Clozapine
It is a dibenzodiazepine derivative which is chemically related toLoxapine,Amoxapine & Clothipine.It acts as an antagonist at D1 & D2 receptors & possibly at newly described D4 receptors.In patients non responsive or intolerant to conventional antipsychotics.
Initial dose of 12.5mg once or twice on second day. The daily dose may be increased slowly in increments of 25 - 50mg upto 300 mg/ day within 2-3 weeks, Maintanance dose is 150-300 mg Max. dose is 900mg/day subarachnoid haemorrhage: continue for 3 wks.
In atients with history of drug induced granulocytopaenia/agranulocytosis/myeloproliferative disorders, alcoholics & toxic psychosis, drug intoxication, comatose conditions & other forms of CNS depression.
Before and during the Treatment blood test must be done .Treatment should be started only : WBC count is more than 3500mm3 Absolute neutrophil count is more than 2000mm3. Paediatrics: Not recommended. Pregnancy: Not usually prescribed. Lactaion: Contraindicated. Elderly: Use with caution.
Phenytoin and other enzyme inducing agents reduces the plasma concentration of clozapine. Sedatives increase the sedative properties of clozapine.
