Effectiveness of Naltrexone and Lofexidine in Treating Detoxified Heroin Addicts - 1

• Retention in treatment; measured throughout 8 weeks
  
• Frequency and amount of opiate use; measured weekly
  
• Stress levels; measured weekly
  

• Tolerability; measured throughout 8 weeks
  

Stress is one of the more common reasons cited by addicts for continual drug use and relapse. Naltrexone treatment of opiate addicts suffers from high rates of drop-out and relapse. This may be a result of naltrexone's inability to reduce symptoms of stress during early recovery. Treatment approaches that target both drug-induced and stress-induced relapse may prove to be more beneficial than targeting drug-induced relapse alone. Lofexidine is a drug that reduces the physical symptoms of opiate withdrawal and may prove to have stress-reducing capabilities. The purpose of this study is to determine the maximal safe dose of lofexidine tolerated in naltrexone-treated opiate addicts and to find an optimal lofexidine induction schedule. The study will also assess any side effects that occur during a discontinuation phase of lofexidine.

This pilot study will last a total of 8 weeks. Recently detoxified opiate dependent participants who are eligible for naltrexone treatment will enter a 4-week single-blind dose tolerability phase, during which participants will receive naltrexone and 1 of 3 twice-daily lofexidine induction schedules. All participants will be required to remain in the clinic for 2 hours immediately following dosing in order to monitor vital signs and side effects. Study visits will occur three times each week, at which time naltrexone medication for self-administration will be handed out and participants will be evaluated in terms of tolerability to treatment. After the 4 weeks of treatment, a double-blind lofexidine detoxification phase using a 5-day taper will occur. Participants will be randomly assigned to one of two maintenance-taper schedules. The first group will undergo a 5-day tapering, followed by a placebo for three weeks, followed by a 5-day tapering during Week 4. Withdrawal symptoms and side effects will be evaluated.