Posts Tagged ‘allergic response’

halothane A potent non-inflammable inhalation anaesthetic. It suppresses mucous and bronchial secretions, and reduces capillary bleeding. It has sonic muscle-relaxant properties, but in major surgery, supplementary treatment with a muscle relaxant is necessary. Halothane may cause some cardiac irregularities, but an occasional serious side-effect is severe hepatotoxicity, particularly after further exposure to the drug within periods of 441 weeks. Such susceptibility cannot yet be detected, so great care is necessary in any cases of liver dysfunction.
(Fluothane).
hamamelis An extract of witch hazel leaves referred to as harnarnelis or witch hazel water is used as a soothing application for bruises and sprains.
Hartmann’s solution An electrolyte-replacement solution containing sodium lactate, sodium chloride, potassium chloride and calcium chloride.
heparin The natural anticoagulant obtained front lung and liver tissue. It is widely used in deep-vein thrombosis and pulmonary embolism.
Dose: by i.v. injection 5000 units initially, followed by 1000-2000 units hourly by i.v. infusion, or 15000 units by s.c. injection 12-hourly under laboratory control. Prophylactic dose before surgery 5000 units, then 5000 units every 8-12 hours for 7 days. Overdosage call be controlled by the i.v. injection of prolamine sulphate. Treatment with heparin may be combined with that of oral anticoagulants such as phenindione or warfarin to provide immediate action before the slow-acting oral drugs begin to take effect. Occasional side-effects include hypersensitivity reactions and alopecia. Heparin is a complex polysaccharide, but certain fragments of that large molecule retain sonic anticoagulant activity, and are referred to as low molecular weight heparins. They are used mainly in the prophylaxis of venous thrombo-embolism, as they have a longer
action than standard heparin. They are given by once-daily s.c. injection, and laboratory control of the bleeding time is not necessary. The dose varies to some extent with the product used.
hepatitis A & 8 vaccines Inactivated hepatitis virus antigens for the protection of individuals highly exposed to the infections. Dose: see data sheets. (I iaverix A;
kncigix B; II–B–Vax).
theroin See diamorphine.
hetastarch A soluble modified starch that is used as a 6% solution with 0.9% sodium chloride as a plasma volume expander. Dose: 500-1500 nil daily by i.v. infusion, up to a maximum of 20 mltkg daily. It is excreted by the kidneys, and care must be taken to avoid circulatory overload. Not for use in congestive heart failure or renal insufficiency. Side-effects are vomiting, chills, fever and urticaria. (clol-IAES; Hespan).
hexachlorophene A slow-acting antiseptic used for skin sterilization, and present in sonic medicated soaps.
hexamine (methenamine) A formaldehyde derivative of low toxicity, occasionally used as a urinary antiseptic. Dose: 2 g daily. It is usually given as hexamine hippurate to ensure the necessary acidification ol’the urine. (Iliprex).
histamine A compound present in a bound form in all mammalian tissues; its release is probably the ultimate cause of many allergic conditions.
histamine H,-receptor antagonists See antihistamines. See page 110 and Table 2.
histamine Hz -receptor antagonists Drugs that (litter from conventional antihistamines in having a selective blocking action on receptors ill the gastric cells that secrete acid. They are widely used in the treatment of peptic ulcer and other conditions requiring a reduction in gastric acid secretion. See page 162 and Table 27.
homatropine An atropine derivative with a similar but more rapid mydriatic action (15-30 minutes), but a shorter duration of effect of about 24 hours. Eye drops
(1-2%) sometimes with cocaine.

hyaluronidase A ’spreading’ factor used to increase the absorption of large-volume s.c. injections. The injection of 1500 units of hyaluronidase, either into the injection site or mixed with the injection fluid, will promote the absorption of 500-1000 mL of electrolyte solution by s.c. drip infusion. (Hyalase).
hydralazine A vasodilator that is useful in the supplementary treatment of hypertension.
