Injectable extended-release naltrexone for opioid dependence

January 01, 0001

Injectable extended-release naltrexone for opioid dependence

The researchers from Russia and the US aimed to assess the efficacy, safety, and patient-reported outcomes of an injectable, once monthly extended-release formulation of the opioid antagonist naltrexone (XR-NTX) for treatment of patients with opioid dependence after detoxification. They did a double- blind, placebo-controlled, randomised, 24-week trial of 250 patients with opioid dependence disorder. They randomly assigned patients (1:1) to either 380 mg XR-NTX or placebo. Participants also received 12 biweekly counselling sessions. Participants, investigators, staff, and the sponsor were masked to treatment allocation.

The median proportion of weeks of confirmed abstinence was 90.0% in the XR-NTX group compared with 35.0% in the placebo group (significant). Patients in the XR- NTX group self-reported a median of 99.2% opioid-free days compared with 60.4% for the placebo group (significant). The mean change in craving was -10.1 in the XR-NTX group compared with 0.7 in the placebo group (significant). Median retention was over 168 days in the XR-NTX group compared with 96 days in the placebo group (significant). Naloxone challenge confirmed relapse to physiological opioid dependence in 17 patients in the placebo group compared with one in the XR- NTX group (significant). XR-NTX was well tolerated. Two patients in each group discontinued owing to adverse events. No XR-NTX-treated patients died, overdosed, or discontinued owing to severe adverse events.

The researchers concluded: "XR-NTX represents a new treatment option that is distinct from opioid agonist maintenance treatment. XR-NTX in conjunction with psychosocial treatment might improve acceptance of opioid dependence pharmacotherapy and provide a useful treatment option for many patients."

This looks very hopeful, but needs longer term follow- up and an arm with other accepted therapies (eg opioid agonists, as mentioned in the conclusion).

For the full abstract, click here.

The Lancet 377 (9776):1506-1513, 30 April 2011
© 2011 Elsevier Limited
Injectable extended-release naltrexone for opioid dependence: a double-blind, placebo-controlled, multicentre randomised trial. Evgeny Krupitsky, Edward V Nunes, Walter Ling et al. Correspondence to Evgeny Krupitsky:

Category: Z. Social Problems. Keywords: injectable, extended realesae, naltrexone, opiod, dependence, double-blind, placebo-controlled, multicentre randomised trial, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 13 May 2011

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.