Marijuana use -- both natural and synthetic -- may cause cannabinoid hyperemesis（剧吐） (CH) a little-known but costly effect that researchers suggest is a serious burden to the health care system as it often leads to expensive diagnostic tests and ineffective treatments in an effort to find the cause of a patient's symptoms and provide relief, according to two separate case reports unveiled October 22 at the American College of Gastroenterology's (ACG) 77th Annual Scientific meeting in Las Vegas. 

Cannabinoid hyperemesis is characterized by a history of chronic cannabis use followed by a cyclic pattern of nausea（恶心，晕船）, vomiting and colicky（肚腹绞痛的） abdominal pain. Interestingly, compulsive hot baths or showers temporarily relieve symptoms, another characteristic which aids clinicians in diagnosis. "Most healthcare providers are unaware of the link between marijuana use and these episodes of cyclic nausea and vomiting so they are not asking about natural or synthetic cannabinoid use when a patient comes to the emergency room or their doctor's office with these symptoms," said co-investigator Ana Maria Crissien-Martinez, M.D. of Scripps Green Hospital and Clinic in San Diego. She said CH was first described in a 2004 case series of 9 patients in Australia and since then, 14 case reports and 4 case series have been published, including a prospective series of 98 patients published by Mayo Clinic in February 2012.

"Patients who use cannabis whether natural or in synthetic form called 'Spice' also don't realize their unexplained episodes of cyclic nausea and vomiting may be a result of this use, with some increasing their cannabis use because they may think it will help alleviate their symptoms -- and it actually makes them worse," said Dr. Crissien-Martinez. "The only resolution is cannabis cessation."

Dr. Crissien-Martinez co-authored the case report, "Marijuana: Anti-Emetic or Pro-Emetic" which described a series of 9 patients with cannabinoid hyperemesis at Scripps Green Hospital with average age at diagnosis 30 years-old; 88 percent male; onset of cannabis use during teen years; 88 percent used cannabis daily; 56 percent compulsive bathing behavior; and 80 percent symptom resolution with cannabis cessation.

The other case report, "Spicing Up the Differential for Cyclic Vomiting: A Case of Synthetic-Cannabinoid Induced Hyperemesis Syndrome (CHS)," may be the first reported case of CH attributed to synthetic cannabinoid, according to Fong-Kuei Cheng, M.D. and his research team from Walter Reed Walter Reed National Military Medical Center/Uniformed Services University of the Health Sciences in Bethesda, MD.