Why more doctors are supporting use of medical marijuana

In Community, Feature Stories by Dr. Tim Sandle, Ph.D.

A recent survey found that 76 percent of North American doctors would approve the use of medical marijuana, as reported by the New England Journal of Medicine. What is persuading doctors, from the U.S. to the U.K., to prescribe a plant that would have never been on their professional radar years ago?

Medical marijuana is gaining favor with physicians because new research is pushing away the fear of embracing cannabis’s potential, according to Mark A.R. Kleiman, Professor of Public Policy at the University of California (UCLA) School of Public Affairs.

Professor Kleiman runs through the positives gained from his years of research: “My reading of the evidence is that there is an overwhelming probability that some of the cannabioids and other chemicals in cannabis will turn out, singly or (more likely, in my view) in combination, to be safe and effective therapies for some conditions and symptoms.”

This promed-cannabis stance is echoed by a doctor on the other side of the Atlantic. Dr. Camille Carroll, Honorary Consultant Neurologist at the Peninsula College of Medicine and Dentistry, agreed that there are “undoubtedly some beneficial effects of specific cannabinoids.” Also in the medical-marijuana corner is Dr. Mark Ware, MD, Associate Professor in Family Medicine and Anesthesia at McGill University (Canada). Dr. Ware says family physicians should “become more familiar with cannabis” and authorize its use in situations where it “can effectively help to alleviate suffering.”

These opinions by leading physicians are also reflected in recent opinion polls. Earlier this year, a poll of New York-based doctors indicated that the majority backed the use of marijuana for medical reasons on the grounds of “compassionate care.” In 2012, a similar poll of medics in Canada indicated that a narrow majority would “provide support in at least some cases.”

This interest by doctors to prescribe medical marijuana is also clearly captured in the British Medical Association’s official stance, which stresses that “users of cannabis for medical purposes should be aware of the risks, should enroll for clinical trials, and should talk to their doctors about new alternative treatments; but we do not advise them to stop.”

The use of medical marijuana to help ease the pain of a condition like breast cancer represents just one use of marijuana that some physicians recommend. Running through the possible uses for pain therapy, Paul Consroe, Professor Emeritus, Department of Pharmacology and Toxicology at the University of Arizona, lists conditions such as “glaucoma, cancer, chronic pain, epilepsy, HIV/AIDS, multiple sclerosis, and retching.”

Another physician, California MD Daniela Drake, writes on her blog about her experiences with patients and the various beneficial effects of medical marijuana: “I heard stories of people who finally found non-addictive pain relief: paralyzed middle-aged men in wheelchairs, moms with fibromyalgia, grandmas with rheumatoid disease, young adults with lupus. There were those who were frozen by anxiety now granted new life.”

Thanks to these positive effects, a number of U.S. states have allowed doctors to prescribe marijuana. While any form of marijuana use remains illegal at the federal level (under the Controlled Substances Act, 2009), 18 states, together with the District of Columbia, allow the use of marijuana for medical purposes. The policy across these states is not a one-size-fits-all approach for the amount that any individual can possess, and where the marijuana can be consumed varies considerably. Nonetheless, the signal is that the number of state licenses is set to grow.

The use of medical marijuana is also of growing interest in Canada. Canada differs from the U.S. in that medical marijuana use is operated at the national level (through Health Canada) rather than regionally. This centralization arguably gives more consistency when licenses are issued.

In the UK, there are greater restrictions in force. These come more from the political level as opposed to reflecting the opinions of most medics.

To help further promote the benefits of medical marijuana, some physicians have become involved with campaign organizations. For example, Dr. Kleiman’s university, UCLA, is the site of one of the U.S.’s leading cannabis research organizations: the Center for Medicinal Cannabis Research (CMCR). The organization sets out to coordinate rigorous scientific studies to assess the safety and efficacy of cannabis and cannabis compounds for treating medical conditions.

