Diagnosis and management of cannabinoid hyperemesis syndrome

Cannabis use has been increasing in the United States and throughout the world. Cannabis (also called marijuana) is the most used psychoactive substance worldwide. The cannabis plant has more than 400 chemicals; among which, more than 100 cannabinoids have been identified. The most important constituents include tetrahydrocannabinol (THC) and cannabidiol (CBD). Of these, THC is the psychoactive ingredient and CBD does not have psychoactive properties. Although cannabis use has been reported for many decades, some of its unique adverse effects of nausea, vomiting, and abdominal pain, termed the cannabinoid hyperemesis syndrome (CHS), were noted relatively recently. CHS is a subtype of cyclical vomiting syndrome (CVS) and has been associated with chronic (typically years) and heavy (typically daily or near-daily) cannabis use and is observed predominantly in males. The prevalence of CHS is rising in the United States, despite low awareness among physicians and the public in general. Early recognition and treatment may decrease the risk of complications, such as dehydration, acute kidney injury, electrolyte and metabolic imbalance, and the much rarer risks of pneumothorax or pneumomediastinum and death. Although patients report that use of cannabis helps to relieve symptoms, including emesis, it is paradoxical that cannabis use may be associated with hyperemesis.