Evaluation of side effects due to clozapine in long-term treatment of psychosis.

17 patients (13 males and 4 females) were examined for side effects due to long-term treatment with 8-chloro-11-(4-methylpiperazin-1-yl)-5H-dibenzo(b,e)(1,4)diazepine (clozapine) with emphasis on alterations in bone marrow, liver, and kidney function. 16 patients were schizophrenic, one patient was diagnosed psychosis e causa dubia. The age range was 25-68 years, with an average of 38.2 years. The daily clozapine dose varied from 225 to 800 mg with a total intake during the trial period of 149.1-891.6 g yielding an average of 479.8 g. The treatment period varied from 20 to 51 months, with an average of 35.9 months. None of the patients had to discontinue the treatment because of side effects. The laboratory data including hematological, and nephrological parameters revealed no significant changes related to clozapine treatment within the treatment period. No changes were observed in ECG. 12 patients experienced side effects, 8 of them receiving concomitant psycholeptic medication. 9 patients complained of temporary fatigue and 5 of these experienced continuous drowsiness. There were 8 cases of nocturnal hypersalivation and two cases of increased appetite. One patient developed light tachycardia and one patient orthostatic hypotension. Clozapine is known to be an effective anti-psychotic drug, but due to reports of agranulocytosis in 16 Finnish patients the drug was withdrawn from the Danish market in 1975 although later its use was merely restricted to special cases. This study does not indicate that clozapine contains greater risk of clinical side effects than commonly used psycholeptic drugs.