A young patient, let’s call him Chad, goes to the doctor. He complains of attacks of nausea from the moment he wakes up in the morning. Sometimes his belly hurts as well. It’s been happening, on and off, for years. He gets cold and shaky. At times, it will progress to full-fledged vomiting, uncontrollable with any medications. The nausea is unbearable. Sometimes, getting in a very hot shower will take the edge off the nausea, but not always. In many cases a trip to the emergency room is needed for rehydration and intravenous anti-nausea medications.
A medical worker would need to know a bit more about this story before making a diagnosis, but the next question would typically be: Do you use cannabis?
With liberalization of the cannabis in many countries—including the legalization of recreational use in Canada—use has increased substantially. Finding people who smoke cannabis daily, for many years, has also become much more common when the use is for medical reasons. Chad, for one, has been smoking cannabis daily since his mid-teens, and suffers from a relatively newly described disorder called cannabis hyperemesis syndrome.
The syndrome is a disorder of cyclic vomiting associated with chronic cannabis use, and may include morning nausea and abdominal pain. Patients typically have a history of daily cannabis use, often for years, before the onset of symptoms. Although only based on small numbers of patients, studies suggest that it is one of the most common causes of recurrent nausea and vomiting in younger people who are seen in emergency departments.
The precise cause of the disorder is unknown. Some speculate that chronic use may affect the functioning of the receptors for the active compounds in cannabis (called cannabinoids) in the body, while others suggest genetics of the user may play a role. Researchers have reported the disorder all over the world, in both men and women. It does not appear to be due to contaminants in the cannabis, and does not appear to be an overdose-like reaction either. However, as the strength of the cannabinoids in cultivated cannabis has grown cannabis hyperemesis syndrome has also become more common.
Cannabis has been used for centuries for treatment of various ailments, but has been illegal throughout the Western world for generations. It shows promise in treating many symptoms, especially ones related to the gut such as nausea or diarrhea. It’s not clear that cannabis works to actually treat diseases of the gut, such as Crohn’s disease, colitis, or liver diseases. Part of the reason for this is due to the difficulty of doing research on illicit substances. Another problem is that people can’t patent a naturally growing plant.
Stopping cannabis completely appears to be the best treatment for the disorder. But it remains unclear how long a person needs to abstain, as it could likely be months before their system readjusts. Doctors have also used antipsychotic medications and hot chili pepper ointment to treat the disorder. Researchers have not yet studied any medication for treatment of the disorder in a controlled clinical trial.
Guidance for physicians remains unclear about the benefits of cannabis use for illnesses and symptoms, and especially where patients may see a benefit but where they are at risk of harm from it in other ways. Most doctors believe that medical cannabis use should not replace approved medical therapy for treatment of any diseases of the gut if the approved therapy is available and has not been used.
The public is enthusiastic about cannabis legalization. Many people appear to believe that marijuana is both harmless and effective. For many chronic users, it strains credulity that a naturally occurring plant so well known for treating nausea could paradoxically cause it. Those factors can make it difficult for people to stop cannabis, especially if they feel it is helping them in some other way.
For Chad’s part, he hasn’t been able to stop completely. I’m sure part of it is due to long-ingrained habits, but also distrust of my medical advice. The addition of some other medications has been able to temper the attacks, but he is not cured. One thing is clear: we need more research on this disorder.