child (age 6 and over): 20 mcg (0.2 mL) at bedtime. Child (under age 6): not recommended.
Nasal Solution—Diabetes Insipidus
Adult: 0.1-0.4 mL a day in 1-3 doses.
Child (age 3 months-12 years): 0.05-0.3 mL a day in 1-2 doses.
Tablets—Nighttime Bed-wetting
Adult and Child (age 6 and over): Begin with 0.2 mg at bedtime, adjusting to individual need up to 0.6 mg.
Child (under age 6): not recommended.
Tablets—Diabetes Insipidus
Adult: Begin with 0.05 mg twice a day. Daily dosage should be increased according to individual need, up to 1.2 mg a day divided into 2-3 doses.
Child (age 4 aid over): Begin with 0.05 mg and adjust according to individual need.
Child (under age 4): not recommended.
Overdosage
Symptoms include headache, difficulty breathing, abdominal cramps, nausea, and facial flushing. Call your doctor or a hospi-tal emergency room if you suspect an overdose. Because there is no known antidote to desmopressin, your dosage may be temporarily reduced until overdose symptoms subside. If you seek treatment, ALWAYS bring the prescription bottle or container.
Special Information
Call your doctor if you develop headache, breathing difficulties, heartburn, nausea, abdominal or stomach cramps, or vulvar pain.
The Stimate Nasal Solution spray pump and Minirin spray must be primed before its first use. To prime the pump, press down 4 times. Stimate delivers 25 doses per bottle. Throw away the bottle after 25 doses have been used, because anything remaining after the 25th dose is likely to deliver less drug than is needed.
If you forget a dose of desmopressin, take it as soon as you remember. If you don’t remember until your next dose, skip the forgotten dose and continue with your regular schedule. Do not take a double dose.
Special Populations
Pregnancy/Breast-feeding: The safety of using desmopressin during pregnancy is not known, though it has been used to treat diabetes insipidus in pregnant women without apparent harm to the fetus. When this drug is considered crucial by your doctor, its potential benefits must be carefully weighed against its risks.
Desmopressin may pass into breast milk. Nursing mothers who must use this drug should use infant formula.
Seniors: Seniors should avoid drinking too much fluid while taking desmopressin.

Generic Name
Diazepam (dye-AZ-uh-pam) rVg_l
Brand Names
Diastat    Valium
Diazepam Intensol    Valrelease
The information in this profile also applies to the following drugs:
Lorazepam &
Ativan    Lorazepam Intensol
Oxazepam M
Type of Drug  Benzodiazepine sedative.
Prescribed For
Anxiety, tension, fatigue, agitation (particularly due to alcohol withdrawal), muscle spasm, and seizures; also prescribed for irritable bowel syndrome and panic attacks.
General Information
Diazepam and other benzodiazepines directly affect the brain. They can relax you and make you more tranquil or sleepy, or they can slow nervous system transmissions in such a way as to act as an anticonvulsant.
Cautions and Warnings
Do not take diazepam if you know you are allergic or sensitive to any of its ingredients or to another benzodiazepine drug, including clonazepam.
Diazepam can aggravate narrow-angle glaucoma, but you may take it if you have open-angle glaucoma and are receiving therapy for it.
Other conditions in which diazepam should be avoided are severe depression, severe lung disease, steep apnea (intermittent cessation of breathing during sleep), liver disease, drunkenness, and kidney disease. In all of these conditions, the depressive effects of diazepam may be enhanced or could be detrimental to your overall condition.
Diazepam should not be taken by psychotic patients. It is not effective for them and can trigger unusual excitement, stimulation, and rage.
Diazepam is not intended for more \han 3-4 months of continuous use. Your comikkni) should be reassessed before continuing YOU( MS-16cation beyond that time.
Diazepam may be addictive. It should be used with caution in people with a history of drug dependence.
Drug withdrawal may develop if you stop taking it after only 4 weeks of regular use but is more likely after longer use. It may start with anxiety and progress to tingling in the hands or feet, sensi-tivity to bright light, sleep disturbances, cramps, tremors, muscle tension or twitching, poor concentration, flu-like symptoms, fatigue, appetite loss, sweating, and changes in mental state. Your dosage should always be reduced gradually to prevent drug withdrawal symptoms.
Possible Side Effects
Y Most common: mild drowsiness during the first few days of therapy. Weakness and confusion may occur, especially in seniors and in those who are sickly. If these effects persist, contact your doctor.
♦ Less common: depression, lethargy, disorientation, headache, inactivity, slurred speech, stupor, dizziness, tremors, constipation, dry mouth, nausea, inability to control urination, sexual difficulties, irregular menstrual cycle, changes in heart rhythm, low blood pressure, fluid retention, blurred or double vision, itching, rash, hiccups, nervousness, hysteria, psychosis, inability to fall asleep, and occasional liver dysfunction. If you have any of these symptoms, stop taking the drug and contact your doctor at once.
•    Rare: Rare side effects can affect your heart, stomach and intestines, urinary tract, blood, muscles, and joints. Contact your doctor if you experience any side effect not listed above.
Drug Interactions
•    Diazepam is a central-nervous-system depressant. Avoid alcohol, other sedatives, narcotics, barbiturates, monoamine oxidase inhibitor antidepressants, antihistamines, and antidepressants. Taking diazepam with these drugs may lead to excessive depression, drowsiness, or difficulty breathing.
•    Smoking may reduce diazepam’s effectiveness by increasing the rate at which it is broken down by the body.
•    Effects of diazepam may be prolonged when taken with cimeti(1(m,, Contraceptive drugs, disulfiram, fluoxetine, isoniazid, ketoconazole, rifampin, metoprolol, probenecid, propoxyphene, propranolol, and valproic acid.
•    Theophylline may reduce the sedative effects of diazepam.
•    If you take antacids, separate them from your diazepam dose by at least 1 hour to prevent them from interfering with the passage of diazepam into the bloodstream.
•    Diazepam may increase blood levels of digoxin and the chances for digoxin toxicity.
•    Levodopa + carbidopa’s effects may be decreased if it is taken with diazepam.
Combining diazepam and phenytoin may increase phenytoin blood concentrations and the risk of phenytoin toxicity.
Food Interactions
Diazepam is best taken on an empty stomach, but it may be taken with food if it upsets your stomach.
Usual Dose
Solution or Tablets
Adult’. 2-40 mg a day. Dosage must be adjusted to individual response for maximum effect. In seniors, less of the drug is usually required to control tension and anxiety.
Child (6 months and over): 1-2.5 mg 3 or 4 times a day; more may be needed to control anxiety and tension.
Child (under 6 months): not recommended.
Rectal Gel
Adult and Child (age 12 and over): 0.09 mg per lb. of body weight. Approximate dosage: 5 mg if 31-60 lbs., 10 mg if 61 -110 lbs., 15 mg if 111-165 lbs., or 20 mg if 166-244 lbs.
Child (age 6-11): 0.14 mg per lb. of body weight. Approximate dosage: 5 mg if 22-40 lbs., 10 mg if 41-82 lbs., 15 mg if 83-121 lbs., or 20 mg if 122-163 lbs.
Child (age 2-5): 0.23 mg per lb. of body weight. Approximate dosage: 5 mg if 13-24 lbs., 10 mg if 25-49 lbs., 15 mg if 50-73 lbs., or 20 mg if 74-97 lbs.
An extra 2.5 mg of the rectal gel may be given if a more precise dosage is needed or as a partial replacement for people who do not retain the full dosage after it is first inserted rectally.
Overdosage
SYMPUns of overdose include confusion, sleepiness, poor coordination, lack of response to pain, loss of reflexes, shallow breathing, low blood pressure, and coma. The victim should be taken to a hospital emergency room. ALWAYS bring the prescription bottle or container.

dimethicone Activated dimethicone is an antifoaming agent, said to reduce flatulence and protect mucous
membranes. It is a constituent of many antacid preparations. It is also present in some water-repellent skin creams.
dipipanana A rapidly acting morphine-like analgesic of value in the sever rain 4 to -1 dk–
Dose: 30-3450 mg (fail),, but it is usually• given in association with cyclizine as Diconal. The side-effects are similar to those of morphine.
dipivefrine A pro-drug that is converted into adrenaline after absorption. It is used
in chronic open angled- glaucoma as eye
drops (0.1%). (Propine). See page 138 and Table 16.
dimethylsulphoxide (DMSO) An organic liquid, it has been used for the symptomatic relief of interstitial cystitis
(Hunner’s ulcer) by the bladder instillation of 50 ml of a 50% solution. (Rimso-50).
dinoprost Prostaglandin F,.. It has actions and uses similar to dinoprostone.
(Prostin 112).
dinoprostone A synthetic form of prostaglandin E,. It has been used to initiate contractions of the pregnant uterus. Dose: 500 pg orally to induce labour, repeated if necessary at hourly intervals; as vaginal tablets or gel, 3 mg. Side-effects are nausea, diarrhoea, shivering and dizziness. (Prostin E2; Prepidil).
dioctyl sodium sulphosuccinate See dOCUSalC.
diodone injection A solution of a complex organic iodine compound, used as a contrast agent in X-ray examination of kidneys and ureters.
diphenhydramine One of the early antihistamines, with a more sedative action, and use(] in the temporary relief of insomnia. Dose: 10-25 trig. (Medinex. Nytol). It is also present in some cough preparations and nasal decongestants.
diphenoxylate A derivative that resembles codeine III reducing intestinal activity. It is used for the symptomatic relief of diarrhoea, and is usually given with a small dose of atropine to discourage excessive dosage and to reduce the risk of dependence. Dose: 10 mg initially, then 5 nig every 6 hours as required. (Lomotil;’Fropergen).
diphenylpyraline An antihistamine used as .I decongestant in colds and sinusitis. Present in Eskornadc.
dipyridamole An inhibitor of thrombus formation by reducing the adhesiveness of blood platelets in the arterial circulation. Dose: 300-600 mg daily before food. s I
ide-effects include nausea, diarrhoea and headache. (Persantill).
disodium cromoglycate See sodium cromoglycatc.
disodium etidronate See etidronate. disodium pamidronate See pamidronate.
disopyramide A quinidine-like drug used in the treatment of cardiac arrhythmias especially after myocardial infarction. Dose: 300-800 mg daily; dose by slow i.v. injection under ECG cover, 2 nig/kg up to 150 mg, followed by oral therapy as soon as possible. By its anticholinergic action care is necessary in glaucoma and prostatic enlargement. Contraindicated in heart block. (Dirythmin; Rythmodan). See page 1;6 and “fable 24.
distigmine An inhibitor of cholinesterase similar to neostigmine but with a longer action.
Dose: in the control of myasthenia gravis 5-20 mg as a single morning dose before breakfast; in urinary retention after surgery, 5 trig daily. It is sometimes used in neurogenic bladder disorders. Side-effects are nausea, abdominal cramp, diarrhoea and weakness. (Ubretid).
disulfiram When taken with even small amounts of alcohol, disulfiram permits the accumulation of acetaldehyde in the body, with side-effects such a flushing, giddiness, vomiting and headache that may be severe. Distilfiram is used in chronic alcoholism, but prolonged treatment and co-operation of the patient are essential.

