Synopsis
Assess the cause and physiological danger of acute agitation, use proportionate calming measures, and administer and monitor emergency sedation without overlooking a medical emergency.
- Agitation is a presentation; distinguish fear and unmet needs from delirium, intoxication, withdrawal, psychosis, mania and medicine adverse effects.
- Use one calm communicator, reduce noise and crowding, offer simple choices and voluntary oral medication when appropriate.
- Rapid tranquillisation means urgent parenteral sedation when oral treatment is unsuitable; the clinical target is safe calmness with preserved respiratory function.
- NICE adult options are intramuscular lorazepam alone or intramuscular haloperidol together with intramuscular promethazine, selected after checking individual risks.
- Use lorazepam when antipsychotic exposure is unknown or there is insufficient history; avoid the haloperidol combination if no ECG is available or cardiovascular disease or prolonged QT is present.
- Prescribe an initial single dose and review its effect before repeating; add scheduled, as-required and already administered medicines when calculating exposure.
- Monitor physical observations and consciousness after injection, with greater frequency when sedation, intoxication, physical illness or restraint injury increases risk.
Key red flags
A suddenly quiet or unresponsive person after prolonged struggle may be deteriorating physiologically; release unsafe restraint, reassess breathing and circulation, and activate emergency help.
Fever, rigidity, clonus, focal neurological findings, head injury or a fluctuating attention deficit suggests a toxicological, neurological or medical cause requiring urgent investigation.
Investigation priorities
Detect hypoxia, hypoglycaemia, hyperthermia and circulatory instability while arranging safe care.
Management branches
The patient is distressed but there is time for verbal engagement and negotiation.
- Introduce one staff member as the main speaker and ask what the person believes is happening and what would help immediately.
- Offer a quieter area with an exit route, communication support, analgesia or other practical relief, and voluntary oral treatment when clinically appropriate.
- Keep other staff available without surrounding the patient and reassess threats, attention and physiology as the interaction develops.
Key medicines
Lorazepam injectionAn adult regimen in Leicestershire Partnership NHS Trust's August 2026 policy is lorazepam 1–2 mg intramuscularly once. After response and safety review, a further dose may be considered after two hours for a partial response, with a total maximum of 4 mg in 24 hours under that policy. Local protocols differ; count all prior benzodiazepine doses and prescribe each injection for the current episode.Use lower individualised doses in frail or older patients; the cited regional policy limits older or frail adults to 2 mg in 24 hours. Respiratory insufficiency, sleep apnoea, myasthenia gravis and severe hepatic insufficiency are important contraindications. Opioids and other depressants amplify respiratory risk; follow the actual product's dilution and administration requirements.
Haloperidol with promethazineThe same regional adult protocol uses haloperidol 5 mg intramuscularly with promethazine 50 mg by a separate deep intramuscular injection. Review each initial dose before any repeat: haloperidol may be repeated after at least one hour, maximum 20 mg in 24 hours; promethazine after at least two hours, maximum 100 mg in 24 hours. Do not repeat both drugs automatically at the shorter interval.Avoid this combination without an ECG or with cardiovascular disease or prolonged QT; check interacting QT-prolonging drugs, electrolytes, Parkinson's disease and Lewy-body dementia. Product maximums are ceilings, not targets, and older patients need substantially lower doses. Promethazine's antimuscarinic effects can worsen delirium.