根据以下资料，回答下列各题： Humans have never lacked for ways to get wasted．The natural world is full of soothing but addictive leaves and fruits and fungi，and for centuries，science has added them to the pharmacopoeia to relieve the pain of patients．In the past two decades，that’s been especially true．As the Joint Commission on the Accreditation of Healthcare Organizations developed new policies to treat pain more actively，approaching it not just as an unfortunate side effect of illness but as a fifth vital sign，along with temperature，heart rate，respiratory rate and blood pressure.a bounty of new opoids(鸦片类药物)has rolled off Big Pharma’s production line． There was fentanyl，a synthetic opioid around since the l960s that went into wide use as a treatment for cancer pain in the l990s．That was followed by Oxycodone，a short-acting drug for more routine pain，and after that came Oxycontin，a 12-hour formulation of the same powerful pill．Finally came hydrocodone．The government considers hydrocodone aSchedule III drug--one with a“moderate or low”risk of dependency，as opposed to Schedule Il’s，which carry a“severe”risk．Physicians must submit a written prescription for Schedule II drugs；for Schedule IIl’s，they just phone the pharmacy．(Schedule I substances are drugs like heroin that are never prescribed．)For patients，that wealth of choices spelled er． The result has hardly been surprising．Since 1990，there has been a tenfold increase inprescriptions for opioids in the U．S．，according to the Centers for Disease Control and Prion(CDCP)．In l990 there were barely 6．000 deaths from accidental drug poisoning in the U．S．By 2007 that number had nearly quintupled to 27，658． Health officials do not tease out which drug is responsible for every death。and it’s not always possible．“There may be lots of drugs on board，”says Cathy Barber，director of the Injury Control Research Center at the Harvard School of Public Health．“Is it the opioid that caused the death?Or is it the combination of opioid，benzodiazepine and a cocktail the person had?”Still，most experts agree that nothing but the exploding availability of opioids could be behind the exploding rate of death． Despite such heavy death toll，the suivellance over these popular pills faces regulatory maze．In early 2009，the FDA announced that it was initiating a“risk．evaluation and mitigation strategy”．The regulations the FDA is empowered to issue include requiring manufacturers to provide better information to patients and doctors，requiring doctors to meet certain educational criteria before writing opioid prescriptions and limiting the number of docs and pharmacies allowed to prescribe or dispense the drugs．“And with all that．”warns Dr．John Jenkins，director of the FDA’s Office of New Drugs，“we do still have to make sure patients have access to drugs they need．”Any regulations the FDA does impose won’t be announced until 2011 at the earliest and could take a year or more to roll out．That leaves millions of people continuing to fiU prescriptions．tens of thousands per year dying and patients in genuine pain wondering when a needed medication will relieve their suffering--and when it could lead to something worse． Opoids are drugs______．