Dose: after at least 24 alcohol free hours: 800 nig on the first day, falling over 5 days to 100-200 mg daily. Acute confusion may occur if given at the same time as tucLro-
llidazole. (Antabuse).
dithranol Synthetic compound used locally in the treatment of psoriasis. It is a powerful irritant, and treatment should be commenced with a simple ointment or zinc paste containing 0.1% ofdithranol, gradually increased to 1% if well tolerated. Higher concentrations are sometimes used in ’short -contact -time’ therapy.
Dose: 100 mg/m’ by i.v. infusion over
I hour. Rapid and severe hypersensitivity reactions (hypotension, bronchospasm) may occur, and treatment must be irrnediat4y available. Reaction risks may be reduced by premedication with jexalnetha&one given the day before treatment and continued for 5 days. Rash, pruritus and neutropenia may occur, and blood counts and liver function tests are necessary. (Taxotere). See page 122 and Table 8.
docusate A surface-active agent used as a faeces -softening laxative.
Dose: ill, to 500 nig daily. (Dioctyl).
diuretics The most widely used group of diuretics is the thiazides, represented by bendrofluazide (see page 14I ). They act mainly by increasing the excretion of
sodium by inhibiting its re-absorption by the distal tubule of the kidney, and evoke a rapid response which may persist over 12-24 hours, although some, such as chlorthalidone, have a still longer action. They are given in mild cardiac failure, oedema and in hypertension, but in more severe conditions, and in pulmonary occlema, the more powerful ‘loop’ diuretics, such as frusemide, which act at a different point, are preferred. A side-effect of some thiazides is an increase in the excretion of potassium which may require the use of potassium supplements or a change to a potassium sparing diuretic such as trianiterene. Spironolactone, an aldosterone antagonist, is a more powerful diuretic, of value in resistant oedema. Osmotic diuretics such as mannitol are used mainly in cerebral oedema. Simple diuretics such as potas slum citrate arc mainly used to alkalize the urine and promote diuresis in cystitis and similar conditions. See page 141 and Table 18.
dobutamine A sympathomimetic agent similar to isoprenaline, but with a more selective stimulant action on the beta, receptors in the heart. It increases cardiac contractility but is less likely to cause tachycardia. Useful in acute heart failure and cardiogenic and septic shock. Dose: 2.5-5 pg/kg/min by i.v, infusion, carefully adjusted to need. (Dobutr= Posiject). See page 141 and Table 18.
docetaxel A potent cytotoxic agent derived from the Pacific Yew. Used in advanced breast cancer resistant to other therapy.
domperidone An antiemetic that functions as a dopamine antagonist, as it prevents dopamine from reaching the receptors in the chemoreceptor trigger zone (see antiemetics). It is mainly of value in the severe nausea and vomiting caused by cytotoxic drugs, and is also useful in fum clonal dyspepsia. It is of little value in postoperative and travel sickness.
Dose: 10-20 mg 4-8-hourly; 30-60 nig by suppository. Sedative side-effects are infrequent, as domperidone does not cross the blood-brain barrier. (Motilium). See page 77.
donepezil A reversible inhibitor of anti-cholinesterase. Alzheimer’s disease is linked with a deficiency of acetylcholine in the brain, and donepezil may relieve sonic of the symptoms of that disease by increasing brain acetylcholine.
Dose: 5-10 mg at night. Diarrhoea and muscle cramps are side-effects. (Aricept ).
dopamine A sympathomimetic agent with actions and uses similar to dobutamine. Dose: 2.5-10 pg/kg/min by slow i.v. infusion. Careful control ofdose is essential, as dopamine may cause vasoconstriction with higher doses and increase the risk of heart failure. (Intropin). Dopamine is also a central neurotransinifter, and a deficiency is associated with parkinsonism. See levodopa, page 141 and “table 18.
dopexamine A short-acting drug of the dopamine type but with a more powerful action on the 0,-receptors. It is used in heart failure during cardiac surgery.

chymotrypsin A proteolytic enzyme of the pancreas used in ophthalmology to facilitate intracapsular lens extraction. (Zonulysin).
cidofovir An antiviral agent used in cytomegalovirus retinitis resistant to ganciclivir.
Dose: 5 nig/kg by i.v. infusion every 2 weeks. (Vistide). See page 144 and ‘['able 19.
cilastatin See imipenem.
chlorthalidone A diuretic similar in action and uses to bendrofluazide, but with a longer duration of activity that permits a single morning dose. It is also useful in diabetes insipidus.
Dose: as diuretic 50-100 mg daily or on .illci nale days; in hypertension 25-50 mg; up to 350 mg daily in diabetes insipidus. (I lygrolon ). See page 148 and Table 21.
cholecalciferol See vitamin D.
cholestyramine An exchange resin that binds with bile acids in the intestines and prevents their absorption. Such acids are essential for cholesterol synthesis, and resin-binding leads indirectly to a lowering of plasma cholesterol levels.
Dose: in hyperlipidaemia: 12-24 g daily, wilh water; similar doses in the diarrhoea of Crohn's disease. It is also used in doses of 4-8 g daily to relieve the pruritus
associated with biliary obstruction. Side-effects are rash and gastrointestinal disturbances. Cholestyramine and related agents may interfere with the absorption of anticoagulants and other drugs. iQuestrari). See page 146 and Table 20.
choline theophyllinate A bronchodilator ,ilh the actions, uses and side-effects of anlinophyllille.
Dose: 400-1600 mg daily, after food. (C'I ioledyl). See page 118 and Table 6.
chorionic gonadotrophin A gonad-stimulating hormone prepared from the Urine of pregnancy. It has bten used in anovulalory sterility, metropathia haernorrhagica, habitual abortion and undescended testis.
cilazapril A long-acting ACE inhibitor with the actions, uses and side-effects of that group of drugs.
Dose: in essential hypertension 1 mg daily initially, increased up to 5 mg daily according to need. In renovascular hypertension 0.25-0.5 mg daily. (Vascace). See page 148 and'I'able 21.
cimitidine A selective histamine H, receptor antagonist. Unlike ordinary antihistamines, it inhibits gastric secretion, and is used in the treatment of peptic ulcer and other conditions of gastric hyperacidity. Dose: 8(m) nig daily for at least 4 weeks, doubled in severe conditions. Dose by i.m. or slow i.v. injection 200 mg 4-4-hourly. The dose should be reduce(] in renal impairment. The drug may increase the effects of oral anticoagulants and phenytoi ii. Side-effects include diarrhoea, rash and dizziness. It has some anti-androgen activity, and gynaecomastia is all occasional side-effect with high closes. (Dysparneu Tagarnet; Zila). See page 162 and Table 27.
cinchor-aine A local anaesthetic used as
ointment 1% in haemorrhoids and
pruritus. (Nupercainal).
cinnarizine An antihistamine, chiefly of value in Wniere’s disease, although it is also used in travel sickness and in peripheral vascular disorders.
Dose: 45-90 ing daily. Drowsiness and gastrointestinal disturbances are side-effects. (Stugeron).
cinoxacin A quinolone derivative with actions, uses and side-effects similar to i hose of nalidixic acid.

Dose: in urinary tract infections,  daily; prophylaxis 500mg daily. Contraindicated in severe renal impairment. (Cinobac).
ciprofbrate A blood-lipid lowering agent used in diet-resistant hyperlipidaemia as a single daily dose of 100-200 mg. (Modalim). See page 146 and Table 20.
ciprofloxacin A quinolone with a wide range of activity against both Gram-positive and Gram-negative bacteria, including Pseudomonas and Fronts. It is effective in many systemic infections, as well as in bone, joint and urinary infections, and in gonorrhoea, but is indicated mainly in infections resistant to other antibacterial agents. Dose: 500 mg -1.5 g daily for 5-7 days; in gonorrhoea, a single dose of 250 mg is given. In severe infections 200-400 mg daily by i.v, infusion for 5-7 days. Side-effects include nausea, dizziness, headache, rash and pruritus. plasma levels of theophylline may be increased and should be closely controlled. Care is necessary in convulsive disorders. (Ciproxin).
cisapride A gastrointestinal stimulant given to relieve gastro-oesophageal reflex and delayed gastric emptying.
Dose: .10-40 mg daily before meals, and at night, for some weeks. Side-effects are abdominal pain and diarrhoea. Drugs that delay the excretion of cisapride and may cause arrhythmias are erythromycin and clarithromycin-antigungal agents of the ketoconazole type should also be avoided. Unlike metoclopramide, it has no central antiemetic properties. (Alimix; Prepulsin).
cisatracurium A non-depolarizing neuromuscular blocking agent with an intermediate duration of activity. It is used as a muscle- relaxing adjunct in general anaesthesia, and to facilitate tracheal ininhation. (Nimbly).
cisplatin A cytotoxic agent containing platinum bound in an organic complex. The action is linked with drug-induced changes in DNA structure that inhibit cell development. It is used in ovarian, testicular and other solid tumours, and in resistant malignant conditions, sometimes in association with other antineoplastic agents.
Dose: by i.v.  for 5 days a month, or 15-120 mgIm’ monthly. Blood tests are essential
throughout treatment. Side-effects, which may be severe, include nausea, vomiting, and oto-, nephro- anti
citalopram A selective serotoninreuptake inhibitor (SSRI).
Dose: used in depression in single daily doses of 20 ing, increased up to 40 mg daily. Treatment for at least 6 months necessary to avoid relapse. (Cipraruil). See page 128 and Table 11.
cladribine A new agent used by specialists in hairy cell leukaemia. (Leustat).
clarithronlycin A macrolide antibiotic similar to erythromycin, but with better absorption and reduced gastrointestinal side-effects.
Dose: 250 rug twice a day for 7 days, doubled in severe infections. Care in hepatic an([ renal impairment. It may potentiate the effects of warfarin and digoxin. Should not be given with astemizole or terfenadine (risk of arrhythinias). (Khricid).
clavulanic acid An inhibitor of betalactanlase. Many penicillin-resistant organisms contain that enzyme in the cell wall, which inactivates the penicillin before it call enter the cell and exert its bacterial action. clavulanic acid inhibits such enzyme activity, and so facilitates the penetration of the antibiotic into the bacterial cell. It is used in association with amoxycillin as coamoxiclav (Augmentin) and with ticarcillin as Tinientin, in the treatment of infections due to amoxycillin-resistant bacteria.
clemastine An antihistamine used in allergic rhinitis, urticaria and allergic derniatoses.
Dose: I mg twice a day. In common with other antihistamines, it may cause drowsiness, and anticholinergic side-effects such as dryness of the mouth. H avegil). See
page 110 and Table 2.
clindamycin An antibiotic used mainly in staphylococcal bone and joint infections not responding to other drugs. It is also useful in anaerobic abdominal infections.  A serious side-effect is a potentially fatal pseudomernbranous colitis, and the drug should be withdrawn immediately if diarrhoea occurs. See vancomycin and nietronidazole.

