Switching bipolar disorder patients treated with clozapine to another antipsychotic medication: a mirror image study.

Bipolar disorder (BD) is associated with periodic symptom exacerbations, leading to functional impairment, and increased risk of suicide. Although clozapine has never been approved for the treatment of BD, it is occasionally used in severe mania. The aim of the study is to evaluate the risks and benefits of switching clozapine in remitted BD patients. This is an observational, mirror image study of 62 consecutive remitted BD outpatients treated with clozapine. Twenty-five patients were switched to another antipsychotic following a change in a drug reimbursement rule, while 37 continued on clozapine. The mean time in remission was shorter for the switched group (9.2±4 months vs 13±6 months, P=0.018), and the number of patients who relapsed was larger (n=21 vs n=8, P<0.0001). The results suggest that switching from clozapine to another antipsychotic may increase the risk of relapses in remitted patients with BD.