Cannabinoid Hyperemesis Syndrome (CHS) — Diagnosis and Treatment
- Cannabinoid Hyperemesis Syndrome (CHS), first recognized in 2005, is characterized by cyclic vomiting precipitated by chronic cannabis use (daily use for longer than one year). CHS resolves after cessation of cannabis consumption.
- Episodic, often profuse vomiting, alleviated by hot showers or baths.
- CHS is the most common cause of ED admission related to cannabis consumption, yet the diagnosis is often missed. On average, 7 ED admissions and 4.1 years elapse before diagnosis.
- Consider in all patients with unexplained profuse vomiting who use cannabis.
- CHS is common, making up approximately 6% of ED admissions for recurrent vomiting in one case study of 1,571 patients*. CHS is most often observed in males between the ages of 18-29.
- While CHS is more common with inhalable cannabis, edible cannabis consumption may also cause CHS. Of all ED visits due to cannabis, CHS was diagnosed in 18% of patients who had inhaled cannabis and 8.4% of patients who had consumed edible cannabis.
- Diagnosis may be confounded by the known anti-emetic properties of cannabis, making the diagnosis of hyperemesis counterintuitive.
- Fatalities associated with electrolyte disturbances have occurred rarely.
*Marijuana consumption was not legal in the jurisdiction of this study. ED admissions related to cannabis increased 2-fold in Colorado after legalization. Therefore, the ‘6%’ figure may underestimate the incidence of CHS in British Columbia.
Major diagnostic criteria include (adapted from Sorensen et al 2017).
- Severe nausea and cyclic vomiting (100%)
- Weekly, daily or >daily cannabis use (97.4%) for longer than 1 year (74.8%)
- Compulsive hot showers or baths that alleviate symptoms (92.3%)
- Abdominal pain (85.1%)
- Age <50 (100%)
Additional Diagnostic Characteristics
- If the patient resumes consuming cannabis after a period of cessation and disease resolution, CHS will recur.
- Some case reports note weight loss >5kg.
- Symptoms are often recalcitrant to the commonly used antiemetics ondansetron and metoclopramide.
Differential Diagnosis Should Include
- Cyclic vomiting syndrome presents similarly but does not involve cannabis consumption and is common in children.
- A broad differential for vomiting with abdominal pain should be considered, such as:
- Hyperemesis gravidarum (beta-HCG if indicated)
- Metabolic disorders (e.g. Addison’s disease, porphyria)
- Pediatric cyclical vomiting
- Migraine variants
- Drug withdrawal syndrome
- Bulimia and anorexia nervosa
- Gastric outlet obstruction (peptic ulcer disease, cancer)
- Gastroparesis – diabetes, previous surgery, scleroderma, hypothyroidism
- Multiple previous similar episodes make the diagnosis of CHS more likely.
- CHS should be a diagnosis of exclusion.
- Cessation of cannabis use resolves CHS (96.8% of cases, n=64) and is the only definitive treatment.
- Management of CHS should include monitoring electrolytes and kidney function as well as providing IV fluid resuscitation.
- While research into pharmacotherapy is limited,
- The pharmacotherapy used most often for acute CHS treatment is haloperidol (1 to 5mg IV/IM x 1 dose).
- Patients may also benefit from topical capsaicin (0.075% x 1 dose) applied to abdomen.
- Some case reports have also found benefit with benzodiazepines (specifically, lorazepam and alprazolam), however, the addiction potential limits their use.
- Abdominal pain may be treated with:
- Acetaminophen 500-1000mg PO Q4H PRN (max 4000mg per 24 hours)
- Ibuprofen 400mg PO Q6H PRN
- Avoid use of opioids
- Traditional antiemetics may be trialed as they are relatively benign, however, available data suggest the following are often ineffective for the treatment of acute CHS:
- Metoclopramide 10mg PO/IV Q6H PRN
- Ondansetron 4 to 8 mg sublingual/PO/IV Q8H PRN
- Dimenhydrinate 25-50mg PO/IV Q6H PRN
- Hot showers or baths are highly effective to alleviate CHS symptoms.
- Counsel patient that cessation of cannabis consumption resolves CHS. Conversely, continued CHS is expected with continued cannabis consumption. Resumption of cannabis consumption after a period of cessation will cause CHS to return. Vomiting that does not improve with cessation of cannabis should be evaluated for other cyclical vomiting syndromes.
Quality Of Evidence?
We are highly confident that the true effect lies close to that of the estimate of the effect. There is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
We consider that the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. There are only a few studies and some have limitations but not major flaws, there are some variations between studies, or the confidence interval of the summary estimate is wide.
When the true effect may be substantially different from the estimate of the effect. The studies have major flaws, there is important variations between studies, of the confidence interval of the summary estimate is very wide.
Evidence is based on case series, case reports and systematic review. No meta-analyses or randomized controlled trials are available.
Monte AM, Shelton SK, Mills E, Saben J, Hopkinson A, Sonn B, Devivo M, Chang T, Fox J, Brevik C, Williamson K, and Abbott D. Acute Illness Associated With Cannabis Use, by Route of Exposure: An Observational Study. Ann Intern Med. 2019; 170(8): 531-537.
The purpose of this document is to provide health care professionals with key facts and recommendations for the diagnosis and treatment of patients in the emergency department. This summary was produced by Emergency Care BC (formerly the BC Emergency Medicine Network) and uses the best available knowledge at the time of publication. However, healthcare professionals should continue to use their own judgment and take into consideration context, resources and other relevant factors. Emergency Care BC is not liable for any damages, claims, liabilities, costs or obligations arising from the use of this document including loss or damages arising from any claims made by a third party. Emergency Care BC also assumes no responsibility or liability for changes made to this document without its consent.
Last Updated Apr 26, 2021
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