Lee 2016: Vivitrol for opioid relapse in the criminal justice system

What they tested

Adults involved in the US criminal justice system who had a history of opioid dependence, preferred opioid-free treatment over opioid maintenance, and were off opioids at the start were randomly assigned to 24 weeks of extended-release naltrexone (Vivitrol) or usual treatment. Usual treatment meant brief counseling and referrals to community programs. Everyone knew which group they were in (open-label).

Relapse meant 10 or more days of opioid use in a 28-day period, by self-report or urine tests every 2 weeks; a missed or positive test counted as 5 days of use. People were followed up at weeks 27, 52 and 78.

What they found

During the 24-week treatment phase, people on Vivitrol went longer before relapse (median 10.5 vs 5.0 weeks), fewer relapsed (43% vs 64%) and more of their urine samples were opioid-negative (74% vs 56%).

The effect didn't last. At week 78, about a year after treatment ended, opioid-negative urine tests were equal at 46% in each group.

Vivitrol did not significantly lower self-reported cocaine, alcohol or injection drug use, unsafe sex or reincarceration compared with usual treatment.

Over all 78 weeks there were no overdoses in the Vivitrol group and 7 in the usual-treatment group.

Limits

• It was open-label, so people knew which treatment they got.
• It compared Vivitrol with usual care, not with methadone or buprenorphine, and only enrolled people who preferred opioid-free treatment.
• The benefits on opioid use did not last after treatment stopped.

What it means if you're considering naltrexone

For people in the justice system who want an opioid-free option, this trial shows the monthly shot lowered relapse while people kept getting it. It also shows the protection faded once the shots stopped. The site's Vivitrol guide covers the overdose warning that applies after stopping.