No single factor lies behind the allergy epidemic — the causes are many and various (see p. 20). What this means for parents interested in allergy prevention is that there is no

single measure which will ensure that your children do not develop allergies. Instead there are a great many different things that can be done, each of which reduces the risk to

some extent. The more of these you do, the lower the risk becomes.
Avoiding allergens
Starting before the birth is best, if you want to reduce allergen exposure for your child (see p. 240). But if you have missed the boat with that one, don’t despair – there is

still a lot to be gained by reducing allergen exposure at a later stage.
If you are ridding your home of allergens after the child’s birth, bear in mind that things will get worse before they get better– there will be a temporary surge in airborne

allergen as a result of the clean-up operation, and you will need to protect the child from this. The best strategy is for the child to be away for a few days while the work is

done, especially if you are taking out carpets, furniture or mattresses. Remember to protect yourself as well, if you are allergy-prone (see p. 109).
One of the most important steps you can take to reduce allergen levels is improve the natural ventilation of your home. This lowers the humidity (assuming you don’t live in an

extremely humid climate), which helps combat both moulds and dust mites. Ventilation also flushes out allergens in the air, especially cat, dog and mould allergens. Half the

problem with modern houses is that the airtight seals around doors and windows, introduced to conserve heat and save energy, turn the indoor air into a rich stew of allergens

and irritants.
House-dust mite
Avoiding high levels of house-dust mite in the home is one of the most valuable things you can do to reduce the risk of allergies in your child. Not only is house-dust mite a

powerful allergen in its own right, it may also act as an agent provocateur as far as the immune system is concerned (see p. 12), and may help to initiate allergic reactions to

other potential allergens – such as those from pets or indoor moulds.
Even if you do nothing else to protect your new baby from mite allergen, at least buy a new mattress and pillow for the cot, with ready-fitted allergen-proof covers. Do the same

for the portable crib, if you have one. Choose anti-mite products that are designed for babies and are guaranteed safe – there is a risk of suffocation with some loose covers

sold for older children and adults (see p. 245).
You may want to eliminate house-dust mite from your own bed as well as the baby’s, because there will probably be times when you take the baby into bed with you for a feed or a

cuddle – and times when, as a toddler, he or she just barges in! It is good to know that your child is still breathing air free from dust-mite allergen in these circumstances.
Deal with your own bed as soon as you can. Some doctors believe that lowering your exposure to dust mite during pregnancy may reduce the risk of sensitising your baby before

birth (see p. 241).
When taking anti-mite measures with your own bed, make sure that there is no risk of suffocation to the baby from the allergen-proof materials used. Microporous membranes based

on plastic could, if sucked onto the baby’s face during sleep, cause suffocation. Loose covers on duvets are worrying in this respect. Buy a new duvet with a built-in

allergen-proof cover, for preference, or a duvet that can be laundered at 60°C or above.
All the other measures for combating dust mites, described on pp. 114-17, will help to protect your child. Buy a good anti-allergen vacuum cleaner if you possibly can, and keep

your baby out of the room while vacuuming if you can’t (open the windows too). Make sure the baby only has new soft toys, preferably washable ones (see p. 116).
It is also an excellent idea to reduce dust-mite levels in the carpets and soft furnishings (see p. 117), because children tend to have very close contact with these in their

early years. A crawling baby, motoring enthusiastically around the sitting room floor, is stirring up the stockpile of dust-mite allergen that is found in any carpet, and

inhaling it in full measure. An adult walking around the same room has a far lower exposure, because dust-mite allergen, being relatively heavy, stays near the ground.
The best option is to go for non-carpet flooring, which doesn’t encourage dust mites. Parents tend to worry about the hardness of this, for a baby or toddler. In fact babies are

far more robust than we generally believe, and a hard floor is no problem for a small child who has never known the luxury of carpeting.
If you really hate the idea of your baby having anything other than carpet to play on, the next best option is to get new carpet, so that you start with zero dust mites. You

must then prevent dust-mite numbers from building up too much, by means of good ventilation, or with the use of a powerful dehumidifier (see p. 117).
Although the first year is the most vulnerable time for your baby, you mustn’t let your guard drop too much as time passes. The moment when a toddler moves from a cot to a ‘big

bed’ is sometimes the beginning of allergy symptoms because, after carefully protecting their child from dust mites in infancy, parents then put him or her into a bed with a

used mattress. This sudden exposure to a high dose of
dust-mite allergen can be the start of asthma. Get a new mattress if you can, and put allergen-proof covers on it. Alternatively, put allergen-proof covers on the existing

mattress.
Moulds
Mould spores are another potent allergen, and you should avoid bringing up a vulnerable child in a damp house if you can, because moulds will be growing there in abundance. Some

new research suggests that heavy exposure to mould allergens in childhood makes allergies in general much more likely. Even in a house that is not obviously damp, it is a good

plan to reduce indoor humidity (see p. 119). Carpets and furnishings that are full of mould spores (see p. 122) should be replaced.
Pets
What about pet allergens – should you find another home for your cat or dog when you are expecting a baby? This is a difficult question because the latest research shows that

pets are a double-edged sword as far as allergies are concerned.
A baby with allergic tendencies who is born into a house with a resident cat or dog is more likely to show allergic reactions to cats or dogs some years later. On the other

hand, there is research showing that having a pet in the house reduces the risk of allergies overall, especially for a child with no brothers or sisters. This is probably

because the pet boosts household levels of endotoxin (see p. 21), and generally makes the environment less hygienic for the child, fulfilling the same anti-allergy role as

brothers and sisters would in the early life of a child (see p. 246).
If you are planning to give your child the kind of grubby childhood that seems to protect against allergy (see p. 246), the additional protection provided by a pet is probably

unnecessary. Or, you could view your pet as having both pros and cons, and decide to keep it, while implementing all the other anti-allergy measures described here. If you do

this, ensure that the house is well ventilated (so pet allergens don’t build up to very high levels) and keep the pet out of the child’s bedroom so that he or she is not

breathing huge amounts of pet allergen while asleep. You could also wash the pet regularly (see p. 125) to reduce allergen levels.
If your child begins to show any signs of allergy to the pet, you must then find it another home.
Avoiding irritants
As well as increasing ventilation and eliminating cigarette smoke from the home completely, it may be worth evicting certain specific items that produce irritant gases.
The main ones are:
•    gas cookers (if you can’t afford to switch to an electric cooker, at least improve the ventilation in your kitchen as much as possible)
•    easy-clean plastic wall coverings and flooring
•    materials such as chipboard and MDF, which give off formaldehyde.
The evidence regarding the possible role of these in increasing the risk of allergies and asthma is described on pp. 128-9. In addition, although there is no evidence on this

point, common sense would suggest getting rid of any plastic or lacquered items that have a powerful smell.
Generally speaking, although traffic pollution can act as an irritant, it seems to play a lesser role in causing allergies and asthma than most people imagine. However, it may

sometimes play a part, especially if there are high levels of diesel fumes in the air (see p. 131).
Infections - friend or foe?
A large group of Italian military cadets were recently studied by doctors interested in the causes of allergy. By taking blood samples and testing them for antibodies to common

infections, the doctors could see what diseases the men had been exposed to early in life. At the same time, the young conscripts were assessed for allergies.
Allergies were least frequent among the young men with antibodies against three common infections that are dispersed via food and faeces – Hepatitis A, Toxoplasma gondii and

Helicobacter pylori. Only one in twelve of the cadets in this group had allergies.
Among the men with no antibodies against any of these infections, the rate of allergy was nearly three times as high – one in five of these cadets had allergies.
The doctors who carried out this experiment believe that these three infections are not necessarily important in themselves, but that they identify individuals who were ‘reared

in an environment that provides a higher exposure to many other orofecal or foodborne microbes’. In other words, they grew up in the kind of household where washing your hands

before meals wasn’t considered too important.
This study adds to the growing body of evidence (see p. 21) which shows that an over-clean environment during childhood encourages the development of an allergic disposition.
Those with lower rates of allergy include:
•    children raised on farms with livestock. The more exposure the children have to farm animals, the less the likelihood of them developing allergies.
•    children from homes with high levels of bacterial endotoxin in the household dust (see p. 21)
•    children who have fewer baths, and wash their hands less often (see p. 21)
•    children with brothers and sisters, especially those with older siblings. Some of the protection here may be due to the impact of the mother’s hormones and immune system

on the foetus in the womb: these effects change with successive pregnancies. But close contact with older siblings, and thus exposure to more microbes, probably plays a part.
•    children who go into kindergarten, nursery school or day care with other children at an early age – this is only valuable for children without brothers and sisters
•    children with pets at home – the benefits are much more pronounced for children without brothers and sisters.
The Italian study is especially important because, for the first time, it gives detailed information about the kinds of infections that make a difference in allergy prevention.

The military cadets were also checked for antibodies to measles, mumps, rubella, chickenpox and herpes. None of these infections gives protection against allergies – only

infections carried in food and faeces do.
Exactly what practical use you make of these discoveries is up to you. For most of us, the importance of hygiene was so firmly instilled during our own childhood that it is

quite hard to suddenly become more relaxed about it. But do let your children play in the garden, if you have one, and don’t worry so much about how dirty they get. Encourage

them to do some gardening – medical researchers believe that harmless bacteria in the soil may be particularly important in educating the immune system away from allergies (see

p. 21). Let them play with pets, as long as the animals are not carrying harmful parasitic worms (talk to your vet about whether pets should be treated for parasites). Ease up

or, hand-washing and, if this is your first baby, make sure he or she plays with other children as early in life as possible.
A few chest infections do seem to increase the risk of asthma, notably Respiratory Syncytial Virus (RSV). If this Infects babies, it provokes an IgE-reaction (see box on p. 12)

which may encourage the development of allergies. Unfortunately, there is very little you can do to protect your child from this common virus, but it makes sense not to take the

baby to a hospital for unnecessary trips (visiting relatives, for example) because RSV infections are often picked up in hospital.
Taking care with antibiotics
The possible role of antibiotics in making allergies more likely to develop is an exceedingly controversial topic. Before making any practical decisions in this respect, you

must consult your doctor. Never go against your doctor’s advice, if he or she thinks that antibiotics are necessary.
Several different studies have now produced evidence of a link between antibiotic use before the age of one or two, and the later development of allergies, asthma or both. The

best of these studies was carried out by doctors in Oxford, who followed 1900 children up to the age of sixteen. Among children at risk of allergy (because their mothers had

allergies) taking antibiotics before the age of two was linked with an increase in the rate of allergy from 32% to 54%. The more courses of antibiotics a child received, the

greater the risk.
The type of infection for which the drugs were prescribed was not important, as far as the risk of allergy was concerned, but the type of antibiotic did make a difference.

Broad-spectrum antibiotics, which kill a wide range of bacteria, were more risky –suggesting that the depletion of friendly bacteria in the gut (see p. 204) could be responsible

for increasing the allergy risk. Penicillins seemed less likely to promote allergies than erythromycin or cephalosporins.
This research is not widely known, as yet. And because there is a widespread assumption that giving an antibiotic can do no harm, even if it is unnecessary, antibiotics are

sometimes prescribed when they serve no purpose. In particular, antibiotics are often given for virus infections, especially in childhood, despite the fact that antibiotics are

of no value whatever against viruses. Research shows that doctors are sometimes responding to pressure from anxious parents when they prescribe antibiotics – it is difficult for

some parents to accept that a virus infection cannot easily be treated and just has to ‘run its course’. (Although there are drugs that combat viruses, these are expensive and

produce unpleasant side effects – they are reserved for very serious virus infections such as hepatitis.)
Obviously. when a child needs antibiotics to deal with a serious infection there can be no question about giving them. This is why you should always follow your doctor’s advice.

