How cannabis and cannabinoid isolates have revolutionized the treatment of medication-resistant nausea, dizziness, and anorexia
Considerable evidence demonstrates that manipulation of the endocannabinoid system regulates nausea and vomiting in humans and other animals.  Recently, evidence from animal experiments suggests that cannabinoids may be especially useful in treating the more difficult to control symptoms of nausea and anticipatory nausea in chemotherapy patients.
Cannabis, or extracts thereof, has been used for several centuries for a number of therapeutic applications.  Included among them was the attenuation of nausea and vomiting.  The prevalence of cannabis-based therapeutics evaporated with the passage of the 1937 Marihuana Tax Act, yet ineffective treatment of chemotherapy-induced anorexia prompted oncologists to investigate these anti-emetic properties of cannabinoids in the late 1970s and early 1980s. To show how far we’ve come, just look at a 2014 WebMD poll of oncologist, which indicated an 82% belief that patients should have access to cannabis to support their oncological medical care.  Talk about resurrecting a medication from the dead.
Cannabis: Patient-tested, doctor-approved
According to the American Cancer Society, there are two chemically pure drugs based on cannabinoid scaffolds that have been approved in the United States for medical use. Dronabinol, brand name Marinol®, is a gelatin capsule containing purely synthetic THC. It is approved by the FDA to treat nausea and vomiting caused by cancer chemotherapy, as well as to counteract weight loss and poor appetite in patients with AIDS. Nabilone, called Cesamet®, is a synthetic THC cannabinoid analogue specifically licensed to be administered orally as a treatment for medication-resistant, chemotherapy-induced nausea and emesis. 
Studies indicate that the efficacy of Dronabinol alone is comparable to traditional pharmaceutical intervention in the treatment of delayed nausea and vomiting, while reporting the lowest nausea intensity by more than half. Important to note is that this study was done at a 50% lower dose than other similar studies, demonstrating the efficacy at even low cannabinoid concentrations.
There are some concerns with the way previous clinical trials have been conducted.  Patients enrolled in these studies have consistently expressed a preference to smoked rather than oral cannabis delivery vehicles.  Conversely, all reported adult clinical trials for the effectiveness of cannabinoid compounds on chemotherapy-induced nausea and vomiting have involved oral use of isolated cannabinoids.  These may be less effective than sublingual or inhaled doses due to the absence of the “entourage effect,” or synergetic activity of multiple cannabinoids working physiologically in concert.  Oral doses likewise have a longer onset period, and dosing can represent a particular challenge in patients who are having trouble with nausea in the first place. 
Aside from problems with these adult-based cancer models, there is evidence to suggest sublingual doses of cannabinoid preparations are effective in treating the more difficult to control symptoms of nausea and delayed nausea plus vomiting in children. In a model evaluating the anti-emetic effectiveness of delt-8-THC, a close but less psychoactive relative of delta-9-THC, in children receiving chemotherapy treatment, both acute and delayed nausea and vomiting were controlled by cannabinoid administration before and after chemotherapy sessions. Notably, no serious side effects were reported for the entire cohort of 480 children. 
Cannabis might be less potent than other available anti-emetics, but for some patients, it is the only agent that works. It is also the only medication in this class that concurrently increases appetite. To illustrate, an oncologist practicing for over 30 years published an e-mail from a 42-year-old patient with metastatic colon cancer regarding his use of medical cannabis:
“Although I did not use it [cannabis] until my last 5 sessions of chemo (me getting over the stigma of its use), it did what no other drug could do, completely solve the severe nausea I had.
It allowed me to play with my children, attend their sports and school functions, and just function very normally in day to day activities.
I cannot thank you enough for giving me that option!” 
We can only wish similar success for all cancer patients, suffering so much already, who’s pain may be even slightly eased by this harmless herbal preparation.
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