AP - Government regulators on Friday said encouraging wider use of a powerful painkiller made by Cephalon Inc. raises the risk of potentially fatal misuse of the drug. Shares of the Frazer, Pa. drugmaker fell $2.7, or 4.2 percent, to $60.72 in morning trading. Cephalon’s drug Fentora is already approved to treat severe pain flare-ups in cancer patients. On Tuesday FDA will ask a panel of outside experts whether it should be approved to treat pain in non-cancer patients, a larger market that includes those suffering from back and nerve pain.