Haloperidol

How it works

It is a potent dopamine D2 receptor antagonist, and reduction of dopaminergic transmission in mesolimbic pathways underlies its antipsychotic effect.

Prescribing in practice

• Haloperidol prolongs the QT interval and carries a risk of torsade de pointes and sudden death, so perform a baseline ECG, correct electrolytes and avoid combination with other QT-prolonging drugs.
• It frequently causes extrapyramidal symptoms including acute dystonia, parkinsonism and akathisia, and can cause tardive dyskinesia and neuroleptic malignant syndrome.
• Use cautiously in the elderly, in whom antipsychotics increase stroke and mortality risk in dementia, and in cardiac, hepatic or Parkinson's disease.

Monitoring

Monitor ECG and electrolytes, extrapyramidal and movement-disorder signs, temperature and mental state, and watch for neuroleptic malignant syndrome.

Counselling the patient

• Report muscle stiffness, fever, abnormal movements or fainting promptly.
• Restlessness and stiffness can occur and should be reported so treatment can be adjusted.
• Avoid alcohol and tell other clinicians about this medicine before new prescriptions.

Evidence & guidelines

MHRA advice highlights the dose-related QT-prolongation and arrhythmia risk of haloperidol, and it remains an established option for psychosis and acute agitation.