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haloperidol

Antipsychotic

LAI available

Brand: HALDOL

Published 2026-03-24 · Last reviewed 2026-03-31 · 5 references

Content sourced from FDA labeling (DailyMed) and peer-reviewed literature.

Print sheet Review evidence

At a glance

Class: Antipsychotic·Typical dose: Schizophrenia (oral): initiate 1–5 mg two or three times daily; maintenance 5–20 mg/day divided; doses >30 mg/day increase EPS risk.·Half-life: Steady-state mean 21 h·LAI available: Yes

Class: Antipsychotic
Typical dose: Schizophrenia (oral): initiate 1–5 mg two or three times daily; maintenance 5–20 mg/day divided; doses >30 mg/day increase EPS risk.
Half-life: Steady-state mean 21 h
LAI available: Yes

Quick answers

What is haloperidol?: Haloperidol (brand Haldol) is a first-generation (typical) antipsychotic of the butyrophenone class, used for schizophrenia, acute agitation, and maintenance in patients who benefit from high-potency D2 blockade.
What is HALDOL?: HALDOL is a brand name for haloperidol.
What is HALDOL (haloperidol) used for?: Label indications include: Schizophrenia; severe behavior disorders; Tourette's syndrome (tics/vocal utterances); adjunct in acute agitation.
What drug class is HALDOL (haloperidol)?: Typical Antipsychotic.
What is the mechanism of action of HALDOL (haloperidol)?: Potent dopamine D2 receptor antagonist; minimal anticholinergic.
What strengths does HALDOL (haloperidol) come in?: Tablets: 0.5–20 mg; oral solution 2 mg/mL.
Is HALDOL (haloperidol) a controlled substance?: No — it is not scheduled as a controlled substance under U.S. federal law.
What is HALDOL (haloperidol) dosing for schizophrenia?: Schizophrenia (oral): initiate 1–5 mg two or three times daily; maintenance 5–20 mg/day divided; doses >30 mg/day increase EPS risk.
How is haloperidol started as a long-acting injectable (LAI)?: Decanoate LAI: initial total dose 10–20× total daily oral dose; max 100 mg per injection (split remainder 3–7 days later) with short oral overlap as needed; maintenance 50–200 mg IM every 4 weeks.

General information

Haloperidol (brand Haldol) is a first-generation (typical) antipsychotic of the butyrophenone class, used for schizophrenia, acute agitation, and maintenance in patients who benefit from high-potency D2 blockade.

This profile emphasizes adult schizophrenia management, acute agitation protocols, and long-acting decanoate maintenance; pediatric and Tourette’s uses fall outside current scope.

The compare tool, evidence library, the Schizophrenia hub, and the LAI Navigator support side-by-side dosing/risk review and maintenance planning.

U.S. approvals

Schizophrenia (adults) (1967)
Acute psychosis and severe behavior disorders (1967)

Formulations & strengths

Tablets: 0.5–20 mg; oral solution 2 mg/mL.
Short-acting IM/IV injection: 5 mg/mL lactate formulation.
Long-acting haloperidol decanoate: 25–100 mg/mL IM monthly.

Generic availability

All formulations are generic and widely available.

Favored for cost, familiarity, and depot availability, but high EPS, tardive dyskinesia, and QTc prolongation risks limit chronic use compared with SGAs.

View labelExact

Mechanism of action

Refer to the Glossary entry on Neurotransmitters for background on receptor systems involved in serious mental illness.

Haloperidol is a potent antagonist of dopamine D2 receptors with limited serotonergic activity, yielding strong antipsychotic efficacy and high EPS risk.

Minimal histamine or muscarinic blockade confers lower sedation and anticholinergic burden than low-potency FGAs.

High-affinity antagonist at dopamine D2 receptors.
Moderate antagonist at adrenergic α1 receptors.
Minimal serotonergic, histaminergic, or muscarinic receptor activity.

