As the old saying goes, everything in moderation.
That includes weed, where it’s legal.
Part of the pitch for liberalizing marijuana laws has been the drug’s use as a way to curb nausea, especially in cancer patients undergoing chemotherapy. But it turns out that heavy, regular marijuana use over a long stretch can cause intense bouts of vomiting and painful cramps.
Doctors aren’t certain why it happens, and they say there’s little evidence linking it to popular accounts of people screaming as they hurl. But as more places legalize weed, doctors are seeing what’s been dubbed “cannabinoid hyperemesis syndrome” turn up more often.
“I wouldn’t say it’s common,” Dr. Rob Hendrickson, associate medical director of the Oregon Poison Center, told Seeker. “We don’t know exactly how often it happens, but certainly most physicians and nurses who work in emergency departments will tell you they see these patients.”
Hendrickson is preparing a study to put a number to that question, which can be complicated. There’s no clear diagnostic criteria for cannabinoid hyperemesis syndrome, and physicians can have trouble distinguishing the condition from other illnesses that cause vomiting.
Researchers who re-examined emergency room records from two Denver hospitals found that the number of people showing up with episodes of repeated vomiting nearly doubled after Colorado started liberalizing its marijuana laws — from about 41 cases in the year before medical marijuana was legalized in 2009 to about 87 in a one-year period from 2010-2011.
“Paradoxically, the association of marijuana use with cyclic vomiting contrasts its well-touted antiemetic properties,” the Colorado study noted.
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Researchers believe heavy consumption exposes users’ brains to a long-term dose of cannabinoids, compounds found in the marijuana plant, Dr. Frank Friedenberg, chief of gastroenterology at Temple University’s Lewis Katz School of Medicine in Philadelphia, told Seeker. That “sort of resets the nausea and vomiting centers such that it actually triggers nausea and vomiting, instead of causing the opposite effect,” he remarked.
“It’s not in everybody. It’s relatively uncommon, otherwise we’d been seeing it in a ton of people,” said Friedenberg, who co-authored a 2013 study on the phenomenon. “But in some individuals, they get kind of a paradoxical effect, where the long-term high dose can trigger this condition.”
Oregon legalized medical marijuana in 1998 and allowed recreational use in 2015. Hendrickson said most people stricken with the syndrome “are using cannabis at least once a week, probably much more than that.”
“This is not the kind of thing that happens to someone using recreational cannabis once a month or every couple of months. These are people who are using several times a week for a minimum of two years or more straight,” said Hendrickson, who’s also a professor of emergency medicine at Oregon Health Sciences University in Portland.
Conventional anti-emetic drugs will often stop the vomiting, Hendrickson said. But some of those stricken with the condition appear to find relief in multiple hot showers or baths a day, or by rubbing capsaicin cream — an ointment derived from chili peppers — on their skin. Capsaicin cream “does seem to work in certain groups of people,” Hendrickson said, “But it does not work every time by any stretch of the imagination.”
Friedenberg said a hot shower can release endorphins, chemicals in your body that mask pain. That gives the body a pleasant feeling and temporary relief — but “It’s very, very short lived,” he said. “As soon as they get out of the shower, it starts to come back again.”
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The simplest cure may be to set aside the bong for a while. “Cannabis cessation may result in complete symptomatic recovery,” a 2010 study concluded.
But Friedenberg said long-term users should be weaned off the drug rather than quitting cold turkey. People who use large quantities of marijuana will have some withdrawal symptoms, so doctors recommend tapering off use over the course of months.
What about the screaming? Some accounts have described patients crying out in agony, leading a few to describe the condition as “scromiting.” But the vocalization may be more a response to the severe abdominal cramps associated with the condition rather than an effect produced by the drug itself.
“I think that anybody who is having severe, crampy abdominal pain with 30 or 40 episodes of vomiting in a day is going to be pretty distressed,” Hendrickson said. Some patients have described the pain as worse than food poisoning, he said, but “I certainly don’t know of any association of actual screaming with the syndrome.”
And Friedenberg added, “Usually, they’re not screaming out loud. I think that’s overhyped.”
Marijuana remains illegal under federal law, and the Trump administration is trying to douse the spread of legalized pot. But four states — including California — voted to legalize recreational cannabis use in 2016, four more voted to allow medical marijuana use. Legal weed is expected to be an $11 billion industry this year, according to a recent report by New Frontier Data, which studies the cannabis economy.
Colorado’s experience shows emergency rooms should be prepared to see more cases of marijuana-related vomiting, Friedenberg said.
“When you talk about the legalization of marijuana, this almost never gets brought up,” he said. “It’s going to be an issue. It should be discussed more. There should be more public education.”