Generic
Clozapine
Pharmacology
Clozapine is classified as an 'atypical' antipsychotic drug because of its profile of binding to dopamine receptors and its effects on various dopamine-mediated behaviors differ from those exhibited by other typical antipsychotic drug products. In particular, although Clozapine does interfere with the binding of dopamine at D1, D2, D3 and D5 receptors, and has a high affinity for the D4 receptor. This evidence, consistent with the view that Clozapine is preferentially more active at limbic than at striatal dopamine receptors. This may explain the relative freedom of Clozapine from extrapyramidal side effects. Clozapine also acts as an antagonist at adrenergic, cholinergic, histaminergic and serotonergic receptors.
Dosage Administration
Schizophrenia: Adult over 16 years, 12.5 mg once or twice (elderly 12.5 mg once) on first day then 25-50 mg (elderly 25-37.5 mg) on second day then increased gradually (if well tolerated) in steps of 25-50 mg daily (elderly max. increment 25 mg daily) over 14-21 days up to 300 mg daily in divided doses (larger dose at night, up to 200 mg daily may be taken as a single dose at bedtime); if necessary may be further increased in steps of 50-100 mg once (preferably) or twice weekly; usual dose 200-450 mg daily (max. 900 mg daily) Psychosis in Parkinson's disease: Adult over 16 years, 12.5 mg at bedtime then increased according to response in steps of 12.5 mg up to twice weekly; usual dose range 25-37.5 mg at bedtime, usual maximum 50 mg daily; exceptionally, dose may be increased further in steps of 12.5 mg weekly to maximum 100 mg daily in 1-2 divided doses.
Contraindications
Severe cardiac disorders (e.g. myocarditis); renal impairment (avoid if creatinine clearance less than 10 ml/minute); history of neutropenia or agranulocytosis; bone-marrow disorders; paralytic ileus; alcoholic and toxic psychoses; history of circulatory collapse; drug intoxication; coma or severe CNS depression; uncontrolled epilepsy; breast-feeding.
Side Effects
Common side effects are constipation, dizziness or lightheadedness (mild), drowsiness, headache (mild), increased watering of mouth, nausea or vomiting, unusual weight gain. Less common side effects include abdominal discomfort or heartburn, dryness of mouth.
Pregnancy And Lactation
There are no adequate studies of Clozapine in pregnant women. Studies in animals suggest no important effects on the fetus. Clozapine can be used in pregnancy if the physician feels that it is necessary. Animal studies suggest that Clozapine is secreted in breast milk. Therefore, women taking Clozapine should not nurse their infants.
Therapeutic
Do not store above 30�C. Keep away from light and out of the reach of children.
Storage Conditions
Do not store above 30�C. Keep away from light and out of the reach of children.
Over The Counter Products
