Opioid treatment at release from jail using extended-release naltrexone: a pilot proof-of-concept randomized effectiveness trial

Though few seemed willing to try this treatment, among those who did, opiate-blocking injections active for about a month helped formerly dependent prisoners in New York City’s jail avoid relapse to regular opiate use after release. 

http://findings.org.uk/PHP/dl.php?file=Lee_JD_7.cab&s=eb