The Viability of Medical Marijuana

Published Online: Monday, September 12, 2011

The use of marijuana for medicinal purpose has been a hotly debated topic in the United States. While cannabis is still listed as an illegal narcotic under Federal Law, 16 states and the District of Columbia have statutes decriminalizing medicinal marijuana as a therapy for specific ailments. Recently, the American Medical Association released a report urging review of marijuana as a Schedule 1 controlled substance, noting that physicians should be protected from prosecution for recommending marijuana and that further studies should be conducted into marijuana’s use as medicine.

To provide further insight on this controversy, MD Magazine Peers & Perspectives convened two leading experts in the field to debate the merits or lack thereof of medical marijuana: Joel W. Hay, PhD, professor of clinical pharmacology and pharmaceutical economics and policy at the Shafer Center for Health Policy and Economics in the School of Pharmacy at the University of Southern California, and Joseph I. Sirven, MD, professor and chairman of the department of neurology at the Mayo Clinic in Arizona. The panel was moderated by Peter Salgo, MD.


Salgo: Are there any patients with particular conditions for whom medical marijuana is appropriate? If you don’t necessarily believe that’s true, what do the believers in medical marijuana tell you?

Hay: If you just look at the indications for Marinol and Cesamet, there’s no question that cannabinoids can have a positive risk-benefit for certain conditions. I think we’ve already identified some of them, things like chronic pain, wasting syndrome, appetite stimulation, and some other neuropathic conditions. It may be that other cannabinoids in marijuana may have additional benefits along these lines and possibly other lines. There’s no question that isolated, purified, pharmacological cannabinoids may have a very legitimate place in the medical armamentarium.

Sirven: I would agree with that. If after you have the risk-benefit discussion, in a pure fashion with regard to the chemical itself, it may be beneficial in those instances where really the other options have been utilized and this is really the one that seems to work for a given individual. That’s really where the discussion needs to lie, between physician and patient in making that decision for those conditions that are mentioned. But there are a lot of conditions where they’ve attributed a lot of benefit for this from patients. I’m a practicing neurologist. I see a lot of patients with seizures and epilepsy. I hear patients come to me saying how much it helps them, but the truth is we haven’t really seen that it changes those seizures. It just may change the perception of how they feel when they’re having these seizures.

Salgo: Let me dwell on that for just a moment. If nothing else is working to make the seizures better, but the marijuana makes them feel better, maybe makes them feel better about having seizures, isn’t that part of a physician’s responsibility to make the patient better?

Sirven: The reality is that seizures, although a symptom of a larger condition like epilepsy, are still medical emergencies, and to some degree for me—to be simply stating I have 20 anti-epileptics I can prescribe for you but because this one makes you feel the best and I’m not really sure it will do anything for your seizures—I’m not really helping them.

Salgo: Is anyone really arguing that? I mean, what I hear is that we don’t want to use it instead of anything. We certainly want to medicate seizures. We’ll look at seizure disorder here as a stand-in for any other disease state. Go ahead. Take your other meds. But add some marijuana if it makes you feel better, no?

Sirven: I wish it were that simple, but it never turns to that. The belief is most people don’t want to be taking medications. If this is making me feel better, I’m going to go with the agent that makes me feel better as opposed to the agent that’s actually helping prevent a very serious issue from occurring. So, on one hand, yes, that’s theoretically the way you phrase it, it kind of makes sense. Yet, practically speaking, when it really translates to the individual patient, the reality is that’s not the way the conversation goes. It’s more like, “I want to do this instead of the medication.” There’s almost this unusual perception, as though marijuana is the natural product and that the other agents are not.

Salgo: Are people really arguing that marijuana has a known therapeutic benefit in terms of disease states as opposed to symptoms? By that I mean it’s not an anti-cancer drug. It’s not an anti-seizure drug. It is an antiemetic in some people’s minds, which if you’re a chemotherapeutist might be a good thing to give your patients. But nobody’s claiming it cures cancer, are they?

Hay: Let me give you another example of an indication where there’s a lot of controversy— that’s glaucoma. In fact, there is some evidence that cannabinoids improve the intraocular pressure among people who have glaucoma or similar conditions, and the problem here is because marijuana is not developed pharmacologically as an agent, if you smoke marijuana to deal with your glaucoma, you may get some reduction in eye pressure for a few hours, but it’s not going to last the entire day. So, it’s very likely that you will actually make your glaucoma worse by relying on marijuana rather than using an FDA-approved medication that is specifically designed to deal with intraocular pressure in glaucoma. So, the American Academy of Ophthalmologists is on record saying marijuana is not an appropriate treatment for glaucoma. Yet if you go out, the sort of street wisdom is, that’s what people use. There are a lot of people using marijuana to treat their glaucoma, and it’s totally medically inappropriate. These cultural things get out there and people don’t talk to their physicians about them, they don’t find out what the evidence-based medicine literature says, and they actually create more harm than good.