A-Z Principal Drugs (ACTH - Allopurinol )
A-Z Principal Drugs (ACTH - Allopurinol )
ACTH See corticotrophin.
actinomycin D
A cytotoxic antibiotic, also known as dactinomycin, that inhibits cell division by forming a stable complex with DNA. It is used mainly in Wilm’s tumour, and tumours of the
uterus and testes.
Dose: 500 pg daily for 5 days by i.v. infusion, but other dosage schemes are in use. It is highly irritant to soft tissues, and great care must be taken to avoid extravasation.
Close haematological control is necessary. Skin eruptions, alopecia and gastrointestinal disturbances are frequent side-effects. Cosmogen). ‘,cc page 122 and Table 8.
aciclovir (aciclovir)
An antiviral agent highly active against herpes simplex and zoster viruses. It acts indirectly by inhibiting the DNA polymerase essential for viral replication.
Dose: 200 mg 5 times a day for 5 (lays in herpes simplex infections of the skin and mucous membranes, and in genital herpes; in shingles (herpes zoster), 800 mg orally 5 times a
day for 7 days is given, but treatment should be started as soon as possible to obtain the maximum relief of pain. A 5% cream is used for superficial infections, and for herpes
simplex keratitis a 3% ophthalmic ointment is available. Acyclovir is also of’great value in herpes simplex infections in immunocompromised patients. Dose: 200 mg 4 times a day:
800 mg 5 times a day in zoster infections. In severe conditions, 5 mg/kg or more 8-hourly by i.v. infusion. It is also given orally for longterm prophylaxis in such patients.
Reduced doses are necessary in renal impairment and in the elderly. Side-effects include gastrointestinal disturbances, rash and neurological reactions. (Zovirax). See page 144
and Table 19.
adapaleneV
A new retinoid used like tretinoin in the treatment of acne. Applied as a 0.1% gel, once a day, taking care to avoid all mucous surfaces. Irritation may require temporary
withdrawal. (Differin gel).
adenosine
A cardiac drug that slows conduction through the AV node. It is used to restore normal sinus rhythm in paroxysmal tachycardia.
Dose: given by rapid i.v. injection as an initial dose of 3 mg. A second dose of may be necessary after 1-2 minutes, and a third dose of 12 mg if the tachycardia
remains uncontrolled. For use only with close cardiac monitoring. (Adenocor).
adrenaline (epinephrine)
Adrenaline is one of the principal hormones of the medulla of the adrenal gland, but is now made synthetically. It acts on both the alpha and beta receptors of the sympathetic
nervous system. The effects of the alpha receptors result in vasoconstriction with a rise in blood pressure; stimulation of the beta receptors increases cardiac rate and output,
and relaxes bronchial muscles. Dose: in cardiac arrest, 0.2-0.5 nil of 1 1000 solution by sac. or i.m. injection. In anaphylactic shock and allergic emergencies, 0.5-1 mg (0.5-1
nil of 1:1000 solution) is given by i.m. injection and repeated every 15 minutes as required. An i.v. injection of an antihistamine is sometimes given as supportive therapy.
Doses of 100-200 Vg ( 1-2 nil of 1:10000 solution) have been given by intracardiac injection in cardiac arrest and syncope. In hypotensive crises, noradrenaline or meetaraminol
are preferred. Adrenaline is added to local anaesthetic solutions (1:50000-1:200000) to prolong the anaesthetic effect by reducing diffusion of the anaesthetic solution.
Occasionally the solution is applied locally to stop capillary bleeding and epistaxis. it is also used as eye drops (I I%) in chronic open angle glaucoma, but may cause redness
and smarting of the eye. Solutions of adrenaline may darken on storage and lose activity.
albendazole
An anthelmintic used in hydatid disease with larval cysts of the dog tapeworm. The cysts do not develop into worms, but increase in size to simulate liver abscess.
