Objective: To compare two widely used drug treatments for people with aggression or agitation due to mental illness.
Design: Pragmatic, randomised clinical trial.
Setting: Three psychiatric emergency rooms in Rio de Janeiro, Brazil.
Subjects: 301 aggressive or agitated people.
Interventions: Open treatment with intramuscular midazolam or intramuscular haloperidol plus promethazine.
Main outcome measures: Patients tranquil or sedated at 20 minutes.
Secondary outcomes: patients tranquil or asleep by 40, 60, and 120 minutes; restrained or given extra drugs within 2 hours; severe adverse events; another episode of agitation or aggression; needing extra visits from doctor during first 24 hours; overall antipsychotic load in first 24 hours; and not discharged by two weeks.
Results: 151 patients were randomised to midazolam, and 150 to haloperidol-promethazine mix. Follow up for the primary outcome was available for 298 (99%): 134/151 (89%) of patients given midazolam were tranquil or asleep after 20 minutes compared with 101/150 (67%) of those given haloperidol plus promethazine (relative risk 1.32 (95% confidence interval 1.16 to 1.49)). By 40 minutes, midazolam still had a statistically and clinically significant 13% relative advantage (1.13 (1.01 to 1.26)). After 1 hour, about 90% of both groups were tranquil or asleep. One important adverse event occurred in each group: a patient given midazolam had transient respiratory depression, and one given haloperidol-promethazine had a grande mal seizure.
Conclusions: Both treatments were effective. Midazolam was more rapidly sedating than haloperidol-promethazine, reducing the time people are exposed to aggression. Adverse effects and resources to deal with them should be considered in the choice of the treatment.