Dose: 50- 100 nig daily, usually with a IlliaUide diuretic or a beta-blocking agent. Also given in hypertensive crisis by slots, i.v. injection in doses of 5-10 mg; over-rapid injection may cause a marked fall in blood pressure. Side-effects are nausea, tachycardia and fluid retention (less likely with low doses), but a lupus erythematOSLIS- like syndromemay occur with extended high-dose therapy. (Apresoline). See page 148 and “Fable 21.
hydrochlorothiazide A thiazide diuretic that brings about it marked increase in the excretion of salts and water, and is of value in congestive heart failure and other oedematous conditions. It is also of value iii    as it reduces peripheral resistance, and potentiates the action of some other antihypertensive drugs.
Dose: 50-111(1 Ing daily initially in
oedenia; maintenance dose 25-50 mg daily or oil alternate days. III hypertension, 25-30 Ing daily according to need.
I lydrochlorolhiazidc, like other thiazid”, Increases the excretion of potassium as well as sodium, and in extended treatment supplementary treatment with potassium chloride or effervescent potassium tablets may be required. Side-effects include nausea, rash, dizziness and photosensitivity. (I lydroSaluric). See page 148
and ‘I able 21.
acute lyniphoblastic leukaemia and some lymphomas. In common with some other corticosteroids, hydrocortisone inhibits organ-transplant rejection and in high doses it is given to control incipient rejection.
Dose: varies considerably according to need: for replacement therapy, 20-30 mg daily: in shock, 100-300 mg or more by slow i.v. injection, repeated as required. Side-effects are numerous and include hypertension, oedema, mental disturbances, re-activation of peptic ulcer, muscle weakness and diabetes. Cushing’s syndrome may occur with high doses.
I I ydrocortisone, unlike cortisone, is active topically, in(] is used as eye drops 0.3% (usually with an antibiotic), ointment and cream (0.50/o and 11M, often with an antibiotic to control any secondary infection.
hydroflumethiazide A thiazide diuretic N,ith the actions, uses and side-effects of bendrofluazide.
Dose: 25- 100 nig daily in (lie morning; 25-50 Ing daily in hypertension.
ff lydrenox). See page 148.
hydrogen peroxide solution It contains 5-7% of H 02
, equivalent to about 20 volumes oJ oxygen. It has antiseptic and deodorizing properties, and is used mainly for cleaning wounds. It is also used as a mouthwash (diluted 1:7), and as ear drops (1:4 in water or 501% alcohol).
thydromorphone A potent opioid analgesic of the morphine type. Dose: in severe pain 1.3-2.6 Ing 4 t,-hourly. Walladone).
hydrotalcite Aluminium magnesium hydroxide carbonate. An antacid used in dyspepsia and related conditions.
Dose: I g as required.
55
hydrocortisone The principal corticosteroid, also known as cortisol, that is secreted by the adrenal cortex. It plays a major role in the metabolism of glucose, protein and calcium, in maintaining the electrolyte balance, and in reducing inflammatory and allergic responses. It is used in all cases of adrenocortical insufficiency, including Addison’s disease and after adrenalectomy. It is also used in anaphylactic shock, asthma, rheumatoid disease and allergic states. It is valuable in
hydroxocobalamin A derivative of eydnu,obdlaniin, and now the preferred form of vitamin B,, as it has a more prolonged action.
Dose: in pernicious anaemia and other vitamin 13, deficiency states, I Ing initially ian. repeated 5 times at intervals of 2-3 days; maintenance dose 1 mg by I’ll’
by )CC- Lion every 3 months. It is also given
prophylactically after total gastrectonly. (Cobalin-H; NCO-Cytalliell). See
page 112.

hydroxyapatite A natural substance with a mineral composition somewhat similar to that of bone. It is used as a source of calcium and phosphorus in osteoporosis and other deficiency states. Tablets of 830 mg are available. (Ossopan).
hypermotility of the gastrointestinal tract, and may be useful in spasmodic dysmenorrhoea.
