Cannabinoid hyperemesis syndrome: A review.

Cannabinoid hyperemesis syndrome (CHS) is a chronic disorder characterized by episodes of severe vomiting, alternating with asymptomatic or minimally symptomatic periods. The episodes of emesis tend to be disabling, negatively affecting quality of life. The disorder's main characteristic is that it is associated with previous chronic heavy cannabis use. CHS is similar to cyclic vomiting syndrome (CVS), with the exception that the sustained cessation of cannabis use is expected to resolve the vomiting episodes. The average time between the onset of acute CHS episodes and diagnosis ranges from three to six years, based on previously published cases. This delay in the diagnosis reflects a lack of awareness of the condition on the part of physicians. Delayed diagnosis of CHS results in frequent emergency room visits and increased healthcare costs, and the lack of effective treatment leads to poor patient outcomes. The diagnosis is challenging, and some authors have diagnosed CHS when patients had cyclic vomiting, in the context of chronic cannabis use, regardless of the duration of use or the potency of the product used. The aim of this narrative review is to provide a detailed and critical analysis of current knowledge about CHS. The present document focuses on a thorough review of the literature on worldwide cannabis use, the role of the endocannabinoid system in the pathophysiology of CHS, diagnostic criteria, and current management of CHS.