But it is also worth asking the doctor the following questions before giving antibiotics to your child:
•    are you sure that this is a bacterial infection, and not a virus infection?
•    would it be possible to do tests and check that it is a bacterial infection, before prescribing antibiotics?
•    what is the chance of the child overcoming the infection without antibiotics?
•    would it be dangerous to wait and see if the infection clears up naturally?
Vaccination
The same Oxford research team that investigated antibiotics (see left) also looked at the question of vaccination and allergy. They found a link between vaccination for

pertussis (whooping cough) and increases in asthma, eczema and hayfever. However the increases were not large, and a study from Sweden found that whooping cough vaccination did

not have any effect on rates of allergy and asthma. And researchers in Ethiopia have found that whooping cough vaccination actually reduces the risk of allergy in their country.
This is clearly a complex issue. The contradictory results from different parts of the world suggest that the ‘big picture’ is what counts here – the overall combination of

childhood infections, antibiotic treatment and exposure to harmless bacteria such as those in the soil or from animals. Depending on this big picture, vaccination against

whooping cough may push the allergy risk one way or the other.
There are many other arguments both for and against vaccination and, given our current state of ignorance about the possible effect on allergy, these other considerations are

probably more relevant. Discuss the matter in detail with your doctor before making a decision.

Doctors in Japan recently tried a very simple experiment in allergy prevention. They chose babies suffering from atopic eczema who were allergic to foods, but not allergic to

house-dust mite. Dividing the babies into two groups, the doctors put special allergen-proof covers, designed to protect against house-dust mite (see p. 115), on the mattresses

of all the babies in the first group. Babies in the second group were given ordinary cotton covers.
When the babies were one year old, they were tested again for allergy to house-dust mite. Two out of three children in the second group now gave a positive skin test to

house-dust mite.
By comparison, only one in three of the children from the first group gave a positive skin test. In other words, using the anti-allergy covers for these high-risk children had

cut by half the number who developed an allergic reaction to dust mite.
As this experiment shows, even if a child has already developed allergies, it is not too late to bring protective measures into play. Indeed, an allergy problem in infancy, such

as atopic eczema, can be seen as a warning sign to parents, telling them that they should reduce the child’s exposure to allergens as much as possible.
As well as reducing dust-mite levels, you should minimise your child’s exposure to moulds at home by limiting indoor humidity (see p. 119) and cleaning up any existing mould

growth (see pp. 122-3). This will lessen the chance of mould allergy developing.
Try to avoid staying, even temporarily, in any house that is damp or has old carpets and mattresses. When you are moving house, or carrying out any kind of renovation work,

remember that this will stir up a lot of dust-mite and mould allergens. Protect your child by arranging for a stay away from home.
This pro-active approach should not just apply to airborne
allergens, but also to food, in the opinion of some experts. They
suggest that any child with a true allergy to cow’s milk or egg
should not be given peanuts, tree nuts, fish or shellfish until three
years of age, to avoid sensitisation to these potent food allergens.
Pets are a more difficult issue, with both pros and cons as
regards allergy-prone children (see p. 245). If you decide to keep
your cat or dog, always ventilate the house well, and wash the animal regularly if you can (see p. 125). Be alert for your child developing an allergic reaction to your pet –

don’t turn a blind eye to the symptoms, as parents sometimes do because they are reluctant to accept that the child has become allergic to the family’s much-loved pet. If your

child does develop an allergy to the pet, the best option is to find the animal another home as quickly as possible (see p. 124).
Breast-fed babies with atopic eczema
Although breast-feeding is a good way of protecting children against atopic eczema, it is no guarantee. Sometimes babies become sensitised to food, in spite of being breast-fed,

and then they may react to traces of that same food, eaten by the mother and coming through in her breast milk.
Skin-prick tests (see p. 91) may help to identify the foods responsible for the eczema. Otherwise, a simple elimination diet by the mother, as used for colic (see p. 203), may

pinpoint the offending food. Keeping that food out of the mother’s diet will often clear the baby’s eczema.
Sometimes a breast-fed child’s eczema remains severe, despite the elimination of suspect foods from the mother’s diet. In this case, what should be done? New research from Or

Erika Isolauri – a staunch advocate of breast-feeding – suggests that the best option at this point is to stop breast-feeding promptly. Her research team found that breast-fed

children with persistent eczema had a slower growth rate. If these babies are switched to hypoallergenic formula – either an extensively hydrolysed formula or an artificial

amino-acid formula (see box on p.66) – their eczema symptoms usually subside, and their growth picks up.
Is vaccination safe for those with allergies?
The influenza vaccine and a few others (e.g. yellow fever) are grown in eggs and are not usually given to people with egg allergy. Measles vaccine is grown in cells taken from

eggs and may contain a minute trace of egg allergen, but only those who are extremely sensitive will react: there should be resuscitation equipment available for children who

have had anaphylactic reactions to egg and for those with severe asthma as well as egg allergy. Some vaccines come in vials with latex seals that are designed to be pierced by

the needle of the syringe. A different method should be used for latex-allergic patients. Smallpox vaccine (for bio-terrorism threats) is dangerous for children with atopic

eczema.
Never too late?
The role of modern ultra-clean lifestyles in promoting allergies is now well established (see p. 21). If your child already has allergies, it may seem as if these discoveries

have come too late to help —but that is not the case. Some research suggests that the battle for supremacy between Th1 and Th2 cells (see p. 11) — the unseen power struggle

which decides whether a child will be allergy-prone — is not really settled until some time between the ages of five and seven years. So there is still some potential for

intervening right up to this age. Some studies have suggested that the immune system can be pushed away from an allergic disposition at an even later age, right into adulthood,

by exposure to endotoxin, a bacterial product found around livestock and in `lived-in’ homes.
Several research groups are working on vaccination strategies (for example, using extracts of soil bacteria) that might also be able to achieve this. The initial results are

promising and they suggest that these vaccines can even help adults with allergies. Unfortunately, such treatments will not be available for many years. In the meantime, you can

probably reduce your child’s chance of developing new allergies, and perhaps make the existing ones less severe, by easing up on hygiene (see p. 246).
Fresh air and exercise
With the boom in watching TV and videos, and playing on computer games, some modern children hardly go outdoors at all. As far as allergies and asthma are concerned, there are

two big disadvantages to being a juvenile couch potato. For a start, the couch is also home to dust mites in their millions, and secondly the child is not running about and

using his or her lungs to the full. Airways that are never stretched (because the child never gets out of breath) lose their youthful flexibility in time. Once this has

happened, the airways can never be stretched to their full capacity. Some doctors believe that this may make asthma more likely to develop, or help to make it more severe once

it has developed. Inactivity also encourages obesity, which increases the risk of asthma developing.
Getting outside and running around, or engaging in other vigorous exercise, should be encouraged for any child with allergies. Obviously, you should balance this against the

need to protect the child from pollution peaks and (if your child has hayfever) pollen peaks. Children with exercise-induced asthma should use their reliever inhalers to allow

them to take exercise (see p. 41).
Keep the air at home free from irritants such as nitrogen dioxide (see p. 128), formaldehyde, air fresheners, paint, polish and strong-smelling cleaning fluids. These may

encourage new allergies to develop, and can make existing asthma worse.
Medical treatments
Antihistamines may have a preventive role in very young children with allergies. A study of one- to two-year-olds with atopic eczema found that the antihistamine cetirizine,

taken daily for 18 months, halved the chances of the children developing asthma later.
The children who benefited in this study were those with several risk factors for becoming asthmatic. They had moderate to severe atopic eczema, at least one close relative with

allergies, and allergic sensitisation to pollen or house-dust mite, as shown by skin-prick tests (see p. 91).
The cetirizine was taken at fairly low doses and had no bad effects on the children in this study. What is more, it seemed to benefit their skin as well as reducing the risk of

asthma: those taking the drug had less need of high-strength steroid creams. There is some controversy about the validity of these results, so few children with atopic eczema

are receiving antihistamines at present.
No one yet knows if other antihistamines might have the same effect as claimed for cetirizine. Ketotifen, which is an atypical antihistamine (see p. 159), may do so.
Immunotherapy may also have a protective effect. One study, involving children suffering from nasal allergies, found that those given immunotherapy were less likely to develop

asthma (see p. 165). Another study shows that immunotherapy for children with mite allergy halves the risk of their developing new allergic reactions to other allergens.

