U.K. Approves Pot-Based Drug: A High or Low for Medical Marijuana?

It looks like marijuana sales may be moving from the street corner to the pharmacy in the U.K., where a drug derived from cannabis went on sale Monday. Sativex, which was developed by GW Pharmaceuticals and will be marketed by Bayer, is intended for multiple-sclerosis patients. It's the world's first prescription drug made from pot, according to The Wall Street Journal, and Canadian regulators approved its use back in 2005.

British regulators approved the drug Friday. GW Pharmaceuticals also plans to seek approval for Sativex in other countries, including Spain, Germany and Italy. In the U.S., where Phase III (late-stage) clinical trials are set to start later this year, the company hopes to market the drug as a painkiller for cancer patients. Analysts estimate that annual revenues from Sativex will ultimately reach $74 million to $148 million.

These massive potential revenues have reignited the controversy over medical marijuana. If the active chemical in pot, tetrahydrocannabinol, or THC, has proven its effectiveness for medical purposes in Sativex, could that lend more legitimacy to the idea of using marijuana leaves directly for medical purposes? Or will new pharma-developed drugs like Sativex outcompete marijuana in its original form?

Pricing the Pot Market

First, let's take a look at how Sativex and marijuana would compete on cost. Of course, the current average prices for pot are much higher than they would be if the plant could be widely grown legally, and it's hard to tell exactly what it would cost in that case. Because of its illegality, marijuana cultivation, transportation and sales are fraught with peril. The lack of secure supply chains and the potential cost of run-ins with the law tend to keep black market prices high.

However, a few open markets hint at what the actual market value of marijuana could be. In Amsterdam, for example, prices range from $1.50 to $10 per gram, depending upon the quality and origin of the marijuana. In Canada, the per-gram price for medical marijuana is only $4.91 ($5 Canadian).

The overall range, then, is $1.50 to $10 per gram for legal marijuana, with $5 per gram as a workable baseline. In Canada, the standard daily dose of medical marijuana ranges between 0.5 and 1.5 grams, which would cost roughly $2.50 to $7.50 for most patients. By comparison, a basic daily dose of Sativex costs roughly $16 per day. And a daily dose of Marinol, a drug containing synthetic THC that's prescribed for AIDS and cancer patients in the U.S., runs between $9 and $13.50 per day.

This translates into a monthly price of $150 for marijuana, $337 for Marinol and $480 for Sativex. The comparatively high prices of Sativex and Marinol aren't surprising. In fact, it's a little shocking that they don't cost more. Sativex is a processed version of marijuana, which means that its cost is directly tied to the base cost of the plant. Marinol, on the other hand, is a synthesized version of THC and contains far more THC than marijuana. In both cases, the cost of manufacturing massively increases the price that patients -- or health-care providers -- pay.

Challenges to Medical Marijuana

The basic argument against medical marijuana lies in its classification as a Schedule 1 substance, which means that it has a high potential for abuse, that it does not have an accepted medical usage and that there is a lack of accepted safety for its use in a medical setting. This, by the way, puts marijuana in the same class as heroin, LSD and peyote.

But with the increased acceptance of THC-based drugs like Marinol and Sativex, the Schedule 1 argument starts to crumble. In fact, Marinol contains far more THC than standard marijuana, which can provoke some unpleasant reactions. One consumer, Robert Randall, complained, noting: "When I took Marinol, I found it anxiety-provoking and intense, like I had wandered into a short story by Flannery O'Connor." (Sativex avoids this effect with a different chemical composition and delivery system, GW claims.)

Another argument is that pharmaceutical companies can produce THC content with higher consistency and quality than medical marijuana. Critics of medical marijuana question whether actual marijuana can have the consistent THC content necessary for prescription use. Sativex, which is made from medical marijuana cultivated in secret farms around the UK, seems to suggest that marijuana plants can be grown with relatively consistent THC.

Smoked Medication vs Pills

The final key argument against medical marijuana is that it's usually smoked. No medicines that are smoked are approved by the U.S. Food and Drug Administration today, and the U.S. Drug Enforcement Agency claims that a marijuana cigarette contains four times more cancer-causing tar than a normal cigarette. Then again, other methods of consumption -- including vaporizers, water pipes, and cooked goods -- can reduce or even eliminate the tar problem.

For supporters of medical marijuana, Sativex may seem to be a step backward. After all, the marijuana derivative is yet another stopgap separating sick people from a cheap, common, easily produced medication. Then again, as accepted medications start to draw closer and closer to actual marijuana, the arguments against the "the demon weed" increasingly seem to be going up in smoke.