关键词：药物；美沙酮；阿片类治疗；滥用药物
摘 要：An estimated 2 million people in the United States are dependent upon or abuse opioids, including heroin and prescription opioids such as oxycodone and hydrocodone. Withdrawal from these drugs is generally so intense that those who are dependent upon them continue taking the drugs in increasing dosages to avoid withdrawal or to maintain the high produced by the drugs. Withdrawal symptoms may begin within 6 hours after the last heroin usage and may last for up to several months. An effective treatment for opioid dependence and addiction includes medication-assisted therapy with the opioid medications methadone or buprenorphine, the only two opioids federally approved for the treatment of these conditions. Methadone relieves cravings, blocks the euphoric effects associated with heroin and other opioids, and prevents withdrawal. Buprenorphine aids in treatment by preventing symptoms of withdrawal.