skip to main content

RT in Known Antipsychotic User — MRCPsych Paper B MCQ

Instant feedback + full explanation. One question, done properly.

EasySchizophrenia & PsychosisRT in Known Antipsychotic UserMRCPsych Paper B

A 45-year-old man with schizophrenia becomes severely agitated and threatens immediate harm despite attempted de-escalation. Oral medication is refused, and urgent rapid tranquillisation is required. He takes regular haloperidol without adverse effects, and IM lorazepam was ineffective during a previous similar episode. He has no cardiovascular disease or suspected intoxication, a recent ECG shows a normal QTc interval, and the proposed dose would not result in an excessive total daily haloperidol dose. According to NICE NG10, which is the most appropriate IM treatment?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — IM haloperidol plus IM promethazine

NICE recommends either IM lorazepam alone or IM haloperidol combined with IM promethazine for adult rapid tranquillisation. Here, haloperidol has been tolerated, lorazepam was previously ineffective, cardiovascular contraindications have been excluded, an ECG confirms a normal QTc interval, and the total daily antipsychotic dose has been considered. These features make **IM haloperidol plus IM promethazine** the most appropriate choice. IM lorazepam would be preferred if clinical information were insufficient, the patient were antipsychotic-naive, cardiovascular disease or prolonged QT were present, or no ECG had been obtained. Although IM olanzapine and aripiprazole may be used under some local protocols, they are not among the two adult regimens specified by NICE NG10. IM chlorpromazine is not recommended for rapid tranquillisation.

Reference: National Institute for Health and Care Excellence. Violence and aggression: short-term management in mental health, health and community settings (NG10), recommendations 1.4.37–1.4.39. 2015. https://www.nice.org.uk/guidance/ng10/chapter/recommendations