<1%, postmarketing, and/or case reports: Abnormal hepatic function tests, acneiform eruption, acute hepatic failure, agitation, agranulocytosis, akathisia, alopecia, amenorrhea, anaphylaxis, anemia, blurred vision, bronchopneumonia, bronchospasm, cardiac arrhythmia, cholestasis, cogwheel rigidity, confusion, decreased libido, depression, dizziness, dyskinesia, dysmenorrhea, dyspnea, edema, erectile dysfunction, exfoliative dermatitis, extrasystoles, facial edema, galactorrhea, gynecomastia, heatstroke, hepatic insufficiency, hepatitis, hyperammonemia, hyperhidrosis, hyperprolactinemia, hyperpyrexia, hypersensitivity angiitis, hypersensitivity reaction, hypertension, hyperthermia, hypoglycemia, hypokinesia, hypotension, hypothermia, injection site reaction, insomnia, jaundice, laryngeal edema, laryngospasm, leukocytosis, leukopenia, lymphocytosis with monocytosis, maculopapular rash, mask-like face, mastalgia, menorrhagia, motor dysfunction, muscle rigidity, muscle twitching, nausea, neonatal withdrawal, neuroleptic malignant syndrome, neutropenia, nystagmus, opisthotonus, orthostatic hypotension, pancytopenia, priapism, prolonged Q-T interval on ECG, pruritus, restlessness, rhabdomyolysis, sedation, seizure, SIADH, skin photosensitivity, skin rash, tachycardia, tardive dyskinesia, tardive dystonia, thrombocytopenia, torsades de pointes, torticollis, trismus, urinary retention, urticaria, ventricular arrhythmia, ventricular fibrillation, ventricular tachycardia, vomiting, weight gain, weight loss
As with all antipsychotic agents Haloperidol has been associated with persistent dyskinesias. Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements, may appear in some patients on long-term therapy or may occur after drug therapy has been discontinued. The risk appears to be greater in elderly patients on high-dose therapy, especially females. The symptoms are persistent and in some patients appear irreversible. The syndrome is characterized by rhythmical involuntary movements of tongue, face, mouth or jaw (., protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements). Sometimes these may be accompanied by involuntary movements of extremities and the trunk.
The intravenous route is not FDA approved and is generally not recommended except when no other alternatives are available. Intravenous administration appears to be associated with a higher risk of QT prolongation and torsade de pointes (TdP) than other forms of administration. The manufacturer recommends ECG monitoring for QT prolongation and arrhythmias if IV administration is required. A dose in the range of 1 to 5 mg IV has been suggested, with the dose being repeated at 30 to 60 minute intervals, if needed. A maximum IV dose has not been established. The lowest effective dose should be used in conjunction with conversion to oral therapy as soon as possible.