Can’t stop vomiting? Maybe it’s the marijuana.

There is a condition known as cyclic vomiting syndrome which causes people to develop episodes or “attacks” of frequent vomiting lasting for a few days at a time without an apparent cause. Sufferers of cyclic vomiting are totally fine between episodes…it’s kind of like a migraine of the upper gastrointestinal tract! Just like treating migraine headaches, treatment of cyclic vomiting syndrome is aimed at identifying and removing triggers, and using medication to prevent episodes or treat acute attacks.

Did you know that a common trigger of a cyclic vomiting-like syndrome is cannabis? Cannabis goes by many other names, such as marijuana, pot, weed, herb, bud, ganja, reefer…and like 100 other names, but we’ll mostly use the term cannabis for the sake of this article!

Called cannabinoid hyperemesis syndrome (CHS), this condition refers to cyclic vomiting that happens in the setting of regular cannabis use. With 8.4% of the US population (22 million people) using cannabis in one form or another, and the ongoing trend of legalizing the drug, more and more cases of CHS are being reported every year. In my own practice, I have noticed that many patients who carry a diagnosis of plain-old cyclic vomiting syndrome also use some cannabis. In fact, many patients state that it helps their nausea and vomiting (which incidentally is one of the reasons people are prescribed “medical marijuana”). So how are we supposed to tell the difference between patients using cannabis to help treat their cyclic vomiting syndrome, vs. patients who have cannabinoid hyperemesis syndrome caused by smoking too much grass?

I know this goes against modern medical thinking, but I have found that one of the least helpful ways to figure out if a patient is vomiting from using too much cannabis is to ask the patient if they’re vomiting from using too much cannabis! Most patients will say something like “Nah, smoking weed helps with the vomiting!” or, “I’ve been smoking like this forever, there is no way it’s causing these problems!” Let’s also remember that smoking cannabis is only one of the ways that people use the drug. Vaping with e-cigarettes is not just for tobacco products anymore…people are vaping cannabis in record amounts and the potency is potentially much higher too! Vaping the wacky tobacky does not produce the telltale odor that smoking cannabis does, and therefore can also be more difficult to detect.

OK, so how does one figure out if smoking the chronic is the cause of all the vomiting? There are actually several characteristics of patients at risk for developing CHS. Patient with cannabinoid hyperemesis syndrome usually:

  • use cannabis at least weekly, but usually daily or several times per day
  • have been using cannabis for more than a year
  • started using cannabis in their teenage years, but didn’t develop vomiting issues until their 20s
  • are more often male (although roughly 25% of CHS cases occur in females)
  • report symptom relief with hot showers or baths (we are talking really hot, almost scalding water!)

How do we treat cannabinoid hyperemesis syndrome?

Fortunately, CHS is really simple to treat! Cannabinoid hyperemesis syndrome resolves when the patient stops using cannabis! (I said it was simple, but not easy for some.) However, abstinence takes time to really work…what do you do with the CHS patient who is on day 2 of vomiting his guts out, and comes to the hospital dehydrated with severe abdominal pain?

Evidence is sparse, but it seems that basic supportive care with intravenous fluids, antiemetic medications, and sometimes pain medication, antianxiety medication, and antipsychotic medications like haloperidol (Haldol) are needed to break the cycle of vomiting and allow the patient to be discharged from the hospital. However, if the patient continues to use cannabis after discharge, studies show that cannabinoid hyperemesis syndrome will recur 100% of the time.