Efficacy and safety of lower doses of aripiprazole

Objective: This study evaluated the effects of aripiprazole in patients with schizophrenia when administered at doses lower than those previously investigated systematically.

Method: 367 hospitalized patients with acute relapse of schizophrenia were enrolled in this double-blind, placebo-controlled, randomized, 6-week, multicenter trial. Trial subjects were randomized to placebo or one of three fixed doses (2, 5, and 10mg/day) of aripiprazole. The key measure for efficacy was the mean change from baseline to endpoint (Week 6 LOCF) in the PANSS Total score.

Results: Patients treated with aripiprazole 10mg/day showed a significantly greater reduction in PANSS Total score than those receiving placebo from week 2 through endpoint (–11.3 vs. –5.3, P=0.030 at endpoint). The 5mg/d dose separated from placebo at weeks 3 through 5, but was only numerically superior to placebo at endpoint (–10.6, P=0.058). There was no difference between the 2mg/d dose and placebo at any point during the trial. All doses of aripiprazole were well tolerated.

Conclusions: The aripiprazole 10mg/d dose demonstrated efficacy for the treatment of hospitalized patients with acute exacerbation of schizophrenia; the 5mg/d dose may be effective for treatment of some patients, and the 2mg/d dose seems to be lower than the minimally effective dose.