Reporting is often subjective and qualitative, and there is no metric for how much physiologically active compounds are contained in one joint, cone, bong, etc. In addition, higher THC content through selective breeding of plants and more selective use of female buds that contain more concentrated THC levels may cause CHS to appear in patients who report lower amounts of cannabis use [170]. Twenty-four additional articles were identified through the bibliographies of articles returned in the primary search. After removal of duplicates, 1253 abstracts were independently screened by reviewers, of which 170 satisfied criteria for inclusion. The strength and quality of each study were evaluated using the GRADE working group metrics [83]. Grading and Recommendations Assessment, Development, and Evaluation (GRADE) defines high-quality studies as randomized trials or double-upgraded observational studies.
At time of writing, the patient had gone 20 months without requiring hospitalization; however, he had a recent relapse of marijuana use and subsequently required hospitalization. Two distinct cannabinoid receptors, CB1 and CB2, have been identified in human and animal models. The CB1 and CB2 receptors function as G-protein coupled receptors that act by inhibiting adenylate cyclase [7].
It is typical that CHS symptoms resolve in a matter of days once marijuana is stopped; in some case reports, symptoms resolved in hours. Some important questions for patients to better and more rapidly diagnose CHS are shown in cannabinoid hyperemesis syndrome Table Table11. Two reviewers (CS and AM) independently reviewed all titles generated by the search to identify potentially relevant articles. Articles that were clearly not relevant based on title and abstract were excluded.
Rimonabant, a CB1 antagonist, blocks the appetite stimulating qualities of the cannabinoids in the hypothalamus and has been marketed for the treatment of obesity and metabolic dysfunction [34]. THC exhibits an anti-emetic effect in the central nervous system. In animal models, CB1 receptor activation in the dorsal vagal complex of the brainstem mediates this effect [35,36]. Dronabinol (synthetic THC) and nabilone (a CB1 receptor agonist) are two commercially available cannabinoids for the treatment of chemotherapy-induced nausea and vomiting [37]. THC accumulates largely within body fat which serves as a long-term storage site for the drug [20,22]. This characteristic partially explains its prolonged elimination half-life.
With the liberalization of marijuana laws and growing favorable public opinion about the benefits of marijuana, CHS is likely to become increasingly more common. Immersing oneself in very hot water relieves vomiting symptoms in CHS patients but has no antiemetic effect on patients with other types of CVS or PV. Thus, learned behavior of bathing in hot water may be used to help diagnose CHS and differentiate it from other CVS [93]. Over 90% of CHS patients exhibit this behavior [75], which is sometimes described as compulsive. The patient found that hot water relieved his symptoms better than anything else. After 3 days in the hospital (and no marijuana use), his symptoms resolved [94].
CHS symptoms include nausea, abdominal pain, and uncontrollable vomiting. CHS symptoms can lead to severe dehydration, which can be life-threatening. Nausea, vomiting, and abdominal pain are diffuse symptoms that may derive from any of several diverse etiologies. For CHS patients, these tests typically offer normal-range results, but they are expensive, time-consuming, and place a hardship on the patient as well as the healthcare system.
In a case study of a 26-year-old woman who suffered from CHS for years and had been using marijuana nonmedically for 11 years, symptoms resolved in the relatively long period of 3 weeks of cannabis abstinence [117]. In America, 22.2 million Americans reportedly used some form of cannabinoids in the past month [3]. The Drug Abuse Warning Network (DAWN) states that marijuana mentions (the number of times “marijuana” is mentioned in a medical record) have increased 21% from 2009 to 2011 [3].
Many authors have proposed diagnostic criteria (see Table Table7),7), but it is unclear if these criteria consistently capture patients with the diagnosis. Additionally, criteria vary significantly, which may contribute to diagnostic uncertainty among providers. Therefore, our objectives are to summarize and evaluate the available scientific evidence on CHS diagnosis, pathophysiology, and treatment utilizing systematic literature review methodology. Hospital admission in and of itself can serve to resolve CHS in that patients abstain from marijuana during the time they are inpatients. Since marijuana resumption will cause CHS to return, patient education is important in order to prevent recurrence. Marijuana cessation relieves CHS, sometimes in a matter of hours or a couple of days.