Efficacy and Tolerability of Seven Antipsychotic Drugs in Acutely Ill Patients With Schizophrenia: A Randomized, Multicenter, Assessor-Blinded Trial

OBJECTIVE: Antipsychotic drugs are the mainstay of schizophrenia treatment; yet, controversy persists regarding their relative efficacy and side effects, and guideline recommendations on efficacy differences are particularly vague. The aim of this trial was to compare seven antipsychotics in acutely ill patients with schizophrenia. METHODS: The authors performed a multicenter (32 hospitals), industry-independent, parallel, assessor-blinded, flexible-dosage randomized trial (Schizophrenia in Non-Occidental Participants). Eligible inpatients 18-45 years of age with schizophrenia experiencing acute exacerbation were recruited and randomized to 6 weeks of monotherapy with one of seven antipsychotic drugs: olanzapine, risperidone, quetiapine, aripiprazole, ziprasidone, perphenazine, and haloperidol. RESULTS: A total of 3,067 patients were randomized, of whom 82% completed follow-up. The mixed model indicated significant differences in the primary outcome percentage change in Positive and Negative Syndrome Scale (PANSS) score between the antipsychotics. At week 6, olanzapine and risperidone showed a significantly higher percentage change in PANSS score than aripiprazole, ziprasidone, and quetiapine (mean differences: 5.52-7.93) but not haloperidol or perphenazine. Olanzapine was associated with the highest risk of weight gain (relative risk: 1.44-3.22). Aripiprazole was associated with lower risk of hyperprolactinemia than all the other drugs (relative risks: 0.11-0.21). Ziprasidone and aripiprazole were associated with lower risks of weight gain and metabolic side effects. Haloperidol was associated with a higher risk of extrapyramidal symptoms than all other drugs (relative risks: 0.13-0.61). Aripiprazole was least sedating (relative risks: 0.30-0.39). Olanzapine and risperidone showed lower all-cause discontinuation rates than ziprasidone and haloperidol (hazard ratios: 0.61-0.73). CONCLUSIONS: This trial fills important knowledge gaps in acute antipsychotic treatment of schizophrenia. It confirms hierarchies in efficacy and side effects of antipsychotics from related evidence.