Comments by Lester Grinspoon MD on

Britain Poised to Approve Medicine Derived From Marijuana

January 27, 2004. New York Times

I am pleased that the New York Times carried the piece, "Britain Poised to Approve Medicine Derived from Marijuana" if for no other reason than it contributes to the growing understanding that cannabis has some remarkable medicinal utilities. However, I am disappointed that it did not address some of the concerns about Sativex and G. W. Pharmaceuticals.

GW Pharmaceuticals sold this product to the Home Office on the assertion that it will provide all of the medical benefits of cannabis without imposing on the patient the two "dangerous" effects -- those of smoking and getting high. There is very little to support the proposition that smoking marijuana represents a great risk to the pulmonary system. Although cannabis has been smoked widely in this country for four decades now, there are no reported cases of cancer or emphysema which can be attributed to marijuana. I suspect that breathing a day's worth of the air in Houston or any other city with poor air quality poses more of a threat than inhaling a day's dose of smoked marijuana. Furthermore, those who are, in today's antismoking climate, concerned about any toxic effects on the pulmonary system can now use a vaporizer, a device which frees the cannabinoid molecules from the plant material without the necessity of burning it and thereby producing smoke. As for the psychoactive effects, I am not convinced that the therapeutic benefits of cannabis can be separated from the psychoactive effects nor am I persuaded that that is always a desirable goal. For example, many patients with multiple sclerosis who use marijuana speak of mood elevation as well as the relief of muscle spasm and other symptoms. If cannabis contributes to this feeling better, should patients be deprived of this effect? The statement that, "The company maintains that Sativex, when taken properly, does not cause the kind of intoxication that people routinely experience from smoking marijuana" hinges on the phrase, "when taken properly". Properly here means taking a dose which is under the dose level required for intoxication. One has to question whether that dose is always therapeutic and whether cannabis taken sublingually can be so carefully titrated to find that precise dose. It is also true that people who want to use Sativex to get high will certainly be able to do so.

One of the most important characteristics of cannabis as a medicine is its capacity for self-titration when taken through the pulmonary system. Because the effects are achieved so rapidly through this means of administration, the patient can determine precisely the amount needed for symptom relief; the risk of underdosing or overdosing is minimized. While sublingual absorption of cannabis leads to faster relief than oral administration (which may take one and a half to two hours), it is not nearly as fast as pulmonary administration and therefore makes self-titration much more difficult if not impossible. Furthermore, many patients cannot hold the Sativex under the tongue long enough for it to be absorbed so as a consequence varying amounts trickle down the esophagus; it then behaves like orally administered cannabis with the consequent delay in the therapeutic effect.

Cannabis will one day be seen as a wonder drug as was penicillin in the 1940s. Like penicillin, cannabis is remarkably nontoxic, has a wide range of therapeutic applications, and will be quite inexpensive when it becomes free of the prohibition tariff. Even now illicit or homegrown marijuana, which is no less useful than Sativex, is less expensive than Sativex will be. This will be noted by people with medical insurance whose copayments are regularly increasing and it will be particularly important to the 43 million Americans who do not have health insurance.

While the pharmaceutical industry will undoubtedly produce analogs of cannabis which will be useful in ways that whole smoked cannabis is not, Sativex provides only one advantage over whole smoked (or vaporized) marijuana: its use will be legal. I have yet to see a patient who has used both dronabinol and smoked marijuana who has not found the latter more useful and manageable. The primary reason people use dronabinol rather than cannabis is a function of the law. Without the prohibition, few would use dronabinol. Similarly, the commercial success of Sativex will largely depend on the vigor with which the prohibition is enforced. It is not unreasonable to believe that as the pharmaceutical armamentarium of cannabinoids increases, so will the pharmaceutical industry's interest in sustaining the prohibition. Dr. Geoffrey Guy claims that he founded the company to keep people who find marijuana useful as a medicine out-of-court; there is, of course, a way to do this which would be much less expensive economically and in terms of human suffering.