Chemotherapy is a common form of cancer treatment that uses potent drugs to stop rapidly producing cells in your body from multiplying. Although it’s meant to prevent tumor cells from reproducing, chemotherapy can also affect the healthy cells in your body.
Nausea and vomiting are the most common chemotherapy side effects. Chemotherapy may also cause fatigue, hair loss, diarrhea, constipation, and loss of appetite, among other adverse reactions.
For decades, many individuals have turned to cannabis to help restore their appetite and decrease their nausea during chemotherapy. The antiemetic (nausea-reducing) properties of cannabis have been recognized for centuries, as well.
Prior to cannabis prohibition in America, cannabis was added to the U.S. Pharmacopeia in 1850 for alleviating nausea, labor pains, and rheumatism, among other ailments. However, it was removed in 1944 due to political pressure to ban its use nationwide.
So, what do modern medicine and science have to say? Can cannabis help alleviate some of the side effects associated with chemotherapy?
Can Cannabis Reduce Chemotherapy Side Effects?
Many studies have further investigated the efficacy of using cannabis to alleviate chemotherapy side effects. Most of these studies have focused on whether THC can relieve nausea and vomiting among individuals undergoing chemotherapy.
There have also been some studies on the efficacy of cannabis for reducing cancer-related pain.
Furthermore, the Food and Drug Administration authorized the use of Δ9-THC to create medicine that would alleviate chemotherapy-induced nausea and vomiting during the 1980s. Since then, several THC-based pharmaceutical drugs have been developed, including Dronabinol (a.k.a. Marinol), Nabilone, and Levonantradol.
Cannabis & Chemotherapy Nausea Relief
Several studies have investigated the efficacy of cannabinoid-based pharmaceuticals and cannabis extracts for alleviating chemotherapy-induced nausea.
One study reviewed 30 papers on the efficacy of Dronabinol, Nabilone, and Levonantradol in comparison to conventional antiemetic medications. Although the sample sizes of the studies were small, Dronabinol had better efficacy than conventional antiemetic medications.
Nabilone and Levonantradol didn’t have statistically significant superior efficacy to the traditional antiemetic medications, though.
However, the study says that cannabinoid medicines were associated with more frequent side effects, including a “high sensation,” euphoria, sleepiness, and sedation.
Yet, the authors note these side effects “would be potentially ‘beneficial’ for most patients; in other words, they would be pleasant during the chemotherapeutic treatment.” Despite their potential side effects, most patients said they preferred the cannabinoid medications in double-blind and cross-over studies, too.
Another study assessed the efficacy of an oral, 1:1 THC:CBD extract on chemotherapy-induced nausea and vomiting. Eighty-one participants were randomized and either received a 1:1 capsule of 2.5mg THC & 2.5mg of CBD or a placebo three times per day for five days.
Twenty-five percent of participants who received the 1:1 THC:CBD extract had a “complete response,” meaning they experienced no vomiting or nausea after taking it. Sixty-nine percent reported no vomiting, and twenty-one percent reported “no significant nausea.”
One-third of the participants reported adverse side effects from the 1:1 extract, with the most common being sedation, dizziness, and disorientation. However, eighty-five percent still preferred the 1:1 extract over the placebo medication.
The participants also reported minor but significant improvements in their quality of life scores on the dimensions of mental health and pain.
Cannabis & Appetite Stimulation
Weight loss due to nausea, vomiting, and lack of appetite during chemotherapy is another side effect researchers have turned to cannabis to evaluate whether it may help.
Regarding appetite stimulation, several studies cited by the review demonstrated that cannabis may increase appetite among chemotherapy patients. In one study on patients taking Dronabinol, the participants not only reported improvements in their appetite but reported that food seemed to taste better.
The authors explain that CB1 receptors in your brain’s hypothalamus may help regulate feeding behaviors. Moreover, the authors suggest that CB1 receptors — which are activated by endocannabinoids and THC — ”may be involved in the motivational or reward aspects of eating.”
Cannabis & Cancer-Related Pain Management
“In 2016, The American Society of Clinical Oncology published guidelines to help cancer survivors manage chronic pain,” says a review article by Byars et al. “These recommendations included the use of cannabis and cannabinoid-based medicines.”
