Television shows like "Weeds" poke fun at so-called "medical" marijuana, inferring that it has more in common with reefer madness than real medicine. Nevertheless, as of this writing, medical marijuana is legal in 16 U.S. states as well as Washington, D.C., and six more states have pending legislation for the legalization of medical marijuana.
The reported benefits of cannabinoids, of which THC (the main psychoactive compound in marijuana) is one, have been confirmed in multiple randomized trials. A recent review concluded that 15 out of 18 trials showed that cannabinoids provided a significant pain-relieving effect when compared with a placebo. Cannabinoids were also shown to improve sleep [source: Lynch and Campbell].
The study of cannabinoids and why they work on chronic pain, including the neuropathic variety, is a hot topic among today's pharmacological researchers. Current studies are looking at cannabinoid receptors and ligands in the human body to try and provide a scientific explanation for why medical marijuana is effective in reducing pain.
Like all the other treatments for neuropathic pain, however, medical marijuana may only partially relieve the pain. In one Canadian study, patients who smoked medical marijuana reported their neuropathic pain level at 5.4, whereas patients who were given the placebo reported pain levels of 6.1 [source: Lowry]. If medical marijuana doesn't provide the necessary relief, more traditional analgesics may be indicated. We discuss the pros and cons of painkillers next.