Comparison of ziprasidone and aripiprazole in acutely ill patients with schizophrenia or schizoaffective disorder: a randomized, double-blind, 4-week study.

We compared the efficacy and safety of ziprasidone and aripiprazole in the treatment of acutely ill patients with schizophrenia. Patients were randomized to receive double-blind treatment with ziprasidone (80-160 mg/day), or aripiprazole (10-30 mg/day) for up to 4 weeks. Primary efficacy measures were the Clinical Global Impression of Severity scale (CGI-S) and Brief Psychiatric Rating Scale (BPRSd) total (derived from the Positive and Negative Syndrome Scale). Noninferiority for ziprasidone (N=125) relative to aripiprazole (N=128) was established for CGI-S score (P=0.007), but was not confirmed for BPRSd total score (P=0.248). Effect sizes for within-group improvement, however, were robust for both ziprasidone and aripiprazole (effect size range 1.0-1.1 for CGI-S; and range 1.1-1.2 for BPRSd total). A mixed model repeated measures analysis of BPRSd total score favored ziprasidone at day 4 compared with aripiprazole (P=0.04), with no significant differences between treatment groups at other visits (P=0.001 for interaction between treatment and visit). No statistically significant difference was found in CGI-S score between groups across all visits. Our findings suggest that ziprasidone and aripiprazole exhibit similar efficacy and tolerability profiles in the treatment of acute schizophrenia. Differences between the two drugs in the onset of therapeutic effect warrant further investigation.