The medical marijuana controversy rages on. Is it a "medicine?" Does it work? Is it safe? Are claims of medical benefits merely a ploy for legalization?The FDA weighed in several months ago by endorsing a multi-agency study that found "no animal or human data supported the safety or efficacy of marijuana for general medical use." This enraged those who claim that cannabis is an appropriate treatment for ailments from nausea and vomiting to muscle spasticity and intractable pain. They accused the FDA of elevating politics over science -- more specifically, over the conclusions of a 1999 report from the Institute of Medicine (IOM), a branch of the prestigious National Academy of Sciences. It also rubbed Charley Hooper ("The FDA's Marijuana Problem," TCS Daily, 18 August) the wrong way. However, his arguments are typical of the specious arguments in favor of using smoked marijuana -- as opposed to purified, standardized drug preparations -- for medicinal purposes. For example, he asserts that the FDA's statement, "no sound scientific studies supported medical use of marijuana . . . for general medical use," conflicts with the IOM report and other findings. The operative phrase here is for general medical use. No reputable group has made that claim.In fact, the FDA's position both makes sense and is consistent with the requirements of the Federal Food Drug and Cosmetic Act. And in spite of claims to the contrary by cannabis supporters and much of the media, it is also consistent with the 1999 IOM report. The IOM's experts rejected the idea that crude herbal (usually smoked) cannabis had been shown to be a safe and effective medication for various medical conditions, concluded that there is "little future in smoked cannabis as a medically approved medication," and emphasized that smoked plant material is a crude drug delivery system that exposes patients to a significant number of harmful substances. They recommended smoked cannabis only for short term use (less than 6 months), and only for patients who suffer from debilitating conditions like intractable pain or vomiting, who have failed on all other therapies, and who are under the close supervision of a physician and an institutional review board-type process. Finally, they predicted that "if there is any future of marijuana as a medicine, it lies in its isolated components, the cannabinoids and their synthetic derivatives," and called for clinical trials to develop "rapid-onset, reliable and safe delivery systems." The IOM's analysis is far from an endorsement of crude cannabis, in whatever form, as a safe and efficacious medicine that should be made available to patients for a wide variety of medical conditions, as is permitted in eleven states. In the context of the IOM report and federal law, the FDA's position was perhaps inevitable. First, federal law requires that to be marketed, a drug must have been judged safe and effective by experts who have evaluated evidence obtained from well-controlled clinical trials. Second, there is the question of what constitutes "evidence". Contrary to the implications of the news reports, it is not an amorphous collection of anecdotal reports and patient testimonials, but rather hard data arising out of carefully designed preclinical and clinical trials. Although there are some recent data from small safety and efficacy trials using smoked cannabis, as the IOM pointed out such trials are merely a first step towards the development of a suitably defined and tested pharmaceutical.That brings us to a critical third point: What is a "medicine?" In order for a company to sell a drug, and a physician to prescribe it, it must be standardized by composition, formulation, and dose, have been tested for a particular medical condition in rigorous trials, and be administered by means of an appropriate delivery system.
From these, as it were, first principles, it is clear that smoked marijuana will have great difficulty in meeting the required scientific and legal standards. There is insufficient evidence that smoked cannabis is a safe and effective medicine (leaving aside the question of whether the federal soldiers in "the war on drugs" have obstructed clinical testing). Different cannabis strains vary radically in cannabinoid composition and contaminants; plant materials may be contaminated with fungi, bacteria, pesticides, heavy metals and other substances; and there is no safe and reliable delivery system for crude cannabis products.