Is marijuana an effective treatment for pain, illness and disease?
It's a question many Minnesota physicians are pondering as the Legislature prepares to debate a measure that would allow doctors to prescribe some form of the drug.
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Mayo psychiatrist Michael Bostwick reviewed more than 100 medical studies and reports on the possible benefits and risks of marijuana. He published his findings in February 2012 in the journal Mayo Clinic Proceedings. Bostwick says most marijuana studies are not high-quality because they're not randomized, controlled studies -- the kind the U.S. Food and Drug Administration requires to approve any new medication.
Randomized patient trials have been nearly impossible to conduct in the U.S. because marijuana has been classified as a Schedule I drug under the federal Controlled Substances Act since 1970. Schedule I substances are regarded as having high abuse potential and no currently accepted medical use - which puts a damper on almost any treatment research.
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There have been a handful of international, randomized studies on medical marijuana. But in the U.S., the bulk of marijuana research has been observational, frequently involving individual or group case reports.
Bostwick says it's interesting that there's scant evidence that anyone has ever died from a marijuana overdose. But he says there is a growing body of research linking marijuana to addiction in approximately 10 percent of users. By comparison the addiction rate for alcohol is 15 percent and for tobacco it's 32 percent. Marijuana is also associated with worsening psychosis in a small number of patients who are predisposed to schizophrenia.
"And if you keep on using the drug while you have the illness, you'll have a worse course," Bostwick said. "It will be harder to treat. You'll be more likely more psychotic."
Even so, Bostwick says he found plenty of believable evidence that supports marijuana's potential medical benefits for relieving cancer pain, nausea, wasting syndrome from AIDS and muscle problems associated with Multiple Sclerosis. In that context, he says concerns about addiction seem hardly worth worrying about for patients who cannot get relief in other ways.
"If you're a person dying of a terminal illness and you have intractable pain, and smoking marijuana actually helps you, then it can be a great thing," he said.
Yet Bostwick concludes that from a research perspective, the verdict on medical marijuana is still out, largely because rigorous studies that would answer lingering questions have been stymied. He argues that the federal government should reclassify marijuana as a Schedule II drug. That would allow research to move forward more easily.
“If you're a person dying of a terminal illness and you have intractable pain, and smoking marijuana actually helps you, then it can be a great thing.”
Mayo psychiatrist Michael Bostwick
Dr. Jacob Mirman, medical director at Life Medical, a private, primary care clinic in St. Louis Park that offers conventional medicine and homeopathy, agrees that more research is needed, but he doesn't think the Minnesota Legislature should wait for that to happen. Two of his patients have admitted to him that they have used marijuana to treat their pain. One patient has Multiple Sclerosis and the other had end-stage cancer. Mirman sees no convincing reason why Minnesota should continue to deny access to marijuana for medical purposes.
"I feel it's safe, much safer than some of the other drugs we use and some of the substances that are sold in stores without a prescription," he said.
Many psychiatrists and addiction medicine physicians disagree with that reasoning. The American Society of Addiction Medicine opposes state ballot measures to legalize marijuana. ASAM member Dr. Sheila Specker is a an addiction psychiatrist at the University of Minnesota. She says lawmakers shouldn't circumvent the federal drug-approval process.
"I don't think that the public or legislators understand the medical aspect of this or should be voting," Specker said. "That's not their domain."
Specker says she's worried that if Minnesota lawmakers legalize medical marijuana, it will be much easier for kids to get pot. She says states that have allowed access to the drug for medical reasons have seen increases in adolescent marijuana use.
The Minnesota Medical Association will hold a policy forum in Eagan Tuesday to gauge physician interest in medical marijuana legislation.