One subject the CMCR discusses is the best way for patients to take med-cannabis. What scientists call the “drug delivery system” is all about the drug reaching the appropriate parts of the body to relieve pain quickly and effectively. One of the most common ways to take marijuana, as Dr. Kleiman explains, is smoking it. An advantage of smoking is that the effects of smoked marijuana are felt within minutes, whereas when med-cannabis is eaten or drunk it can take up to an hour before the patient feels the benefits.

There are, however, downsides to smoking: inhaling makes it difficult to standardize the dose (how much each patient takes in). Peninsula College’s Dr. Carroll adds she is worried about some of the “potentially serious side effects” associated with smoking on the health of the patient.

Given the different ways to ingest medical marijuana, adopting a universal approach to its use is probably not the best policy, according to Dr. Kleiman. “The optimal delivery system is not yet known; topical, oral, mucosal, and inhaled administrations are all possibilities, and the optimal system might not be the same for all conditions or all patients.” So smoking might work best for one patient, where as a tablet form might best suit another.

The form in which medical marijuana should be taken also interests Dr. Carroll. The UK physician is less in favor of unprocessed or “pure” marijuana, and instead prefers it to be taken in the form of THC extracts (tetrahydrocannabinol, the principal psychoactive constituent of the cannabis plant). “There are plenty of clinical trial data supporting the efficacy of THC extracts so I would support the use of this compound, not cannabis as a whole,” Dr. Carroll adds.

One interesting research area is aimed at looking at how med-pot can be used as a new treatment for different pain- related conditions. Certainly the full range of possibilities has yet to be realized. According to Dr. Kleiman, “Cannabis is not a single drug like aspirin or oxycodone. It contains at least three, and probably dozens of different psychoactive molecules and their effects interact with one another in as-yet-unknown ways.”

Dr. Carroll discusses some of these research applications further: “There is plenty of research into the potentially beneficial effects of specific cannabinoids. For example, the neuroprotective effects of THC, or the symptomatic potential of THC in animal models of Parkinson’s disease.” This ailment’s symptoms include tremors while at rest, slow movement and muscle rigidity.

This type of research requires clinical trials. While most medics agree that such trials should be prepared to consider all sorts of pain-related conditions, many caution that the trials should be run as they would be for any other Big Pharma drug.  According to Dr. Carroll, medical cannabis trials “should be developed as pharmaceuticals and subject to the same degree of investigation and regulation.” Other medical professionals agree. Dr. Stanley Zammit of Cardiff University advises that patient health should be the main focus, with special attention paid to the “mental health outcomes of cannabis use.”

Although the majority of medical opinion is broadly in support of the use of med-cannabis, there are some dissenting voices. Eric A. Voth, MD, chairman of the influential Institute on Global Drug Policy, is worried about the unpredictable nature of the marijuana drug. Voth goes on to list several side effects of concern, including “changes in behavior, intoxication, psychosis, anxiety, dysphoria, stimulation of bipolar illness, respiratory difficulties, and changes in fetal development.”

The association of medical marijuana with major side effects is not a view shared by Professor Consroe, who states that “tolerance develops to the cardiovascular effects and most subjective effects, and only a mild withdrawal syndrome occurs on cessation of the drug.” He adds that “marijuana does not pose greater risks than licit social drugs such as alcohol, tobacco and caffeine.”

Meanwhile, Dr. Ware recounts the long history of marijuana being used to successfully relieve pain: “Crude preparations of herbal cannabis have been used for thousands of years to treat many symptoms, including pain, spasms, and nausea.”

Another concern raised by Dr. Voth looks at the lack of medical controls in relation to doctors prescribing medical marijuana: “The legalization and legislative processes bypass the FDA and that jeopardizes consumer safety,” he says.

Not all physicians agree with the need for more regulation. Dr. Kleiman would rather see less bureaucracy, as he discusses from a U.S. perspective: “The federal government ought to get out of the way of doing that research by ending the current monopoly on the supply of research cannabis and the unnecessary extra research-approval step that now applies to cannabis and no other drug.”

Flickr photo courtesy Life Mental Health