The once-a-month drug naltrexone was more effective at preventing drug relapse in ex-prisoners addicted to heroin and other opioids compared to the usual treatment modalities, including counseling and community treatment programs, according to results from a multisite, randomized trial led by researchers at the Center for Studies of Addiction at the Perelman School of Medicine at the University of Pennsylvania and published online today in the New England Journal of Medicine.

For patients battling opioid addiction, the other common treatment is the once-a-day methadone or suboxone, which both activate the same neurological receptors as heroin, but prevent withdrawal and relapse. Methadone remains controversial, with many in the criminal justice system viewing it as merely exchanging one drug addiction for another. Antagonist drugs, such as naltrexone, which was approved in 2010 by the US Food and Drug Administration for opioid dependence, have gained increasing acceptance to treat prisoners, despite limited data on effectiveness.

“Judges and parole officers equate methadone with ‘giving in’ to the addict, giving them what they want,” said Charles O'Brien, MD, PhD,vice chair of Psychiatry and founding director of Penn's Center for Studies of Addiction, and senior author of the study.  “But, you can give it in a controlled way so that a person can function very well and does not go into withdrawal. On the other hand, it is a drug that can be sold; it is dangerous and there is a certain amount of abuse."

Such concerns have spurred the search for different treatment approaches. 

In an investigation of the effectiveness of antagonist treatment in a high-risk population, O'Brien, lead author Joshua D. Lee, MD, MSCE, an associate professor in the departments of Population Health and Medicine at NYU Langone Medical Center, and collaborators followed 153 ex-prisoners in a six-month randomized trial of extended-release naltrexone with a control group of 155 persons receiving the usual treatment of counseling and community treatment programs.

Along with the lead site at Penn, four other centers participated in the study, including New York School of Medicine and Bellevue Hospital Center, Rhode Island Hospital, Columbia University Medical Center, and Friends Research Institute.

Over 24 weeks of treatment, the naltrexone group received monthly injections, with both groups routinely followed and monitored. The naltrexone group showed a significantly reduced rate of relapse than the control group (43 percent vs. 64 percent) and had a longer median time to relapse (10.5 vs. 5 weeks).

“They did not all stay clean, but you can shoot up heroin while you are on this medication and you do not really feel it; it's blocked,” O’Brien said.

 While some of the members of the control group suffered from overdoses, none occurred in those taking naltrexone, even by 18 months after the end of treatment.

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