Seventeen years after it was withdrawn from U.S. markets, a synthetic version of the active ingredient in marijuana is going back on sale as a prescription treatment for the vomiting and nausea that often accompany chemotherapy, the drug's manufacturer said Tuesday. Valeant Pharmaceuticals International hopes to begin selling Cesamet in the next two to three weeks, company president Wes Wheeler said. The Costa Mesa, California, company received Food and Drug Administration approval Monday to resume sales of the drug, which it bought from Eli Lilly and Co. in 2004. Valeant currently sells the drug, also called nabilone, in Canada. Lilly...