When OxyContin, a drug of choice for middle class kids, was reformulated to prevent the pills from being crushed for snorting or injecting to achieve a more intense high, resourceful drug abusers switched to another powerful prescription pain killer, Opana. Now the manufacturer of Opana is changing its formula to make it harder to abuse. In a USA Today article, Jeffrey Reynolds, executive director of the Long Island Council on Alcoholism and Drug Dependence in Mineola, N.Y. is quoted as saying, "It's almost like a game of Whac-A-Mole. You get a handle on OxyContin; they switch to Opana. My guess is it will be something new tomorrow." What’s the next medicine to rise and fall for addictive cravings?