Injectable extended-release naltrexone (XR-NTX) for opioid dependence: long-term safety and effectiveness
Article first published online: 24 MAY 2013
© 2013 Society for the Study of Addiction
Volume 108, Issue 9, pages 1628–1637, September 2013
How to Cite
Krupitsky, E., Nunes, E. V., Ling, W., Gastfriend, D. R., Memisoglu, A. and Silverman, B. L. (2013), Injectable extended-release naltrexone (XR-NTX) for opioid dependence: long-term safety and effectiveness. Addiction, 108: 1628–1637. doi: 10.1111/add.12208
- Issue published online: 16 AUG 2013
- Article first published online: 24 MAY 2013
- Manuscript Accepted: 27 MAR 2013
- Manuscript Revised: 20 NOV 2012
- Manuscript Received: 26 SEP 2012
- National Institute on Drug Abuse. Grant Number: R43DA013531
- National Institute on Alcohol Abuse and Alcoholism. Grant Number: N43AA001002
- depot naltrexone;
- extended-release naltrexone;
- heroin dependence;
- injectable naltrexone;
- opioid dependence;
- long-term safety;
- sustained release formulations
To describe drug use and safety with intramuscular injectable extended-release naltrexone (XR-NTX) in opioid dependence during a 1-year open-label extension phase.
Following 6 months of randomized, double-blind, placebo (PBO)-controlled injections given every 28 days, patients receiving XR-NTX 380 mg continued and PBO patients were switched to open-label XR-NTX, with monthly individual drug counseling, for a further year.
Thirteen clinical sites in Russia.
Adult opioid-dependent outpatients.
Monthly urine samples; reports of craving and functioning; adverse events.
For the open-label extension (n = 114), 67 continued on XR-NTX and 47 switched from PBO during the double-blind phase to XR-NTX during the open-label phase. Overall, 62.3% (95% CI: 52.7%, 71.2%) completed the extension. Discontinuation occurred most commonly because of withdrawal of consent (18.4%) and loss to follow-up (11.4%); two patients discontinued as a result of lack of efficacy and one because of adverse events. Urine testing revealed that 50.9% (41.5%, 60.4%) were abstinent from opioids at all assessments during the 1-year open-label phase. Adverse events reported by 21.1% of patients were judged to be study drug-related. Injection site reactions were infrequent (6.1%) and the majority were mild. Elevations in liver function tests occurred for 16.7% of patients, but none of these elevations was judged to be clinically significant. No patients died, overdosed or discontinued as a result of severe adverse events.
During a 1-year open-label extension phase of injectable XR-NTX for the prevention of relapse in opioid dependence, 62.3% of patients completed the phase and 50.9% were abstinent from opioids. No new safety concerns were evident.