[Cannabinoid Hyperemesis Syndrome: A Scoping Review]

Cyclic vomiting attacks associated with chronic cannabis use were virtually unknown until 25 years ago. Following legalization of cannabis for recreational use in North America and the resulting increase in high-potency cannabis use, the prevalence of cannabis-related cyclic vomiting in emergency departments was increasing at an alarming rate. In the ROME-IV criteria, cannabis-induced cyclic vomiting is now defined as cannabinoid hyperemesis syndrome (CHS). This review is intended to provide information on the current state of knowledge on CHS, as an increase in CHS cases is also to be expected in Germany following the partial legalization of cannabis for recreational use.Scoping review on the diagnosis, complications, treatment options and prognosis of CHSCannabis-related cyclic vomiting attacks are better known in emergency medicine than in general medicine and addiction medicine. Young adults are often affected. A reliable differentiation between CHS and the nosologically related cyclic vomiting syndrome (CVS) - in which 30% of those affected also use cannabis chronically - is only possible by establishing remission during at least 6 months of abstinence. For this reason, mixed forms of CVS and CHS are usually seen in emergency departments (suspicious CHS), sometimes with masked life-threatening comorbidities. Severe vomiting can also lead to serious complications. Common antiemetics are often ineffective. Hot showers and baths (diagnostic secondary criterion in ROM-IV) and haloperidol (up to 5 mg i.m.) can acutely alleviate the severe vomiting. Rubbing the abdomen with 0.075-0.1% capsaicin cream also helps, but less quickly. After several cyclical CHS clusters, the individual threshold for their occurrence decreases continuously (chronification): Cannabis relapses, even at low doses, lead to stronger and longer cyclic CHS clusters than experienced before (sensitization).CHS is nosologically classified in ROME-IV as a specific variant of CVS, but it is also a specific and mostly a severe cannabis-related disorder. As full remission and cure (full remission for at least 5 years) can only be achieved through sustained abstinence from cannabis, suspected CHS presents an interdisciplinary challenge for various medical disciplines, consultation/liaison psychiatry and addiction support systems.