ARTICLES YOU MIGHT HAVE MISSED
Articles You Might Have Missed
Melissa H. Gittinger
Joseph Edward Carpenter
Camille Ashley Dunkley
Brian Patrick Murray
Received: 11 May 2018 / Accepted: 15 May 2018
American College of Medical Toxicology 2018
Opioid use disorder
Opium lead toxicity
Lee JD, Nunes Jr. EV, Novo P, et al.: Comparative effective-
ness of extended-release naltrexone versus buprenorphine-
naloxone for opioid relapse prevention (X:BOT): a
multicentre, open-label, randomised controlled trial. Lancet
Detoxification and counseling-only aftercare have been treat-
ment mainstays for patients with opioid use disorder. Since
long-term abstinence is rarely achieved, additional treatment
with medication has been increasing. In the USA,
buprenorphine-naloxone (BUP-NX) is the most commonly
prescribed agent for medication-assisted opioid treatment.
Naltrexone is similarly employed in patients diagnosed with
an opioid use disorder. It is available in a long-acting, inject-
able form (XR-NTX); however, concerns surrounding induc-
tion limit its use to well selected individuals. A concurrent
Norwegian study concluded that XR-NTX is noninferior to
BUP-NX for preventing short-term relapse to opioid use.
Is there a difference in relapse rate between patients receiving
XR-NTX and those receiving BUP-NX? Are there differences
in induction success, safety, and frequency of non-study opi-
This was a 24-week, multicenter, open-label, and randomized trial
including subjects who had been admitted to inpatient detoxifica-
tion centers. Subjects were randomized to receive ~ 380 mg of
XR-NTX every 28 days or daily doses of 8–24 mg BUP-NX,
supplied weekly. Those randomized to the XR-NTX group were
required to have an opioid-negative urine screen and negative
naloxone challenge before initiating treatment. Withdrawal symp-
toms were managed according to usual care at each study site.
After discharge from the inpatient center, subjects had weekly
office visits out to 24 weeks, then again at 28 and 36 weeks.
Psychosocial counseling was available to all subjects.
Five hundred seventy subjects were randomized, 283 to the XR-
NTX group and 287 to the BUP-NX group. Two hundred four
(72%) subjects in the XR-NTX and 270 (94%) in the BUP-NX
group successfully initiated treatment (p < 0.0001). In an
intention-to-treat analysis, 185 (65%) subjects in the XR-NTX
group and 163 (57%) in the BUP-NX group had relapsed to
non-study opioid use by 24 weeks post-randomization (HR
1.36, 95% CI 1.10–1.68). In a per-protocol analysis, there was
no significant difference in relapse rate between the two groups.
Secondary analysis found similar results with respect to opioid-
negative urine samples and self-reported opioid-free days.
Cravings were initially better controlled in the XR-NTX group;
however, there was no significant difference at week 24. Finally,
the frequencies of adverse drug effects, overdose, and overdose
deaths did not differ between groups.
Initiation of therapy is more difficult with XR-NTX than
BUP-NX. Once subjects were started on therapy, both medi-
cations had similar relapse rates and side effect profiles.
* Melissa H. Gittinger
Department of Emergency Medicine and Georgia Poison Center,
Emory University School of Medicine, Atlanta, GA, USA
Journal of Medical Toxicology