Intravenous midazolam–droperidol combination, droperidol or olanzapine monotherapy for methamphetamine-related acute agitation: subgroup analysis of a randomized controlled trial

AimTo examine the efficacy and safety of (1) midazolam-droperidol versus droperidol and (2) midazolam-droperidol versus olanzapine for methamphetamine-related acute agitation. Design and settingA multi-centre, randomized, double-blind, controlled, clinical trial was conducted in two Australian emergency departments, between October 2014 and September 2015. ParticipantsThree hundred and sixty-one patients, aged 18-65years, requiring intravenous medication sedation for acute agitation, were enrolled into this study. We report the results of a subgroup of 92 methamphetamine-affected patients. Intervention and comparatorPatients were assigned randomly to receive either an intravenous bolus of midazolam 5mg-droperidol 5mg combined, droperidol 10mg or olanzapine 10mg. Two additional doses were administered, if required: midazolam 5mg, droperidol 5mg or olanzapine 5mg, respectively. MeasurementsThe primary outcome was the proportion of patients sedated adequately at 10 minutes. Odds ratios with 95% confidence intervals (ORs, 95% CI) were estimated. FindingsThe baseline characteristics of patients in the three groups were similar. At 10minutes, significantly more patients in the midazolam-droperidol group [29 of 34 (85.3%)] were sedated adequately compared with the droperidol group [14 of 30 (46.7%), OR=6.63, 95% CI=2.02-21.78] or with the olanzapine group [14 of 28 (50.0%), OR 5.80, 95% CI=1.74-19.33]. The number of patients who experienced an adverse event (AE) in the midazolam-droperidol, droperidol and olanzapine groups was seven of 34, two of 30 and six of 28, respectively. The most common AE was oxygen desaturation. ConclusionA midazolam-droperidol combination appears to provide more rapid sedation of patients with methamphetamine-related acute agitation than droperidol or olanzapine alone.