Risperidone long-acting injection

We were pleased to read of the positive experience with long-acting risperidone by Paton & Okocha (Psychiatric Bulletin, January 2004, 28, 12-14). The abstract, however, appeared inconsistent with the data describing generally positive patient outcomes. From the abstract alone, the findings with long-acting risperidone sound more negative than they actually were.

Specifically, the authors studied a difficult-to-treat population (42 of 50 patients with histories of non-compliance or unacceptable extrapyramidal sideeffects). Even in this population, a majority (54%) had at least minimal improvement, with 40% (20 of 50 patients) being seen as ‘much or very much improved’. This is impressive considering the population examined, but the authors do not mention this context when drawing their conclusions.

Further, one might view a 40% attrition rate to be a positive outcome given that patients were selected largely on the basis of noncompliance. Comparison with a published one-year trial (Fleischhacker et al, 2003) may not be entirely appropriate as patients in the latter were selected on the basis of clinical stability, not noncompliance, and most were switched from oral atypical, not depot, antipsychotics.

We agree with Paton & Okocha about the need for additional information regarding long-acting risperidone, including mention that at least 6 months of therapy are needed before assessing outcome. However, we interpret their findings as supportive of the potential for further improvements among more severely ill or difficult to treat patients, complementing the ‘ average’ patients studied by Fleischhacker et al. Hopefully, readers will consider the full report before reaching conclusions about the potential impact of long-acting risperidone for their particular patients.