Dose: given as an adjunct to surgery in doses of 800 mg daily for 28 clays, repeated after a 2-week rest period for 3 cycles, with liver tests and blood counts. (Eskazole).
albumin (human) Human albumin, obtained from pooled human plasma. Given by i.v. infusion as a 5-20% solution in the treatment of shock and other conditions where restoration of
blood volume is urgent; in severe burns to prevent haemoconcentration, and in some conditions of
oalbumaemia, and in acute oedema.
alclometasone
A highly potent topical cortikosteroid. It is used as a 0.05% cream or ointment in inflammatory and pruritic dermatoses likely to respond to such about 90 seconds after i.v.
alcohol (ethanol)
Used occasionally by injection to destroy nerve tissue in (he treatment of intractable trigeminal neuralgia. Industrial alcohol or methylated spirit contains 5% of wood naphtha;
surgical spirit is industrial alcohol with the addition of methyl salicylate and other substances and is used for skin preparation and the prevention of pressure sores.
Ordinary, coloured, methylated spirit contains pyridine, and is not suitable for medical purposes.
aldesleukin
A recombinant form of interleukin-2, a lymphokinine that stimulates the production of interferon and T-Iymphocytes. Used in metastatic renal cell
carcinoma; severe toxicity is common. (Proleukin).
aldosterone
The main mineralocorticoid hormone of the adrenal cortex. An excessive secretion of aldosterone may occur in some oedematous states and reduce the action of thiazide diuretics.
See spironolactone and canrenoate.
alendronate
A bisphosphonate used in postmenopausal osteoporosis. It inhibits osteoclast activity and increases bone strength, but continuous treatment is necessary. Dose: 10 mg daily in
the morning with water on an empty stomach, 30 minutes before food. Side-effects include severe oesophageal reactions. (Fosomax).
alfacalcidol
A derivative of calciferol, with a more powerful and rapid action. It is used to treat hypocalcaemia in hypoparathyroidism, neonatal hypocalcaemia and other hypocalcaemic
states, and in vitamin D-resistant conditions. Regular blood calcium determinations are
essential as a drug-induced hypercalcaemia percalcaemia may take weeks to subside after
withdrawal.
Dose: 1 mg orally or i.v. daily initially, according to response. (,Alpha 1); OneAlphal.
alfentanil
A potent, rapidly acting narcotic analgesic, useful in short surgical procedures, or for longer operations in ventilated patients. The peak effect occurs
alfuzosin
A selective alpha-adrenoceptor blocking agent for the symptomatic treatment of benign prostatic hypertrophy (BPH).Dose: a first dose of 2.5 mg should be given in bed to avoid a marked first-dose hypotensive response, then 7.5 mg daily. Side-effects are dizziness, hypotension and
tachycardia. (Xatral). See page 164 and Table 28.
alglucerase
An enzyme product used i.v. by specialists in Gaucher’s disease. (Ceredase).
alkylating agents
Cytotoxic drugs which act by damaging DNA, and so interfere with cell replication. Chlorambucil and cyclophosphamide are examples.
allantonin
A natural substance said to promote wound healing. Present in some locally applied products for skin disorders.
allergen vaccines
Weak allergen vaccines prepared from allergens such as grass pollens, house dust mites and bee stings are used to desensitize hypersensitive individuals but such treatment
carries the risk of severe anaphylactic reactions, which may prove fatal in asthmatics, and it is now recommended that desensitization therapy should be carried out only when
full cardiorespiratory resuscitation
measures are immediately available.
allopurinol
An enzyme inhibitor that blocks the formation of uric acid, and so is useful in the treatment of chronic gout. It also reduces the formation of uric acid calculi. It is usefulin the hyperuricaemia of leukaemia but it should be given before cytotoxic therapy is commenced.Dose: 100 mg daily as a single dose with food, slowly increased to 300 mg daily or more as required, reduced in cases of renal impairment. It may cause gouty arthritisinitially, requiring colchicine or non-steroidal anti-inflammatory agent (NSAID) treatment for at least I month. Side-effects include nausea, headache and gastrointestinal
disturbances, but skin reactions indicate withdrawal of the drug. (Zyloric). See page 140 and Table 17.