Extended-Release Naltrexone an Option for Opioid Dependence

October 27, 2017

By Marilynn Larkin

NEW YORK—Extended-release naltrexone is as effective as daily buprenorphine-naloxone in helping people abstain from heroin and other addicting substances and should be considered as a treatment option for opioid-dependent individuals, researchers in Norway say.

“The risk for opioid overdose, lethal or non-lethal, or relapse to opioid abuse is very high during the first weeks after detox or after being dismissed from prison or residential treatment,” Dr. Lars Tanum of the University of Oslo told Reuters Health.

“Our study has demonstrated that in such short-term treatment, blocking the opioid receptors with long-acting naltrexone works just as well, and in fact slightly better, than continuing the opioid dependence by switching to a lower-harm opioid medication,” he said by email.

Dr. Tanum and colleagues conducted an open-label trial involving opioid-dependent outpatients at five urban addiction clinics in Norway from 2012 to 2015. In all, 159 participants (mean age, 36; 28% women) were randomized to receive intramuscular extended-release naltrexone (380 mg) every four weeks or daily oral, flexible-dose (4 to 24 mg) buprenorphine-naloxone - for a total of 12 weeks. Two-thirds of the participants (105) completed the trial.

As reported in JAMA Psychiatry, online October 18, retention in the extended-release naltrexone group was noninferior to the buprenorphine-naloxone group, with mean participation of about 70 and 64 days, respectively.

Treatment with extended-release naltrexone was noninferior to buprenorphine-naloxone, as determined by the group proportion of opioid-negative urine drug tests (mean, 0.9 and 0.8, respectively) and use of heroin and other illicit opioids.

However, a superiority analysis showed significantly less use of heroin and other illicit opioids in the extended-release naltrexone group. The two groups did not differ significantly in their use of most other illicit substances.

“Maintaining short-term opioid abstinence with extended-release naltrexone should be considered an equal treatment alternative to buprenorphine-naloxone as medication-assisted treatment for opioid-dependent individuals,” the authors conclude.

Dr. Tanum explained, “Since we did not know on beforehand how the study would come out, we ‘played safe’ and postulated (that) long-acting naltrexone (would be non-inferior) to buprenorphine-naloxone. Even that would have been a great finding.”

“There are no safety issues that should influence the cost-benefit decision,” he added. “Given the Norwegian healthcare system, we think that treatment of heroin-dependent individuals with long-acting naltrexone will represent a reduction in costs both for hospitals and for society.”

“However,” he concluded, “this must be adapted, (depending on) how a healthcare system is organized and (how costs are) calculated for each country or region.”

Dr. Christopher Gharibo, associate professor of Anesthesiology, Perioperative Care, and Pain Medicine and Orthopedic Surgery at NYU Langone Health in New York City, commented in an email to Reuters Health, “Injectable naloxone offers superior efficacy, reliability and compliance to once-daily oral alternatives that run the risk of abuse, diversion, and non-compliance, while reminding the individual that they're in an opioid-dependence program.”

“It’s easier to be compliant with a monthly injection that is more convenient and does not have high street value,” he concluded.

Dr. Ben Nordstrom, Chief Clinical Officer of Phoenix House and Phoenix Life Centers, told Reuters Health by email, “What I am most taken by is that, despite working completely differently, the two medications were equally effective for the most important outcomes.”

“This really drives home the importance of educating patients so they can pick the medication that most closely aligns with their individual preferences and goals for recovery."

SOURCE: http://bit.ly/2y1Ig19

JAMA Psychiatry 2017.

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