Dose: 40-80 mg daily; in acute spasm, .10 mg by injection. (Buscopan).
hydroxychloroquine An antimalarial with the actions, uses and side-effects of chloroquine. It is also useful in rheumatoid arthritis in doses of 200-400mg daily, and in lupus erythematosus, but side-effects are numerous, and treatment requires expert supervision. (Plaquenil). See page 165.
hypromellose A cellulose-derivative that dissolves in water to form a viscid, colloidal solution. Such a solution is used as a base for eye drops to extend the action of a dissolved ophthalmic drug; to lubricate contact lenses; and to act as a lubricant in chronic, sore eye conditions.
5-hydroxytryptamine See serotonin.
hydroxurea (hydrocarbamide) A cytotoxic agent sometimes used in chronic myeloid leukaemia.
Dose: 20- 30 mg/kg as a single dose daily or 80 nig/kg every third day. Side-effects are nausea, skin reactions and myelo- suppression. (Hydrea). See page 122 and Table 8.
hydroxyzine A mild tranquillizer with some sedative and antihistaminic properties. It is given in the short-term treatment of anxiety, and in pruritus and dermatoses complicated by emotional tension. Dose: 50-400 mg daily. It has the side-effects of the antihistamines, and is not recommended where some sedation is undesirable. (Atarax; Ucerax). See page 117 and Table 3.
hyoscine (scopolamine) An alkaloid obtained from plants of the belladonna group. It is a powerful hypnotic and is widely used together with papaveretum for premedication before anaesthesia in doses of 300-600 pg by s.c. or i.m. injection. It has some antiemetic properties, and is useful in travel sickness and vertigo. Dose: 300 mg 30 minutes before starting the iourney, followed by up to 3 doses 6-hourly. Scopoderm is a patch of 500 pg. Thc side-effects of mouth dryness and dizziness are those of the anticholinergic drugs generally. It is contraindicated in glaucoma. It is used occasionally in terminal care for bowel colic and excessive respiratory secretions. Dose: 600 pg-2.4 mg daily by s.c. infusion.
hyoscine butylbromide A derivative of hyoscine that differs in lacking any central action. It is given in spasm and
I
ibuprofen A non-steroidal anti-inflammatory agent (NSAID) widely used in rheumatoid and arthritic conditions. It is also given as an analgesic for mild to moderate pain, but not for acute gout. Dose: 1.8 g daily initially; lly; maintenance duos, 600 lllg-L2 daily after food. A 5% cream is available for local use. The sideeflicts are those of the NSAID& generally. (BrUlen; Feribid). See page 165.
ichthammol A thick, dark brown liquid with a characteristic odour, derived from certain bituminous oils. It is a mild antiseptic and is used mainly in chronic eczema as a 100A, ointment or zinc paste. A solution (10% in glycerin) has been used oil ulcers and inflamed areas.
idarubicin A potent cytotoxic agent similar in actions and uses to doxorubicin. It is given orally and i.v. in acute nonlymphocytic leukaemia, breast cancer, and as second-line therapy in acute lymphatic leukaemia. Dose is based on skin area. (Zavedos). See page 122 and Table 8.
idoxuridine An antiviral agent now virtually superseded by acyclovir and related drugs. Used occasionally in herpes zoster skin infection by local application of a 5% solution. See page 144 and Table 19.

fosfamide A derivative of cyclophosphamide with similar actions and uses. It is effective in lung, ovary, breast and soft-tissue tumours, as well as some malignant lymphomas.

Various anti-allergy drugs
An allergic reaction is a lengthy, complex process, and the various anti-allergy drugs all work on different stages of that process. That is why it often makes sense to use several different drugs for the same allergic condition: they each tackle the problem in their own way.
Steroids (see p. 140) intervene at a very late stage, quelling the inflammation that follows on from an allergic reaction. Using a steroid is rather like calling the fire brigade to put out a fire, whereas using an antihistamine (see p. 138) is like having fire-proof doors, to prevent the fire spreading at an early stage. Cromoglycate-type drugs (see below) intervene at an even earlier stage. They are like basic fire prevention - teaching children not to play with matches, or fitting smoke detectors.
