To compare the efficacy of aripiprazole and haloperidol for the treatment of acute relapse in chronic schizophrenia.

Across two 52-week double-blind studies, 1294 patients with acute relapse of chronic schizophrenia were randomized to aripiprazole 30 mg/day (n=861) or haloperidol 10 mg/day (n=433). The mean change in (Positive and Negative Syndrome Scale) PANSS Total score, PANSS Positive score were secondary endpoints in both studies. Post-hoc, a measure of excitement and hostility was derived from PANSS score items by factor analysis. The scales were administered at baseline and at each double-blind study visit (Weeks 1-8, 10, 12, 14, then every 4 weeks to Week 52).

Aripiprazole produced similar improvements to haloperidol in PANSS Total score (last observation carried forward, LOCF). Among those patients who completed the study, aripiprazole showed a significantly greater improvement in PANSS Total score compared with haloperidol at Weeks 26 and 52. A similar improvement in PANSS Positive score was seen with aripiprazole and haloperidol (LOCF and observed cases [OC]). Symptoms of excitement and hostility also improved similarly with both agents throughout the study (LOCF and OC).

Aripiprazole showed similar efficacy to haloperidol over the 52-week study, and significantly greater efficacy among those patients who stayed on treatment. Thus, aripiprazole is a useful agent for long-term maintenance therapy in schizophrenia.