Clinical Review of Cannabis Hyperemesis Syndrome
Epidemiology of Cannabis Use
A clinical review of cannabis hyperemesis syndrome (CHS) outlines the epidemiological and pathophysiological aspects of this illness. Cannabis, derived from the Cannabis sativa plant, is the most widely cultivated, trafficked, and consumed drug globally. Approximately 2.5% of the population engages in cannabis use, which is abused more rapidly than cocaine and opiates. Since the 1960s, cannabis prevalence has significantly increased in developed regions, including North America, Western Europe, and Australia. In Canada, 42% of adults have reported using cannabis at some point in their lives. The United States sees an influx of new users at a rate of 2.6 million annually, primarily among those aged 18 to 25. Europe has also experienced a dramatic rise in prevalence, increasing from 5% to 15% over a decade.
Understanding Cannabis Hyperemesis Syndrome
As chronic cannabis use escalates, research has begun to uncover clinical syndromes associated with long-term consumption. One such syndrome, cannabis hyperemesis syndrome, was first recognized in 2004 and is characterized by a cyclical pattern involving chronic cannabis use, episodes of nausea and vomiting, and a compulsive behavior of frequent hot bathing.
Phases of Cannabis Hyperemesis Syndrome
The clinical diagnosis of CHS encompasses three distinct phases: prodromal, hyperemesis, and recovery.
– **Prodromal Phase**: Patients experience abdominal discomfort, nausea, and anxiety about vomiting, which can persist for months or years. While normal eating habits may continue, cannabis use may be either reduced or increased in an attempt to alleviate nausea.
– **Hyperemesis Phase**: This phase is marked by severe and persistent nausea and vomiting, with patients often experiencing diffuse abdominal pain and vomiting episodes that may exceed 20 times daily. A study indicates that 70% of those afflicted lost at least 5 kilograms during this period. Symptoms can be debilitating, leading to dehydration and potential acute kidney failure, though hydration treatment can reverse kidney issues. Patients often resort to long hot showers, which they find temporarily alleviates their discomfort.
– **Recovery Phase**: This phase can last from days to months, during which patients gradually return to normal health and eating patterns. Their body weight stabilizes, and compulsive bathing behaviors diminish.
Mechanisms of Action
Cannabinoids influence gastrointestinal and nervous system functions. Despite cannabis being thought to have anti-emetic properties, its interaction with CB1 and CB2 receptors affects both the brain and gastrointestinal systems. Endogenous cannabinoids are released on-demand by neurons, while exogenous cannabinoids, like tetrahydrocannabinol (THC), have a longer elimination half-life. THC is highly fat-soluble, leading to storage in fatty tissues and a gradual release into the bloodstream, which may trigger CHS symptoms in chronic users.
Cannabidiol (CBD) and cannabigerol (CBG) are non-psychotropic cannabinoids that mimic THC’s anti-emetic properties; however, their effects on vomiting are dose-dependent. THC also alters psychomotor functions, disrupts memory, stimulates appetite, and affects hormone release in the hypothalamus and pituitary gland. Research has noted delayed gastric emptying in animal models following cannabis use, a condition that could lead to nausea and vomiting.
Treatment Approaches
Current treatment strategies focus on managing symptoms during the hyperemesis phase and preventing relapse. Hospitalization may be necessary for patients with severe symptoms. Supportive care typically includes pain management with narcotics, intravenous fluids for dehydration, and acid suppression therapy for esophagitis and gastritis. Notably, hot showers remain one of the most effective, albeit temporary, treatments for CHS symptoms, potentially correcting cannabis-induced imbalances in the hypothalamic thermoregulatory system.
Psychological interventions are crucial for addressing the underlying issues related to cannabis dependence. Educational programs, cognitive behavioral therapy, and motivational enhancement therapy are effective means to encourage cessation of long-term cannabis use.
Challenges in Diagnosis and Future Research
Research indicates that most patients experience a delay in symptom onset by several years following chronic cannabis use, and CHS can recur with symptom-free intervals. Symptoms can often be confused with cyclical vomiting syndrome (CVS), although CVS is typically associated with a family history of psychiatric issues and migraines. The complexity of potential underlying causes for nausea and vomiting complicates immediate diagnosis of CHS.
Further research is needed to understand the epidemiology and mechanisms of cannabis hyperemesis syndrome, as it remains underreported and often misdiagnosed. The absence of long-term studies creates knowledge gaps about the illness’s course. Some researchers suggest that genetic predispositions may contribute to dysregulated cannabinoid metabolism, making certain individuals more vulnerable to nausea and vomiting. Additionally, future studies should explore gastrointestinal physiology in CHS patients during and between episodes.
References
Galli, J. A., Sawaya, R. A., & Friedenberg, F. K. (2011). Cannabinoid hyperemesis syndrome. Current Drug Abuse Reviews, 4(4), 241–249.
Holmes, A., King, C. (2015). Five things to know about cannabinoid hyperemesis syndrome. Canadian Medical Association Journal, 187(5). doi: 10.1503/cmaj.140154.