CANADA OKS POT MEDICINE Cannabis-Derived Prescription Drug for MS to Be Sold There Soon; Approval Reopens the Debate in the U.S. Canada is the first nation to approve a pharmaceutical spray derived from the cannabis plant, a move that could rattle the medical marijuana debate in the United States. The new drug, Sativex, is produced by GW Pharmaceuticals of Britain and is expected to be available on pharmacy shelves in Canada within weeks, principally for the treatment of pain from multiple sclerosis. "I think the Canadian approval will change an awful lot of things," said Geoffrey Guy, GW Pharmaceuticals executive chairman. In particular, Guy said, it could help "create momentum" for approval in other countries, including the United States. The company isn't expected to apply for approval in the United States until late this year. A study of the drug's merits could take three to five years. But Canadian approval, announced Tuesday, is already creating ripples in the United States. Bush administration officials declined comment but have said privately that approval of a prescription form of cannabis here might ease wrangling by drawing a line between real patients and recreational users. Some medical marijuana activists see approval of Sativex as proof cannabis is indeed a worthy medicine. "Sativex is for all practical purposes liquid marijuana, so the question of whether marijuana is medicine has been settled," said Bruce Mirken of the Marijuana Policy Project. "The only question is what form people use, and that's best left to doctors and patients." Meanwhile, a few activists have vowed to travel to Canada for Sativex rather than await the drug's approval here. "It's not the fault of MS patients that the United States is so far behind in medical marijuana research and development," said Steph Sherer of Americans for Safe Access, a Berkeley, Calif.-based medicinal marijuana advocacy group. Ten states allow medical marijuana, but the federal government maintains strict prohibitions. The Supreme Court is expected to soon decide a case involving two California women who smoke marijuana to assuage illnesses. Sativex gives physicians more consistent quality and ability to set standardized dosages. "I think physicians will feel a lot more comfortable with this," said Dr. David Bearman, a Santa Barbara, Calif., internist who specialized in medical marijuana. "One of the reasons cannabis fell out of favor was a lack of standardization." The spray, laced with a peppermint taste, contains no carcinogenic smoke, Guy said, and patients in trials reported that they could avoid the drug's intoxicating effects once they discovered which dose worked best for them.