Evidence Summaries

A Cochrane review ¹ included 10 RCTs with a total of 1549 patients with schizophrenia or schizophrenia-like psychosis. Amisulpride was compared with olanzapine, risperidone and ziprasidone, the duration of studies ranged from 6 to 26 weeks. The outcome in most of the reports was the number of patients leaving early due to any reason, adverse events and lack of efficacy. The overall attrition rate was considerable (34.7%) with no significant difference between the groups. Amisulpride was as effective as olanzapine and risperidone and more effective than ziprasidone as regards leaving the study early due to inefficacy (RR 0.21, 95%CI 0.05 to 0.94, NNT 8, 95%CI 5 to 50; 1 RCT, n=123). Amisulpride induced less weight gain than risperidone (MD -0.99, 95%CI -1.61 to -0.37; 3 RCTs, n=585) or olanzapine (MD -2.11, 95%CI -2.94 to -1.29; 3 RCTs, n=671). Olanzapine was also associated with a higher increase of glucose (MD -7.30, 95%CI -7.62 to -6.99; 2 RCTs, n=406). There was no difference in terms of cardiac effects and extrapyramidal symptoms compared with olanzapine (akathisia: RR 0.66, 95%CI 0.36 to 1.21; 2 RCTs, n= 587), risperidone (akathisia: RR 0.80, 95%CI 0.58 to 1.11; 3 RCTs, n=586) or ziprasidone (akathisia: RR 0.63, 95%CI 0.11 to 3.67; 1 RCT, n=123).

Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment, more than 20% loss to follow up), reporting bias (most included studies were conducted by pharmaceutical companies) and indirectness (short follow-up).

References