January 7, 2021

Background/Introduction: Emergency department visits related to cannabis use appear to be increasing nationally secondary to continued trends of legalization, decriminalization, or less restrictive medical cannabis use laws in many states. The number of individuals with daily cannabis use in the United States increased from 5.1 million in 2005 to 8.1 million in 2013 (Bollom 2018). With an increase in the accessibility and consumption of cannabis, there has also been an increase in the utilization of emergency departments for potential adverse effects of cannabis use, particularly gastrointestinal adverse effects. For example, in Colorado, the emergency department visits for cyclic vomiting nearly doubled after liberalization of medical marijuana (Kim 2015). Studies attempting to look at nationwide sampling have noted that the number of persistent vomiting related hospitalization related to cannabis use had a significantly increased trend, with a 286% increase over a 5-year period (Patel 2019). This has led to a renewed interest in the understanding of cannabis hyperemesis syndrome, first well-described in 2004, and recently defined by the Rome IV criteria (Allen 2004). The effective management of cannabis hyperemesis syndrome is still being elucidated as commonly used antiemetics are often ineffective for acute exacerbations. The role of haloperidol as an off-label treatment is being explored but anecdotal evidence suggests it may be an effective adjunct in the treatment of cannabis hyperemesis syndrome.