When medical cannabis laws made their debut in the latter half of the 90s, they were intended to protect cancer patients from prosecution. These patients found a medication that combatted the harsh side effects of chemotherapy.
What is CINV And How Is It Treated?
Debilitating and overpowering, that’s how cancer patients describe the onslaught that occurs within the first 24 hours after starting chemotherapy sessions. Certainly, patients fear the loss of hair, but the most dreaded side effect is the extreme bouts of nausea and vomiting. Make no misstate as this isn’t just regular nausea – Chemotherapy Induced Nausea & Vomiting (CINV) is severe and usually occurs right away, with a peak window of 6-24+ hours after treatment.
Traditional pharmaceuticals are used as anti-nausea therapies to prevent or minimize CINV. Dexamthasone, a corticosteroid, is most commonly prescribed and is very effective in treating CINV. Serotonin receptors agonists called 5-HT3 have been effective when used with dexamethasone. Even antihistamines, antidepressants and anticonvulsants have been tried.
But what happens if these drugs don’t alleviate symptoms? Many chemo patients don’t respond to traditional drugs and report that they can leave them feeling more drugged, delusional and lethargic. Cannabinoids have shown great success in treating the symptoms of CINV. Two medicines, nabilone and dronabinol, are orally-administered synthetic cannabinoids.
How Do Cannabinoids Work To Prevent Nausea?
Naboline and dronabinol work by blocking the binding of serotonin and dopamine, both of which are associated with CINV, at receptor sites. Some of the body’s endocannabinoid receptors exist within emetic reflex pathways, making them a promising target for managing CINV. The dorsal vagal complex (DVC) in the brainstem is the overall regulator of emesis (nausea/vomiting), and it is responsible for communication between signals in the blood (like chemotherapy) and the nerve cells that initiate emesis. The DVC and gastrointestinal tract have endocannabinoid receptors, and all have shown to exhibit anti-emetic responses when the receptors are activated by Δ9-THC.
Natural Cannabis & Nausea Treatment
Natural cannabis can also be used for all types of nausea, not just CINV. Most evidence has come from strains containing some degree of THC. The therapeutic outcomes, of course, depend on the THC concentration. Other formulations involve THC and cannabidiol (CBD) in different ratios. Cannabis strains are specifically grown to have different ratios/concentrations to achieve a particular pharmacologic effect.
Many people have started using CBD to treat nausea and vomiting, based on preliminary results showing that CBD activates a neurotransmitter that decreases the sensation of nausea. More research—to identify appropriate combinations, dosages, and drug interactions—is needed for both natural and synthetic cannabinoids used for CINV as well as other types of nausea.