Haloperidol
A high-potency butyrophenone antipsychotic used for schizophrenia, acute agitation, mania and Tourette's tics.
Drug card
- How it works
- Blocking dopamine D2 receptors in the brain
- Used for
- Schizophrenia and other psychoses
- Acute agitation in psychosis or mania
- Mania in bipolar disorder
- Tourette's syndrome and other tic disorders
- Known for
- Dystonia and parkinsonism (extrapyramidal effects)
- Tardive dyskinesia with long-term use
- QT prolongation and torsades, more at high doses
- Its name
- -peridol means a butyrophenone antipsychotic (haloperidol type)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does haloperidol work?
Haloperidol, a butyrophenone, is a potent D2 antagonist with low α1-blocking and no antihistamine or anticholinergic activity at usual doses. Blocking mesolimbic D2 receptors suppresses delusions and hallucinations, while its action in the basal ganglia probably explains its frequent extrapyramidal effects.
Like other first-generation antipsychotics: First-generation antipsychotics block dopamine D2 receptors. Blockade in the mesolimbic pathway suppresses hallucinations and delusions, and in the chemoreceptor trigger zone it stops vomiting; blockade in the basal ganglia causes extrapyramidal effects, and in the anterior pituitary it lifts dopamine's brake on prolactin. Low-potency drugs such as chlorpromazine also block α1, muscarinic and H1 receptors.
Uses
What is haloperidol used for?
- Schizophrenia and other psychoses
- Acute agitation in psychosis or mania
- Mania in bipolar disorder
- Tourette's syndrome and other tic disorders
Side effects
Side effects of haloperidol
- Dystonia and parkinsonism (extrapyramidal effects)Known for
- Tardive dyskinesia with long-term useKnown forSerious
- QT prolongation and torsades, more at high dosesKnown forSerious
- Akathisia (inner restlessness)
- Neuroleptic malignant syndromeSerious
- Raised prolactin
- Low blood pressure
- Fast heartbeat
- Drowsiness
- Low white cell count, even agranulocytosisSerious
- SeizuresSerious
- Higher death rate in older people with dementiaSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Contraindicated in Parkinson's disease, severe CNS depression and coma.
- QT risk rises with dose: check the ECG, correct low potassium or magnesium, and avoid other QT-prolonging drugs.
- If low blood pressure needs a vasopressor, avoid epinephrine: haloperidol can reverse its effect and lower pressure further.
Good to know: High-potency: strong D2 block with little anticholinergic action, so movement effects are common; a decanoate depot is injected into muscle every 4 weeks.
Remember it
A way to remember it
TEMPO
- T
- Tardive dyskinesia
- E
- Extrapyramidal effects
- M
- Malignant syndrome (neuroleptic)
- P
- Prolactin raised
- O
- Orthostatic hypotension
Written for biofideX
Its name
-peridol means butyrophenone antipsychotic (haloperidol type)
Haloperidol and droperidol share it; droperidol is used mainly against nausea and vomiting around surgery. Don't confuse it with -peridone, the risperidone group.
- Every drug name stem
Its class
First-generation antipsychotics
Other first-generation antipsychotics with a card:
Easily mixed up with second-generation antipsychotics and dopamine antagonist antiemetics.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Haloperidol tablets: label (DailyMed)
- Haloperidol decanoate injection: label (DailyMed)
- Haloperidol 1 mg/ml oral solution: SmPC (emc)
- Haloperidol (NCI Thesaurus)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Psychosis, mood and ADHD
Haloperidol is one of 9 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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