There is a continuing search for more effective opiate detoxification treatments. This study's purpose is to investigate the effects of adding very low doses of naltrexone to a methadone tapering treatment in opioid dependent individuals.

Although many different techniques for opiate detoxification exist, the search continues for more effective approaches to reduce the duration and discomfort associated with opioid withdrawal. It has been shown that very low doses of naltrexone administered in the presence of opiates has analgesic and dependency reducing properties. The purpose of this study is to investigate the effects of very low doses of naltrexone administered during a methadone tapering schedule for opiate detoxification. In addition, this study will compare the effectiveness of two different dose regimens of naltrexone.

Participants in this double-blind study will be recruited among opioid dependent individuals already enrolled in a 6-day inpatient opioid detoxification program. Participants will be already receiving standard treatment to control discomfort during a methadone tapering schedule. Participants will be randomly assigned to one of three groups. Two of the groups will be given naltrexone; Group 1 will receive 0.125 mg each day, and Group 2 will receive 0.250 mg each day. Group 3 will receive a placebo. Participants will be evaluated upon enrollment for opiate addiction severity. They will continue to be evaluated daily for signs of withdrawal and salivary cortisol. An additional evaluation and urine test will be completed 1 day following discharge. Daily evaluations will take 15 minutes to complete. Seven days following discharge, participants will be contacted for a 20-minute phone interview. During the phone interview, participants will schedule an appointment to provide a final urine specimen for the detection of drugs of abuse.

Inclusion Criteria:

• Current DSM-IV diagnosis of opiate dependence
• Reads and understands English

Exclusion Criteria:

• Serious medical disorders (e.g., uncontrolled hypertension, acute or chronic active hepatitis, kidney failure, uncontrolled diabetes)
• Psychiatric conditions that require intensive services (e.g., depression with suicidal ideation, psychosis)
• Mental retardation or other disorder that might limit ability to give informed consent
• Pregnant