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Point of View : Jan 15, 2010 ( )
Medical Marijuana Policy Catches Up with Science
Shifting Stance on Herbal Medicine by Government and Physicians Benefits Patients
Marijuana’s recorded use as a medicine goes back nearly 5,000 years. The ban on such use is a much newer phenomenon—72 years in the U.S., a bit more or less in other nations and in specific U.S. states—and one whose unhappy tenure is now apparently near an end. Simply put, research has made that ban increasingly untenable.
The two clearest signals of the sea change that is occurring came this past fall. In October, the Obama administration signaled a careful but hugely significant softening of the federal government’s dogmatic hostility toward medical marijuana. Instead of treating state medical marijuana laws either as nullities or as affronts to be attacked any way possible, a memo from the Department of Justice signaled a hands-off policy toward medical marijuana activities when such activities are clearly permitted by state law.
Less than a month later, the American Medical Association (AMA)—the largest and most institutionally conservative U.S. physicians’ group—announced a major reversal of its policy on the issue. The AMA’s old language had urged that marijuana “be retained in Schedule I” of the federal Controlled Substances Act. That classification deemed marijuana as having a high potential for abuse, lacking accepted medical uses in the U.S., and as unsafe for use even under medical supervision.
In contrast, Schedule II—still considered to have high abuse potential but declared to have accepted medical uses and to be safe for use under physician supervision—includes cocaine, morphine, and even methamphetamine. Stranger still is the fact that in pill form, THC—the component responsible for marijuana’s “high,” though not all of its therapeutic effects—is in Schedule III, with controls so mild that phoned-in prescriptions are allowed.
Some of us thought this classification of marijuana was ludicrous from the get-go, but a recent succession of controlled clinical trials has made the case irrefutable. And the AMA has noticed, replacing its old position with this: “Our AMA urges that marijuana’s status as a federal Schedule I controlled substance be reviewed with the goal of facilitating the conduct of clinical research and development of cannabinoid-based medicines and alternate delivery methods.” While carefully avoiding an endorsement of existing state medical marijuana laws, the new AMA stand represents a major shift.
The report accompanying the new policy makes clear that this shift was driven by research into medical marijuana, some of the most interesting of which has looked at marijuana for neuropathic pain. This type of pain, stemming from nerve damage that can be caused by a wide variety of illnesses (including HIV/AIDS, multiple sclerosis, and diabetes) and injuries, is notoriously hard to treat. Standard pain drugs, even opioid narcotics, often provide incomplete relief at best. Sometimes anticonvulsant drugs such as gabapentin can be helpful, but some patients do not respond or cannot tolerate these medications. The need for better treatments is universally recognized.
The first human trial of marijuana for HIV-associated neuropathy, conducted by Donald Abrams and colleagues at the University of California, San Francisco, was published in Neurology in February 2007. Abrams compared smoked marijuana to placebo (marijuana with the cannabinoids removed) in patients who had a chronic pain score of at least 30 on a 100-point scale. The first marijuana cigarette reduced pain 72%, compared to just 15% with placebo. No serious adverse events were reported, and while some experienced the side effects one would expect (like dizziness or disorientation), these were mild enough that the researchers concluded that they “do not represent any serious safety concerns in this short-term study.”
A second HIV neuropathy study, out of UC San Diego and published in 2008 by Neuropsychopharmacology, focused on patients for whom at least two classes of analgesic drugs had failed. Again, smoked marijuana was, as the study concluded, “generally well-tolerated and effective... cannabis was associated with a sizeable (46%) and significantly greater (vs. 18% for placebo) proportion of patients who achieved what is generally considered clinically meaningful pain relief.”
A third University of California study, also published in 2008, found smoked marijuana effective for relief of neuropathic pain from a variety of non-HIV causes, including multiple sclerosis and spinal cord injury. Notably, the researchers explained, “cannabis does not rely on a relaxing or tranquilizing effect (e.g., anxiolysis), but rather reduces both the core component of nociception and the emotional aspect of the pain experience to an equal degree.”
Meanwhile, a 2007 Columbia University study, published in the Journal of Acquired Immune Deficiency Syndromes in August 2007, compared relatively weak marijuana (2.0 or 3.9% THC) with relatively high doses of Marinol (dronabinol), the prescription THC pill. Margaret Haney and colleagues compared the drugs’ effects on a variety of parameters, including caloric intake, weight, mood, sleep, and cognitive performance.
The pill was administered at five or 10 mg four times a day, four or eight times the standard dose for appetite stimulation.
Both treatments were rated as effective, but the 3.9% THC marijuana outperformed even the highest dose of dronabinol at stimulating hunger/desire to eat, increase in daily caloric intake, sleep duration, and in patients’ self-rated quality of sleep. The researchers also tracked patient requests for over-the-counter medications to treat nausea, diarrhea, and upset stomach, and both marijuana and dronabinol reduced these to almost zero. Strikingly, the article notes no effect on patient performance on a series of tests used to measure psychomotor or cognitive functioning: “Compared with placebo, neither marijuana nor dronabinol significantly altered performance on any of the tasks.”
As Dr. Abrams has been known to observe, it’s not surprising that an herbal medicine that’s been safe and effective for 5,000 years is still safe and effective today. But as the evidence piles up in favor of this natural plant product, the pharmaceutical industry is energetically pursuing its own versions of cannabinoid medicines.
Some, such as GW Pharmaceuticals’ Sativex, are made from the plant, while others are synthetic single cannabinoids. No doubt Western medicine’s preference for single chemical entities—along with politicians’ continuing desire not to recognize anything good about marijuana—will exert a powerful pull in favor of prioritizing these new pharmaceutical products over the plant.
And maybe, someday, Big Pharma will produce a synthetic cannabinoid medicine that works better than Marinol, which is unloved by patients. At that point, the policy question will be this: Is it appropriate for government to push customers toward expensive pharmaceutical products, when many can get adequate and safe relief from a plant they can grow in their own backyard?
The right answer is obvious. What will happen in the real world is less so.
Bruce Mirken (email@example.com), a longtime health reporter, served as director of communications for the Marijuana Policy Project (www.mpp.org) from 2001 to 2009.
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