Intramuscular droperidol, olanzapine, midazolam, or lorazepam to treat methamphetamine intoxication in the emergency department.

INTRODUCTION

Emergency department (ED) visits for acute methamphetamine-associated agitation are increasing. Many cases require parenteral medications. Benzodiazepines are often recommended first-line, however randomized trials of intravenous medications suggest antipsychotics are also effective. High-quality data on intramuscular medications are lacking.

OBJECTIVE

To compare the effectiveness of intramuscular droperidol, olanzapine, midazolam, and lorazepam to treat methamphetamine-associated agitation in the ED.

METHODS

This was a secondary analysis of previously published data from 2019 to 2020; medication, dose, route, and agitation etiology were determined by treating physicians. The primary outcome was time to adequate sedation (TAS), assessed via the Altered Mental Status Scale (AMSS), defined as time to AMSS≤0. Secondary outcomes included use of additional (rescue) medications and adverse events.

RESULTS

We analyzed 122 patients with similar baseline characteristics; 37 received droperidol (median dose 5 mg, TAS 16 min), 44 received olanzapine (median dose 10 mg, TAS 16 min), 15 received midazolam (median dose 5 mg, TAS 13 min), and 26 received lorazepam (median dose 2 mg, TAS 29 min). Proportional hazards analysis showed lorazepam was associated with longer TAS (p < 0.001). The proportion of patients adequately sedated at 15 min was 43% for droperidol, 45% for olanzapine, 60% for midazolam, and 32% for lorazepam. The proportion of patients receiving rescue medication was 16% for droperidol, 20% for olanzapine, 13% for midazolam, and 46% for lorazepam. We found no difference in adverse events.

CONCLUSIONS

Intramuscular droperidol, olanzapine, and midazolam were all similarly effective for treating methamphetamine-associated agitation. All three medications provided more rapid and effective sedation than intramuscular lorazepam.