Faster onset of antimanic action with haloperidol compared to second-generation antipsychotics. A meta-analysis of randomized clinical trials in acute mania

Background: there is a lack of scientific data regarding speed of action of antimanic treatments, a relevant issue in clinical practice.

Objective: to assess differences in the speed of onset of antimanic efficacy between haloperidol (as most studied first-generation antipsychotic) and second-generation antipsychotics.

Experimental procedures: meta-analysis of double-blind randomized clinical trials in acute mania, comparing treatment with haloperidol and with second-generation antipsychotics. Search was conducted in MEDLINE and CENTRAL databases (last search: September 2011). Differences in mania scale score reduction at week 1 were assessed.

Results: 8 randomized clinical trials fulfilled inclusion criteria and 1 of them was excluded due to low methodological quality. 2037 Manic patients had been treated with antipsychotics in the 7 trials. Haloperidol was found to be significantly more efficacious in the reduction of the mania scale score at week 1. The effect size was small, the Standardized Mean Difference (SMD) being 0.17, with a 95% Confidence Interval ranging from 0.01 to 0.32. Haloperidol was significantly more efficacious than olanzapine (SMD: 0.40 [0.21, 0.59]) and ziprasidone (0.39 [0.18, 0.61]). A non-significant trend towards superiority of haloperidol was found over aripiprazole (SMD: 0.13 [-0.02, 0.19]). There were no significant differences between haloperidol and quetiapine (0.17 [-0.11, 0.44]), and haloperidol and risperidone (SMD: -0.10 [0.30, 0.09]).

Conclusions: haloperidol shows a faster onset of antimanic action than second-generation antipsychotics. This difference may be related to D2 affinity. Haloperidol may be considered a treatment option in severely ill manic patients who require urgent relief of symptoms.