Anti - leukotnene drugs (see p. 149) work at roughly the same stage of the process as anti-histamines but tackle an entirely different aspect of the allergic reaction.
Cromoglycate-type drugs
These drugs are also referred to as mast-cell stabilisers or mast-cell Mockers.
There are three drugs in this group, sodium cromoglycate (also spelled cromoglicate), nedocromil sodium, and lodoxamide. All operate at an early stage of the allergic reaction, stopping it before it actually starts. They stabilise the outer membrane of the mast cells (see box on p. 12), which prevents the allergic response from occurring.
Some common brand names
Common brand names of cromoglycate-type drugs include:
inhalers - Cromogen Easi-Breathe, Intal, Tilade
eye drops - Hay-Crom, Opticrom, Rapitil, Vividrin, Viz-on nose sprays - Rynacrom, Vividrin
capsules - Nalcrom
This is a far more satisfactory way of dealing with an allergic reaction than trying to tackle it after the reaction has occurred. But from a purely practical point of view, it has a drawback. I order to work at all, these drugs must reach the mast cells in advance of the allergen. They are of very little use if taken after the allergic reaction has begun.
For those who are taking cromoglycate-type drugs on a regular schedule, several times a day, it is very important to be conscientious about taking them on time. This maintains the protective effect of the drug, without any gaps.
If you are using these drugs on an ‘as-needed’ basis, you should take them 30 minutes before an allergen is encountered. or 30 minutes before a bout of exercise, if they are being prescribed for exercise-induced asthma. (Note that children sometimes respond differently, getting protection from these drugs immediately.)
The effect of these drugs takes time to build up. You should take them regularly for at least four weeks before deciding whether they are helping you or not.
One point in favour of cromoglycate-type drugs is that they are extremely safe, with few or no side effects in most people. Sadly, they do not work for everyone. A fairly high percentage of children respond well to them, but the response rate is much lower for adults. Nevertheless, adult allergy sufferers, especially those who need steroids to control their symptoms, should always be given the opportunity to try out these drugs. When cromoglycate-type drugs do work, they are very effective and almost always trouble-free, so they are a good alternative to steroids.
Both sodium cromoglycate and nedocromil sodium are available in inhaler form for asthma (see p. 157). Sodium cromoglycate is also available as nose drops for hayfever and other nasal allergies.
All three drugs are available as eye drops. Recent evidence suggests that sodium cromoglycate drops are less effective than the other two, particularly for the treatment of severe allergic conjunctivitis (inflammation of the eye).
Sodium cromoglycate is available in capsule form for food allergy. Note that these capsules are of very limited value in food allergy, and are certainly not a substitute for food avoidance. They do reduce sensitivity a little and can sometimes be helpful for those with multiple food allergies (see p. 67).
Side effects
There are no serious side effects at all for nedocromil sodium. cromoglycate can, very rarely, cause joint pain and swelling. An allergic reaction to the drug itself is even more uncommon. Stop taking the drug and see your doctor promptly if either of these occurs.
The only other side effects that have occasionally been reported are headache, nausea and vomiting. None of these indicates any damaging effect by the drugs – they are all minor side effects.
Eye drops containing these drugs may cause stinging and burning when inserted, but this is a minor side effect and usually wears off. Flushing and dizziness have sometimes been reported with lodoxamide eye drops.
Nose drops may also cause local irritation. This could be due to the drug itself, in which case it is a minor side effect. Alternatively, the irritation may be due to the preservative used or some other non-drug ingredient (see box on p. 33).
Occasionally cromoglycate nose drops cause bronchospasm – contraction of the airway muscles – but this tends to wear off quite quickly. Bronchospasm can also occur when cromoglycate-type drugs are inhaled (see p. 157).
Anti - leu kotriene drugs
These drugs, which have a set of very specific effects (see p. 159), were originally designed to treat asthma. Their potential for treating other allergic diseases is currently being explored:
•    Several studies show that they work well for perennial allergic rhinitis brought on by allergens such as house-dust mite. They also have some effect on hayfever, but standard treatment (such as antihistamines plus a steroid spray for the nose) is more effective.
