What is pimozide?

First generation ‘typical’ antipsychotics such as pimozide are an older class of antipsychotic than second generation ‘atypical’ antipsychotics. They are used primarily to treat positive symptoms including the experiences of perceptual abnormalities (hallucinations) and fixed, false, irrational beliefs (delusions). First generation antipsychotics may cause side effects which can differ depending on which antipsychotic is being administered and on individual differences in reaction to the drug. Reactions may include dyskinesias such as repetitive, involuntary, and purposeless body or facial movements, Parkinsonism (cogwheel muscle rigidity, pill-rolling tremor and reduced or slowed movements), akathisia (motor restlessness, especially in the legs, and resembling agitation) and dystonias such as muscle contractions causing unusual twisting of parts of the body, most often in the neck. These effects are caused by the dopamine receptor antagonist action of these drugs.

What is the evidence for pimozide?

Moderate to low quality evidence found fewer relapses at medium term (3-12 months) after augmentation of thioridazine with pimozide compared to no augmentation.

Compared to first generation antipsychotics thioridazine, trifluoperazine or fluphenazine, moderate quality evidence found no differences in relapse rates, rigidity or tremor.

Only low quality evidence was available for the comparison of pimozide with placebo, so no conclusions can be drawn.

October 2020

Last updated at: 4:03 am, 14th October 2020
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Title Colour Legend:
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Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.