Pollen

Do you ever wake up in the middle of the night with an attack of hayfever or pollen asthma? And do you ever wonder why this should happen? The explanation is that warm air, rising up from ground level on a summer’s day, takes pollen with it high into the Earth’s atmosphere. When the air cools down after sunset, this pollen slowly descends again — an invisible ‘pollen shower’.
This pollen shower falls quite quickly in the countryside, reaching ground level between 8 p.m. and 10 p.m., but hot city pavements and buildings keep upward air currents going, and pollen stays aloft for longer. Most pollen lands on the city between about midnight and 2 a.m. That’s why you wake up sneezing or wheezing – especially if you sleep with the windows open.
Understanding facts like these about pollen can help you to reduce exposure substantially. Pollen is by far the most difficult allergen to avoid, but don’t believe the defeatists who tell you ‘You can’t do anything about pollen.’
Pollen counts and forecasts
Pollen counts are based on the amounts of pollen collected at specific sites earlier in the day, or on the previous day.
Forecasts for the coming day are really just informed guesswork, based on the present pollen count, the time of year, the temperature and rainfall over the last few days, and the weather forecast for the next day. At best, pollen forecasts are only as good as the weather forecast.
Forecasts of pollen can be useful in deciding when to start taking antihistamines for hayfever or when to Increase your asthma preventer drugs (steroid or cromoglycate inhalers). The start of the grass-pollen season is now predicted quite accurately.
Avoiding pollen outdoors
One thing that really can help here is an air-conditioned car. In an ordinary car, closing the windows (and perhaps fitting a filter to the air intake) helps a lot, but the heat is terrible.
The size of the allergen particles
The pollen grains that cause allergies are between 10 and 40 microns in size, with the majority between 20 and 35 microns. An ordinary dust mask takes out particles larger than 5 microns, so it will be adequate for most pollens. However, a few plants — including rye grass — produce tiny allergenic fragments, some no bigger than half a micron. These are about the same size as cat allergen and will therefore need much better masks. For these fragments, it is worth using a HEPA air filter, and getting a high-quality vacuum cleaner.
A cycle mask, or special nose filters sold for hayfever, will keep out pollen at peak pollen times. Just wearing a scarf over the mouth and nose will also give some protection. Another option is to smear a little Vaseline just inside each nostril and breathe through your nose only. Much of the pollen coming into your nose will stick to the Vaseline. If you ’suffer symptoms in the eyes, sun- glasses will keep some pollen out. Even better are wrap-around shades, or safety goggles with side panels sold in DIY stores.
Pollen release occurs at different times of day for different plants. Grasses release pollen from about 7.30 a.m, onwards, but if the ground is damp the release will be delayed until the moisture has evaporated. Unfortunately, a few grass species wait until the afternoon, so there will be some pollen entering the air all day. If you get up at 6 a.m. for a walk or run, you can be safely home by 7.30 a.m. Alternatively, go out In the early evening, after grasses have finished releasing pollen, and before the ‘pollen shower’.
Birch is an afternoon pollen: release peaks between noon and 6 p.m. Unfortunately, there is no information at present for other types of plants.
All types of plants favour warm sunny days for releasing pollen, and they all avoid rainy weather. On cloudy days there is a build-up of pollen in the flowers, so a massive release of pollen occurs on the next day of good weather.
Avoiding pollen indoors
Pollen grains have one huge point in their favour: compared to other allergenic particles, they are big and heavy. This means that they settle more quickly from the air. In a room with 3m- (1 Oft-) high ceilings, all the pollen will settle within four minutes, as long as the air is completely still. In other words, if you close all the doors and windows, block off any draughts, and sit fairly still, within four minutes you will be breathing pollen-free air.
This does not mean that all your symptoms will instantly vanish, because the ‘Late Phase Reaction’ (see p. 13) can go on for up to 24 hours. But you should feel better and, by not starting a new cycle of allergic reaction, you are improving the prospects for the next day. Escaping from pollen for a few hours every day should produce a general improvement in the long run, with your nose and airways becoming less inflamed.
The bad news is that some plants produce allergenic fragments much smaller than the pollen grains themselves. Various grasses do this, as do birch trees and certain plants not generally found in Britain, such as ragweed. These tiny particles take much longer – up to six hours – to settle from the air.
Some plants even produce ‘volatiles’ – airborne chemicals that provoke symptoms. Birch trees release volatiles from their buds in early spring, weeks before the pollen itself is released, and they affect a great many people, including some who are not allergic to birch pollen. Volatiles can only be removed by masks or air filters if they contain an activated carbon filter (see p. 109).
The notorious effects of oil-seed rape on the nose are also due to volatiles, not pollen. These volatiles are simply irritants and there is no allergic reaction.
To cut down on the amount of pollen you inhale at home:
• Dry all your laundry indoors during the pollen season, to stop it collecting pollen.
• Pets bring in pollen on their fur, so keep them outdoors during the pollen season, and avoid stroking them or getting too close. Brushing them thoroughly before they come in is another option, but the allergic individual should not do this.
• Close the windows when your offending pollen is being released, and during the evening ‘pollen shower’ (see p. 126).
• Change your clothes when you arrive home, since they will be coated with pollen, and wash or rinse your hair. Keep some clothes for indoor use only.
• Aim for still air (no draughts, no fans and no vigorous movement) in the rooms where the allergic individual studies, sits or sleeps. Air currents stir up pollen from the floor and furnishings. (No draughts means poor ventilation, of course, which is acceptable during the pollen season – but ventilate again afterwards, to discourage moulds and dust mites.)
• If tranquil air is an impossibility, consider getting a high quality air cleaner, or air conditioning. Alternatively, wet-dust and vacuum every day (using a vacuum cleaner that keeps allergen particles in – see pp. 116-17) to reduce the amount of pollen residue. Those who are very sensitive may need to do this as well as having an air cleaner.
• Cover your armchair and bed with a dust sheet during the day. In the evening, fold this up very gently and wash it. This removes the layer of pollen that accumulates on furniture during the day, before it is disturbed and inhaled. If you are studying, cover your desk and books when not working.
Places to go, places to avoid
• For the grass-sensitive, mown grass is usually fine (it won’t flower) although some people react to skin contact with grass (see p. 43). Unmown grass does flower, and will cause symptoms. Wheat, barley and oats, although they are grasses, release little pollen and rarely cause problems. Rye and sugarcane do release pollen, and may affect some people, but maize (corn) has heavy pollen that does not travel far, so it rarely causes much trouble.
• The levels of most pollens do not differ much between town and country. In fact, high up in a tower-block may be one of the worst places, because of pollen rising on warm air.
• The seaside is often pollen-free thanks to onshore breezes. Mountain peaks and ridges are also good, but deep mountain valleys can be pollen traps.
Roses are not the problem
The pollens that cause allergic reactions almost all come from plants with inconspicuous greenish flowers. These plants are pollinated by the wind, which is why there is so much of their pollen wafting about in the air. Colourful and scented flowers are pollinated by insects and have big sticky pollen grains that don’t float about and rarely cause allergies. However, strong scents can irritate the nose of those who already have hayfever, and make their symptoms worse.

Allergies and Pregnancy
Great care is taken in prescribing drugs during pregnancy. This is something that doctors are now exceedingly cautious about, but do tell the doctor as soon as you decide to try for a baby. The foetus is most vulnerable to damage by drugs during the first three months, and especially the first few weeks after conception.
Your prescription will be changed if the drugs you are currently taking could pose any threat to the unborn child. A drug that has not had sufficiently rigorous testing for safety during pregnancy, or lacks a long track record, will probably be withdrawn. New drugs are generally considered to be slightly more risky than the tried-and-true older drugs: rare side effects may not come to light during the testing which precedes release of a drug, but they do become apparent once the drug is in widespread use for a long time (see pp. 136-7).
If you are already pregnant as you read this, don’t worry too much. With a few notable exceptions – certain antihistamines and antibiotics – most of the drugs used for allergic diseases do not pose any major risk to the unborn child. There is probably nothing to worry about, but see your doctor as soon as you can – and talk to a pharmacist, in the meantime, if you are concerned. Don’t panic, and don’t stop taking your drugs unless you are absolutely sure that you can do without them. Do not stop taking your drugs if you have asthma.
Some non-prescription medicines are best avoided during pregnancy. Read the packet carefully, and talk to your pharmacist if you have any doubts.
From the moment you start trying for a baby, remember to tell any medical personnel who treat you, and any pharmacist you buy medicines from, that you could be pregnant.
Immunotherapy and skin testing
Immunotherapy should not begin during pregnancy, because of the risk of anaphylaxis (see below), but pregnant women who are already undergoing immunotherapy can continue.
The safety procedures described on p. 166-7 should be followed with meticulous care.
Most doctors continue immunotherapy at a steady ‘maintenance dose’ because there is always a small risk of anaphylaxis with immunotherapy when the dose is increased. Some doctors are even more cautious and reduce the maintenance dose during pregnancy, but give more frequent injections – this minimises the chance of bad reactions.
Many doctors do not give skin tests for allergy during pregnancy, as these also carry a very small risk of anaphylaxis. If you do have skin tests, there must be resuscitation equipment available. Intradermal tests (see p. 92) are best avoided.
Severe allergic reactions (anaphylaxis)
Special care should be taken to avoid anaphylaxis during pregnancy as this may increase the chance of a miscarriage.
Injecting adrenaline during the first three months of pregnancy may carry some small risk of malformation of the baby. But the evidence here is uncertain, whereas the danger to your own life, if you don’t use adrenaline when you need it, is both certain and substantial. If you have an adrenaline self-injection kit, talk to your doctor now about what you should do in an emergency. The best policy is to be ultra-careful about avoiding your allergen, so that anaphylaxis does not happen.
Women who suffer from exercise-induced anaphylaxis (see p. 59) generally play safe by exercising less strenuously while pregnant. The problem can get worse during pregnancy, but it does not usually do so. Labour itself is very strenuous of course, but problems during the birth are uncommon. If anaphylaxis does occur, the reaction is usually quite mild – nettle rash only – and the baby is delivered alive and well. However, many women find that the attacks of exercise-induced anaphylaxis are more frequent and severe when they start exercising again after the baby is born. It is best to resume exercise very gradually.
Eczema and other skin problems
Atopic eczema may improve during pregnancy, probably because the body produces slightly more of its own natural steroid, hydrocortisone. Contact dermatitis may either improve or flare up.
Stretch marks often itch a great deal, and widespread itchy skin, with or without a rash, is a common problem during pregnancy. These are not usually allergic reactions, and no cause can be identified in most cases. The skin tends to recover a few days after the birth.
If there is itching in the vulva) area, this could be due to a Candida infection (your doctor can prescribe a safe treatment) or it might be just another of those unexplained itches of pregnancy.
Hayfever and other nasal allergies
The natural hormone changes of pregnancy affect the nose, which can become more blocked. If you have allergic rhinitis this will add to your woes. See your doctor and make sure that your drug treatment is adequate (see p. 29). The nose-clearing exercises on pp. 230-31 might also help.
Asthma
Severe asthma can be bad for both the pregnant mother and the unborn child. Uncontrolled asthma increases the risk of the baby being born prematurely – and premature babies are more likely to develop asthma themselves. The death rate for newborn babies is also higher if the mother has poorly controlled asthma.
Treating a severe asthma attack promptly helps to prevent any damage to the baby, so don’t hesitate to call an ambulance –and tell the operator you are pregnant. The ambulance should be carrying oxygen which is particularly important for helping the unborn baby through the attack.
If you have asthma, don’t stop using your drugs or reduce the dose unless advised to do so by a doctor. Because it is so important to keep asthma under control during pregnancy, your doctor may want to add, or increase, preventer drugs such as inhaled corticosteroids or sodium cromoglycate (see p. 148). It
also makes sense to monitor your peak flow twice a day (see p. 97) so that you have advance warning of serious attacks.
Unfortunately, some asthmatics – usually those who have severe asthma to begin with – get much worse during their pregnancy. In such cases, careful monitoring and increased use of preventer medicines are essential. The symptoms usually increase from week 24 to week 36 of the pregnancy. The last four weeks tend to be much better, and things are back to normal by about three months after the birth.
Some women with asthma have fewer symptoms while they are pregnant, and for others their asthma stays about the same.
Asthma can also appear for the first time during pregnancy, and may be quite severe. However, a relatively mild breathlessness can be due simply to the fact that, as the pregnancy advances, the chest cavity, and therefore the lungs, become compressed. This is not necessarily asthma.
This simple physical effect can also add to the difficulties experienced by women who were already asthmatic before they became pregnant.
GER (acid reflux) – see p. 38 – can contribute to asthma during pregnancy, and treating this problem may help.
Asthma attacks during the birth
Severe asthma attacks very rarely occur during labour, but it is still important that all the medical staff in attendance know you have asthma. They should also be told if you have taken steroid tablets during the previous two years. A record of when you took steroids, how long for, and at what dose, will be valuable. You may need a low dose of steroid to get you through the physical stress of labour (see p. 142). Some doctors believe that patients who have been using high-dose inhaled steroids should be treated in the same way.
Smoking
Smoking is a bad idea if you have allergies or any allergic tendency in the family. Smoking is a very bad idea indeed if you are pregnant, or a parent. This is the moment, if ever there was one, to give up.
Enlist your doctor’s help, and ask if counselling, psychotherapy or other forms of support are available. If you have tried all this before, and failed, then talk to your doctor about the possibility of using nicotine patches. Some doctors believe that, for pregnant women who smoke 20 cigarettes or more a day, the advantages of nicotine patches outweigh the risks to the foetus. Nicotine levels in the blood are lower with patches than with heavy smoking, and your baby is not enduring the hundreds of other toxins found in cigarette smoke.