•    They are especially useful for both rhinitis and asthma in patients suffering from triad (see box on p. 28). Research shows that they also reduce asthmatic reactions to very small test doses of aspirin, but they don’t give protection against anaphylaxis brought on by normal doses.
•    They have also been used successfully in cases of chronic urticaria and for some patients with delayed pressure urticaria. It seems plausible that they would also be helpful for chronic urticarla linked to aspirin sensitivity.
•    Preliminary trials suggest that these drugs might be useful in atopic eczema. Some studies show a very good response that allows a reduction in steroid creams.
•    Montelukast works very well for eosinophilic gastroenteritis and eosinophilic oesophagitis (see p. 72), according to some new studies.
For side effects of these drugs see pp. 159-60.
Anti-IgE drugs
Since the antibody IgE (see box on p. 12) is such a crucial player in allergic reactions, developing drugs that disable this antibody should help allergy sufferers. The first such drug is omalizumab (brand name Xolair) which was licensed for use in the United States in 2003. It is expected to become available in Britain some time in the next few years.
Omalizumab binds to IgE antibodies and stops them from interacting with mast cells, so blocking any allergic reaction. The drug is given as a ‘depot injection’, just under the skin, every 2-4 weeks. It is gradually released from the injection site and moves around the body in the blood, mopping up IgE molecules.
At present, omalizumab is used for severe hayfever and for people with asthma who are not responding well to the usual treatments. It is only worth using if there is clear evidence that allergies play a part in the asthma. Patients who use omalizumab are often able to reduce their dose of inhaled steroids – and they suffer fewer serious asthma attacks and have better lung function. Some patients can even stop using steroids completely.
Other anti-IgE drugs are in the pipeline. Pilot studies show that one works very well for peanut allergy: after just four injections, sensitivity to the allergen falls sharply, reducing the risk of anaphylaxis from traces of peanut eaten accidentally.
More powerful anti-allergy drugs
Occasionally people with severe allergies, who are on constant high doses of steroid tablets, or who fail to respond to steroids, need treatment with powerful anti-inflammatory drugs, such as methotrexate or cyclosporin. These suppress the immune system, and extremely careful monitoring for side effects is needed.
Adrenaline (epinephrine)
Anyone who has suffered anaphylactic shock (see p. 58) should be carrying a special syringe, called an auto-injector, loaded with adrenaline. The injector is very simple to operate and is designed for emergencies. Most allergy sufferers, even children, can give themselves the injection – or a parent or other adult can give it.
Some asthmatics, and those with food allergy who suffer swelling of the throat, may be given adrenaline in inhaler form as well (see pp. 155-6). This can be useful as an additional treatment but it’s definitely not a substitute for an injector.
See pp. 98-9 for instructions on using adrenaline in a crisis.
Wherever you go, take your injector with you. Always keep it close at hand: you need to be able to use it within minutes of the allergic reaction starting. You may be unable to speak (and therefore unable to ask someone else to fetch it) quite soon after the attack begins. The injector must never be refrigerated. It can also be damaged by sunlight and excess heat.
If you live in the countryside or in an area with a poor ambulance sevice, or if you are going camping or hiking somewhere remote, ask your doctor for a second injector, or one that can deliver multiple injections. Also ask about the maximum number of injections that can be given, and never exceed this total. Some doctors believe everyone should have two injectors, just in case the first dose doesn’t do the trick and help is slow in coming.
It is vital that you are shown exactly how to use the auto-injector. Canadian researchers discovered that only one in four
Some common brand names
Common brand names of adrenaline preparations include: auto-injectors – Anapen, EpiPen
inhalers – AsthmaHaler Mist, Bronkaid, Epiphrine
health professionals got the technique correct when demonstrating how to use an auto-injector In this study, pharmacists were much the best as regards accurate instructions. Dummy injectors are useful for training purposes and most pharmacies have them.
