May alter cardiac conduction (avoid use in underlying QT prolongation, in patients taking medicines which prolong QT interval, or cause polymorphic ventricular tachycardia). May cause anticholinergic effects (use with caution in decreased gastrointestinal motility, paralytic ileus, urinary retention, BPH, xerostomia, or visual problems). Myelosuppression (e.g. leukopenia, agranulocytosis) observed with antipsychotic use. Antipsychotic use associated with esophageal dysmotility and aspiration (use with caution in risk of pneumonia). May cause extrapyramidal symptoms, including pseudoparkinsonism, acute dystonic reactions, akathisia, and tardive dyskinesia. Use may be associated with neuroleptic malignant syndrome (risk may be increased in Parkinson’s disease or Lewy body dementia). May cause orthostatic hypotension (use with caution in cerebrovascular disease, cardiovascular disease, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia). May be associated with pigmentary retinopathy. May be sedating. Impaired core body temperature regulation may occur. Use with caution in severe cardiovascular disease. Pimozide not approved for treatment of dementia-related psychosis (increased incidence of cerebrovascular adverse events, including fatalities). Use with caution in narrow-angle glaucoma (may be exacerbated by cholinergic blockade), in hepatic impairment, in myasthenia gravis (may be exacerbated by cholinergic blockade), and in Parkinson’s disease (may be more sensitive to adverse effects). Use with caution in breast cancer or other prolactin-dependent tumors (elevates prolactin levels), in renal impairment, in respiratory disease, and in risk of seizures, including patients with history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold. May mask toxicity of other drugs or conditions (e.g. intestinal obstruction, Reye’s syndrome, brain tumor) due to antiemetic effects.