Metabolism & pharmacokinetics

Oral bioavailability ~60%; peak levels 2–6 hours after oral dosing; IM onset within 20 minutes.
Approximately 92% protein bound with volume of distribution ~18 L/kg.
Metabolized hepatically via CYP3A4 and CYP2D6 with glucuronidation to reduced haloperidol and other metabolites.
Half-life ~18 hours (oral); decanoate apparent half-life ~21 days.
Eliminated ~60% fecal and ~40% renal primarily as metabolites.

Dosing & administration

Schizophrenia (oral): initiate 1–5 mg two or three times daily; maintenance 5–20 mg/day divided; doses >30 mg/day increase EPS risk.
Acute agitation: 2–5 mg IM/IV every 4–8 hours (max 20 mg/day IM); ECG and vital-sign monitoring are commonly used with IV administration.
Decanoate LAI: initial total dose 10–20× total daily oral dose; max 100 mg per injection (split remainder 3–7 days later) with short oral overlap as needed; maintenance 50–200 mg IM every 4 weeks.

Monitoring & labs

Extrapyramidal symptoms are monitored periodically; prophylaxis is generally reserved for clear need.
QTc: ECG monitoring is often considered when risk factors or higher doses are present.
LAI: Haloperidol decanoate every 4 weeks—product-specific conversion guidance is typically used.
Regular AIMS screening for tardive dyskinesia (typically every 3–6 months; every 3 months in higher-risk groups or with dose increases).
Prolactin-related symptoms (sexual dysfunction, amenorrhea, galactorrhea) and overall quality-of-life impact—consider switching if persistent.
Orthostatic vitals and falls risk, especially in older adults and when combined with other CNS depressants or antihypertensives.
Metabolic monitoring (weight/BMI, glucose, lipids) periodically as part of comprehensive schizophrenia care, even though metabolic risk is lower than many SGAs.

Monitoring focuses on EPS/TD prevention and cardiac safety (QTc), with additional attention to prolactin effects and falls risk in vulnerable patients.

Long‑acting injectable (LAI) options

Haloperidol decanoate
Interval
q4wk
Oral overlap
Consider short overlap during conversion
Injection site
Gluteal
Notes
- Typical conversion ~10–15× daily oral dose monthly; max first injection 100 mg (split remainder 3–7 days later)
- Typical effective range 50–200 mg every 4 weeks; individualize
Citations
Label DOI DOI DOI

Adverse effects

FDA boxed warnings

Increased mortality in elderly patients with dementia-related psychosis (class warning).

Common side effects (≥10%)

Extrapyramidal symptoms: Parkinsonism, dystonia, akathisia in >20%, dose-dependent.
Tardive dyskinesia: Risk increases with cumulative exposure and age.
QT prolongation: Especially with IV/high-dose use; torsades cases reported.
Hyperprolactinemia: Amenorrhea, galactorrhea, gynecomastia may occur.
Orthostatic hypotension: Due to α1 blockade, particularly in elderly.

Other notable effects

Neuroleptic malignant syndrome, though rare, requires prompt recognition and management.
Seizure threshold reduction at high doses; caution in seizure disorders.
Mild sedation and cognitive dulling; less than low-potency FGAs.

Interactions

CYP3A4 or CYP2D6 inhibitors (ketoconazole, clarithromycin, fluoxetine, paroxetine, quinidine) increase levels—EPS/QTc risk can rise and dose reduction may be needed.
CYP3A4 inducers (carbamazepine, rifampin) decrease levels—may require higher doses with careful monitoring.
Combinations with other QTc-prolonging drugs (class IA/III antiarrhythmics, macrolides, fluoroquinolones) are generally avoided when possible.
Additive CNS depression with alcohol, benzodiazepines, opioids.
Antagonizes levodopa/dopamine agonists; use is generally avoided in Parkinson’s disease.

Other useful information

Baseline and periodic ECG monitoring is often considered, especially with IV use or cardiac risk factors.
Prophylactic anticholinergic therapy is sometimes used during initiation in high-risk patients for acute dystonia or Parkinsonism.
Regular AIMS assessments help track tardive dyskinesia.
Decanoate is administered deep IM using Z-track technique; IV administration is avoided.

References

Related hubs:Schizophrenia hub·Bipolar hub·LAI hub