The opioids: abuse liability and treatments for dependence.

The opioids vary greatly in addictive potential, from the highly addictive such as heroin to the opioid antagonists such as naltrexone, which can be used to treat opioid dependence and overdose. The various opioid compounds have different euphorigenic properties and also produce withdrawal syndromes of distinct patterns of duration and intensity. Dependence liability is affected by both the pleasure-seeking motives for initiating drug use and the painful consequences of abstinence or withdrawal. Detoxification, which takes 7-10 days for the short-acting opioids, is usually the first stage in treatment. Methadone is often used as a preliminary stage in detoxification, but some patients are maintained on methadone for years, since it allows them to lead relatively normal lives. Non-opioid drugs used to control withdrawal symptoms include clonidine. After detoxification, naltrexone, a long-acting opioid antagonist, can be administered orally to prevent relapse.