Disabling cannabis condition gets formal clinical identity

Over the past decade, doctors have increasingly treated people who come into the emergency department with abdominal pain and severe or prolonged vomiting. The patients’ common trait: chronic cannabis use.  

Not until last month, however, were clinicians able to reference a diagnostic code for “cannabis hyperemesis syndrome,” a gut problem that starts within 24 hours of the most recent use and can last for days. Users experience symptoms cyclically three or four times a year.   

On Oct. 1, the World Health Organization’s International Classification of Diseases manual (ICD-10, currently) standardized the new code, R11.16, which also was updated for U.S. clinicians by the Centers for Disease Control and Prevention.  

The development has a few upsides: Clinicians can formally identify the condition with one billing code instead of describing it with two or three less exact codes. They also can see the code in a patient’s medical history to help identify similar symptoms at future visits.  

One big advantage: The code will enable investigators like Beatriz Carlini to more accurately recognize trends in incidence and parallels among patients.  

“It helps us count and monitor these cases,” said Carlini, a research associate professor at the University of Washington School of Medicine who studies adverse health effects of cannabis use. “In studying addiction and other public health concerns, we have three sources of data: what clinicians tell us, what people in the communities tell us, and what health records tell us. A new code for cannabis hyperemesis syndrome will supply important hard evidence on cannabis-adverse events, which physicians tell us is a growing problem.” 

Despite the upsurge of these hospital cases, many providers are still unfamiliar with the syndrome because of its relative newness. 

“A person often will have multiple [emergency department] visits until it is correctly recognized, costing thousands of dollars each time,” Carlini said. 

Even when diagnosed appropriately, patients frequently reject the notion that cannabis is causing their gut distress, said Dr. Chris Buresh, an emergency medicine specialist with UW Medicine and Seattle Children’s. He noted that cannabis often relieves nausea in people who undergo chemotherapy or who manage chronic conditions such as HIV and migraines.   

“Some people say they’ve used cannabis without a problem for decades. Or they smoke pot because they think it treats their nausea,” he said. “It seems like there’s a threshold when people can become vulnerable to this condition, and that threshold is different for everyone. Even using in small amounts can make these people start throwing up.” 

It's unclear why the condition affects cannabis users variably.  

“We don’t know if it’s related to the greater general availability of cannabis or the higher THC potency of some products or something else,” Buresh said.  

In treating these patients, he added, standard anti-nausea medications are not reliably effective, so “we end up going to second- and third-line treatments like Haldol,” which is prescribed more typically to manage psychotic episodes.  

One over-the-counter treatment that may ease symptoms is capsaicin cream, an analgesic that creates a sensation of heat. Some people in the throes of this illness rub the cream on their belly for relief, Buresh said. Hot showers are widely considered helpful, too.  

“That’s something that can clinch the diagnosis for me, when someone says they’re better with a hot shower. Patients describe going through all the hot water in their house,” he said. 

Subtle barriers exist to quick recoveries: The syndrome is intermittent, so cannabis users may feel like a recent bout of illness was a fluke. They may continue to use multiple times without incident, but then become violently sick again. As well, for patients who accept the diagnosis and want to abstain from cannabis to resolve symptoms, addiction can be a powerful counterforce, Carlini said. 

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