Reefer Medicine

By Henry I. Miller, a doctorand a fellow at the Hoover Institution, headed the Food and Drug Administration's Office of Biotechnology from 1989 to 1993 (THE NEW YORK TIMES, 28/04/06):

Last week, the Food and Drug Administration staked out its position on the long-standing controversy over the medical use of marijuana — and made a lot of people smoking mad. The F.D.A. endorsed a multi-agency study that found that "no animal or human data supported the safety or efficacy of marijuana for general medical use." This came as an affront to those who claim that cannabis is an appropriate treatment for ailments from nausea and vomiting to muscle spasticity and intractable pain.

Many news reports and commentaries accused the F.D.A. of contradicting a 1999 report by the Institute of Medicine that recommended further research on marijuana's medical potential. The regulators were denounced as elevating politics over science.

But the F.D.A. did no such thing. To be sure, its one-page statement was far shorter and less detailed than the institute's book-length report, but its conclusions were essentially the same. The F.D.A. also recently gave the go-ahead for clinical trials of a new drug derived from marijuana — further demonstrating that its position is both sensible and proper.

In their 1999 report, the Institute of Medicine's panel of experts flatly rejected the idea that herbal (usually smoked) cannabis would ever be considered a safe and effective medicine for widespread use. They noted that marijuana appears to be modestly effective in treating the nausea and vomiting induced by chemotherapy and the wasting caused by AIDS — though not as effective as some approved medicines are. But they also said that because smoked marijuana can increase the risk of lung damage, cancer and complications during pregnancy, it is appropriate only for short-term use (less than six months) by acutely suffering patients who have failed to find relief with other therapies and who are under the close supervision of a doctor.

It is not the F.D.A. but the 11 states that have passed laws allowing the use of smoked marijuana for various medical problems that are at odds with the Institute of Medicine's position.

More promising than smoked marijuana, the institute said, is the potential of drugs made with cannabinoids — the bioactive substances found in marijuana. It called for clinical trials of such medicines and the development of safe ways to deliver them.

In January, the F.D.A. approved advanced clinical trials of a marijuana-derived drug called Sativex, which comes in the form of a mouth spray. Sativex has been approved in Canada for the treatment of neuropathic pain associated with multiple sclerosis, and it is available by prescription (though not yet fully licensed) in Spain and Britain. According to GW Pharmaceuticals, the British company that makes the drug, more than 1,500 patients in those three countries are using Sativex to alleviate pain, muscle spasticity and other serious problems.

Federal law requires that before any drug is marketed, it must first be judged safe and effective by qualified experts. And that judgment requires the review of scientific evidence — not anecdotal reports and patient testimonials but hard data from carefully designed animal testing and clinical trials. While far from perfect in practice, this approach goes a long way toward ensuring that patients are protected from exposure to unsafe or ineffective products. Even for terminally ill patients, this commitment to safety and effectiveness is important, because the suffering of a dying patient can be aggravated by an imprudent medical intervention.

Smoked marijuana cannot be subjected to careful, well-controlled trials, because it does not come in a standard, reproducible formula or dose, and cannot meet the accepted standards for drug purity, potency and quality. Different strains of cannabis vary radically in their cannabinoid composition and in the contaminants — fungi, bacteria, pesticides, heavy metals and other substances — they contain. And smoking is not a precise way of delivering any substance to the bloodstream.

Other plant-derived drugs — morphine, codeine and Taxol, to name a few — have made it through the F.D.A.'s review process, and there is no reason drugs made from cannabis should not be required to meet the same standards.

Sativex contains an equal ratio of two cannabinoids: tetrahydrocannabinol, which is psychoactive, and cannabidiol, which is not. Its spray dispenser delivers a precise dose of the drug, which is absorbed through the mucous membranes of the mouth. The composition of the drug and the manner in which it is delivered together ensure that its active ingredients can be medically effective without causing the kind of "high" that many patients view as an undesirable side effect.

THE availability of drugs like Sativex should (but won't) end the rancorous debate over medical marijuana. Even if it did, the issue of whether marijuana should be legalized as a recreational drug would remain.

Meanwhile, F.D.A. officials must ensure that the testing and potential approval of cannabinoid-containing drugs are not hindered by political agendas or other nonscientific considerations, inside or outside the agency. For the benefit of patients in need, this is something about which the F.D.A., the parts of our government waging the "war on drugs" and other interested parties should be able to agree.