The review also describes how phytocannabinoids and terpenes can help reduce inflammation and pain. Furthermore, the review details how cannabinoids can alleviate the following types of pain:
- Nociceptive Pain: This is pain caused by damage to bodily tissue. Nociceptive pain may feel sharp, throbbing, or aching and may be caused by bruises, inflammation, sprains, or bone fractures. The presence of CB2 receptors throughout the immune system suggests that cannabinoids can modulate inflammatory responses since inflammation is part of the body’s immune system.
- Neuropathic Pain: This is pain caused by damage or injury to nerves. Neuropathic pain can feel like burning, tingling, numbness, or an “electric shock.” Several studies cited throughout the review found cannabis effective for alleviating neuropathic pain.
- Nociplastic Pain: Nociplastic pain is similar to nociceptive pain in terms of sensation but differs in its mechanism. While nociceptive pain results from active/recent damage to the body, nociplastic pain results from ongoing inflammation and damage. The authors suggest that hypoactive or hyperactive endocannabinoid systems may cause nociplastic pain, and regulation through cannabinoids may help rebalance the ECS and reduce nociplastic pain.
Key Takeaways: Cannabis May Alleviate Chemotherapy-Induced Nausea
Nausea and vomiting are some of the most common symptoms of chemotherapy. These symptoms can also lead to loss of appetite and weight loss, which can be very troublesome for patients with cancer to manage.
The nausea-relieving properties of cannabis have long since been acknowledged and studied. Since the 1980s, several cannabinoid-based pharmaceutical drugs have been approved by the FDA for managing chemotherapy-induced nausea and vomiting.
Several studies, reviews, and clinical trials have demonstrated the efficacy of cannabinoid-based pharmaceuticals and cannabis extracts for alleviating these side effects of chemotherapy.
Additionally, studies have also reported that cannabinoids may increase appetite and help with the management of cancer-related pain.
To learn more about the effects of cannabis on cancer cells, listen to episode 13 of the Cannabis Science Today podcast. In this episode, host Emily Fata interviews Professor Hinanit Koltai, a biologist and the Director of Cannabis Research at the Volcani Center in Israel. Together, they discuss what cannabis molecules have been showing the most therapeutic potential against specific lines of cancer cells.
- MACHADO ROCHA, F., STÉFANO, S., de CÁSSIA HAIEK, R., ROSA OLIVEIRA, L., & da SILVEIRA, D. (2008). Therapeutic use ofCannabis sativa on chemotherapy-induced nausea and vomiting among cancer patients: systematic review and meta-analysis. European Journal of Cancer Care, 17(5), 431–443. https://doi.org/10.1111/j.1365-2354.2008.00917.x
- Grimison, P., Mersiades, A., Kirby, A., Lintzeris, N., Morton, R., Haber, P., Olver, I., Walsh, A., McGregor, I., Cheung, Y., Tognela, A., Hahn, C., Briscoe, K., Aghmesheh, M., Fox, P., Abdi, E., Clarke, S., Della-Fiorentina, S., Shannon, J., Stockler, M. (2020). Oral THC:CBD cannabis extract for refractory chemotherapy-induced nausea and vomiting: a randomised, placebo-controlled, phase II crossover trial. Annals of Oncology, 31(11), 1553–1560. https://doi.org/10.1016/j.annonc.2020.07.020
- Abrams, D., & Guzman, M. (2015). Cannabis in cancer care. Clinical Pharmacology & Therapeutics, 97(6), 575–586. https://doi.org/10.1002/cpt.108
- Byars, T., Theisen, E., & Bolton, D. L. (2019). Using Cannabis to Treat Cancer-Related Pain. Seminars in Oncology Nursing, 35(3), 300–309. https://doi.org/10.1016/j.soncn.2019.04.012
- Wilkie, G., Sakr, B., & Rizack, T. (2016). Medical Marijuana Use in Oncology. JAMA Oncology, 2(5), 670. https://doi.org/10.1001/jamaoncol.2016.0155