HALOPERIDOL LACTATE

Clinical safety rating: safe

CNS depressants may enhance sedative effects Can cause extrapyramidal symptoms and QT prolongation.

How it works

Haloperidol lactate is a typical antipsychotic that exerts its effects primarily by blocking dopamine D2 receptors in the brain, particularly in the mesolimbic and mesocortical pathways. It also has antagonistic activity at alpha-1 adrenergic receptors and limited affinity for serotonin receptors.

What the body does with it

Metabolism	Haloperidol is extensively metabolized in the liver via multiple pathways, including glucuronidation, carbonyl reduction, and CYP3A4-mediated N-dealkylation. The major active metabolite is reduced haloperidol, which can be reoxidized to haloperidol.
Excretion	Renal (approximately 40% as metabolites, <1% as unchanged drug); fecal (approximately 15%); remainder metabolized with unknown fate.
Half-life	14–26 hours (terminal elimination half-life); may be prolonged in hepatic impairment or with repeated dosing due to accumulation.
Protein binding	Approximately 92%; primarily bound to albumin and alpha-1-acid glycoprotein.
Volume of Distribution	10–20 L/kg (large volume indicating extensive tissue distribution, high lipophilicity, with preferential uptake in brain and adipose).
Bioavailability	Intramuscular: 100% (immediate-release); Oral: 60–70% (due to first-pass metabolism); Intravenous: 100%.
Onset of Action	Intramuscular: 30–45 minutes; Intravenous: 5–10 minutes; Oral: 1–2 hours.
Duration of Action	Intramuscular: 4–8 hours (acute effects); Intravenous: 3–6 hours; Oral: 12–24 hours (dose-dependent), with prolonged effects after chronic use due to depot formulations.

Classification & Brands

Dosing & administration

2-5 mg intramuscularly or intravenously every 4-8 hours for acute agitation. Maximum 20 mg/day.

Dosage form	SOLUTION
Renal impairment	No dosage adjustment required for renal impairment; monitor for adverse effects.
Liver impairment	Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid or reduce dose by 75%.
Pediatric use	Children 3-12 years: 0.05-0.15 mg/kg/day intramuscularly in divided doses every 4-8 hours, not to exceed 0.5 mg/kg/day.
Geriatric use	Initiate at 0.5-2 mg/day intramuscularly; increase gradually. Reduce dose by 50-75% compared to younger adults; monitor for QT prolongation and EPS.

Use during pregnancy

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

Clinical note

CNS depressants may enhance sedative effects Can cause extrapyramidal symptoms and QT prolongation.

FDA category	Animal
Breastfeeding	Haloperidol is excreted into human breast milk; the milk-to-plasma ratio is approximately 0.5-0.8. In breastfed infants, reported adverse effects include sedation, developmental delay, and extrapyramidal symptoms. Use with caution and monitor infant for adverse effects.
Teratogenic Risk	First trimester: Epidemiological data do not suggest a substantial increased risk of major malformations, but there is limited evidence of possible risk of limb defects (rare). Second and third trimesters: Risk of extrapyramidal symptoms and/or withdrawal symptoms in neonates after in utero exposure. Use only if benefit outweighs risk.

Warnings & precautions

■ FDA Black Box Warning

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. Haloperidol lactate is not approved for the treatment of dementia-related psychosis.

Side Effect Profile

Common Effects	Tourette's syndrome
Serious Effects

Absolute Contraindications

["Comatose states","Severe central nervous system depression","Parkinson's disease","Known hypersensitivity to haloperidol","QTc interval prolongation (congenital or acquired)","Recent acute myocardial infarction","Uncompensated heart failure","Concomitant use with other drugs that prolong QT interval"]

Clinical Precautions

Precautions

["Increased mortality in elderly patients with dementia-related psychosis","QT interval prolongation and risk of torsades de pointes","Tardive dyskinesia with prolonged use","Neuroleptic malignant syndrome (NMS)","Hypotension and hypertension","Seizures","Leukopenia, neutropenia, and agranulocytosis","Drug interaction with alcohol and CNS depressants","Avoid use in patients with Parkinson's disease or Lewy body dementia"]

Drug interactions

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HALOPERIDOL LACTATE

Clinical safety rating: safe

CNS depressants may enhance sedative effects Can cause extrapyramidal symptoms and QT prolongation.

