Dimercaprol

Dimercaprol has been reported to induce hemolysis (which may be severe) in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Therefore, high-risk individuals should be screened for G6PD deficiency, and susceptible patients should be monitored for hemolysis during therapy with dimercaprol.

Dimercaprol injection has been used in Wilson’s disease with successful full-term pregnancies, but since there is no other experience of its use in pregnancy, it should be prescribed with caution during this period.

There is no experience of its use in lactation. It should be prescribed with caution during this period.

No adverse effects known.

Side effects are relatively frequent, but at the therapeutic dosage employed, are seldom severe enough to warrant cessation of treatment and are almost invariably reversible. There is some evidence to indicate that 30-60 mg of ephedrine sulphate by mouth, given half an hour before each injection of dimercaprol, will reduce these reactions. Also, a minimum interval of four hours between doses appears to reduce side effects.

Dimercaprol may cause the following side effects, particularly at the higher dosage levels:

Blood and lymphatic system disorders: Haemolysis, transient reductions in leukocyte count have also been reported

Psychiatric disorders: Anxiety, restlessness

Nervous system disorders: Headache, tingling of the hands and other extremities, tremor. High doses have produced hypertensive encephalopathy with convulsions and coma.

Eye disorders: Burning sensation of the eyes, lacrimation, conjunctivitis, blepharospasm

Cardiac disorders: Elevation of blood pressure accompanied by tachycardia

Respiratory, thoracic and mediastinal disorders: Rhinorrhoea, a feeling of constriction in the chest and throat

Gastrointestinal disorders: Nausea and possibly vomiting, salivation, abdominal pain, burning sensation of the lips, mouth and throat

Hepatobiliary disorders: Hepatotoxicity/liver injury

Skin and subcutaneous tissue disorders: Sweating of the forehead and hands

Musculoskeletal and connective tissue disorders: Muscle pain and spasm, pain in jaw

Renal and urinary disorders: Renal impairment

Reproductive system and breast disorders: Burning sensation in the penis

General disorders and administration site conditions: Local pain may occur at the site of injection and gluteal abscess has occasionally been encountered. Pyrexia.

Investigations: Activated partial thromboplastin time prolonged, blood zinc decreased

Paediatric population

A side effect apparently peculiar to children is a fever which develops after the second or third injection, and persists until treatment with dimercaprol is terminated.