Adult: As maintenance treatment in patients currently stabilised with oral haloperidol: As haloperidol decanoate: Dose is based on the severity of symptoms and current oral haloperidol dose. Transition from oral haloperidol: 10-15 times the daily oral dose. Treatment continuation: Adjust dose by up to 50 mg every 4 weeks until optimal effect is achieved, based on patient’s response. Max: 300 mg every 4 weeks. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines). Elderly: Dose reduction may be required.
Intramuscular, Intravenous Aggression, Agitation
Adult: In cases associated with acute psychosis: As haloperidol base: 2-10 mg via IM or IV inj; may give subsequent doses hourly based on patient’s clinical response and tolerability. Use the lowest effective dose. Max: 20 mg daily. Dosage, treatment and administration recommendations may vary among countries and between individual products (refer to specific product guidelines). Elderly: Initiate at half of the usual initial dose.
Intramuscular Postoperative nausea and vomiting
Adult: As prophylaxis in patients with moderate to high-risk cases and when alternative drugs are ineffective or not tolerated: As haloperidol base: 1-2 mg given at induction or 30 minutes before the end of anaesthesia. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines). Elderly: Initiate at half of the usual initial dose.
Oral Tourette's syndrome
Adult: For the management of tics and vocalisations: 0.5-5 mg daily as a single dose or in 2 divided doses based on patient’s clinical response and tolerability. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines). Elderly: Initiate at half of the usual initial dose. Child: 10-17 years 0.5-3 mg daily in 2-3 divided doses based on patient’s clinical response and tolerability. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines).
Oral Bipolar I disorder
Adult: In moderate to severe manic episodes: 2-10 mg daily as a single or in 2 divided doses based on patient's clinical response and tolerability. Max: 15 mg daily. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines). Elderly: Initiate at half of the usual initial dose.
Oral Schizoaffective disorder, Schizophrenia
Adult: 1-10 mg daily as a single dose or in 2-3 divided doses. Max: 30 mg daily. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines).
Elderly: Initiate at half of the usual initial dose. Child: 13-17 years 0.5-3 mg daily in 2-3 divided doses based on patient’s clinical response and tolerability. Max: 5 mg daily. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines).
Oral Psychomotor agitation
Adult: In cases associated with psychotic disorder: 5-10 mg, repeated after 12 hours if needed. Max: 20 mg daily. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines). Elderly: Initiate at half of the usual initial dose.
Oral Behavioural disorders
Child: In non-psychotic cases: 3-12 years 0.05-0.15 mg/kg daily in 2-3 divided doses based on patient’s clinical response and tolerability. Use the lowest effective dose. Dosage and treatment recommendations may vary among countries and between individual products (refer to specific product guidelines).
What are the brands available for Haloperidol in Hong Kong?
Haloperidol is mainly metabolised via glucuronidation and to a lesser extent by CYP2D6, CYP3A4 and carbonyl reduction. Gene variants changing CYP2D6 activity may affect the exposure of haloperidol, resulting in adverse effects and/or affecting its effectiveness. Genetic testing for CYP2D6 may be considered to help guide dosage adjustments and prevent potential adverse effects.
Royal Dutch Pharmacists Association - Pharmacogenetics Working Group (DPWG) Guideline as of May 2021:
Phenotype and Genotype
Description
Recommendations
CYP2D6 intermediate metabolisers
Higher plasma concentration of haloperidol, but the effect is small and no clinically significant effects were found.
No dose adjustment is needed.
CYP2D6 poor metabolisers
Decreased conversion of haloperidol, resulting in haloperidol plasma concentrations that are approx 1.7-fold higher and increased risk of adverse effects.
Use 60% of the normal dose.
CYP2D6 ultrarapid metabolisers
Increased conversion of haloperidol, resulting in haloperidol plasma concentrations that are approx 40% lower and reduced effectiveness.
