In the wake of our State's dust-up over Medical Marijuana, I revisited a question I've had long simmering: Is pot a medicine?

Medicine, that is, in the sense that I think of a medicine as a physician: Is it demonstrably effective and safe at achieving some goal, preferably via a double-blind placebo controlled study. There is a paucity of such studies for pot; such studies are expensive. Neither of the two major funders of such studies—the pharmaceutical industry and the federal government of the United States—is particularly interested in knowing the answer. Further, the widespread availability of illegal pot makes running such studies difficult—people simply do not wish to participate in a study where they might receive a placebo.

Still, we have some rigorous studies of medical marijuana we can dig through.

The strongest data supporting the medical use of marijuana comes from those with HIV infection. The HIV virus—beyond attacking the T-cells of the immune system—attacks nerve cells in the body, frequently resulting in neuropathic pain—pain that is notoriously difficult to treat. (Chronic opiates are a poor treatment for nerve-originated pain; repurposed anti-seizure medicines like gapabentin, and repurposed
antidepressant meds like Nortriptyline are mainstays of traditional treatment.) A double-blinded, randomized and placebo controlled study of pot for this specific kind of pain (HIV-induced neuropathy) was published in 2007 by Abrams et al, showing decent pain control by smoking and few serious side effects.

Wallace et al, also publishing in 2007, randomized healthy volunteers to receive placebo or varying doses of THC via smoking, and then induced pain by injecting capsaicin (the chemical that makes hot peppers feel painfully hot) beneath the skin of the volunteers. Low to moderate doses of THC (intriguingly, not high doses) were significantly more analgesic than placebo.

Neuropathic pain is an important—and growing—problem, thanks to diabetes. A randomized, placebo controlled, double-blind study testing for this indication was unable to show any benefit of pot smoking over placebo for diabetic neuropathy.

In fact, a systematic review of the available double-blinded, placebo-controlled, randomized studies of pot cannot show a consistent benefit for pot, when used for neuropathic pain. Neuropathic pain is one—admittedly important and common—medical problem for which people in Washington State seek out medical marijuana.

Pharmaceutical companies have pounced on the potential here—devising an increasing variety of synthetic agonists and antagonists of the complex family of receptors that pot works through. These synthetic drugs are 'cleaner' by design—able to help with pain, cachectia, glaucoma and so on, with fewer side effects and more reliable efficacy than the complex, variable and often contradictory (in physiologic effects) from smoking the plant. You might feel 'natural' is better or safer. As a scientist, driven by data, I'm telling you this now: Pharma is going to win this one in the lab—legitimately. Eventually, for any medical indication pot might sometimes help, a pharmaceutical company will have devised a safer, more effective, related drug.

There is a nudge-nudge, wink-wink, aspect to medical marijuana. The secondary gain here—a plurality of us would be fine with recreational pot being legal, taxed and regulated—roils just below the surface of the medical marijuana 'debate'. On that basis, it's much easier to prove a few basic points. Smoking pot is pleasurable. It's demonstrably safer than other, legal, recreational substances. Alcohol, comparatively, is a disaster of health concequences—mental and physical. Alcohol, despite being legal, is vastly more expensive socially as well.

If you want pot to be legal for recreation, ask for pot to be legal for recreation.