"The primary objective of this study was to evaluate the efficacy of smoked cannabis when used as an analgesic in persons with neuropathic pain from HIV-associated distal sensory polyneuropathy (DSPN). In a double blind, randomized, five-day clinical trial patients received either smoked cannabis or placebo cannabis cigarettes. Patients continued on any concurrent analgesic medications (e.g., gabapentin, amitriptyline, narcotics, NSAIDs) which they were prescribed prior to the trial; the dose and amount of the medications were recorded daily.
"The full results of this study appear in the journal Neurology (Abrams, et al., 2007– see reference list). In brief, 55 patients were randomized and 50 completed the entire trial. Smoked cannabis reduced daily pain by 34% compared to 17% with placebo. The study concluded that a significantly greater proportion of patients who smoked cannabis (52%) had a greater than 30% reduction in pain intensity compared to only 24% in the placebo group."

Source

Center for Medicinal Cannabis Research, "Report to the Legislature and Governor of the State of California presenting findings pursuant to SB847 which created the CMCR and provided state funding," University of California, (San Diego, CA: February 2010), p. 10.
http://cdc.coop/docs/neuropat…