BSN Tracker

haloperidol

Brand: Haldol

⚠ BBW Beers Criteria Prototype Drug
Drug Class: antipsychotic
Drug Family: antipsychotic
Subclass: typical antipsychotic / butyrophenone
Organ Systems: cns

Mechanism of Action

Potent antagonist of dopamine D2 receptors in the mesolimbic and mesocortical pathways, reducing positive psychotic symptoms; also blocks D2 in nigrostriatal pathway (EPS) and tuberoinfundibular pathway (hyperprolactinemia); histamine H1 and alpha-1 blockade is minimal.

dopamine D2 receptors

Indications

  • schizophrenia
  • acute psychosis / agitation
  • Tourette's syndrome
  • delirium (IV/IM)
  • anti-emesis in palliative care

Contraindications

  • CNS depression
  • Parkinson's disease (relative)
  • QTc prolongation (IV route)
  • dementia-related psychosis

Adverse Effects

Common

  • extrapyramidal symptoms (EPS): parkinsonism, akathisia, dystonia
  • hyperprolactinemia (galactorrhea, amenorrhea)
  • QTc prolongation

Serious

  • tardive dyskinesia (long-term)
  • neuroleptic malignant syndrome (NMS)
  • torsades de pointes (IV haloperidol)
  • laryngospasm (acute dystonia)

Pharmacokinetics (ADME)

Absorption Well absorbed orally (~60–70%); IM onset faster
Distribution Highly protein-bound (~92%); Vd 9.5–21.7 L/kg; crosses BBB
Metabolism CYP3A4 and CYP2D6; active reduced metabolite
Excretion Renal and biliary
Half-life 12–36 hours
Onset IM: 20–40 min; oral: 2–6 hours; decanoate (depot): 3–9 days
Peak 2–6 hours (oral); 20 min (IM)
Duration 8–12 hours
Protein Binding 92%
Vd 9.5–21.7 L/kg

Drug Interactions

Drug / Agent Mechanism Severity
QTc-prolonging agents additive QTc prolongation and torsades risk (especially IV haloperidol) major
lithium potential for irreversible neurological toxicity at high serum levels major
CYP2D6 inhibitors (fluoxetine) increase haloperidol levels and EPS risk moderate

Nursing Considerations

  1. Monitor ECG before IV administration and during infusion; IV haloperidol carries higher QTc risk than oral/IM — keep IV doses ≤2 mg and monitor continuously
  2. Assess for extrapyramidal symptoms at each visit using AIMS scale for tardive dyskinesia; akathisia (restlessness) is often confused with worsening anxiety or psychosis
  3. NMS is a medical emergency: fever, rigidity, altered consciousness, autonomic instability — stop haloperidol immediately and provide supportive care
  4. For acute dystonia (torticollis, oculogyric crisis): administer benztropine 1–2 mg IV/IM or diphenhydramine 25–50 mg IV/IM immediately

Clinical Pearls

  • Haloperidol decanoate (long-acting injection every 4 weeks) dramatically improves adherence in patients with schizophrenia who have difficulty maintaining oral regimens
  • Haloperidol has the most evidence for treating delirium in ICU patients of all antipsychotics, though it does not reduce duration or mortality — use lowest effective dose

Safety Profile

Pregnancy use-with-caution
Lactation avoid
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.

Acute Psychosis / Agitation Anti-emesis In Palliative Care Antipsychotic Delirium (IV/IM) Schizophrenia Tourette's Syndrome
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