May alter cardiac conduction and prolong QT interval. Use with caution or avoid use in electrolyte abnormalities (e.g. hypokalemia, hypomagnesemia), hypothyroidism, familial long QT syndrome, concomitant medications which may augment QT prolongation, or any underlying cardiac abnormality which may also potentiate risk. May cause anticholinergic effects (constipation, blurred vision, urinary retention, xerostomia). Use with caution in decreased GI motility, paralytic ileus, urinary retention, BPH, xerostomia, or visual problems. Myelosuppression (e.g. leukopenia, agranulocytosis) observed with antipsychotic use. Use contraindicated in bone marrow suppression. Antipsychotic use associated with esophageal dysmotility and aspiration. Use with caution in risk of pneumonia (e.g. Alzheimer’s disease). May cause extrapyramidal symptoms, including pseudoparkinsonism, acute dystonic reactions, akathisia, and tardive dyskinesia (risk of these reactions is high relative to other neuroleptics). Neuroleptic malignant syndrome possible. May cause orthostatic hypotension. May be associated with pigmentary retinopathy. May be sedating. Impaired core body temperature regulation may occur. Use with caution in severe cardiovascular disease. Haloperidol not approved for treatment of dementia-related psychosis in elderly patients. Use with caution in narrow-angle glaucoma, myasthenia gravis (condition may be exacerbated by cholinergic blockade). Use with caution in Parkinson’s disease. Use with caution in breast cancer or other prolactin-dependent tumors (elevates prolactin levels). Use with caution in renal impairment, and in respiratory disease. Use with caution in risk of seizures. Avoid use in thyrotoxicosis. May mask toxicity of other drugs or conditions (e.g. intestinal obstruction, Reye’s syndrome, brain tumor) due to antiemetic effects. Some tablets contain tartrazine. Hypotension may occur, particularly with parenteral administration. Risk of QT prolongation, torsade de pointes, and sudden death appear to be increased with I.V. administration, particularly at higher doses. Although short-acting form (lactate) is used clinically intravenously, I.V. use of injection is not an FDA-approved route of administration. The decanoate form should never be administered intravenously.