For years, we've heard all about medical marijuana for cancer patients. It's even been legalized in California. But what about marijuana for chronic joint pain?
The preliminary findings of an $8.7 million California study, the first major research conducted on the effects of marijuana in two decades, found that smoking pot can soothe tingling or burning pain -- but you don't need to get high to find relief.
Researchers concluded that marijuana can provide relief for neuropathic pain caused by injuries, infections, diabetes, strokes and other medical conditions affecting the nervous system.
The studies, conducted since 2000 by the Center for Medical Cannabis Research at the University of California, San Diego, also found that smoking pot offers at least short-term relief for muscle spasms.
The findings, released last week in a report to the Legislature, are sure to drive debate over public policy governing California's burgeoning medical marijuana market.
But while the research endorsed medical benefits of marijuana, it was anything but an endorsement for getting stoned.
In fact, a clinical trial for 38 patients who smoked marijuana for pain from spinal cord injuries, multiple sclerosis, diabetes and other conditions found higher doses were not more effective than lower doses in relieving pain.
"We found that low strength was as good as high strength in resolving pain," said Dr. Barth Wilsey, a UC Davis specialist in pain medicine and anesthesiology. "But the lower dose did not cause confusion." The state authorized and funded the marijuana research project under 1999 legislation known as the Medical Research Act. The report released Wednesday reflected findings from a compilation of studies involving about 200 patients, including experienced pot smokers and others with no familiarity with the drug. They were given pot with varying levels of tetrahydrocannabinol (THC), the main active chemical in cannabis, or placebo cigarettes that smelled of marijuana but contained no THC. With five of seven clinical trials completed, researchers found marijuana to be a reliable pain remedy. The studies also found that participants experienced "adverse side effects," including cough, nausea, dizziness, sedation and changes in cognition. However, the report concluded: "These effects were typically mild and resolved rapidly." As a pain remedy, "there is good evidence that cannabinoids (in marijuana) may be an adjunct or a first-line treatment," said Dr. Igor Grant, a UC San Diego professor of psychiatry who directed the research.
The report did not address the potentially harmful effects of inhaling marijuana smoke. But researchers said they are studying whether a "smokeless" ingestion system may be healthier. Researchers obtained marijuana for the studies from the National Institute on Drug Abuse, which grows marijuana for research. The marijuana used in the testing was maintained under intense security, and the research was conducted in consultation with the U.S. Drug Enforcement Administration and the Food and Drug Administration, Grant said. While the results could have policy implications for state government, Grant said the ramifications are unclear for the hundreds of medical marijuana dispensaries operating in California, because the pot they sell may vary greatly in content and potency. "We don't know the composition of the product on the street," Grant said. "We don't know what the patients are getting. In a sense, that is not a good situation." But Grant said the research indicates marijuana can benefit a wider range of symptoms than lack of appetite in AIDS patients and nausea in cancer patients. Those were key ailments dramatized by proponents of Proposition 215, the medical marijuana law passed by California voters in 1996. The measure gave physicians the ability to recommend pot for "cancer, anorexia, AIDS, chronic pain, spasticity, glaucoma, arthritis, migraine, or any other illness for which marijuana provides relief." Former state Sen. John Vasconcellos, who authored legislation for the research, said the study should bring broader acceptance for medical pot use. "This is the latest, best, most objective clarifying research," Vasconcellos said. "That ought to solve the issue."