NEW YORK (Reuters Health) – Long-term treatment with the atypical antipsychotic asenapine prevents relapse of schizophrenia and is well tolerated, according to a report in the Journal of Clinical Psychiatry online February 22.

Asenapine in approved by the US Food and Drug Administration for the treatment of schizophrenia and manic/mixed episodes of bipolar I disorder, the authors note in the introduction to their paper. The efficacy of sublingual asenapine in the treatment of acute schizophrenia was demonstrated in two 6-week trials.

The assess its long-term efficacy, Dr. John M. Kane with Zucker Hillside Hospital in Glen Oaks, New York, and colleagues conducted a trial with 386 schizophrenia patients who had already remained stable on open-label asenapine treatment for 26 weeks. The participants were randomly assigned in double-blind fashion to continue asenapine or switch to placebo for a further 26 weeks.

Among the 207 patients who completed the study, relapse or impending relapse occurred in 12.1% of those on asenapine and 47.4% of those on placebo, according to the report. The relative risk of relapse was 0.26 with asenapine versus placebo over the 6-month study period.

Treatment-emergent adverse effects experienced by more than 5% of the subjects included anxiety, weight gain, and insomnia among those given asenapine; and schizophrenia, insomnia, anxiety, weight loss, hallucinations, agitation, and delusions among those on placebo, the researcher found.

The incidence of clinically significant weight gain was 3.7% with asenapine versus 0.5% with placebo, while corresponding rates of weight loss were 3.2% and 9.6%, Dr. Kane and colleagues report.