Cannabis Hyperemesis
Fact sheet
Overview
Cannabis Hyperemesis Syndrome (CHS) is typically seen with chronic cannabis use in older adolescents and adults. Characterised by episodic vomiting associated with high-dose (nearly daily) recreational cannabis use and it resolves with cannabis cessation.
Cause
Triggered most commonly by chronic (e.g > 2 years), frequent (e.g. >4 times weekly), high-dose cannabis use.
Aetiology
Vomiting is complex
Noxious stimuli are perceived (can be anything, fearful sight, foul odour, distressing memory)
Area postrema in brain activated
Vagal stimulation
Result is salivation, closure of the glottis to stop aspiration, relaxation of stomach sphincters, retroperistalsis of small intestine contents to the stomach, stomach contraction and abdominal muscles to propel contents out the mouth
Several receptors exist in the gut including cannabinoids, histamine, others
Cannabis works on multiple receptors including cannabinoid receptor 1 and 2 scattered through the brain and the parasympathetic nervous system
Current theory is CHS results from chronic overstimulation of the endocannabinoid receptors, causing derangement of the the body’s intrinsic control over nausea and vomiting
Another theory involves the transient receptor potential vanilloid-1 (TRPV1)
Another factor is that there has been a progressive change in the composition of the plant, which increases the THC levels and reduction in cannabidiol (CBD)
Epidemiology
5% of the world has used cannabis at least once
50% of the US have their first use by age 20
Symptoms
Patients may complain of cyclic abdominal pain, vomiting, or nausea that is typically relieved by hot showers or baths.
Diagnosis
Multiple checklists have been proposed, including the latest known as the Rome IV criteria:
Criteria fulfilled for at minimum three months, with symptomatic onset occurring at least six months before diagnosis
Stereotypical episodic vomiting resembling cyclical vomiting syndrome in onset, duration, and frequency
Presentation after prolonged, excessive cannabis use
Relief of vomiting by a sustained cessation of cannabis use
May be associated with “pathologic” bathing behavior, e.g., prolonged hot baths and showers.
Management
For cannabis users with a first presentation of abdominal pain and vomiting likely due to CHS
Anti-emetics
Ondansetron preferred
Metoclopramide
If persisting can consider benzodiapezines e.g. Lorazepam
Fluid repletion
1L normal saline over 1 hour
Exclude other causes
Blood tests include FBC, UEC, LFT, Lipase, Amylase
ECG / Troponin if considering an atypical cardiac presentation
CXR / AXR if concerns about bowel obstruction
Urinalysis to exclude UTI
Pregnancy test if appropriate
Can consider abdominal ultrasound
For patients who do not respond to supportive measures consider a trial of topical capsaicin
If the above fails try droperidol or haloperidol
All patients should forego further cannabis. It may take weeks after abstinence for symptoms to fully resolve. If difficult to stop, use products at lower doses and frequency with the eventual goal of cessation.
Heat
A survey of 500 chronic cannabis users with CHS showed two-thirds had improvement in symptoms with hot showers.
Capsaicin
Limited observational evidence suggests that topical capsaicin applied once in a thin film over the abdomen may improve severe abdominal pain and vomiting (0.025 to 0.1%). In a small study of 43 ED patients, capsaicin cream decreased the total number of other medications used and two-thirds of patients required no further treatment before discharge. In another study of 201 patients with CHS, capsaicin was linked to greater efficacy for symptom relief than other treatments.
It is hypothesized that capsaicin may provide relief by its potent agonism on the transient receptor potential vanilloid 1 (TRPV1) receptor.
Haloperidol
Haloperidol was superior to Ondansetron in the improvement of self-rated abdominal pain and nausea.
Reference
Cannabis: Acute Intoxication - UpToDate
