HALDOL

Clinical safety rating: caution

Comprehensive clinical and safety monograph for HALDOL (HALDOL).

How it works

Haloperidol is a typical antipsychotic that blocks dopamine D2 receptors in the central nervous system, particularly in the mesolimbic and mesocortical pathways, reducing positive symptoms of schizophrenia. It also has moderate affinity for sigma receptors and weak affinity for serotonin 5-HT2, alpha-adrenergic, and histamine H1 receptors.

What the body does with it

Metabolism	Extensively metabolized in the liver primarily via CYP3A4 and CYP2D6, with minor contributions from other CYP enzymes. Major metabolites include reduced haloperidol (via ketoreduction) and other inactive or minimally active compounds.
Excretion	Renal (approximately 40%, with 1% unchanged; remainder as metabolites) and fecal (approximately 60%, primarily via bile).
Half-life	Terminal elimination half-life is approximately 21 hours (range 12–37 hours). Extended half-life in chronic administration supports once-daily dosing; dose adjustments required in hepatic impairment.
Protein binding	92% bound primarily to albumin and alpha-1-acid glycoprotein.
Volume of Distribution	Vd approximately 17 L/kg (range 10–22 L/kg). Large Vd indicates extensive tissue distribution, particularly to brain and adipose tissue.
Bioavailability	Oral: approximately 60–65% (first-pass metabolism); IM: 100%.
Onset of Action	Oral: 30–60 minutes (IM: 15–30 minutes; IV: 2–5 minutes).
Duration of Action	Oral: 12–24 hours (IM: 12–24 hours; IV: 4–8 hours). Clinical effects persist beyond plasma half-life due to redistribution and sustained receptor binding.

Classification & Brands

Action Class	Typical Antipsychotics
Brand Substitutes	Larenase 5mg Tablet, Hapdol 5mg Tablet, Zeedol 5mg Tablet, Helinase 5mg Tablet, Halodyl 5mg Tablet, Helinase 10mg Tablet, Zeedol 10mg Tablet, Halodyl 10mg Tablet, Halopace 10mg Tablet, Hpl 10mg Tablet

Dosing & administration

Initial: 1-5 mg PO/IM twice daily; titrate up to 5-10 mg/day. Acute agitation: 5-10 mg IM every 1-8 hours. Maintenance: 5-10 mg/day PO/IM. Maximum: 100 mg/day.

Dosage form	CONCENTRATE
Renal impairment	No dose adjustment required for mild-to-moderate renal impairment. For severe impairment (GFR <10 mL/min), use with caution and consider 50% dose reduction.
Liver impairment	Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 30-50%. Child-Pugh Class C: avoid use or reduce to 25% of usual dose.
Pediatric use	3-6 years: 0.01-0.03 mg/kg/day PO divided twice daily; 6-12 years: 0.02-0.05 mg/kg/day PO divided twice daily; >12 years: 0.5-5 mg/day PO divided twice daily. IM: 1-5 mg IM every 4-8 hours as needed.
Geriatric use	Initial dose: 0.5-2 mg PO/IM daily; maximum 5 mg/day. Increase slowly by 0.5-1 mg every 5-7 days. Monitor for extrapyramidal symptoms and QT prolongation.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for HALDOL (HALDOL).

Breastfeeding	Haloperidol is excreted in breast milk with an M/P ratio of approximately 0.5-0.7. Infant exposure is estimated at 1-5% of maternal weight-adjusted dose. Monitor infant for sedation and extrapyramidal symptoms. Benefit of breastfeeding should be weighed against potential risks.
Teratogenic Risk	First trimester: Increased risk of congenital malformations, particularly limb defects, with first-trimester exposure. Second and third trimesters: Risk of extrapyramidal symptoms and withdrawal in neonates (e.g., agitation, hypertonia, tremors). Overall, benefits may outweigh risks in severe psychiatric conditions.

