Generic Name : clozapine
Brand Name: Clozaril, FazaClo, Gen-Clozapine (CAN)
Classification: Antipsychotic, Dopaminergic blocker
Pregnancy Category B
Dosage & Route
- Initial therapy: 12.5 mg PO once or twice daily. If using orally disintegrating tablets, begin with 1/2 (12.5 mg) of a 25-mg tablet and destroy the remaining half. Continue to 25 mg PO daily or bid; then gradually increase with daily increments of 25–50 mg/day, if tolerated, to a dose of 300–450 mg/day by the end of second week. Adjust later dosage no more often than twice weekly in increments < 100 mg. Do not exceed 900 mg/day.
- Maintenance: Maintain at the lowest effective dose for remission of symptoms.
- Discontinuation of therapy: Gradual reduction over a 2-wk period is preferred. If abrupt discontinuation is required, carefully monitor patient for signs of acute psychotic symptoms.
- Reinitiation of treatment: Follow initial dosage guidelines, use extreme care; increased risk of severe adverse effects with re-exposure.
- Safety and efficacy in patients < 16 yr not established.
- Clozapine has relatively weak dopamine receptor-blocking activity at D1, D2, D3 and D5 receptors but has high affinity for the D4 receptor. It has also blocking effects on serotonin, α-adrenergic histamine H1 and cholinergic receptors.
- Management of severely ill schizophrenics who are unresponsive to standard antipsychotic drugs
- Reduction of the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder (not orally disintegrating tablet)
- Drowsiness, dizziness, headache; nausea, vomiting, constipation; anxiety, confusion, fatigue, transient fever. Rarely, dysphagia, acute pancreatitis, cholestatic jaundice; orthostatic hypotension, tachycardia; seizures; hypersalivation.
- Potentially Fatal: Rarely, thromboembolism. Reversible neutropenia which may progress to a potentially fatal agranulocytosis. Fatal myocarditis.
- History of bone marrow disorders including agranulocytosis, circulatory collapse, alcoholic or toxic psychosis, drug intoxication, uncontrolled epilepsy, severe renal, hepatic or cardiac disease; paralytic ileus. Pregnancy and lactation.
CLINICAL ALERT! Name confusion has occurred between Colazal (balsalazide); dangerous effects could occur. Use caution.
- History: Allergy to clozapine, myeloproliferative disorders, history of clozapine-induced agranulocytosis or severe granulocytopenia, severe CNS depression, comatose states, history of seizure disorders, CV disease, narrow-angle glaucoma, lactation, pregnancy
- Physical: T, weight; reflexes, orientation, IOP, ophthalmologic examination; P, BP, orthostatic BP, ECG; R, adventitious sounds; bowel sounds, normal output, liver evaluation; prostate palpation, normal urine output; CBC, urinalysis, LFTs, renal function tests, EEG
- BLACK BOX WARNING: Use only when unresponsive to conventional antipsychotic drugs; risk of serious CV and respiratory effects.
- Obtain clozapine through the Clozaril Patient Assistance Program. For more information, call 1-800-448-5938.
- Dispense only 1 wk supply at a time.
- Monitor WBC carefully prior to first dose.
- BLACK BOX WARNING: Weekly monitoring of WBC during treatment and for 4 wk thereafter. Dosage may be adjusted based on WBC count. Potentially fatal agranulocytosis has been reported.
- Monitor T. If fever occurs, rule out underlying infection, and consult physician for comfort measures.
- BLACK BOX WARNING: Monitor for seizures; with history of seizures, risk increases as dose increases.
- Monitor elderly patients for dehydration. Institute remedial measures promptly; sedation and decreased thirst related to CNS effects can lead to dehydration.
- Monitor patient regularly for signs and symptoms of diabetes mellitus.
- Encourage voiding before taking drug to decrease anticholinergic effects of urinary retention.
- Follow guidelines for discontinuation or reinstitution of the drug.
- Educate patient on seriousness of potential agranulocytosis.
- Weekly blood tests will be taken to determine safe dosage; dosage will be increased gradually to achieve most effective dose. Only 1 week of medication can be dispensed at a time and will depend on your white blood cell count. Do not take more than your prescribed dosage. Do not make up missed doses, instead contact your health care provider. Do not stop taking this drug suddenly; gradual reduction of dosage is needed to prevent side effects.
- If you think you are pregnant or wish to become pregnant, contact your health care provider.
- You may experience these side effects: Drowsiness, dizziness, sedation, seizures (avoid driving or performing tasks that require concentration); dizziness, faintness on arising (change positions slowly); increased salivation (reversible); constipation (consult your health care provider for correctives); fast heart rate (rest, take your time).
- Report lethargy, weakness, fever, sore throat, malaise, mouth ulcers, and flulike symptoms.