Pimozide augmentation of clozapine inpatients with schizophrenia and schizoaffective disorder unresponsive to clozapine monotherapy.

[Correction Notice: An erratum for this article was reported in Vol 36(10) of Neuropsychopharmacology (see record [rid]2011-22335-020[/rid]). In the original article, the name of the twelfth author is incorrect; the correct name is Vladan Novakovic.] [Correction Notice: An erratum for this article was reported in Vol 36(6) of Neuropsychopharmacology (see record [rid]2011-11423-019[/rid]). In the original article, Dr. Saurabh Kaushik was inadvertently omitted from the byline. The correction is given in the erratum.] Despite its superior efficacy, clozapine is helpful in only a subset of patients with schizophrenia unresponsive to other antipsychotics. This lack of complete success has prompted the frequent use of various clozapine combination strategies despite a paucity of evidence from randomized controlled trials supporting their efficacy. Pimozide, a diphenylbutylpiperidine, possesses pharmacological and clinical properties distinct from other typical antipsychotics. An open-label trial of pimozide adjunctive treatment to clozapine provided promising pilot data in support of a larger controlled trial. Therefore, we conducted a double-blind, placebo-controlled, parallel-designed 12-week trial of pimozide adjunctive treatment added to ongoing optimal clozapine treatment in 53 patients with schizophrenia and schizoaffective disorder partially or completely unresponsive to clozapine monotherapy. An average dose of 6.48 mg/day of pimozide was found to be no better than placebo in combination with clozapine at reducing Positive and Negative Syndrome Scale total, positive, negative, and general psychopathology scores. There is no suggestion from this rigorously conducted trial to suggest that pimozide is an effective augmenting agent if an optimal clozapine trial is ineffective. However, given the lack of evidence to guide clinicians and patients when clozapine does not work well, more controlled trials of innovative strategies are warranted. (PsycInfo Database Record (c) 2021 APA, all rights reserved)