Therapeutic Showering

Cannabinoid Hyperemesis Syndrome

Cannabinoid hyperemesis syndrome is an under appreciated condition associated with long-term or excessive  cannabis use. It is characterised by cyclical vomiting associated with abdominal pain. Patients are often noted to compulsively shower as it provides transient symptomatic relief.

Evidence is scarce but the following theories are postulated:

• Susceptible patients may develop a hypersensitivity to cannabis following several years of exposure.
• Cannabis has a long half-life of weeks or months in the body. Regular use leads to accumulation and this gives rise to toxicity in the hypersensitive patient.
• It has been shown that cannabis delays gastric emptying and in the toxic patient this may lead to gastric stasis and hence hyperemesis.
• The patient may compulsively bathe because of the presence of the cannabinoid receptors in the limbic system of the brain.  The toxicity may disrupt the thermoregulatory systems of the hypothalmus and this disruption might settle with hot bathing or showering.

Features of cannabinoid hyperemesis syndrome include:

• A history of several years of cannabis abuse prior to the onset of  hyperemesis in susceptible individuals.
• Hyperemesis will follow a cyclical pattern every few weeks or months, often for many years, against a background of regular cannabis abuse.
• Cessation of cannabis leads to cessation of the hyperemesis in the presence of a negative urine drug screen for cannabinoids.
• A return to cannabis use will see a return of the hyperemesis many weeks or months later.
• The patient will compulsively bathe i.e. will take multiple hot showers or baths during the acute phase of the illness in an attempt to quell the hyperemesis.

Yes that’s true.

• Cannabinoids do have an active compound (delta-nine-tetrahydrocannabinol) that has been shown to act on the CB1 receptors in the brain to suppress emesis.
• However the majority of research is from animal trials and human data is limited.

Cyclical vomiting is characterised by intermittent episodes of nausea and vomiting punctuated by symptom-free periods.

• Hyperemesis gravidarum (always check beta-HCG in women of child-bearing age)
• Metabolic disorders (e.g. Addison’s disease, porphyria)
• Paediatric cyclical vomiting
• Migraine variants
• Drug withdrawal syndrome
• Bulimia and anorexia nervosa

These patients are often extensively worked up on previous presentations to the emergency department. Be sure to determine what previous investigations were performed and the findings obtained.

Investigations may include:

• Bedside: BSL, VBG for acid-base status, lactate and electrolytes, urinalysis including bHCG
• Laboratory: FBC, U&E, LFT, lipase
• Consider a drug screen: may assist in the diagnosis of patients that deny cannabis use but clinical suspicion remains. Cannabinoids can be detected up to six weeks post-cessation of chronic use.

Management involves supportive care, symptom relief and behavioural modification.

Initial measures

• Attend to life threats:  airway, breathing and circulation and check glucose
• Commence cannabis withdrawal chart (if available)
• Consider intravenous hydration if dehydrated
• Correct any electrolyte imbalances (especially potassium and magnesium)
• Administer antiemetics:
  e.g. Metoclopromide 10-20mg IV, ondansetron 4-8mg IV, or prochlorperazine 12.5mg IV
• Consider an antispasmodic: buscopan 10-20mg IV

If nausea and vomiting persists consider:

• Antipsychotics and low dose benzodiazepines —
  these have antiemetic effects and help relieve agitation:
  Droperid0l 1-2.5mg IV
  Midazolam 0.5-1mg IV boluses titrated to effect

Long-term management

• Abstinence is the definitive treatment. Cessation of canabinoid use will lead to resolution of all symptoms and recommencement will lead to a delayed relapse of the canabinoidhyperemesis syndrome.
• Follow-up by drug and alcohol counseling service.

• Allen JH, de Moore GM, Heddle R, Twartz JC. Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse. Gut 2004;53:1566-1570.
• Donnino MW, Cocchi MN, Miller J, Fisher J. Cannabinoid hyperemesis: a case series. J Emerg Med. 2011 Apr;40(4):e63-6 PMID: 19765941