Skin-prick tests
This is an indirect method of detecting true allergic reactions. It is one of a family of skin tests that use a similar approach. The three different tests in this family are known as: skin-prick tests or prick tests, puncture tests, and scratch tests.
For the skin-prick test - the technique used in Britain - a small drop of liquid containing an allergen, such as grass pollen, is placed on the arm. The doctor makes a small prick in the skin, under the drop of liquid, allowing a minuscule amount of the allergen to get into the skin. A positive reaction is recorded if a red bump develops soon afterwards. For accuracy, the bump must be compared to positive and negative controls (see below).
The puncture method is very similar to the skin-prick test but uses a slightly different technique for breaking the skin. The term prick-puncture test covers both techniques.
With the scratch method, the skin is scratched lightly, and the allergen solution is then applied over the scratch. This method gives less consistent results than prick-puncture testing.
It is important to include a negative control in the test - a skin-prick test with plain salt water (saline). This should not produce much of a bump - if it does, the skin is clearly over-reactive and the tests more difficult to assess. The doctor should also include a positive control - a skin-prick test with histamine, the substance that plays a central role in allergic reactions. This should always produce a bump. If it does not, the skin is decidedly under-reactive, and the tests are invalid.
Taking antihistamines will make the skin under-reactive, and you should stop taking them before the testing, for a period ranging from a day to several weeks - it varies depending on the particular antihistamine. Ask your doctor for specific instructions about stopping these and other drugs before testing.
Skin tends to be over-reactive to testing in people with dermatographism (see p. 52). Blood tests for specific IgE,
such as RASTs (see p. 92), are needed for anyone who has this condition. Eczema sufferers with a rash over large areas of the body may also require blood tests, if there is too little clear skin for testing.
Skin-prick tests can produce both false positives and false negatives (see box below). Some allergic diseases will give a lot of false negatives and relatively few false positives, while for others the reverse is true. The allergen itself influences the rates of misleading reactions: for example, tests for soya allergy are notoriously unreliable, whereas those for peanut are far more accurate. The age of the person being tested also makes a difference. With all these influences at work, interpreting the test responses is a real art, and the doctor’s experience counts for a lot.
All sorts of people offer skin-prick tests, including alternative practitioners. Get them done by a qualified doctor, preferably by an allergist, who will know how to make sense of the reactions.
Note that the purpose of these tests, and of blood tests for specific IgE, is to identify the allergens that are bringing on your symptoms, not to predict how strongly you will react to those allergens. The tests may give some indication of the intensity of your reaction, but they cannot be regarded as a good guide to how you will respond to the allergen in the future.
The safety record of skin-prick tests is very good. Occasionally a systemic reaction (anaphylaxis) occurs with these tests, but there are no records of any deaths. Nevertheless, if you suffer from severe asthma or have experienced anaphylactic shock in the past, it is advisable for the doctor to have adrenaline and resuscitation equipment available. Those with strong allergic reactions to latex may also react badly if they are tested with an allergen that cross-reacts with latex (e.g. cypress pollen), not just when tested with latex itself. Taking beta-Mockers (see box on p. 150) increases the risk of a life-threatening reaction for anyone in these higher-risk categories.
False positives and false negatives
Apart from challenge tests, none of the tests used for allergy works with 100% accuracy. Most give both false positives and false negatives.
A false positive means that there is a positive test but no actual reaction when the allergen is encountered (e.g. eaten or inhaled). A false negative means that there is a negative test result despite a genuine reaction (as shown by a challenge test, for example).
A test that gives relatively few false positives has good positive predictive value - in other words, if it suggests you are allergic to something, you probably are.
A test that gives relatively few false negatives has good negative predictive value. If it comes up negative, you are probably not allergic to that allergen.
Some tests for allergic reactions show good positive predictive value but poor negative predictive value, while for other tests the reverse is true.
Fresh is best
The fruit and vegetable allergens that provoke Oral Allergy Syndrome (see p. 63) are chemically unstable, so commercially produced extracts for skin-prick testing quickly lose their potency and give false-negative results. Most allergists now favour using a drop of fresh juice from the fruit or vegetable concerned.
Intradermal tests
These tests (also called ‘intracutaneous tests’) put allergen more deeply into the skin than prick-puncture tests. The skin tends to react more when penetrated to this depth, so there are more false positives. There is also a greater risk of a serious reaction which may require emergency resuscitation. Don’t undergo these tests if you are taking beta-Mockers (see box on p. 150).
Blood tests for IgE
There are blood tests that look at the total amount of IgE (the allergy antibody), which is sometimes useful in diagnosis. But more important are blood tests for specific IgE – against egg or grass pollen or latex, for example. There are different ways of measuring the IgE in the blood, the most commonly used being a radio-allergosorbent test or RAST.
Research shows that RASTs are no more accurate than skin-prick tests in confirming real-life allergic reactions. However, they are useful for patients who can’t discontinue their antihistamines without developing severe symptoms, and for those with dermatographism or very severe eczema (see p. 91).
Patch tests
These tests, used primarily for contact dermatitis, are similar to straightforward challenge tests, because the suspect substances are applied directly to the skin.
The test substances are placed on the skin – usually on your back – in small chambers. They are held in place with sticky tape, and left there for several days. Ideally, the reaction of the skin should be checked three times: after two days, again the next day, and again the day after that. It really is worth going back for all these separate visits, because the accuracy of the test increases greatly with repeated checking.
The substances chosen for testing are a standard set of antigens that most commonly cause contact dermatitis. This standard set will pick up 60-80% of all sensitivity reactions in contact dermatitis. If you have substances that you suspect may be causing symptoms, such as cosmetics, the doctor can usually test for these too.
You should not be tested while you still have a rash, as the testing will probably make the existing rash flare up, even though the test patches are applied well away from the rash.
Use of steroid creams and any light treatments (including exposure of the test area to ordinary sunlight) must stop at least a week before testing starts, or the results will not be accurate.
Interpreting patch tests requires a huge amount of skill, plus extensive knowledge of the finicky details of the different test substances. You need a dermatologist with considerable experience in this area.
False positives (see box on p. 91) can occur, especially if you react very strongly to one of the substances tested – some people develop what dermatologists call an ‘angry back’, and this generates false positives to various other substances being tested at the same time. Should you be told that you are sensitive to a great many different things, you may want to query this reading of the test. Ernest N. Charlesworth, an allergist and dermatologist at the University of Texas, describes patients who ‘develop into environmental cripples’ after being told that they are definitely sensitive to multiple antigens, on the basis of misinterpreted false-positive patch tests.
False negatives (see box on p. 91) are also possible, even with very careful testing. Should this occur, a type of challenge test known as a ROAT (Repeat Open Application Test) is possible. The suspect substance is applied to the inner fold of the elbow twice a day for a week. Get your doctor’s agreement before trying this test.
Endoscopy and biopsy
Miniaturised cameras and sophisticated fibre-optics have allowed modern doctors to do something that their predecessors could never have imagined possible – look right inside the human body. This procedure is called endoscopy, and it has a useful role in a few sensitivity reactions.
Looking inside the sinus cavities can assist in understanding exactly what is going wrong in chronic sinusitis. Inspecting the digestive tract can be valuable in several of the non-IgE immune reactions to food, such as coeliac disease (see p. 70) and eosinophilic gastroenteritis (see p. 72).
A biopsy is often carried out at the same time as endoscopy.
s involves taking a small sample from the affected area, such as
I ning of the gut, and studying it in detail under a microscope.
One purpose of a gut biopsy is to look for characteristic :goes of damage to the lining of the gut – such as the distinctive charges produced by untreated coeliac disease. A biopsy can also reveal what kind of immune cells are present. Abnormal numbers of certain immune cells, for example, eosinophils (see p 19), may suggest a particular diagnosis.
Another way of looking at what kind of immune reactions are going on, used for lung diseases, is a bronchoalveolar lavage – iterally a ‘washing out’ of the airways and lungs, allowing immune cells to be collected and studied. This diagnostic technique is lased for Heiner’s Syndrome (see p. 72).
Tests for food intolerance
The only really effective way of testing for food intolerance is an el ruination diet (see pp. 194-7). This is the gold standard. However, it is neither easy nor quick – which has led to a constant search for alternative tests.
The proposed alternatives are all indirect tests, that is to say, non-dietary. The results of the tests are used as a basis for an avoidance diet. In other words, the foods that give a positive test result are avoided.
Some of these tests use samples of hair or blood, others use pulse testing, pendulums, or muscle strength tests (’applied kinesiology’). A few of these tests do show some promise. Pulse tests, and a blood test called the ‘lymphocyte transformation test’. for example, can give a general indication of sensitivity reactions – sometimes. However, even in the most expert hands, these do not give a result that is accurate enough to be useful.
Of the other tests that are available, most have not been evaluated at all objectively.
Many of them are advertised directly to the public, and one of the problems with this approach is that the testing company starts by assuming that food is the problem. The same is usually true of ‘dietary therapists’ and others in the alternative health field offering tests of this kind.
Almost everyone who undertakes such tests is given a fairly long list of foods which have come up positive in the tests. This does not fit with the evidence from medical trials in which a group of people with irritable bowel or migraine (typical food intolerance symptoms) undertake an elimination diet. A significant proportion of them always find that they do not have food intolerance. Of the rest. many find that they react to one or two foods only. The long lists of foods produced by the commercial tests are, to put it mildly, implausible.
With tests that require a sample of blood, sending off two blood samples from the same person, under different names, is a simple way of assessing the tests’ validity. This exercise has been tried several times with different testing companies, and every time two completely different lists of foods have been sent back.
Covert studies of this kind have also shown that the tests overlook genuine reactions. In one alarming case, a woman with a true allergy to peanuts was assured by a ‘dietary therapist’ that she really could eat peanuts safely.
Many people with food intolerance will tell you that they did well after following a diet based on such tests – and they may well have done. Given that common foods such as wheat and milk are regular offenders in food intolerance, and that these foods very frequently feature on the lists of positive test results generated by commercial testing companies, quite a few people should do well. The problem is that these people may also be avoiding many other foods quite unnecessarily.
Furthermore, if people have sensitivities to some other foods that are not on the list, they will be missing out. They could enjoy a far better level of health if all the foods causing symptoms were Identified and removed from their diet.
In the end, an elimination diet is both cheaper and far more likely to give the right answers.
Testing for IgG antibodies
In diagnosing food intolerance, a few doctors offer tests for a type of antibody called IgG. This antibody is formed to any food molecules that get Into the bloodstream after a meal – and some do, even in entirely healthy people. So finding IgG antibodies to food molecules is not indicative of any disease at all. It occurs in everyone and is perfectly normal.
Nevertheless, some doctors feel that by measuring the level of IgG antibodies to foods, they can get a general idea of the permeability of the gut wall (which might possibly be true) and of particular foods that could be causing intolerance reactions (very doubtful – the tests just tell you what you eat most, and you know that already).
This test does measure something real, unlike some of the alternative tests for food intolerance. But the relevance of what it measures to the health of the individual concerned is partial and indefinite. A recent study of IgG testing for irritable bowel syndrome has confirmed this view.
In short, blood tests for IgG antibodies to food molecules seem like very poor value for money, and potentially misleading, whereas an elimination diet is a far more precise way of pinpointing food intolerances.

