Cannabinoid Hyperemesis

By Cheryl Smith

Oregon Cannabis Connection

At a social event I attended last year, the conversation at one point turned to doctors and the health care system. A friend lamented that it wasn’t worth the time to go to a doctor because they often can’t figure out what’s wrong. As an example, she mentioned her teenage daughter—a heavy pot smoker—who for months had had a problem with abdominal pain, nausea and vomiting. They had done test after test and could find nothing wrong. She was frustrated and felt it was a waste of money.

I was familiar with cannabis hyperemesis (AKA cyclical vomiting due to cannabis), and so was the friend sitting across from me—a nurse in a Eugene hospital—who had told me about the cases he had encountered there over the past few years. He asked whether the daughter took lots of hot showers or baths to relieve her symptoms—something done by most people who have this condition. Not unexpectedly, as we described what was going on, we learned that that diagnosis had been suggested, along with the need for her daughter to stop smoking cannabis. We soon learned that both mother and daughter had rejected that diagnosis—because it would require that she quit smoking pot and acknowledge that it was the cause.

The medical condition was first reported in Australian in 2004. (3) Since then reports have come from Canada, France, Germany, Netherlands, Spain, New Zealand, the UK and the US. The usual course is that every 4-6 months or so the patient, who is usually a long-term cannabis user, develops nausea, abdominal pain and vomiting that they cannot stop. They believe that cannabis relieves their nausea, because it may have in the past. Most take hot showers or baths during one of these episodes—sometimes for hours at a time—which provides temporary relief. They eventually appear at an emergency department, with dehydration, weight loss, and sometimes even kidney failure. (2)

When health care providers are unaware of this syndrome, patients are often subjected to expensive and invasive testing, as well as rehydration and treatment with pain medications and antiemetics to stop the pain and vomiting. Because the patient is hospitalized, he no longer is using cannabis, which also causes the symptoms to subside.

What is actually happening has been a puzzle; but the pieces are coming together as studies are done. Last month, someone in the press who was previously unaware of this phenomenon published a version of the story for the general public, with a headline calling it a “mysterious illness.” Extreme cannabis defenders immediately jumped on the subject—in blogs and in comment sections—with the usual claims that cannabis has no side effects, is totally safe and this is fake news. This holy herb surely could not be causing an adverse effect, especially when everyone knows that it prevent and treats nausea. Others speculated that a neem oil product is the culprit. (We will discuss this in the next issue of OCC)

A 2012 case study of 98 patients at the Mayo Clinic was published in 2012 (3), with the objective of promoting “wider recognition and further understanding of cannabinoid hyperemesis (CH).” A total of 1571 records of patients seen between January 1, 2005, and June 15, 2010 who met criteria (long-term marijuana use prior to the start of symptoms, history of recurrent vomiting and the absence of a major illness that could explain the symptoms) were screened by investigators were narrowed to 98 patients who clearly met criteria.

Of these, investigators determined:

– 67% were male
– 77% were between the ages of 20 and 40, with a mean of 32
– About half also used tobacco
– Only 10% reported weekly use of alcohol
– 78% were Caucasian
– 68% had used cannabis products for more than two years prior to symptoms
– 59% of patients used cannabis daily; 95% used it more than once a week
– 71% had symptoms in the morning, and in only 21% were symptoms associated with meals
– 86% had abdominal pain, as well as the nausea and vomiting
– In 58%, hot water bathing was documented, bringing relief in 91% of those cases
– 83% of patients reported weight loss
– 70% of patients reported more than 7 episodes a year

Because the diagnosis of cannabinoid hyperemesis had not yet been made for these patients, most had diagnostic testing done, ranging from blood tests to abdominal CAT scans, upper endoscopy and colonoscopy. Almost half had a test to determine whether there were gastric emptying abnormalities; these findings showed that in 46% it was normal, in 30% it was delayed and in 25% it was rapid.

A shortcoming of the study results was that in only 10% was there documented follow-up. Of these 60% had stopped cannabis and all symptoms were resolved. Thirty percent, who did not stop cannabis, continued to have symptoms. The other 10% did not show improvement, but did not return for follow-up.

It is important for physicians to be aware of this condition—asking patients who present with recurrent nausea and vomiting whether they regularly use cannabis and whether hot showers or baths help relieve symptoms—to avoid the expense, invasiveness and uselessness of diagnostic testing and hospitalization. To be sure, it only affects a small percentage of cannabis users (4), but can lead to use of a disproportionate amount of resources, when there is an easy solution: Stop using cannabis and see if the problem resolves.

In the next issue, we will discuss theories regarding the specific causation.

Cheryl K. Smith is a freelance writer and editor. She was formerly a health information administrator and an attorney, and the Executive Director of Compassion Center in Eugene, Oregon.

(1) Allen JH, de Moore GM, Heddle R, Twartz JC. Cannabinoid hyperemesis: cyclical hyperemesis in association with chronic cannabis abuse. Gut. 2004;53(11):1566-1570
(2) Case Report, Am J Emerg Med 32 (2014) 690.e1–690.e2
(3) www.mayoclinicproceedings.org/article/S0025-6196(11)00026-7/pdf
(4) A 2015 article from Colorado at www.ncbi.nlm.nih.gov/pmc/articles/PMC4939797/ showed a doubling of ED visits for cyclic vomiting (from 41 per 113,262 visits to 87 per 129,095 visits) after legalization.

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