Marijuana: Anti-Emetic or Pro-Emetic?

Abstract

Purpose: Cannabinoid hyperemesis (CH), a pro-emetic paradoxical effect of marijuana use, carries serious consequences in regards to health services utilization and the cost of medical care. First described in 2004, a total of 14 case reports and 4 case series have been published in the medical literature to date. We describe a series of 9 patients with CH at our institution. CH is characterized by long-term cannabis use, severe cyclic nausea and intractable vomiting, temporary relief of symptoms with hot showers or baths, and resolution of symptoms with cannabis cessation. Proposed mechanisms involve the CB-1 cannabinoid receptor in the central nervous system and enteric plexus, and include delayed gastric emptying and thermoregulatory disturbances via the limbic system. Our patient's characteristics were compared to and coincide with those of prior reports: average age at diagnosis 30 years-old; 88% male; onset of cannabis use during teen years; 88% used cannabis daily; 56% compulsive bathing behavior; and 80% symptom resolution with cannabis cessation. Minimum workup in our patients included basic laboratories, abdominal US and/or CT, and EGD. We estimate $10K to be the minimum cost of one admission. On average, our patients required admission to the hospital 2.8 times (a total of almost $30K for workup). To that cost we must add visits to their primary care physician and/or gastroenterologist and the emergency room, which averaged 2.5 and 6 times respectively. From a health care cost perspective it is important to recognize CH as it often leads to an expensive diagnostic approach and ineffective treatments. Chronically, the only therapy reported to be of benefit is cessation of cannabis use. 80% of our patients who stopped cannabis experienced symptom resolution; however, only one of them remained abstinent and consequently symptom free. While CH is under-diagnosed, we suspect its incidence is in the upraise. Multiple factors account for this prediction: (1) clear increase in recreational marijuana use; (2) decriminalization of the use of medical cannabis in 16 states of the USA; (3) increase temporal trend in cannabis potency (and while it has not been demonstrated, a toxic THC concentration may be playing a role); and (4) the emergence of new generation, of legal and easily accessible synthetic cannabinoids, commonly known as “Spice,” which act as potent agonists of the CB1 receptor. As health care providers, we must be aware of the potential side effects of chronic cannabis use. CH is diagnosed clinically. Expensive diagnostic and therapeutic modalities should be avoided. Instead the focus should be shifted towards counseling and resources allocated towards marijuana cessation.