Clozaril

What is it?

An antipsychotic drug and dibenzodiazepine, clozapine, produced as yellow scored tablets (25mg strength) and marked CLOZ 25, and 100mg strength, marked CLOZARIL 100.Used for schizophrenia which has failed to respond to, or patient is intolerant of other conventional antipsychotic drugs.

Dosage

First day, 12.5mg once or twice. Second day, 25mg once or twice; dose is gradually increased over a period of 2 to 3 weeks by 25-50mg each day until patient is receiving 300mg daily in divided doses. Depending upon response, a further increase may be required by giving an additional 50100mg every 4 to 7 days to a maximum of 900mg each day in divided doses. Usual maintenance dose is in the order of 150-300mg in divided doses. Elderly persons, 12.5mg each day in first instance slowly increasing by 25mg daily.

Special Care

Patient, prescribing doctor and pharmacist must be registered with Sandoz Clorazil Patient Monitoring Service (CPMS). Patients should report signs of infection and must take contraceptive precautions. Special care in pregnant women, patients with enlarged prostate gland, liver disease, glaucoma, paralytic ileus, heart failure (discontinue), tachycardia - investigate for myocarditis. Persons with epilepsy should be monitored, history of disease of colon or previous surgery to lower abdomen, history of problems with gut motility. Regular blood counts of leucocytes should be carried out before and during treatment. Drug should be immediately withdrawn if whole blood count falls below 3000/ mm3 or neutrophil (a type of white blood cell) count below 1500/ mm3.Usually, drug should be stopped gradually.

Avoid Use

Children; patients with history of drug induced blood disorders-neutropenia, agranulocytosis (a serious fall in the number of white blond cells called eosinophils, basophils and neutrophils), bone marrow disorders. Also, patients with history of drug intoxication, toxic and alcoholic psychoses, CNS depression or those in comatose states. Avoid use in breast-feeding mothers, persons with serious kidney, liver, heart disease or circulatory collapse and cardiac failure.

Possible Drug and Food Interactions

Narcotics, benzodiazepines, alcohol, MAOIs, CNS depressants, other drugs which cause agranulocytosis, anticholinergics, antihistamines, hypotensive drugs, lithium, phenytoin, warfarin, cimetidine. Respiratory depressants, fluvoxamine, sertraline, venlafaxine, adrenaline, noradrenaline, paroxetine, erythromycin, carbamazepine, phenothiazines, omeprazole, azole antifungals, class lc antiarrhythmic drugs, TCADs, rifampicin, smoking and stopping smoking.

Known Side Effects

Neutropenia leading to agranulocytosis (characterized by fever, collapse, bleeding ulcers of vagina, rectum and mouth) which may be fatal, effects on heart muscle and brain activity, tachycardia, fits, fatigue, dizziness, headache, over-production of saliva in mouth, retention of urine, gastrointestinal upset, disturbance of body temperature regulation. High blood pressure, pancreatitis, hyperthermia, skin reactions, weight gain, liver disorders, impaired gut motility, enlarged salivary glands, restlessness, paralytic ileus, increased CPKvalues. Neuroleptic malignant syndrome; sudden death has occurred.