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

Abstract

The pharmacological management of violence in people with psychiatric disorders is under-researched. To compare interventions commonly used for controlling agitation or violence in people with serious psychiatric disorders. We randomised 200 people to receive intramuscular lorazepam (4 mg) or intramuscular haloperidol (10 mg) plus promethazine (25-50 mg mix). 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. Both interventions are effective for controlling violent/agitated behaviour. If speed of sedation is required, the haloperidol-promethazine combination has advantages over lorazepam.