Intramuscular Sedatives for Methamphetamine Agitation in the ED

Key Takeaways

• Droperidol, olanzapine, and midazolam were similarly effective, while lorazepam was associated with slower sedation.
• Rescue medication was reported in 16% of droperidol cases, 20% of olanzapine cases, 13% of midazolam cases, and 46% of lorazepam cases.
• Adverse events were not reported as different across groups, and investigators concluded the three non-lorazepam agents were more rapid and effective than lorazepam.

In a 122-patient emergency department analysis of methamphetamine-associated agitation, median time to adequate sedation with intramuscular lorazepam was 29 minutes, compared with 13 to 16 minutes for droperidol, olanzapine, and midazolam. The comparison examined those four intramuscular agents. Overall, lorazepam was associated with a slower course to sedation than the other intramuscular medications.

Researchers conducted a secondary analysis of previously published emergency department data collected from 2019 to 2020. The cohort included 122 patients with methamphetamine-associated agitation who were treated with intramuscular droperidol, olanzapine, midazolam, or lorazepam during the ED encounter. Group sizes were 37 for droperidol, 44 for olanzapine, 15 for midazolam, and 26 for lorazepam. The primary outcome was time to adequate sedation, measured as the time to an Altered Mental Status Scale score of 0 or less. Secondary outcomes included rescue medication use and adverse events, while treating physicians determined medication, dose, route, and agitation etiology in this four-arm comparison.

Median time to adequate sedation was 16 minutes with droperidol, 16 minutes with olanzapine, 13 minutes with midazolam, and 29 minutes with lorazepam. At 15 minutes, adequate sedation was reported in 43%, 45%, 60%, and 32% of patients in those groups, respectively. Proportional hazards analysis associated lorazepam with a longer time to adequate sedation, with p < 0.001. Midazolam had the shortest median time, while droperidol and olanzapine shared the same median result. Across both the 15-minute and median measures, lorazepam trailed the other three agents in this emergency department dataset.

Median intramuscular doses were 5 mg for droperidol, 10 mg for olanzapine, 5 mg for midazolam, and 2 mg for lorazepam. Rescue treatment was reported more often with lorazepam than with droperidol, olanzapine, or midazolam in the same dataset. Investigators reported no difference in adverse events across the four treatment groups.

They concluded that droperidol, olanzapine, and midazolam were similarly effective and more rapid and effective than intramuscular lorazepam.