Use 1.5 times the normal dose or choose alternative antipsychotics which are not metabolised by CYP2D6 (e.g. flupentixol, penfluridol, quetiapine, olanzapine, clozapine).
Administration
Haloperidol May be taken with or without food. May be taken w/ meals to minimise GI irritation.
Contraindications
Parkinson's disease, severe CNS depression, dementia with Lewy bodies, comatose state, known QT interval prolongation or congenital long QT syndrome, recent acute MI, progressive supranuclear palsy, uncorrected hypokalaemia, uncompensated heart failure, history of ventricular arrhythmia or torsades de pointes.
Special Precautions
Patient with risk factors for ventricular arrhythmias (e.g. cardiac disease, family history of QT prolongation, uncorrected electrolyte disturbances, subarachnoid haemorrhage, alcohol abuse), myasthenia gravis, thyroid dysfunction; risk factors for stroke; epilepsy or predisposition to convulsions (e.g. brain damage, alcohol withdrawal); phaeochromocytoma, arteriosclerosis; hyperprolcatinaemia and with possible prolactin-dependent tumours; thyrotoxicosis. CYP2D6 ultrarapid and poor metaboliser. Avoid abrupt withdrawal. Renal and hepatic impairment. Children; elderly (particularly those with dementia). Pregnancy and lactation. Concomitant use with QT-prolonging drugs.
Adverse Reactions
Significant: CNS depression; somnolence, orthostatic hypotension, motor or sensory instability which may lead to fall and subsequent fractures or other injuries; tachycardia; rapid mood swing to depression (when used to control mania in bipolar disorder); exacerbate myasthenia gravis; tardive dyskinesia (prolonged use); extrapyramidal symptoms (e.g. tremor, rigidity, hypersalivation, bradykinesia, akathisia, acute dystonia, drug-induced parkinsonism); seizures, hepatitis, cholestatic; hyperprolactinaemia which may cause galactorrhoea, gynaecomastia and oligomenorrhoea; VTE; haematologic abnormalities (e.g. leucopenia, neutropenia, thrombocytopenia, agranulocytosis, pancytopenia). Very rarely, hypoglycaemia and SIADH. Eye disorders: Oculogyric crisis, blurred vision, visual disturbance. Gastrointestinal disorders: Constipation, dry mouth, salivary hypersecretion, nausea, vomiting. General disorders and administration site conditions: Inj site reaction. Investigations: Increased or decreased weight, abnormal LFTs. Nervous system disorders: Dizziness, masked facies, somnolence, hyperkinesia, hypertonia, headache. Psychiatric disorders: Depression, insomnia, agitation, psychotic disorder. Renal and urinary disorders: Urinary retention. Reproductive system and breast disorders: Erectile dysfunction, decreased libido. Skin and subcutaneous tissue disorders: Rash. Potentially Fatal: Increased risk of mortality in elderly with dementia-related psychosis; bronchopneumonia, neuroleptic malignant syndrome, hypothermia. Very rarely, QT prolongation and/or ventricular arrhythmias, torsades de pointes.
This drug may cause sedation and impairment of alertness, if affected, do not drive or operate machinery.
Monitoring Parameters
Obtain ECG before and during therapy. Monitor electrolytes, renal and liver function, TSH, CBC, prolactin levels, fasting blood glucose, HbA1c, lipid panel, vital signs and weight. Assess for signs and symptoms of extrapyramidal symptoms, mental status.
Overdosage
Symptoms: Severe extrapyramidal reactions, manifested by muscular weakness or rigidity and generalised or localised tremor; sedation; ventricular arrhythmias associated with QT prolongation; comatose with respiratory depression and hypotension which may result in a shock-like state; paradoxical hypertension.
