RSS

Medical marijuana in cancer patients

June 2015

MD, ABFM, ABIHM, Director, Medical Student Education Program, WD and Laura Nell Nicholson Family Professor of Integrative Medicine, Professor, Family Medicine University of Texas Distinguished Teaching Professor

 Recently, I was making a house call. The family of a hospice patient with metastatic lung cancer asked me about using marijuana as part of her plan to manage pain, anorexia, nausea, weight loss, and sleep problems. I discussed with her and the family some of the work of Dr. Donald Abrams at the University of California at San Francisco. His carefully done research on medical marijuana for over a decade helps us sort out these kinds of questions. Abrams, an oncologist and HIV specialist, has been funded by National Institutes of Medicine and provided him with officially approved, though low potency herbal preparations.

In his research, he uses a Volcano Vaporizer, which heats and vaporizes the dried herb rather than combusting it as in the typical marijuana cigarette, joint, pipe, or reefer. This avoids the delivery of carbon monoxide and various chemicals and ash that irritate the airways and are toxic. Blood levels of THC, the active ingredient, are noted within about 2 ½ minutes with the vaporizer. Abrams prefers this delivery system to ingested marijuana, say in muffins, brownies, or cookies, since absorption is much less predictable from food sources and tetrahydrocannabinol (THC) levels do not go up until a couple of hours or more after eating. This may lead to patients ingesting an extra cookie or so and knocking themselves out for a day or two with too much THC.

It turns out in both human and animal models, the cannabinoids in marijuana offer a broad spectrum of benefits, especially for cancer patients. Cannabinoids are psychoactive or somatically active chemicals that give marijuana its clinical effects. The human body has natural cannabinoid receptors, and there are endogenous cannabinoids even in breast milk, in women who are not using marijuana. No wonder nursing infants seem so happy!

Marijuana has multiple effects in the kinds of problems cancer patients suffer from insomnia, lack of appetite, anxiety and depression, pain, neuropathy, and nausea. While there is a genomic variability in response, with some people getting very stoned quickly and others getting more anxious or even paranoid, it turns out that marijuana is pharmacologically very safe with little or no potential for overdose, even at high doses.

On the other hand, most cancer drugs, painkillers, and many prescription medicines are lethal at high doses. A recent article reported that hydrocodone products for pain are the number one prescribed drug paid for by Medicare. It is prescribed mostly by primary care doctors, despite its risk of addiction, and there are thousands of deaths annually due to prescription opiate overdose, roughly 50 deaths a day. This lethality is not seen with marijuana, so at least the safety of marijuana is reassuring. Though there is a large margin of physiological safety, it does not extend to recommending it while driving or doing other hazardous things under the influence. Marijuana can definitely affect reaction time, driving skills, and can impair judgment and memory.

Medical marijuana has been legal in California for over 18 years and the patient and physician population there have developed a lot of clinical and streetsmart experience with different species, delivery systems, and dosing. Physicians can legally counsel their cancer or chronic pain patients on whether marijuana could or should be part of their treatment plan and if so to prescribe it there. It is not for everyone. Those with a strong personal or genetic tendency to addiction or certain mental problems such a paranoia and excess anxiety would not be optimal candidates, for example, except perhaps in terminal illness.

As you know, there is widely voiced opposition to liberalizing the rules against marijuana cultivation, distribution, and possession. Abrams believes our society suffers from “euphorophobia”, a deep suspicion of any substance that makes us feel happy. However, in a population of cancer patients, a little happiness is not a bad thing.

So while the legal and moral debates on the wisdom of making medical marijuana legal rage on, some cancer patients are benefitting from his and others’ careful research on its pharmacodynamics, safety, and clinical effects. It is legal now in about two-dozen states for medical purposes. Still, medical marijuana use is in a legal morass now since it is illegal by federal law while legal at the state level, even for recreational purposes in four states. Oklahoma and Nebraska are even suing Colorado in federal court since those buying legal pot in the Rocky Mountain high state, are stashing it and carrying it across state borders into the lowlands.

If you are a physician, it is not legal yet to prescribe it in Texas, and I told my hospice patient this. I warned that she needed to be careful about her source of marijuana if she and her family decided to use it medically. Street sources may be laced with other drugs with serious side effects. This is one reason that controlled, licensed medical marijuana pharmacies have arisen in other states. The family told me that it would not be a problem as they had a reliable source of quality organic weed on Main Street who could supply all they needed.

As I left from my house call, walking past family members of this lung cancer patient, who were smoking cigarettes in the driveway, I scratched my head at the legally and ethically paradoxical situation. Here she was dying from a legal drug, tobacco that she had used for over 60 years and could not legally get a potentially palliative botanical medicine.

She died less than two weeks later. I am not sure if her hospice care team knew about the marijuana question or even if she ultimately used it. It made me wonder though if lawmakers might rethink the question of legalization here in the Lone Star state for medical compassion purposes, particularly in advanced cancer patients.