Rapid tranquillisation of violent or agitated patients in a psychiatric emergency setting. Pragmatic randomised trial of intramuscular lorazepam v. haloperidol plus promethazine

Abstract

Background: The pharmacological management of violence in people with psychiatric disorders is under-researched.

Aims: To compare interventions commonly used for controlling agitation or violence in people with serious psychiatric disorders.

Method: We randomised 200 people to receive intramuscular lorazepam (4 mg) or intramuscular haloperidol (10 mg) plus promethazine (25-50 mg mix).

Results: At blinded assessments 4 h later (99.5% follow-up), equal numbers in both groups (96%) were tranquil or asleep. However, 76% given the haloperidol-promethazine mix were asleep compared with 45% of those allocated lorazepam (RR=2.29,95% CI 1.59-3.39; NNT=3.2,95% CI 2.3-5.4). The haloperidol-promethazine mix produced a faster onset of tranquillisation/sedation and more clinical improvement over the first 2 h. Neither intervention differed significantly in the need for additional intervention or physical restraints, numbers absconding, or adverse effects.

Conclusions: Both interventions are effective for controlling violent/agitated behaviour. If speed of sedation is required, the haloperidol-promethazine combination has advantages over lorazepam.