By: Aislinn Antrim, Assistant Editor
ALTHOUGH CANNABIS IS still considered a Schedule I agent by the Drug Enforcement Administration, many patients with cancer turn to cannabis products for relief from some of the adverse events (AEs) associated with treatment. For this reason, and because of changing attitudes around marijuana use, oncology pharmacists should educate themselves on the uses of marijuana and the dangers of combining it with chemotherapy, according to information presented in a session at the Hematology/Oncology Pharmacists Association 2020 Meeting in Tampa, Florida.
Cannabis is composed of more than 480 compounds and 70 distinct cannabinoids, but tetrahydrocan-nabinol (THC) and cannabidiol (CBD) are the 2 most commonly used, according to presenter Alyssa Heiden, PharmD, BCOP, clinical oncology pharmacist at Children’s Hospital Colorado (CHC). “At my institution, I have seen a lot of cannabis use in patients in recent years,” Heiden said.
In a cross-sectional anonymous survey of 926 adult patients with cancer, 222 respondents said they were active cannabis users, according to Heiden. Notably, most respondents said they preferred to get information about cannabis products from their cancer team, but less than 15% actually received this information from their cancer physician or nurse.
Legally, cannabis exists in a gray space. Heiden explained that decisions about legalization have been left largely to individual states, adding that pharmacists should stay aware of changing laws. Pharmacists should not recommend a specific source for obtaining cannabis among states that allow medical marijuana, Heiden said, and should refrain from giving patients specific instructions on use and from obtaining the drug for patients.
The most important step for pharmacists, Heiden said, is to ask patients about which product they are using or are interested in.
Based on current research and recommendations, Heiden said THC’s proposed therapeutic effects include control of nausea and vomiting, appetite stimulation, pain management, and decreased ocular pressure.CBD has a low affinity for CB1 and CB2, and it works to break down anandamide, GPR55, and TRPV. Heiden said its proposed therapeutic effects include treatment of epilepsy, appetite stimulation, and pain management.
Overall, Heiden said cannabis products can counter some negative aspects of chemotherapy.
- Controlled clinical trials and anecdotal evidence have supported the use of cannabis for nausea and vomiting. In addition, the FDA has approved 2 THC-derived drugs, dronabinol and nabilone, for chemotherapy-induced nausea and vomiting.
- Some evidence supports the use of cannabis products for increasing appetite in patients receiving chemotherapy. Dronabinol is indicated for the loss of appetite due to AIDS.
- Limited data support the use of cannabis products to treat and prevent peripheral neuropathy from vinca alkaloids, platinum agents, and taxanes. CBD also has notable anti-inflammatory properties.
- Studies have supported the use of cannabis products as short-term sleep aids, especially for patients with chronic cancer-related pain.
- In patients with anxiety, THC may increase symptoms,while CBD can act as an anxiolytic.• Notably, Heiden said there is insufficient evidence that cannabis can have anticancer effects in humans.
Despite these potential positive effects, Heiden emphasized that cannabis products can interact significantly with some cancer drugs. She recommended several resources for understanding these interactions, including TRC Healthcare’s Natural Medicines database and resources available online from Memorial Sloan Kettering Cancer Center.
Aside from drug interactions, significant AEs of cannabis can include cardiovascular effects (tachycardia, hypotension, and hyper-tension), hyperemesis syndrome, bronchodila-tion, decreased gastrointestinal motility, and sedation.
Heiden also outlined her hospital’s policy as a case study of the various issues health systems should consider when designing a cannabis policy. Heiden said that any CHC patient who wants to use medical marijuana must complete a release and waiver of liability form. The pharmacist is involved only in ensuring that the method is either oral or topical (inhaled methods are not permitted) and that patients have a medical marijuana card.
Heiden said that CHC has a cannabis consult team to meet with patients and their families about the use of medical marijuana.
Finally, Heiden said, it is important to keep an open dialogue with patients.
“We need to keep an open mind, and be honest with [patients] so that they can come to us, and be honest with us, at any point during their care,” Heiden concluded.
Heiden A. Chemotherapy and Cannabis: Best Buds? Presented at: Hematology/Oncology Pharmacists Association 2020 Meeting in Tampa, FL: March 12, 2020.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.