Efficacy and safety of risperidone in psychotic patients: an open study.

This open prospective study was undertaken to determine the efficacy and safety of a fixed dose (6 mg) of risperidone in psychotic patients. Hospital in-patients who fulfilled DSM-111-R criteria for schizophrenia, schizoaffective and bipolar disorders were eligible for entry into the study (n = 15). Patients who were on other antipsychotics had a washout period of 1 week before they were started on the drug. A fixed dose of risperidone was administered (6 mg). The Brief Psychiatric Rating Scale (BPRS), Negative Symptom Rating Scale (NSRS) and Abnormal Involuntary Movement Scale were used to measure psychopathology and extrapyramidal side-effects. Five patients dropped out of the study. Two patients became very agitated and potentially aggressive, one patient became very restless and did not respond to benzodiazepines, and one dropped out because of restlessness that did not respond to clonazepam. Of the 10 patients who completed the study, 50 per cent reduction on BPRS and NSRS was achieved by five and six patients respectively. There was a marginally significant trend towards a greater reduction in the magnitude of negative symptoms. Four patients required treatment with anticholinergic drugs. Risperidone was effective in resistent psychotic patients, but agitated and impulsive psychotic patients with positive symptoms may not be best candidates for treatment with risperidone. On average, negative symptoms respond better than positive symptoms.