Used for the suppression of motor and phonic tics in patients with Tourette's Disorder who have failed to respond satisfactorily to standard treatment.
Pimozide is an orally active antipsychotic drug product which shares with other antipsychotics the ability to blockade dopaminergic receptors on neurons in the central nervous system. However, receptor blockade is often accompanied by a series of secondary alterations in central dopamine metabolism and function which may contribute to both pimozide's therapeutic and untoward effects. In addition, pimozide, in common with other antipsychotic drugs, has various effects on other central nervous system receptor systems which are not fully characterized. Pimozide also has less potential for inducing sedation and hypotension as it has more specific dopamine receptor blocking activity than other neuroleptic agents (and is therefore a suitable alternative to haloperidol).
Mode of Action:
The ability of pimozide to suppress motor and phonic tics in Tourette's Disorder is thought to be primarily a function of its dopaminergic blocking activity. Pimozide binds and inhibits the dopamine D2 receptor in the CNS.
Notable first-pass metabolism in the liver, primarily by N-dealkylation via the cytochrome P450 isoenzymes CYP3A and CYP1A2 (and possibly CYP2D6). The activity of the two major metabolites has not been determined.