ABSTRACT
Risperidone is a novel serotonin-dopamine antagonist antipsychotic in a class of benzisoxazole derivative which has been shown to be effective in reducing psychotic symptoms in schizophrenia. The study was designed as perspective, 8-week, multicenter, open label study in schizophrenic patients from 6 psychiatric hospitals. One hundred and twenty cases were recruited and 105 patients completed the study. The average total PANSS score at the baseline was 90.6 (range 60-133). Patients were evaluated with quantitative rating scales for the efficacy (PANSS score) and extrapyramidal rating scale at week 4 and 8 after starting risperidone treatment. The titrated dose of risperidone was given to the patients with the final dose of 6 mg risperidone throughout the study period. At week 4, the average PANSS score was significantly reduced to 73.4 (p < 0.05). The average PANSS score at week 8 was further declined to 61.9 which was significantly different (P < 0.05) from the baseline. Seventy-eight cases (74.3%) were classified as responders (those patients showing more than 20 per cent decrease in PANSS score). Extrapyramidal side effect was occurred in some patients, but usually mild and tolerable. However twenty-four patients (22.9%) required medications for this side effect. Other adverse reactions were insomnia found 15 cases (14.3%), elevated hepatic enzyme 5 cases (4.8%) and weight gained 2 cases (1.9%). Our data suggested that risperidone is effective and well-tolerated in chronic schizophrenic Thai patients.