Management: Supportive treatment. Perform aspiration and lavage to empty the stomach. Establish patent airway and provide artificial ventilation if needed. Monitor ECG and vital signs; maintain adequate fluid intake. Give antiarrhythmic drugs for arrhythmias. Place the patient in the head-down position and give plasma expanders and vasopressors (e.g. norepinephrine) for hypotension. Administer parenteral antihistamine or antiparkinsonian drugs for severe extrapyramidal reactions.
Drug Interactions
Increased risk of ventricular arrhythmias (including torsades de pointes) or QT interval prolongation with class IA and III antiarrhythmics (e.g. quinidine, disopyramide, procainamide, amiodarone, sotalol), certain antibiotics (e.g. moxifloxacin, erythromycin IV), TCAs (e.g. amitriptyline), maprotiline, other neuroleptics (e.g. pimozide, phenothiazines), antihistamines (e.g. terfenadine), cisapride, bretylium tosilate, diuretics, and antimalarials (e.g. quinine, mefloquine). Increased plasma concentration with CYP2D6 inhibitors (e.g. bupropion, chlorpromazine, duloxetine, paroxetine, promethazine, sertraline, venlafaxine) and/or CYP3A4 inhibitors (e.g. alprazolam, itraconazole, verapamil, fluoxetine, ritonavir). Decreased plasma concentration with CYP3A4 inducers (e.g. carbamazepine, rifampicin, phenobarbital). May enhance the CNS depressant effect of other CNS-depressant drugs (e.g. hypnotics, sedatives, strong analgesics). May antagonise the action of epinephrine, phenindione and other sympathomimetic agents. May reverse the blood pressure-lowering effects of guanethidine. May increase the plasma concentration of TCAs (e.g. imipramine, desipramine). Increased risk of severe neuromuscular symptoms (including impairment of consciousness and fever) and encephalopathic syndrome with lithium. May impair the antiparkinson effect of levodopa. May cause severe drowsiness and confusion with indometacin. May increase IOP with anticholinergic drugs (including antiparkinsonian drugs).
Food Interaction
Increased CNS depressant effect with alcohol. Decreased plasma concentration with St. John's wort.
Action
Description: Overview: Haloperidol is a butyrophenone-derivative, 1st-generation antipsychotic agent. Mechanism of Action: Haloperidol non-selectively inhibits the postsynaptic dopaminergic D2 receptors in the brain. Pharmacodynamics: In mania and other agitation syndromes, haloperidol supresseses delusions and hallucinations and produces efficient psychomotor sedation.
Hyperprolactinaemia appears to be caused by the antidopaminergic effects of haloperidol on lactotropes in the anterior pituitary, which occurs due to the inhibition of dopamine-mediated tonic inhibition of prolactin secretion. Additionally, the extrapyramidal motor effects (e.g. dystonia, akathisia, parkinsonism) of haloperidol appears to be due to the activity on the basal ganglia. Pharmacokinetics: Absorption: Readily absorbed from the gastrointestinal tract (oral). Bioavailability: 60-70% (oral). Time to peak plasma concentration: 20-40 minutes (as haloperidol base [IM]); 6 days (as haloperidol decanoate [IM]); 2-6 hours (oral). Distribution: Widely distributed in the body. Crosses the blood-brain barrier and placenta; enters breast milk. Plasma protein binding: 88.4-92.5%. Metabolism: Extensively metabolised in the liver by CYP3A4 and CYP2D6 via oxidative N-dealkylation, glucuronidation and reduction of the ketone group into reduced haloperidol (an alcohol). Excretion: Via urine (30%, 1% as unchanged drug). Elimination half-life: 21 hours (as haloperidol base [IM]); 21 days (as haloperidol decanoate [IM]);14-26 hours (IV); 14-37 hours (oral).
Chemical Structure
Haloperidol Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 3559, Haloperidol. https://pubchem.ncbi.nlm.nih.gov/compound/Haloperidol. Accessed Nov. 26, 2025.
Storage
Store between 20-25°C. Storage recommendations may vary among countries and between individual products (refer to specific product guidelines).
Sign Out
Continue with Google