Haloperidol Contraindication Delirium — MRCPsych Paper B MCQ

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ModerateLiaison PsychiatryHaloperidol Contraindication DeliriumMRCPsych Paper B

A 78-year-old inpatient has delirium and remains severely distressed and at risk of harming himself despite treatment of reversible causes and appropriate verbal and non-verbal de-escalation. Short-term haloperidol is being considered. Which comorbidity is an explicit contraindication to haloperidol?

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Correct answer: A — Parkinson's disease or dementia with Lewy bodies

Haloperidol is explicitly contraindicated in Parkinson's disease and dementia with Lewy bodies because dopamine blockade can cause marked neurological deterioration and extrapyramidal adverse effects in these patients. Advanced age and frailty increase susceptibility to cardiac and neurological toxicity but are not, by themselves, contraindications; use requires the lowest appropriate dose, brief duration and close monitoring. Stable cardiac disease is not an absolute contraindication, although an ECG and risk assessment are required because haloperidol is contraindicated in specific conditions such as known QTc prolongation, recent myocardial infarction, uncompensated heart failure and ventricular arrhythmia. Renal impairment may require additional caution but is not itself contraindicated. Diabetes and obesity are also not listed contraindications. Lorazepam should not be presented as an automatic substitute, because management must be individualised and benzodiazepines are not routine treatment for delirium.

Reference: Electronic Medicines Compendium, HALDOL 2 mg/ml oral solution, Summary of Product Characteristics, sections 4.1–4.4; text revised 2023. https://www.medicines.org.uk/emc/product/15252/smpc