What Causes Cannabinoid Hyperemesis Syndrome?
Cannabis has very complex effects on the body. Experts are still trying to learn exactly how it causes Cannabinoid Hyperemesis Syndrome in some people. Here are a few of the possible theories behind the cause of CHS:
Tetrahydrocannabinol (THC) is a fat-soluble cannabinoid that can be deposited into a person’s fat stores, accounting for the long elimination half-life of THC. During periods of stress or food deprivation, a person’s fat stores can be mobilized (lipolysis) for energy consumption, releasing the previously stored THC as well. THC can then leach back into the bloodstream, leading to progressively higher concentrations in the blood. The mechanism can be characterized as a “reintoxication effect.” Another cannabinoid called cannabigerol acts as an antagonist at cannabinoid 1 (CB1) and serotonin 1A receptors, antagonizing the anti-emetic effects of cannabidiol that occurs through its effects on serotonin.
Cannabidiol, a cannabinoid found in cannabis, can increase the expression of the CB1 receptors in the hypothalamus of the brain. Additionally, THC acts at the CB1 receptors to induce a hypothermic effect, lowering body temperature. This might explain how exposure to hot water can relieve symptoms of cannabinoid hyperemesis syndrome, reversing the decrease in the thermoregulatory set point induced by cannabinoids. Some patients have found that symptoms subside when running or engaging in physical activity, which may be because they are changing their body temperature.
The transient receptor potential cation channel subfamily V member 1, also known as the capsaicin receptor and the vanilloid receptor 1, is a protein that, in humans, is encoded by the TRPV1 gene. It is proposed that chronic cannabis use decreases TRPV1 signaling and alters gastric motility, thus leading to patients nausea and vomiting. There have been multiple documented cases of patient’s symptoms subsiding after capsaicin cream was applied to the abdomen.