Long-acting risperidone: Focus on safety

Although atypical antipsychotics are generally regarded as having more favorable tolerability profiles than conventional antipsychotics, differences between specific atypical agents can be important when individualizing treatment. Long-acting risperidone (LAR), the first long-acting injectable atypical anti-psychotic, has been found to be effective in the treatment of schizophrenia and schizoaffective disorder.This review summarizes clinical evidence for the tolerability profile of LAR in patients with schizophrenia and schizoaffective disorder and assesses its utility in specific patient groups, including younger patients and the elderly.MEDLINE and EMBASE were searched for studies published between January 1994 and March 2006 that evaluated the tolerability of LAR. The primary search terms were long-acting risperidone, schizophrenia, schizoaffective, long term, tolerability, and safety. Abstracts and posters presented at major psychiatry and schizophrenia conferences during this period also were reviewed. Articles were included if they were reports of clinical studies and included tolerability data for LAR.The literature search identified 7 open-label trials, 3 double-blind trials, 15 subanalyses, and 1 pooled analysis. When patients were switched directly or indirectly from another antipsychotic agent, LAR was generally well tolerated, with a low incidence of withdrawals due to adverse events (1%-16%). Moreover, LAR was associated with a weight-gain profile of 1 to 2 kg in the short term and did not appear to negatively affect lipids or glucose metabolism. Although LAR was associated with elevations in serum prolactin levels in 2% to 7% of patients, these elevations were not symptomatic, and levels decreased over time.LAR was generally well tolerated in several patient groups, including the elderly and those with schizoaffective disorder. When patients were switched from other antipsychotics, use of LAR was not associated with an increased risk of adverse events compared with placebo.