A Nonopioid, Nonbenzodiazepine Treatment Approach For Intractable Nausea and Vomiting in the Emergency Department.

Goal: We sought to assess the feasibility and efficacy of a treatment protocol for nausea and vomiting using the combination of chlorpromazine, a dopamine antagonist antiemetic, and ketamine, a nonopioid analgesic. Background: Increasing numbers of patients with cannabis use disorder are presenting to emergency departments with a poorly understood syndrome characterized by intractable nausea and vomiting. Methods: This is a prospective, observational study involving a convenience sample of patients with unexplained nausea and vomiting. Subjects were given ketamine 15 mg slow intravenous push and chlorpromazine 12.5 mg intravenous over 15 minutes. Outcomes were number of episodes of emesis after study drug administration; change in nausea severity; change in pain severity; adverse events; and patient satisfaction. Results: We enrolled 28 subjects on 30 emergency department visits. Twenty-three subjects (82%) reported at least weekly cannabis use with 19 reporting daily use. Initial symptoms were severe, with median pain and nausea scores both 10. After receiving study medication, the mean decrease in pain score over 120 minutes was 4.1 (95% confidence interval: 3.2, 5.0) and the mean decrease in nausea score was 4.9 (95% confidence interval: 4.0, 5.8). There were no adverse events. All 28 subjects who were asked reported they would want to receive these medications again. Conclusion: In this single-center study, the majority of patients presenting with intractable nausea and vomiting reported heavy cannabis use, and symptoms were severe. The combination of chlorpromazine plus ketamine resulted in rapid, definitive cessation of symptoms in most of these patients without the need for opioids or benzodiazepines.