Some patients with schizophrenia switch medications due to lack of efficacy or side effects; improvement in symptoms and side effects following a switch must be assessed.

In a 12-week, open-label, baseline-controlled, flexible dose switch study, adult outpatients with schizophrenia experiencing suboptimal efficacy or tolerability problems were switched from haloperidol (n=99), olanzapine (n=82), or risperidone (n=104) to ziprasidone (80¬–160 mg/d; dosed bid with food). The primary efficacy evaluation was the BPRS score at Week 12. Safety evaluations included change from baseline in movement disorders (SAS, BAS, AIMS), weight, prolactin, and fasting lipids levels. Statistical tests were 1-sided non-inferiority comparisons with correction for multiple comparisons (0.025/3 significance level), for the primary efficacy endpoint, or 2-sided (0.05 significance level), for secondary endpoints.

BPRS scores improved significantly compared with all 3 preswitch medications at Week 12. Mean change from baseline (SD) for patients switched from haloperidol, olanzapine, and risperidone was –11.3 (16.3), –6.3 (14.2), and –9.9 (13.2), respectively (p < 0.0001 vs baseline). Movement disorders, measured by SAS, BAS, and AIMS, improved significantly for subjects switched from haloperidol and risperidone. Change in weight (kg ± SD) from baseline was 0.4 ± 3.97, –2.0 ± 3.99 (p < 0.001), and –0.6 ± 3.21 for subjects switched from haloperidol, olanzapine, and risperidone, respectively.

Patients switched to ziprasidone demonstrated improvement in symptoms and movement disorders, with a weight neutral effect. Ziprasidone is an appropriate switch option for patients experiencing suboptimal efficacy or poor tolerability with their current treatment.