Switching antipsychotic treatment in patients with bipolar disorder: reasons and outcome

Background

Conventional and atypical antipsychotics are widely used in the treatment of Bipolar Disorder. Switches between antipsychotic medications often occur for several reasons – mostly due to adverse events or lack of efficacy. BIRDird (Bipolar dDisorder Retrospective Data) was conducted to document the experience with conventional and atypical antipsychotics in Greek patients with bipolar disorder and to investigate the effects of switching their antipsychotic medication to atypical antipsychotics.

Materials and methods

In this retrospective survey, data from patients with bipolar disorder whose previous antipsychotic medication – conventional or atypical – had been switched to atypical antipsychotics within the last 12 months were investigated. CRFs from 300 patients in private and state clinics across Greece were evaluated. Information was collected on demographics, patient history, diagnosis, comorbidities, side effects and clinical global impression three months prior to, at the time and three months following switching. Effects of medication on Patients Global Condition (PGC) could be scored as "very much improved", "much improved", "minimally improved", "no change", "minimally worse", "much worse" or "very much worse". As the primary goal of this study was descriptive, no sample size has been calculated; data were descriptively analyzed.

Results

Patients had mean age of 40.7 years and mean period between onset of disorder and current diagnosis was 3 years. 80% of 240 evaluable patients (240 out of 300, 80%) had a diagnosis of Bipolar Disorder I, 51 (17%) Bipolar II, 3 (11%) cyclothymic and 6 (2%) NOS. 175 (58%) of the patients switched from conventional to atypicals and 125 (42%) switched between atypicals. In both groups patients switched mainly to risperidone (75%) and olanzapine (16%).

Improvement on PGC CGI scores was observed in the 71% most of the patients: in 75% of patients switching between atypicals antipsychotics and in 68% of patients switching from a conventional to an atypicals. Respectively, "no change" was observed in 27% of the patients: in 23% of switches between atypicals and in 29% from conventional to atypical; finally, worsening as observed in 3% of the patients: 2% between atypicals and in 3% from conventional to atypical.

Main reasons for switching were adverse events and "lack of efficacy". Side effects was the main reason for switching, with "weight gain" most frequently mentioned in the atypical group and EPS most frequently mentioned in the conventional group.

Discussion

In this retrospective study, the switch of antipsychotic medication to an atypical drug for the treatment of Bipolar Disorder was associated with a clinical improvement in 71% of the patients as assessed by the PGCaccording CGI scores.