A retrospective study on the long-term efficacy of clozapine in 96 schizophrenic and schizoaffective patients during a 13-year period.

The effect of long-term treatment with clozapine in schizophrenia and schizoaffective disorder was evaluated in a retrospective study comprising 96 patients treated with the drug during the period 1974-1986 at the Psychiatric Research Center in Uppsala. All patients had previously been treated with different kinds of antipsychotic drugs but with insufficient clinical effect or distressing extrapyramidal side effects. When clozapine treatment was initiated, the mean duration of the illness was 8 years and 9 months. In 36% of the patients clozapine treatment was discontinued, the main reasons being lack of efficacy, poor compliance or temporary withdrawal from the market in 1975. Clinical evaluation of the effect revealed that 85% of the patients could be discharged from the hospital within a year and that 43% of the patients were significantly and 38% moderately improved compared to previous treatments. Of those patients who were still on clozapine 2 years after the treatment was initiated, 39% had employment compared to only 3% before clozapine. In ten patients a transient decrement in white blood cells (WBC) was noted but normalized during ongoing treatment. One patient developed leukopenia and one agranulocytosis, none with fatal outcome. Common side effects were sedation, hypersalivation, weight gain and obstipation. In one patient clozapine treatment was stopped because of grand mal seizures. No extrapyramidal side effects were observed or reported during clozapine treatment. It is concluded that clozapine offers particular advantages for many "therapy-resistant" schizophrenic patients when compared to classical neuroleptics.