Observations on switching patients with schizophrenia to risperidone treatment. Risperidone Switching Study Group

This study examined one possible strategy for switching patients to treatment with risperidone involving immediate cessation of current neuroleptics and gradual withdrawal of anticholinergic treatments. All patients received risperidone monotherapy for at least 4 weeks. Side-effects and symptoms were rated and successful switching was defined as completion of the study with no consistent worsening in any rating scales. Of the 41 patients entered, five withdrew for reasons unconnected with the study. Of the remaining 36 patients, 64% (23 patients) were switched successfully. Overall, the rating scales showed significant improvements (mean score on Krawiecka scale, 11.0 to 6.6, P < 0.001), and side-effects decreased (mean score on Simpson & Angus scale, 5.1 to 2.9, P = 0.004). The strategy appeared to be successful for most patients, especially those who had previously received depot medication. However, more gradual withdrawal of previous treatments, including anticholinergics, may be advisable in some cases.