Amisulpride, an atypical antipsychotic, in the treatment of acute episodes of schizophrenia: a dose‐ranging study vs. haloperidol

Abstract
This 4‐week, double‐blind, randomized study was undertaken to determine the dose‐response relationship of amisulpride in 319 patients with acute exacerbation of schizophrenia. Fixed doses of amisulpride (400, 800 and 1200 mg/day) and haloperidol (16 mg/day) were compared to amisulpride, 100 mg/day, as a potentially subtherapeutic dose. Efficacy data (BPRS total score and PANSS positive subscale) in the amisulpride groups generated a bell‐shaped dose‐response curve, with 400 mg/day and 800 mg/day being the most effective treatments for positive symptoms. Parkinsonism did not increase significantly between baseline and endpoint with amisulpride 400, 800 and 1200 mg/day compared to the amisulpride 100 mg/day group, whereas the difference was significant for haloperidol (P<0.05). It is concluded that amisulpride 400 mg and 800 mg/day is highly effective in treating the positive symptoms of schizophrenia, with less extrapyramidal side‐effects than haloperidol 16 mg/day.