Medical charts of 480 schizophrenic in-patients (581 treatments) were analysed to evaluate the efficacy and side-effects of clozapine. Clozapine treatment lasted for mean 49 (s.d. 38) days. Of the sample, 11.0% showed worsening or no change, 31.5% slight improvement, 53.0% marked improvement and 4.5% almost total reduction of symptoms. At least one major side-effect occurred in 68.0% of patients. A combination of clozapine with classical neuroleptics, antidepressants, benzodiazepines or lithium is tolerated by most patients, but increases the incidence of some side-effects. Clozapine treatment had to be discontinued because of severe side-effects in 8.6% of patients. In 81 schizophrenic out-patients, clozapine significantly reduced the days of in-patient treatment and number of hospital readmissions. Two patients developed leucopenia but had no complications after clozapine withdrawal. This study indicates a satisfactory benefit/risk ratio and compliance in most of the patients.
