Introduction: Cannabinoid hyperemesis syndrome (CHS) is an uncommon but unique disorder defined by recurrent abdominal pain, intractable nausea, and emesis in patients who regularly smoke cannabis. The syndrome does not reliably respond to intravenous administration of the usual antiemetics but improves with hot showers and baths (hydrothermotherapy). Complete resolution of CHS occurs only after cessation of cannabis use.

Area covered: The authors review the clinical features of CHS, the differences between CHS and cyclic vomiting syndrome, putative etiology, incidence, and different treatment options with analgesics, antiemetics, antipsychotics, beta blockers, and transient receptor potential vanilloid (TRPV) agonists, hydrothermotherapy and capsaicin.

Expert opinion: CHS is frequently unrecognized by clinicians, leading to extensive and unnecessary testing and treatment. Directed questions about cannabis use and the effect of hydrothermotherapy on CHS symptoms frequently confirm the diagnosis, enabling appropriate pharmacotherapy and referral to addiction treatment. CHS prevalence will continue to rise in parallel with increasing worldwide cannabis use and potency. Classic antiemetics may be tried initially but often fail to alleviate CHS. Antipsychotics (such as haloperidol), benzodiazepines, and/or capsaicin cream appear to be the most efficacious in the treatment of this unique disorder.