Overview
Haloperidol is a first-generation (typical) antipsychotic medication primarily used to treat schizophrenia and other psychotic disorders. It is also used for the management of Tourette's syndrome, severe behavioral problems in children, and as an antiemetic. Haloperidol works by blocking dopamine D2 receptors in the brain, which helps reduce psychotic symptoms such as hallucinations and delusions.
Mechanism of Action
Haloperidol is a butyrophenone derivative that acts as a potent antagonist at dopamine D2 receptors in the mesolimbic and mesocortical pathways of the brain. It also has moderate antagonistic effects at alpha-1 adrenergic receptors and weak anticholinergic properties. The blockade of dopamine receptors is primarily responsible for its antipsychotic effects, but also contributes to extrapyramidal side effects.
Indications
- Schizophrenia
- Psychotic disorders
- Tourette's syndrome
- Severe behavioral problems in children (aggression, hyperactivity)
- Nausea and vomiting (as an antiemetic)
- Delirium
- Acute agitation
Dosage
Dosage varies based on indication, patient age, and severity. For schizophrenia in adults: Initial dose 0.5-5 mg 2-3 times daily, maintenance dose 1-15 mg/day. For children: 0.05-0.15 mg/kg/day. For Tourette's: 0.5-2 mg 2-3 times daily. Always titrate to the lowest effective dose. Haloperidol decanoate (long-acting injection): Initial dose 10-15 times the daily oral dose, administered every 4 weeks.
Contraindications
- Hypersensitivity to haloperidol
- Parkinson's disease
- Severe CNS depression
- Comatose states
- Patients with dementia-related psychosis (increased mortality risk)
- Severe cardiac disorders (QT prolongation risk)
- Concurrent use with other QT-prolonging drugs
Side Effects
- Extrapyramidal symptoms (dystonia, akathisia, parkinsonism)
- Sedation
- Dry mouth
- Blurred vision
- Constipation
- Weight gain
- QT prolongation
- Tardive dyskinesia
- Neuroleptic malignant syndrome
- Hyperprolactinemia
- Orthostatic hypotension
- Photosensitivity
Interactions
- CNS depressants (alcohol, benzodiazepines, opioids): increased sedation
- Anticholinergic drugs: increased anticholinergic effects
- QT-prolonging drugs (antiarrhythmics, some antibiotics): increased arrhythmia risk
- Lithium: increased neurotoxicity risk
- Enzyme inducers (carbamazepine, phenytoin): decreased haloperidol levels
- Enzyme inhibitors (fluoxetine, paroxetine): increased haloperidol levels