When the adrenaline auto-injectors expire, they can be very useful for practising with, or for showing a new baby-sitter or teacher – practise on an orange or grapefruit.
If you are taking beta-blockers (e.g. for a heart condition or anxiety), adrenaline may not have much effect.
Heavy daily use of beta-2 relievers for asthma (see p. 152) will also make adrenaline less effective when you need it.
Side effects
The important side effects of adrenaline involve the heart. Anyone with a heart condition should be given special advice in advance by their doctor about using adrenaline. The same goes for people with diabetes, hyperthyroidism or high blood pressure, and anyone taking tricyclic anti-depressants. There are quite a few minor side effects from adrenaline, such as anxiety, trembling, nausea. sweating, dizziness and cold extremities. These soon wear off.
Drugs that can make you worse
Aspirin and its relatives have a very bad effect on some people with rhinitis and/or asthma (see box on p. 151). Unfortunately, recent research shows that paracetamol is not safe either. It makes asthma more likely to develop in those who do not yet have the disease, and increases the severity of asthma symptoms for those who do. Unlike aspirin, paracetamol affects everyone, because it lowers the levels of a natural antioxidant, called glutathione, which the body makes to protect the lungs from oxidants. The greatest effects are seen in people who take paracetamol regularly (once a week or more), but even an occasional dose makes some difference.
All the other drugs that can make you worse are prescription drugs, and your doctor should be alert to the dangers. But doctors are overworked and sometimes forget, so it is sensible to know about the risks for yourself. If you have any doubt about the drugs you are taking, ask a pharmacist.
Beta-blockers are a major hazard for people with allergies. They can make the airways contract, and can bring on a serious asthma attack. They also make anaphylaxis more likely in someone who already has allergic reactions (see p. 59) and they increase the risk of a severe reaction to
immunotherapy (see p. 166) or skin-prick tests (see p. 91). Beta-blockers are prescribed for high blood pressure, angina and other heart problems, migraine and thyroid disease. There are alternative drugs in all cases. Sometimes asthma develops in people who have been taking beta-blockers for years. The beta-blockers are not responsible for this, but once asthma has begun, they will make symptoms worse. Eye drops for the treatment of glaucoma may also contain beta-blockers and can have a bad effect on asthmatics.
ACE inhibitors, used for heart conditions, may cause a cough and airway narrowing. They may also increase the risk of a severe reaction to immunotherapy.
Female hormones affect asthmatics, so taking the contraceptive pill or hormone replacement therapy (HRT) may make asthma worse. Progesterone-only contraceptive pills tend to cause fewer problems.
The drug isoniazid (INH), prescribed for tuberculosis, makes the body far more susceptible to histamine in foods (see p. 200).
An allergic reaction to a specific drug (e.g. penicillin) can also occur in some people, resulting in urticaria, or even anaphylactic shock.
Aspirin sensitivity
Aspirin sensitivity is not an allergic reaction, because neither IgE nor mast cells are involved. What causes this problem is a metabolic abnormality — a malfunction in one aspect of the body’s chemistry. The details of this are very complicated: you may want to skip the next three paragraphs and
simply read about how to cope with the problem.
The exact nature of aspirin sensitivity is still far from clear, but it seems to involve a relatively poor production of prostaglandins, combined with a plentiful production of leukotrienes. Both these substances are messenger chemicals which, broadly speaking, promote inflammation. But the details of their pro-inflammatory activities differ. It seems that, ideally, the body should have a harmonious balance between the two, and an imbalance produces problems.
Both prostaglandins and leukotrienes are manufactured from certain fats that are found in the diet. These fats, the raw materials, are worked on initially by two different enzymes — one that leads to the production of prostaglandins and another that leads to the production of leukotrienes.
If one of these enzymes is defective, it may mean that the other is oversupplied with raw materials, resulting in a serious imbalance between prostaglandins and leukotrienes. In those with aspirin sensitivity, or at risk of developing aspirin sensitivity, the enzyme that produces prostaglandins seems to be defective.