Theophylline
Theophylline-type drugs are also known as xanthines or methylxanthines. These drugs are chemically similar to caffeine. They cannot be inhaled, so are taken as tablets or syrup. They start working about 30 minutes after being taken and their effects last for 6-8 hours. Slow-release preparations take 90 minutes to start working, but they last 12-24 hours, and are therefore useful for nocturnal asthma.
In Britain, doctors generally regard theophylline-type drugs as reliever drugs (see p. 152), but rather risky ones whose use is only justified for people with severe asthma. They are given, as an additional treatment, to asthmatics who are not responding well to the usual drug programme (see p. 160). Unfortunately, fairly high doses are needed for theophylline-type drugs to act as relievers, i.e. to reverse bronchospasm. There is a very narrow margin between such a dose and one that causes major (and sometimes dangerous) side effects.
Such side effects usually occur when the doctor is still trying to work out the correct dose – this varies from one person to another, so prescribing theophylline-type drugs is no easy matter. Once you are established on a safe dose (and provided your general health and your intake of alcohol, nicotine and medicinal drugs does not vary – see p. 158) you can usually continue taking theophylline without serious side effects.
In the United States, many doctors also give theophyllinetype drugs, at much lower doses, to people with mild asthma. At these low doses they do not act as relievers, but they have a slight anti-inflammatory effect and therefore act as preventers. The risk of toxicity is much less. Taking low doses of theophylline allows people with mild asthma to reduce their use of beta-2 relievers. However, inhaled steroids are usually more effective in this role, and are the preferred treatment outside the United States.
Side effects
Typical side effects include nausea, vomiting, stomach pains, diarrhoea (sometimes with blood), headache, anxiety, restlessness, insomnia, dizziness, and a pounding heart or irregular heartbeat.
Any side effect of these drugs should be taken seriously and reported to your doctor as soon as possible. If you cannot get an appointment quickly, it may be best to stop taking the drug before seeing the doctor, as long as you have other drugs to control your asthma. Call your doctor for advice.
It is remarkably easy to overdose when taking these drugs at higher doses (see p. 157). Such overdoses can be fatal. The symptoms include repeated vomiting, shaking, feeling unusually hot, needing to urinate frequently, severe thirst, maniacal behaviour, and irregular heartbeat (palpitations). Delirium and convulsions may occur shortly afterwards, so get hospital treatment urgently if you have any of these symptoms.
Unfortunately, a serious overdose can sometimes occur in people who have taken theophylline-type drugs without trouble for many years. There may be no advance warning that anything is wrong - no mild side effects preceding the serious ones. To protect yourself against this, you need regular blood tests from your doctor.
One fundamental problem with theophylline-type drugs is that many different factors - including diet, illnesses other than asthma, and taking other drugs - can alter the way your body deals with the drug. If your liver is breaking down the drug more slowly than usual, the amount in your blood will rapidly increase, and can reach toxic levels.
These are steps that can help prevent an overdose with theophylline-type drugs:
• If you start taking a new drug of any kind, or stop taking a drug (especially the contraceptive pill), or if you change your intake of nicotine or alcohol, ask your doctor - preferably in advance - if your dose of theophylline-type drug needs to be changed.
• A great many drugs interact with theophylline-type drugs, including the new anti - leukotriene drugs. You should always be cautious with any new drug, but take particular care with two antibiotics - ciprofloxacin (brand name Ciproxin) and erythromycin (various brand names) - and with cimetidine (various brand names), used for stomach ulcers and heartburn.
• If you have flu vaccinations, or develop certain illnesses, especially viral infections, heart disease or liver disease, watch for the typical side effects of theophylline-type drugs (see above) and consult your doctor immediately if any occur. These conditions all change the effects of theophylline-type drugs.
• Don’t eat meals that are very high in fats or oils. A lot of fatty food causes too much of the drug to be released at once from the slow-release preparations and increases the risk of side effects. Avoid sudden, major, changes to your diet.
• See your doctor regularly for check-ups. Simply getting older changes your reaction to these drugs: your dose may need to change over the years.
• If you are at all forgetful about tablets, keep a careful record of when you have taken your theophylline-type drugs. Be very careful never to take a second dose by mistake.
• Talk to your doctor if you are not taking a slow-release form of theophylline (see box below for brand names). There are usually fewer side effects from these than from the ordinary forms of the drug.
• Wear a Medic Alert bracelet (see box on p. 95) saying that you are taking theophylline-type drugs. If you have a severe asthma attack and are taken to hospital, it is important that medical staff know this, so that they do not give you more drugs of this type.
While pregnant or breast-feeding, it may be advisable to stop taking theophylline-type drugs: discuss this with your doctor. Although the drugs do not affect most unborn or newborn babies, there are occasional reports of toxicity. Less seriously, theophylline-type drugs go through into breast milk, and may make babies irritable and restless. This problem can be solved by always taking the drug just after a feed - this reduces the amount in the milk.
Theophylline-type drugs might produce behavioural problems and learning difficulties in young children although this is unproven. Research shows that there are no problems for children over six.
Anti-IgE drugs
For asthmatics with strong allergic reactions, who are not doing well on ordinary treatment, the new anti-IgE drugs, such as omalizumab may be very valuable (see p. 149). They are given as a depot injection under the skin.
Some common brand names
Common brand names of theophylline-type drugs include: slow-release preparations — Lasma, Nuelin SA, Phyllocontin Continus, Slo-Phyllin, Theo-Dur, Uniphyllin Continus
ordinary preparations - Aminophylline, Nuelin Ketotifen
Ketotifen (brand name Zaditen) is an antihistamine (see p. 138), although it has other effects in addition to those of ordinary antihistamines. Most significantly, it stabilises mast cells in a similar way to cromoglycate.
One advantage of ketotifen to many people is that it is taken by mouth, in capsule, tablet or syrup form. When it was first introduced, doctors hoped that it would be of particular help in asthma, but it has not lived up to expectations. However, some asthmatics do find it effective. It is worth trying because, it it works, it could permit you to reduce your dose of steroids.
Ketotifen requires up to six weeks to take effect, so continue taking your previous drugs (e.g. steroids) for at least six weeks, or you will risk losing control of your asthma.
Side effects
Minor side effects from ketotifen include nausea, headache, increased appetite and weight gain, drowsiness, dry mouth and slight dizziness. Do not drive until you are sure that ketotifen does not make you drowsy. Alcohol may pack a more powerful punch than usual, so drink very moderately at first. If drowsiness is a problem, take the drug in the late evening. The sleepy feeling may wear off after a few weeks of taking the drug.
There are no serious side effects from ketotifen, except if taken with drugs for diabetes.
Anti-leukotriene drugs
Leukotrienes are among the messenger chemicals that are produced by mast cells during an allergic reaction (see box on p. 12). They help to perpetuate the inflammatory process begun by histamine, and they amplify the reaction by attracting more immune cells into the area.
The anti - leukotriene drugs fall into two distinct groups:
• those that bind to the receptors for leukotrienes, called leu kotriene- receptor antagonists. Currently, there are two drugs in this group, montelukast (brand name Singulair) and zafirlukast (brand name Accolate). A third drug, pranlukast, is in the pipeline and currently going through its safety trials.
• those that block the production of the leukotrienes altogether, called 5-lipoxygenase inhibitors. There is only one drug in this group at present, zileuton (brand names Leutrol, Zyflo); it is not yet available in Britain.
As regards tackling inflammation, the anti - leukotriene drugs work in a completely different way from either steroids or cromoglycate. This makes them useful as an add-on treatment, supplementing the effects of existing anti-allergy drugs.
For asthmatics, anti-leukotriene drugs may be particularly good in combination with antihistamines – whereas antihistamines alone are singularly unsuccessful in asthma (see p. 138). Recent research suggests that taking antihistamines together with antileukotriene drugs is an effective way to control airway inflammation. However, there have been no large-scale trials of this treatment option yet, and it may be a while before it comes into general use.
In the airways of people with asthma, leukotrienes can directly trigger bronchospasm (contraction of the airway muscles) as well as fostering inflammation and increasing mucus production. This multiple action of leukotrienes makes anti-leukotriene drugs very valuable for asthmatics because they act as both relievers (reversing bronchospasm) and preventers (tackling inflammation). They are especially useful for exercise-induced asthma.
All the anti-leukotriene drugs are taken in tablet form. If you are trying an anti - leu kotriene drug for the first time, don’t expect any noticeable effects to occur for about three days. Once you are taking the drug regularly, each dose requires 2-4 hours to have its full effect, but goes on working for 12-24 hours in total.
Although anti - leu kotriene drugs have a reliever effect, they cannot give you immediate relief from bronchospasm. Asthmatics must therefore carry a short-acting beta-2 reliever (see pp. 152-3) as well, in case of an asthma attack.
For those who dislike inhalers, or tend to forget to use them, the fact that these drugs are taken once a day in tablet form makes them an attractive option. However, they are expensive, and at present doctors prescribe them mainly for young children who have difficulty inhaling their usual drugs.
Side effects
The side effects noted in safety trials of these drugs were all minor ones:
• zafirlukast – headache, nausea, diarrhoea, pain
• montelukast – headache, diarrhoea, abdominal pain, cough, and flu-like symptoms
• zileuton – upset stomach
As with all new drugs, you should report any unusual symptoms to your doctor, just in case these represent a rare or longterm side effect of the drug (see p. 137).
Very occasionally montelukast provokes allergic reactions, with symptoms such as itchiness, widespread nettle rash (urticaria) or swelling (angioedema).
Zafirlukast and zileuton can both cause liver damage, but this is rare. Your liver function should be closely monitored by the doctor, by means of regular blood tests, and the drug withdrawn at the first sign of trouble. Montelukast can also affect the liver, but this is extremely rare.
The most worrying development noticed to date is the appearance, in a very few people taking zafirlukast or montelukast, of a disorder called Churg-Strauss Syndrome. The symptoms may include a blotchy purplish rash (due to vasculitis – see lower box on p. 73), a flu-like illness, worsening asthma, and numbness or tingling in the limbs. The heart, lungs and nerves are all affected, because eosinophils (see p. 19) are present in large numbers and cause damaging inflammation.
A study of the cases reported so far suggests that this syndrome may not be due to the anti-leukotriene drugs themselves but to other causes – usually (though not always) a reduction in the dose of steroids. Other patients who are not taking antileukotriene drugs, but are reducing or stopping steroids, may also (again, very rarely) develop Churg-Strauss Syndrome. Doctors now suspect that all these patients were already suffering from an underlying eosinophilic disease, which first showed itself simply as asthma, and was quelled by the steroid treatment prescribed for the asthma. The disease was thoroughly masked as long as the patient was using steroids, but when steroids were withdrawn, the underlying disease flared up, producing a wide range of symptoms. In most cases, reintroducing steroids brings these symptoms under control again.
Putting it all together
What is the ideal combination of all these asthma drugs? That is something your doctor can only work out slowly, because it varies from one individual to another.
The conventional approach to asthma treatment is to start patients on a short-acting beta-2 reliever and then, if the symptoms are not controlled, to add other drugs. This approach is called ’stepping up’. The standard steps, or stages, are as follows:
1. Use a short-acting beta-2 reliever only.
2. Add cromoglycate or low-dose inhaled steroids.
3. Try a higher dose of inhaled steroid or a long-acting beta-2 reliever.
4. Try out each of the following in turn: theophylline, anticholinergic drugs, cromoglycate and higher doses of beta-2 relievers (either inhaled or as tablets/syrup).
5. If there is still no success in controlling symptoms, add regular steroid tablets.
Short courses of steroid tablets may be used at any stage, for the control of sudden, severe, attacks.
Over the last ten years, there has been a change of strategy, and very few people are now kept on Stage 1. Inhaled steroids are now given to most asthmatics, even those with relatively mild asthma. Research from Sweden, where widespread use of
inhaled steroids first became general policy, shows considerable benefits to this approach.
If you have gone beyond Stage 2, ’stepping up’ is usually followed by ’stepping down’. In other words, when the symptoms have been well controlled for 3-6 months, doses of some drugs are reduced, or certain drugs stopped altogether. If the asthma flares up again, the dose is increased or the drug reinstated. If there are no problems, and symptoms remain stable for a month or two, another reduction is tried.
An entirely different approach to asthma management is now being tried with some patients – starting off with moderate to high doses of inhaled steroids (equivalent to Stage 3) and then ’stepping down’. The idea is to get the inflammation under control promptly and fully at the outset. This often seems to be the best strategy.
A few asthmatics don’t get much benefit from steroids. If your dose of steroid needs to be raised repeatedly, or you still need to use your reliever daily in spite of taking steroids, you may have steroid-resistant asthma. There are other drugs that can help, including anti-leukotriene drugs and the more powerful anti-allergy drugs (see p. 149).
Alcohol, caffeine and asthma
Some asthmatics experience bronchodilation (opening up of the airways) when they drink alcohol, while others experience
bronchospasm (tightening of the airways). For those whose airways open up, there is probably no harm in sometimes having a drink to relieve your asthma symptoms, assuming these are fairly mild. Clearly, it would not be a good idea to make a daily habit of this.
If your airways tighten up with alcohol, you will probably be pleased to hear that it may not be the alcohol itself. Alcoholic drinks contain a great variety of other ingredients, either derived from the original ingredients or generated during the fermentation process. Called ‘congeners’, these vary from one type of alcoholic drink to another, and they are often the culprits in asthma. So you may well find that, while one kind of alcoholic drink has a bad effect, another is fine.
Caffeine has a far more uniform effect — for most asthmatics it opens up the airways. However, the amount needed to relieve an asthma attack will also produce unpleasant side effects, such as a pounding heart or shaky hands. There are also long-term problems with such high doses of caffeine, including insomnia, headaches, nervousness and ‘restless legs’. It is much better to use your reliever inhaler to control an attack: the drug in the inhaler has been chemically tailored to give the maximum therapeutic benefit with the minimum of side effects. Anyone who consumes tea or coffee excessively can make themselves seriously ill, either physically or mentally, and it is not always obvious that caffeine is the cause (see p. 235).

