Pimozide for Schizophrenia or Related Psychoses

A Cochrane review [Abstract] 1 included 32 studies with a total of 1277 patients with schizophrenia. The diagnostic criteria were not specified in 58% of the included studies. Participants in 17 of the studies were inpatients and average age was 43 years. The shortest study was conducted for 4 weeks, and the longest study had a duration of 3 years, many trials were completed within 4 months.

• Pimozide vs. placebo (5 trials): One study (n=20) provided data for global state relapse, for which no difference between groups was noted at medium term (RR 0.22, CI 0.03 to 1.78). None of the 5 studies provided data for no improvement or first-rank symptoms in mental state. Data for extrapyramidal symptoms demonstrate no difference between groups for Parkinsonism (rigidity) at short term (RR 5.50, CI 0.30 to 101.28; 1 RCT, n = 19) or at medium term (RR 1.33, CI 0.14 to 12.82; 1 RCT, n=25), or for Parkinsonism (tremor) at medium term (RR 1, CI 0.2 to 4.95;1 RCT n=25). No data were reported for quality of life at medium term.
• Pimozide vs. any antipsychotic (26 trials): Seven studies (n=227) provided data for global state relapse at medium term, for which no difference was noted (RR 0.82, CI 0.57 to 1.17). Data from one study (n=23) demonstrated no difference in mental state (no improvement) at medium term (RR 1.09, CI 0.08 to 15.41); another study (n=44)demonstrated no difference in the presence of first-rank symptoms at medium term (RR 0.53, CI 0.25 to 1.11). Data for extrapyramidal symptoms demonstrate no difference between groups for Parkinsonism (rigidity) at short term (RR 1.21, CI 0.71 to 2.05; 6 RCTs, n=186) or medium term (RR 1.12, CI 0.24 to 5.25; 5 RCTs n=219), or for Parkinsonism (tremor) at medium term (RR 1.46, CI 0.68 to 3.11; 4 RCTs, n=174). No data were reported for quality of life at medium term.
• Pimozide plus any antipsychotic vs. the same antipsychotic: In one study (n=69) significantly fewer relapses were noted in the augmented pimozide group at medium term (RR 0.28, CI 0.15 to 0.50). No data were reported for mental state outcomes or for extrapyramidal symptoms.
• Pimozide plus any antipsychotics vs. antipsychotic plus placebo (2 studies): Neither study reported data for outcomes of interest, apart from Parkinsonism at medium term and quality of life using the Specific Level of Functioning scale (SLOF).
• Pimozide plus any antipsychotic vs. antipsychotics plus antipsychotic (one study): No data were reported for global state and mental state outcomes of interest. Data were provided for Parkinsonism (rigidity and tremor) using the Extrapyramidal Symptom Rating Scale.

Comment: The quality of evidence is downgraded by indirectness (short follow-up time) and imprecise results (few trials for each comparison).

References

• Mothi M, Sampson S. Pimozide for schizophrenia or related psychoses. Cochrane Database Syst Rev 2013;11():CD001949. [PubMed]