Ondansetron Lorazepam Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to prolonged, high-dose cannabis use.
[7][2] Symptoms usually remit after two weeks of complete abstinence, although some patients continue to experience nausea, cyclic vomiting, or abdominal pain for up to 90 days.
[13][14] CHS is a paradoxical syndrome characterized by hyperemesis (persistent vomiting), as opposed to the better known antiemetic properties of cannabinoids.
[15] The most prominent CHS symptoms are cyclical nausea, vomiting, and abdominal pain, concomitant with chronic cannabinoid use.
[16] During this phase, treatment with compulsive bathing is rarely reported, and some individuals may attempt to treat their symptoms with cannabis use.
[8][5] The hyperemetic phase is characterized by the full syndromal symptoms of CHS, including persistent nausea, vomiting, abdominal pain, and retching.
[8][3] The recovery phase begins after the patient abstains from cannabis consumption, but the time for resolution of symptoms is unclear: it has been reported to occur within two weeks in some cases,[6] but in others it may take one to three months.
Education about this vicious cycle, along with evidence-based treatment for cannabis use disorder, such as motivational interviewing and relapse prevention, often prove beneficial.
[19] Various pathogenic mechanistic theories attempting to explain symptoms have been put forward:[17] It has been hypothesized that certain people may be genetically pre-disposed to metabolize cannabinoids in an atypical manner, making them susceptible to CHS.
[4] The differential diagnoses include, but are not limited to, cyclic vomiting syndrome,[3] bowel perforation or obstruction, gastroparesis, cholangitis, pancreatitis, nephrolithiasis, cholecystitis, diverticulitis, ectopic pregnancy, pelvic inflammatory disease, heart attack, acute hepatitis, adrenal insufficiency, and ruptured aortic aneurysm.
[4][8] However, if simple laboratory tests and imaging have excluded more serious conditions, it is reasonable to monitor for a worsening of the patient's status to prevent the unnecessary application of more invasive, and potentially dangerous, diagnostic procedures (such as exploratory surgery).
[27] Clinical pharmacists can play a role in administering this education, as well as encouraging patients to seek the assistance of mental health providers.
[27] Assessing for dehydration (due to vomiting and hot showers) is important as it can lead to acute kidney failure, and this is easily treated with IV fluids.
[3] Based on the mechanism of the effect, some clinicians have used topical capsaicin cream applied to the periumbilical area in the treatment of acute CHS.
[8] Opioids can provide some relief of abdominal pain, but their use is discouraged due to the risk of worsening nausea and vomiting.
[3] The exact proportion of the population affected by this syndrome is difficult to conclude because there have not always been specific criteria for diagnosis, there are no diagnostic tests to confirm it, and cannabis use may not be reported truthfully.
[23] A 2015 study that surveyed patients from an urban emergency department found that 32.9% of people who reported cannabis use of at least 20 days per month met criteria for CHS.
Researchers estimate that up to one-third of near-daily cannabis users in the U.S. may experience symptoms, ranging from mild to severe, affecting approximately six million people.
It is possible this rise, of around 5+1⁄2 times, may be affected by sampling bias, as initial awareness of CHS prompted more diligent questioning and recording of when such ER attendees were also cannabis users.
[35] A retrospective application of the 2016 Rome IV criteria to cases recorded in prior literature suggested that the number of people with CHS had been over-estimated.
[33] Cannabinoid hyperemesis was first reported in the Adelaide Hills of South Australia in 2004 by an analysis of only 9 patients (originally 19; 10 dropped out of the study) referred to participate in this study with the goal to link cannabis to a vomiting syndrome due to the patients' previously diagnosed cyclical vomiting syndrome and that they happened to use cannabis.
The report focused on nine patients who were chronic cannabis users who presented with cyclical vomiting illness.