Observations that the monthly injectable version of the medication naltrexone holds particular promise for opioid-dependent individuals involved in the justice system appear to be receiving confirmation in a newly published study.
Published online March 30 in the New England Journal of Medicine, the study of 153 men in four Northeast cities found lower relapse rates to opioids in a group that received six monthly injections of Vivitrol, compared with a group receiving only motivational counseling and referral to community treatment (which the Vivitrol group received as well). Similar drug-using rates in the two groups one year post-treatment, however, point to the possible need for a more extended treatment period with the medication, which is also used to treat alcohol dependence.
“We believe our study is the first of its kind to look at the real-world effectiveness of extended-release naltrexone in community settings,” Joshua D. Lee, MD, associate professor in the Departments of Population Health and Medicine at NYU Langone Medical Center and lead author of the study, said in a news release. “It may be particularly effective with populations, such as recently released prisoners, who typically don't have access to other evidence-based daily medications for opiate disorders, like methadone or buprenorphine.”
The study involved men in New York City, Philadelphia, Baltimore and Providence, R.I., who were either recently released from prison, on probation or parole, or with other justice system involvement. Researchers found that after the six monthly injections of Vivitrol, 43% of the medication patients had relapsed to opioid use, compared with 64% of individuals who did not receive the medication.
The researchers also reported that the medication group members who did relapse still used less heroin and other opioids than the non-medication participants. Five members of the non-medication group overdosed during the six-month study, compared with no overdoses in the Vivitrol group.
Similar rates of opioid use one year after the treatment period ended indicate that six months might not be a sufficient duration for Vivitrol treatment in this population, the researchers stated. The study was supported by the National Institute on Drug Abuse (NIDA); the lead researcher reported having received research support from Alkermes, the maker of Vivitrol.