Akathisia occurs less frequently in second generation antipsychotics (SGAs) compared to first generation antipsychotics (FGAs). This analysis was performed to quantify and qualify akathisia in schizophrenia patients receiving one of two SGAs, aripiprazole or olanzapine, or a FGA, haloperidol, in the first 12 weeks of treatment.

A post hoc analysis of the safety dataset was conducted to assess akathisia parameters in three double-blind randomized trials: a 52-week comparison of aripiprazole 30mg/d (n=859) versus haloperidol 10mg/d (n=431); and pooled data from two trials (26- and 52-week) comparing aripiprazole 15-30mg/d (n=504) and olanzapine10-20mg/d (n=505).

In the haloperidol comparative trial, akathisia was reported by 12.5% in the aripiprazole group and 24.1% in the haloperidol group. Akathisia occurred within the first 12 weeks after randomization in 89.6% of aripiprazole-related events and 92.5% of haloperidol-related events. In the olanzapine comparative trials, akathisia was reported by 10.7% of aripiprazole-treated patients and 6.1% of olanzapine-treated patients. Akathisia occurred within the first 12 weeks in 94.4% of aripiprazole-related events and 90.2% of olanzapine-related events. Akathisia was rated as mild or moderate by the majority of patients (≥80% of reports).

Consistent with previous reports, the FGA haloperidol was associated with higher rates of akathisia than the SGAs aripiprazole and olanzapine. Under double-blind conditions, for all antipsychotics, akathisia occurred early in treatment, was time-limited, and of mild to moderate severity. Contrary to previous reports, akathisia was not associated with high rates of discontinuation.