Antihistamines and Allergy

Antihistamines were first introduced in 1947, and are very widely used, so their safety — at least in the case of the older antihistamines — is beyond doubt. Most of the antihistamines have no major ill effects, and no one should feel concerned about taking them. At worst they produce some rather annoying minor side effects, such as drowsiness, which often wear off in time.

These drugs are particularly valuable for hayfever and other allergies in the nose (perennial allergic rhinitis). They are also used for chronic urticaria, sometimes in combination with anotherhistamine-blocking drug — see p. 53.

Antihistamines are not much used for asthma. They have relatively little effect, probably because so many other messenger chemicals are involved in an asthma attack. However, doctors in Japan do use antihistamines for asthma, and it is possible that people of Asiatic origin react differently to them.

Only one antihistamine, ketotifen, is widely used for asthma in the West, and this has other effects besides blocking histamine (see p. 159). A new role may soon develop for antihistamines in thetreatment of asthma, combined with anti-leukotriene drugs (see p. 159).

If you suffer from anaphylaxis you might be given antihistamines in a liquid or chewable form, for use in an emergency. These are not enough in themselves to treat this dangerous condition - you must have an adrenaline injector (see p. 150).

In the past, some doctors prescribed antihistamines for atopic eczema, mainly for their sedative effect(see p. 139) which was thought to help children to sleep better and scratch less at night. This treatment has largely gone out of favour, because its value is in doubt. But a recent study has revealed that the non-sedating antihistamine cetirizine may be useful for very young children with atopic eczema, not only in treating their skin, but also in reducing the chance of them developing asthma (see p. 249).

Most people take their antihistamines in tablet or capsule form. Syrups and sugar-free elixirs areavailable for children.

Antihistamines can also be applied directly, in the form of nasal sprays or eye drops. These are mainlyused to treat hayfever and the conjunctivitis (inflammation of the eye) which often accompanies it.Levocabastine (brand name Livostin) is particularly effective for the eyes.

Antihistamine creams are also sold, without prescription, for the treatment of insect bites - i.e. thenormal non-allergic reaction to such bites. These creams are not recommended for atopic eczema or otherallergic conditions affecting the skin. Not only are they unlikely to help, but they may make mattersworse because, with regular use, skin sensitisation to the antihistamine occurs very readily (see pp.54-5).
Some common brand names

Common brand names include: non-sedating antihistamines - Clarityn, Semprex, Zirtek; Mistamine, Mizollen, Telfast, Terfenadine. Thefirst three are available without prescription.

older (sedating) antihistamines — Atarax, Dimotane, Optimine, Periactin, Piriton, Tavegil, Vallergan eye drops — Emadine, Livostin, Optilast nasal sprays — Livostin, Rhinolast

How antihistamines work
Of the messenger chemicals released when an allergic reaction occurs, the most important is histamine.

This does its work by attaching to specialised receptors in certain parts of the body, and so

triggering various reactions (see box on p. 12). The action of antihistamines is very simple: they bind

to the same receptors as histamine, but they do not trigger any reaction. Histamine cannot bind to the

receptor because the antihistamine is already there.
Unfortunately, the reverse is also true: if the histamine is already there, the antihistamine cannot

elbow it off the receptor, which is why it is important to take the antihistamine well before the

allergen is encountered. Taking antihistamines at the first sign of a snuffle or itch can also work,

but the effects will not be nearly as good as taking them in anticipation of an exposure.
The best approach to treating hayfever, for example, is to start taking the antihistamines at least a

week before the pollen season begins, and preferably two to three weeks before. You should then take

them continuously until it is over. This will make a huge difference to the degree of symptom control

you achieve.
Side effects
The older types of antihistamine, such as chlorphenamine (brand name, Rriton) are relatively

non-specific in their effects – they bind to several different kinds of receptors, not just those for

histamine. As a result they can have some unwanted effects, such as causing drowsiness and poor

coordination. While these sedative effects are no cause for concern in themselves, they can, of course,

be hazardous if you work with dangerous machinery or drive. Avoid both until you are sure how you react

to the antihistamine. Note that the effects of alcohol may be increased.
Very occasionally antihistamines have the opposite effect, causing stimulation rather than sedation;

this is most likely to occur in children and old people. Lowering the dose may solve the problem.
The other possible side effects of the older antihistamines –all of which are minor ones – are

headache, dry mouth, blurred vision, difficulty in passing urine, nervousness, shaky hands, upset

stomach or diarrhoea. A few men suffer impotence while taking antihistamines, but this disappears when

the drug is stopped.
The minor side effects of antihistamines, including drowsiness, often wear off after a while, although

the benefits of the drug remain. So it is worthwhile persisting with an antihistamine, even if it

causes some problems at first. Many people experience side effects from certain antihistamines but not

from others, so try several different types to find one that suits you.
The problem of drowsiness has been reduced, in recent years, thanks to the development of new drugs

that are far more
specific for histamine receptors, the non-sedating antihistamines. A few people do get drowsy even with

these drugs. Again, the effects vary from one drug to another, so if the first one disagrees with you,

try a different one.
It is worth noting – since some people may still have the odd packet in their medicine cabinet – that

two of the non-sedating antihistamines that were available without prescription a few years ago proved

to be unsafe for a small minority of people. One was astemizole (brand names: Hismanal, Pollon-eze),

which has now been withdrawn from use altogether in Britain. The other was terfenadine (brand names:

Triludan, Seldane, Terfenadine) which is still available, but only on prescription.
There are several special precautions relating to terfenadine:
• Never exceed the correct dose.
• If you have ever had any kind of heart problem, talk to your doctor before taking terfenadine.
• Stop taking the drug if you have palpitations, or if you feel faint; see your doctor promptly.
• Do not take terfenadine if you are taking the antibiotic erythromycin, or anti-fungal drugs

such as ketoconazole (Nizoral) or fluconazole (Diflucan), used to treat vaginal thrush.
• Do not take terfenadine if you have liver disease.
• Do not drink grapefruit juice while taking terfenadine: something found naturally in grapefruit

interacts unpleasantly with this antihistamine.
In addition to these special precautions concerning terfenadine, any antihistamine should be treated

with caution by those suffering from epilepsy, Parkinson’s disease, glaucoma, prostate enlargement,

kidney problems, urinary retention, a gastric ulcer, a thyroid disorder, porphyria or liver disease.

Check with your doctor before taking antihistamines if you have any of these conditions.
It may be inadvisable to use antihistamines if you are taking sleeping tablets, anti-depressants or

anti-anxiety drugs – again, see your doctor.
Stop taking antihistamines if you suffer any unusual kind of rash, or if your skin becomes more

sensitive to sunlight.
If you are breast-feeding, note that, because they go through into the milk, the older antihistamines

may make the baby sleepy. However, they do no harm.
Rescue treatment
Most antihistamines perform very badly if you take them once the allergic reaction has set in, but

acrivastine (Semprex) can be good in these circumstances and is non-sedating. No prescription is

required for this drug.
possibly identify all major side effects. We vary in our response to drugs, because we are all so

different at the chemical and cellular level. A drug might have a serious side effect that only affects

one person in 10,000, and no safety trial can hope to identify such a rare response. Only when a drug

is released, and becomes widely used, do such side effects come to light. Other unanticipated side

effects can sometimes arise when people taking the new drug are much older than those in the safety

trials, or belong to a different ethnic group with different susceptibilities. Combining the drug with

certain other drugs can also be a potential source of trouble, although pharmaceutical experts can

often predict such problems from a detailed knowledge of the chemistry of drugs and how they are broken

down in the body. Side effects that take several years to develop - more than the timespan of most

safety trials - will also fail to show up until the drug has been released.
All this may sound very alarming, but in fact severe reactions to new drugs are not that common. And

there are various safety nets in place - doctors keep a close eye on patients taking new drugs, and a

special reporting system ensures that, if unexpected side effects do show up, the information is

quickly shared with others in the medical community.
In order to relate the information here to a particular medicine that you take, you need to know what

drug category it belongs to. Does your inhaler contain a beta-2 reliever, a steroid, a cromoglycatetype

drug or an anti-cholinergic, for example? If you are not sure, ask your pharmacist.
Those are the category names for drugs: they denote families of drugs which are similar chemically
and work in roughly the same way. Within each category, or family, there are a number of individual

drugs. The individual drugs should, ideally, have a standard internationally agreed name - this is

known as the generic name. Unfortunately, a few of the drugs used for allergies and asthma have more

than one generic name - salbutamol is known as albuterol in some parts of the world, and adrenaline is called epinephrine.

Finally there are the brand names, which are the ones most patients are familiar with. These are always

shown with a capital letter, unlike the generic names. Long-established drugs are usually made by

several different pharmaceutical companies, and therefore marketed under several different brand names.

A newer drug, which is still covered by the patent of the pharmaceutical company that developed it,

will be sold under only one brand name.

The issue of brand names is important, because a different brand name might make you think you are taking a different drug, when in fact it is exactly the same drug being marketed in a different guise.If you have suffered side effects from a particular drug in the past, and wish to avoid it in future, take note of its generic name, rather than its brand name. Sometimes the generic name is used as the brand name, in what are called generic drugs. These arerelatively inexpensive copies of popular drug brands -they are just the same chemically, but they costless because there is no advertising of the brand to doctors, and profit margins have been cut to aminimum. In order to reduce National Health Service costs, doctors are now asked to prescribe generic drugs whenever possible.