How it works

What the body does with it

Metabolism	Haloperidol is extensively metabolized in the liver via multiple pathways, including glucuronidation, carbonyl reduction, and CYP3A4-mediated N-dealkylation. The major active metabolite is reduced haloperidol, which can be reoxidized to haloperidol.
Excretion	Renal (approximately 40% as metabolites, <1% as unchanged drug); fecal (approximately 15%); remainder metabolized with unknown fate.
Half-life	14–26 hours (terminal elimination half-life); may be prolonged in hepatic impairment or with repeated dosing due to accumulation.
Protein binding	Approximately 92%; primarily bound to albumin and alpha-1-acid glycoprotein.
Volume of Distribution	10–20 L/kg (large volume indicating extensive tissue distribution, high lipophilicity, with preferential uptake in brain and adipose).
Bioavailability	Intramuscular: 100% (immediate-release); Oral: 60–70% (due to first-pass metabolism); Intravenous: 100%.
Onset of Action	Intramuscular: 30–45 minutes; Intravenous: 5–10 minutes; Oral: 1–2 hours.
Duration of Action	Intramuscular: 4–8 hours (acute effects); Intravenous: 3–6 hours; Oral: 12–24 hours (dose-dependent), with prolonged effects after chronic use due to depot formulations.

Classification & Brands

Dosing & administration

2-5 mg intramuscularly or intravenously every 4-8 hours for acute agitation. Maximum 20 mg/day.

Dosage form	SOLUTION
Renal impairment	No dosage adjustment required for renal impairment; monitor for adverse effects.
Liver impairment	Child-Pugh Class A: no adjustment; Class B: reduce dose by 50%; Class C: avoid or reduce dose by 75%.
Pediatric use	Children 3-12 years: 0.05-0.15 mg/kg/day intramuscularly in divided doses every 4-8 hours, not to exceed 0.5 mg/kg/day.
Geriatric use	Initiate at 0.5-2 mg/day intramuscularly; increase gradually. Reduce dose by 50-75% compared to younger adults; monitor for QT prolongation and EPS.

Use during pregnancy

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

Clinical note

CNS depressants may enhance sedative effects Can cause extrapyramidal symptoms and QT prolongation.

FDA category	Animal
Breastfeeding	Haloperidol is excreted into human breast milk; the milk-to-plasma ratio is approximately 0.5-0.8. In breastfed infants, reported adverse effects include sedation, developmental delay, and extrapyramidal symptoms. Use with caution and monitor infant for adverse effects.
Teratogenic Risk	First trimester: Epidemiological data do not suggest a substantial increased risk of major malformations, but there is limited evidence of possible risk of limb defects (rare). Second and third trimesters: Risk of extrapyramidal symptoms and/or withdrawal symptoms in neonates after in utero exposure. Use only if benefit outweighs risk.

Warnings & precautions

■ FDA Black Box Warning

Side Effect Profile

Common Effects	Tourette's syndrome
Serious Effects

HALOPERIDOL LACTATE

How it works

What the body does with it

Classification & Brands

Dosing & administration

Use during pregnancy

Warnings & precautions

Side Effect Profile

Absolute Contraindications

Clinical Precautions

Drug interactions

HALOPERIDOL LACTATE

How it works

What the body does with it

Classification & Brands

Dosing & administration

Use during pregnancy

Warnings & precautions

Side Effect Profile

Absolute Contraindications

Clinical Precautions

Drug interactions

Clinical Tips & Counseling