Cannabinoid hyperemesis is a syndrome (CHS) characterized by severe intractable nausea, cyclical vomiting, and abdominal pain associated with chronic marijuana abuse. It is often a underrecognized cause of cyclic vomiting syndrome. Despite well established anti-emetic properties of marijuana, paradoxical effects on the GI tract exist through cannabinoid receptors which exert their neuromodulatory properties in the central nervous system and the enteric plexus. Multiple theories of mechanism of CHS are in the literature. Diagnosis is based on the following clinical criteria:

• History of regular cannabis for any duration of time
• Refractory nausea and vomiting
• Gastrointestinal evaluations fail to identify other clear causes
• Compulsive bathing in hot water temporarily alleviates symptoms often done several times a day. A red flag symptom.
• Resolution of symptoms after cannabis is discontinued

Acute care goals are to treat dehydration and terminate nausea and vomiting. Administration of intravenous fluids, dopamine antagonists, topical capsaicin cream, and avoidance of narcotic medications are recommened treatment measures. Benzodiazepines followed by haloperidol and topical capsaicin are reported to be most effective. Capsaicin  activates the transient receptor potential vanilloid 1 receptors (TRPV1) which impairs substance P signalling in the area postrema and nucleus tract solitarius similar to noxious stimuli, such as heat. 

References

Cannabinoid Hyperemesis Syndrome: Diagnosis, Pathophysiology, and Treatment-a Systematic Review. Sorensen CJ, DeSanto K, et al. J Med Toxicol. 2017 Mar;13(1):71-87.

Cannabinoid Hyperemesis and Compulsive Bathing: A Case Series and Paradoxical Pathophysiological Explanation. Patterson D, Smith E, et al. Am Board Fam Med. 2010 Nov-Dec; 23(6): 790-793.

Pharmacologic treatment of cannabinoid hyperemesis Syndrome: A systematic review. Pharmacotherapy. Dezieck L, Hafez Z. 2017 Jun:37(6):725-734.

Resolution of cannabis hyperemesis syndrome with topical capsaicin in the emergency department: a case series. Dezieck L, Hafez Z, et al. Clin Toxicol (Phila). 2017 Sep;55(8):908-913.