Warnings & precautions

■ FDA Black Box Warning

WARNING: Increased mortality in elderly patients with dementia-related psychosis. Haloperidol is not approved for the treatment of dementia-related psychosis. Also, QT interval prolongation and risk of sudden death, especially with high doses or intravenous administration.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Comatose states","Severe CNS depression","Parkinson's disease (relative)","Known hypersensitivity to haloperidol","QTc interval prolongation (congenital or acquired)","Concurrent use with drugs that prolong QTc interval","Uncontrolled hypokalemia or hypomagnesemia"]

Clinical Precautions

Precautions

["Increased mortality in elderly patients with dementia-related psychosis","QT prolongation and risk of torsade de pointes","Neuroleptic malignant syndrome (NMS)","Tardive dyskinesia","Extrapyramidal symptoms (EPS)","Seizures","Hyperprolactinemia","Leukopenia/neutropenia/agranulocytosis","Cognitive and motor impairment","Dysphagia and aspiration"]

Clinical Tips & Counseling

Drug interactions

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HALDOL

Clinical safety rating: caution

Comprehensive clinical and safety monograph for HALDOL (HALDOL).

How it works

What the body does with it

Metabolism	Extensively metabolized in the liver primarily via CYP3A4 and CYP2D6, with minor contributions from other CYP enzymes. Major metabolites include reduced haloperidol (via ketoreduction) and other inactive or minimally active compounds.
Excretion	Renal (approximately 40%, with 1% unchanged; remainder as metabolites) and fecal (approximately 60%, primarily via bile).
Half-life	Terminal elimination half-life is approximately 21 hours (range 12–37 hours). Extended half-life in chronic administration supports once-daily dosing; dose adjustments required in hepatic impairment.
Protein binding	92% bound primarily to albumin and alpha-1-acid glycoprotein.
Volume of Distribution	Vd approximately 17 L/kg (range 10–22 L/kg). Large Vd indicates extensive tissue distribution, particularly to brain and adipose tissue.
Bioavailability	Oral: approximately 60–65% (first-pass metabolism); IM: 100%.
Onset of Action	Oral: 30–60 minutes (IM: 15–30 minutes; IV: 2–5 minutes).
Duration of Action	Oral: 12–24 hours (IM: 12–24 hours; IV: 4–8 hours). Clinical effects persist beyond plasma half-life due to redistribution and sustained receptor binding.

Classification & Brands

Action Class	Typical Antipsychotics
Brand Substitutes	Larenase 5mg Tablet, Hapdol 5mg Tablet, Zeedol 5mg Tablet, Helinase 5mg Tablet, Halodyl 5mg Tablet, Helinase 10mg Tablet, Zeedol 10mg Tablet, Halodyl 10mg Tablet, Halopace 10mg Tablet, Hpl 10mg Tablet

Dosing & administration

Initial: 1-5 mg PO/IM twice daily; titrate up to 5-10 mg/day. Acute agitation: 5-10 mg IM every 1-8 hours. Maintenance: 5-10 mg/day PO/IM. Maximum: 100 mg/day.

Dosage form	CONCENTRATE
Renal impairment	No dose adjustment required for mild-to-moderate renal impairment. For severe impairment (GFR <10 mL/min), use with caution and consider 50% dose reduction.
Liver impairment	Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 30-50%. Child-Pugh Class C: avoid use or reduce to 25% of usual dose.
Pediatric use	3-6 years: 0.01-0.03 mg/kg/day PO divided twice daily; 6-12 years: 0.02-0.05 mg/kg/day PO divided twice daily; >12 years: 0.5-5 mg/day PO divided twice daily. IM: 1-5 mg IM every 4-8 hours as needed.
Geriatric use	Initial dose: 0.5-2 mg PO/IM daily; maximum 5 mg/day. Increase slowly by 0.5-1 mg every 5-7 days. Monitor for extrapyramidal symptoms and QT prolongation.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for HALDOL (HALDOL).

Breastfeeding	Haloperidol is excreted in breast milk with an M/P ratio of approximately 0.5-0.7. Infant exposure is estimated at 1-5% of maternal weight-adjusted dose. Monitor infant for sedation and extrapyramidal symptoms. Benefit of breastfeeding should be weighed against potential risks.
Teratogenic Risk	First trimester: Increased risk of congenital malformations, particularly limb defects, with first-trimester exposure. Second and third trimesters: Risk of extrapyramidal symptoms and withdrawal in neonates (e.g., agitation, hypertonia, tremors). Overall, benefits may outweigh risks in severe psychiatric conditions.