Cannabis has long been held as a beneficial treatment for cancer patients in relieving many unpleasant symptoms that are related to the disease. Early studies into animal models revealed that the psychoactive compound tetrahydrocannabinol (THC) slowed the growth of tumors in mice with different forms of cancer. These findings were not widely publicized, but pharmaceutical companies have since tried to replicate the findings in trials of their own. Still, most of the focus on THC and cancer has been placed on chemotherapy and alleviating its symptoms, including nausea, vomiting, loss of appetite, and malaise. Furthermore, studies reveal that the non-psychoactive compound cannabidiol (CBD) may also suppress vomiting and nausea. THC and CBD have been evaluated in small clinical and observational trials which produced positive results regarding their anti-emetic capabilities, though studies suggest that a combination of both compounds can enhance their therapeutic capabilities.
Cannabidiol (CBD) and Nausea
In an animal model, rats were administered CBD following drug-induced nausea and observed for changes. Evidence of success was present in the suppression of conditioned gaping (an open mouth behavior exhibited by rats experiencing nausea) in the rats. In another experiment, house musk shrews were injected with lithium to induce vomiting and were later given either CBD or THC; both cannabis compounds were effective as anti-emetic treatments in the shrews. These models paved the way for interest into human research and trials focused on cannabis treatment and chemotherapy-induced nausea and vomiting.
Lacking are reports that specifically evaluates CBD alone as a nausea and vomiting suppressor in chemotherapy patients, as well as, reports evaluating the effects of a combination of CBD and THC on vomiting or nausea in an animal model. However, in a human phase II clinical trial, which evaluated the cannabis based oral medicine Sativex (contain a 1:1 ratio of Delta-9-THC and CBD), patients not only tolerated the drug when compared to placebo patients, but incidences of delayed vomiting were also reduced, proving that a combination of THC and CBD may very well be effective in managing nausea and vomiting in chemotherapy patients. In the U.S, Sativex is still awaiting approval by the Food and Drug Administration (FDA), but British GW Pharmaceuticals is in phase III U.S. clinical trials evaluating its efficacy in remedying cancer pain.
Tetrahydrocannabinol (THC) and Nausea
The psychoactive cannabis compound THC has been found to be effective at minimizing chemotherapy-induced nausea. More specifically, there is evidence that suggests Delta-8-THC, a less psychoactive version of Delta-9-THC, can control nausea and vomiting in children going through chemotherapy treatment. In one study, children were given a drop of Delta-8-THC under the tongue or with a bite of food two hours before chemotherapy treatment and six hours after treatment for 24 hours; both acute and delayed nausea and vomiting were regulated, and only two children (age 3.5 and 4) reported slight irritability. Source http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165951/
The closest thing to a cannabis-based THC drug on the market is Dronabinol, a FDA approved synthetic THC prescription drug used to treat nausea and vomiting, along with weight loss and poor appetite resulting from chemotherapy. The downside to Dronabinol is that it can be difficult for patients to swallow, especially those who have bad bouts of vomiting that irritates the throat. Furthermore, digestion is slow, which delays the response. Additionally, another drug Nabiximols, a cannabis oral spray of THC and CBD extracts combined, has been effective in treating pain in cancer patients, but the drug has not been approved in the U.S. However, clinical trials are currently being conducted to evaluate its efficacy in treating a number of conditions (some related to cancer). Research also suggests that the combined administration of both CBD and THC may enhance their therapeutic potency in a way that each could not separately. This is an area that warrants additional research since THC combined with other cannabis compounds could prove beneficial in treating the symptoms of other ailments other than cancer.
While cannabidiol (CBD) has been the focus of many earlier studies into the medical benefits of cannabis in treating different illnesses, tetrahydrocannabinol (THC) has slowly emerged as having therapeutic benefits despite its psychoactive properties. Both compounds have been proven to be effective in treating chemotherapy related nausea and vomiting. The medicinal benefits of cannabis cannot be denied, but in order for research and advancement in the U.S, laws need to be changed. The debate about cannabis and its medicinal use is an evolving one, and will continue to be as long as cannabis compounds such as CBD and THC keeps the conversation open in the scientific and medical world.