Ritanserin as add-on medication to neuroleptic therapy for patients with chronic or subchronic schizophrenia

The effect of ritanserin, a potent 5HT 2A/2C receptor antagonist, used as an add-on medication to neuroleptic treatment in patients with schizophrenia, was compared with that of placebo, in an international, double-blind, parallel-group study. Previously established neuroleptic therapy was maintained, and ritanserin 10 mg or placebo was given once daily for 8 weeks. Psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression (CGI) cale. Safety assessments included the Extrapyramidal Symptom Rating Scale (ESRS), and the requirement for antiparkinsonian medication was monitored. About 70 per cent of patients completed the treatment. There was no difference between the two groups in the numbers of patients with clinical improvement at endpoint on the PANSS negative subscale and total PANSS. The CGIs of overall severity of schizophrenia were better under placebo. The overall prevalence of side effects and the requirements for antiparkinsonism medication were comparable in the two groups. Copyright 2000 John Wiley & Sons, Ltd.