Doctors are well aware that prescribing powerful painkillers known as opioids carries risks for addiction, misuse and accidental overdose - but at least professional guidelines agree on the precautions they can take, say researchers. Opium-related drugs, like Oxycontin, Percocet, Percodan and methadone can be very addictive and are usually prescribed for just a week or two for intense short-term pain, though their use for longer-lasting pain is growing. Sales of opiates in the U.S. increased by 300 percent since 1999, according to the Centers for Disease Control and Prevention. Three out of four deaths due to prescription drug overdose involve opioids. And for every death there are ten admissions to treatment centers for addiction.