Haloperidol is a classical antipsychotic used to treat the manifestations of psychotic disorders (such as schizophrenia), Tourette syndrome and severe behavioural problems in children. It is effective but can cause extrapyramidal effects (involuntary movements, rigidity) that must be monitored.
Also known as: Haldol
Combining Haloperidol with Carbamazepine markedly reduces Haloperidol concentrations, risking loss of the antipsychotic effect.
Haloperidol is metabolised by CYP3A4; carbamazepine, a potent inducer, can reduce its concentrations by about 50%, with loss of psychotic control. Conversely, some patients experience more sedation with the combination. Monitor the clinical response, adjust the haloperidol dose (often upwards) and consider an antiepileptic without enzyme induction (e.g. valproate) when the psychiatric picture allows it.
Carbamazepine + haloperidol: carbamazepine lowers haloperidol levels (CYP3A4 induction), potentially reducing the antipsychotic effect. Adjust the dose and monitor.
As an enzyme inducer, Carbamazepine accelerates Haloperidol metabolism, lowering its serum levels.
Monitor the antipsychotic response and signs of relapse.
Psychotic relapse during the combination requires regimen review.
Monitor the clinical response and consider adjusting the Haloperidol dose or using an alternative antipsychotic.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50 ; approved Carbamazepine label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9f3d91cd-a959-4e07-a51b-8a4e9ba9ece2 — with additional reference: Prontuário Terapêutico do INFARMED, INFARMED (11th ed., 2012)
Combining Haloperidol with Lithium increases the risk of neurotoxicity and severe extrapyramidal symptoms.
An encephalopathic syndrome (weakness, lethargy, fever, tremulousness, confusion, extrapyramidal symptoms, leukocytosis, elevated serum enzymes) followed by irreversible brain damage has occurred in a few patients treated with lithium plus haloperidol, although a causal relationship has not been established; the haloperidol label recommends monitoring patients on this combination closely for early evidence of neurological toxicity and discontinuing treatment promptly if such signs appear. Use the lowest effective doses of both, monitor neurological signs and lithium levels, and reassess the combination if symptoms arise.
Haloperidol + lithium: encephalopathic syndrome/neurotoxicity described. Monitor closely for early neurological signs.
Co-administration of antipsychotics and Lithium can produce encephalopathy, confusion and extrapyramidal syndrome, especially at high doses.
Confusion, rigidity, tremor or signs of neuroleptic malignant syndrome require discontinuation and urgent evaluation.
Confusion, rigidity, tremor or fever require discontinuation and urgent evaluation.
Use cautious doses of both and monitor for the onset of neurological signs.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50 ; approved Lithium label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0e6b0a2d-b79c-44d8-b785-5267df9e8f72 — with additional reference: Prontuário Terapêutico do INFARMED, INFARMED (11th ed., 2012)
Alcohol potentiates haloperidol sedation and hypotension and can worsen extrapyramidal effects.
Avoid alcohol intake during treatment.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50
Grapefruit juice inhibits CYP3A4, the enzyme that metabolises haloperidol, potentially raising its concentrations and adverse effects.
Avoid grapefruit juice during treatment.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50
Haloperidol can prolong the QT interval and cause torsade de pointes, especially at high doses or with risk factors.
Monitor the ECG and electrolytes; avoid QT-prolonging combinations.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50
Antipsychotics block dopaminergic receptors and can worsen the symptoms of Parkinson disease.
Avoid or use with great caution in patients with Parkinson disease.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50
Data on haloperidol in pregnancy are limited; third-trimester use can cause neonatal extrapyramidal symptoms.
Use only if the benefit outweighs the risk; monitor the newborn.
Present in breast milk; use with caution and monitor the infant.
No specific contraception required.
DailyMed/FDA (NIH/NLM) — approved Haloperidol label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e2eed126-cb82-42b1-9b48-9cbeb6873b50
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Typical antipsychotic with potent D2 dopaminergic antagonism (dose-dependent antipsychotic and extrapyramidal effect); no relevant anticholinergic activity. May prolong the QT interval and is associated with ventricular arrhythmias (torsades de pointes), especially at high doses and in predisposed patients.
Antagonist of central D2 dopamine receptors (mesolimbic and nigrostriatal); nigrostriatal blockade is responsible for the extrapyramidal effects. The precise mechanism of antipsychotic action is not fully established.
Oral bioavailability of 60-65% (first-pass effect); peak plasma levels about 2-6 hours after dosing. Protein binding ~90%.
Extensive hepatic metabolism (CYP3A4 and CYP2D6), including reduction to reduced haloperidol (an active metabolite); about 60% of the dose is excreted in urine as metabolites. Elimination is mainly by metabolism, with little unchanged drug.
Elimination half-life of about 14.5-36.7 hours after a single oral dose (mean ~20 h); prolonged in some patients.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
