A-Z Principal Drugs (chymotrypsin - clindamycin)
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.