Even in the absence of aspirin, this imbalance in the production of prostaglandins and leukotrienes causes problems. It leads to symptoms such as chronic urticaria (see p. 51) or rhinitis, nasal polyps and asthma (a cluster of symptoms that is commonly called triad — see box on p. 28).
Taking aspirin can make the imbalance between prostaglandins and leukotrienes even worse in a person with this underlying abnormality. Aspirin exerts its painkilling effects by disabling the main prostaglandin-making enzyme — the enzyme that is already defective.
When someone with aspirin sensitivity takes aspirin, they may suffer worsening asthma, a severe asthma attack or — the worst-case scenario —collapse. This is a potentially fatal reaction, similar to anaphylaxis, requiring emergency medical treatment (see p. 101).
The greatest puzzle about aspirin sensitivity is why it often takes so long to develop in someone who already has the symptoms of triad —indicating the basic metabolic abnormality. It may be as much as 20 years from when someone has their first triad symptoms to when they begin reacting badly to aspirin.
If you have triad symptoms already, but no aspirin sensitivity yet, what should you do? Unfortunately, there are no safe tests for aspirin sensitivity at present — taking a small dose of aspirin and seeing what happens is very hazardous. It is probably best to assume that you are going to become sensitive to aspirin at some stage, and avoid all aspirin and aspirin-like drugs. Caution is the best plan here because aspirin sensitivity can come on very suddenly, and be life-threatening the very first time it occurs. Note
that some triad sufferers have polyps and rhinitis but no asthma until they actually develop aspirin sensitivity — a dose of aspirin suddenly brings on their first asthma attack plus other symptoms of aspirin sensitivity.
Avoiding aspirin itself is not difficult, but aspirin-like drugs pose more of a problem. Every year there are a number of deaths from these drugs. Some cases occur because a busy doctor momentarily forgets that a patient should not take these drugs. The drugs that need to be avoided are all known as non-steroidal anti-inflammatory drugs (NSAIDs), COX-1 inhibitors or COX-2 inhibitors. However you will not see any of these names on the packet. These drugs are very widely used for pain relief (e.g. in headache and backache remedies such as Nurofen), for the treatment of arthritis, and for several other inflammatory diseases.
There are dozens of non-steroidal anti-inflammatory drugs available, and many are sold under several different brand names. The list grows every year, as new drugs or new brands are launched. The only way to avoid these drugs is to be very cautious:
•    When buying any cold- or flu-remedies, painkillers, medicines for sprains or sports injuries (including those you apply directly to the skin), headache tablets or migraine tablets, always buy them at a chemist’s shop rather than a supermarket, and check with the pharmacist that they do not contain aspirin or aspirin-like drugs.
•    Be cautious also about remedies for an upset stomach. A few (e.g. Alka-Seltzer) contain aspirin.
•    Don’t take any drugs unless you are 100% sure of what they contain. Remember that the ingredients of a familiar brand name can sometimes change — read the label every time.
•    When a doctor prescribes any new drug, always mention that you are sensitive to aspirin, or that you have triad symptoms. Alternatively, check with the pharmacist when the prescription is filled.
•    Aspirin-free painkillers almost always contain paracetamol, a drug which can cause a severe reaction (similar to the collapse induced by aspirin itself) in about 5% of those with aspirin sensitivity. If you are taking paracetamol for the first time, start with half a tablet. Be sure that, for the next 2-3 hours, you have a way of getting to hospital quickly should you start to feel ill. (Note that paracetamol has another entirely separate effect, increasing the severity of asthma, and it is best not to take it too often — see box on p. 150.)
Avoiding all aspirin-like drugs will prevent you having anaphylaxis or severe attacks of asthma. Unfortunately, triad symptoms will not go away however careful you are about avoiding aspirin.
It is well worth trying the new anti-leukotriene drugs (see p. 149), especially if you have aspirin-induced asthma. They seem to help with triad symptoms by curtailing the activities of leukotrienes and so redressing the balance between leukotrienes and prostaglandins.