• Blocks dopamine receptors in the CNS.
• Increases brain turnover of dopamine, blocks calcium channels, and may antagonize opiate receptors.

• Decreased tics in patients with Tourette’s disorder.

Therapeutic Classification: antipsychotics

Absorption: 50% absorbed following oral administration.

Distribution: Unknown.

Metabolism/Excretion: Undergoes extensive first-pass hepatic metabolism, primarily by the CYP3A4 isoenzyme and to a lesser extent by the CYP1A2 and CYP2D6 isoenzymes; the CYP2D6 isoenzyme exhibits genetic polymorphism (7% of population may be poor metabolizers [PMs] and may have significantly ↑ pimozide concentrations and an ↑ risk of adverse effects). Some metabolites have CNS activity.

Half-life: 29–111 hr.

(plasma concentrations)

• Advise patient to take medication exactly as directed and to avoid grapefruit juice during therapy. Skip missed doses and return to regular schedule; do not double doses. May require several wk to obtain desired effects. Do not increase dose or discontinue medication without consulting health care professional. Abrupt withdrawal may cause dizziness; nausea; vomiting; GI upset; trembling; or uncontrolled movements of mouth, tongue, or jaw. Dose should be gradually decreased over several wk to minimize withdrawal symptoms.
• Inform patient of possibility of extrapyramidal symptoms and tardive dyskinesia. Caution patient to report symptoms immediately.
• Advise patient to change positions slowly to minimize orthostatic hypotension.
• May cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
• Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications, especially St. John's wort, kava, valerian, and chamomile.
• Caution patient to avoid taking alcohol or other CNS depressants concurrently with this medication.
• Advise patient to use sunscreen and protective clothing when exposed to the sun to prevent photosensitivity reactions. Extremes of temperature should also be avoided, because this drug impairs body temperature regulation.
• Advise patient of possibility of weight gain or cholesterol elevation; refer as appropriate for nutrition/weight management and medical management.
• Instruct patient to use frequent mouth rinses, good oral hygiene, and sugarless gum or candy to minimize dry mouth.
• Advise patient to notify health care professional of medication regimen prior to treatment or surgery.
• Instruct patient to notify health care professional promptly if weakness, tremors, visual disturbances, dark-colored urine, clay-colored stools, sore throat, fever, or symptoms of neuroleptic malignant syndrome occur.
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected and to avoid breastfeeding. Advise patients that use during 3rd trimester may cause extrapyramidal and/or withdrawal symptoms (agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding disorder).
• Emphasize the importance of routine follow-up exams to monitor response to medication and detect side effects.

PI-mo-zide