A study published today in The Lancet found that two different therapies used to treat opioid use disorder – an extended-release naltrexone injection and a combination of buprenorphine and naloxone – have similar outcomes once patients get past the hurdle of starting treatment.
This is the first study to compare the combination therapy and naltrexone head-to-head in the U.S. The study enrolled 570 opioid-dependent adults, 82% of which were using heroin and 16% of which were abusing pain medications.
The study participants were randomized to receive either the combination therapy or naltrexone and researchers followed up with them for 24 weeks of outpatient treatment. The combination therapy, Suboxone, was administered daily as a sublingual film and the naltrexone, Vivitrol, was given as a monthly injection.
“Studies show that people with opioid dependence who follow detoxification with no medication are very likely to return to drug use, yet many treatment programs have been slow to accept medications that have proven to be safe and effective,” Dr. Nora Volkow, director of the National Institute on Drug Abuse, said in prepared remarks.
“These findings should encourage clinicians to use medication protocols and these important results come at a time when communities are struggling to link a growing number of patients with the most effective individualized treatment.”
According to the researchers, 72% of patients successfully started treatment with naltrexone, while 94% successfully initiated the combination therapy. The relapse rates were 65% for the naltrexone group compared to 57% for the combo group when researchers included data from all 570 study participants.
People suffering from opioid use disorder have a harder time beginning treatment with naltrexone, according to the study, since it requires a full detoxification process.
However, among the participants who successfully started treatment, the 24-week relapse rates were similar. Outcomes including days abstinent and negative urine tests were more prevalent in the combination group when considering the full sample of participants, the study found, but those same outcomes favored naltrexone for the participants who successfully started therapy.
There were five fatal overdoses during the study – three of the patients taking the combination therapy and two of the participants receiving naltrexone died.
“The good news is we filled the evidentiary void, and also learned that for those who were able to initiate treatment, the outcomes were essentially identical, as were adverse events,” lead investigator Dr. John Rotrosen said. “This gives patients the freedom to choose a treatment approach that best suits their lifestyle, goals and wishes.”
The study’s researchers pointed out that patients who can’t finish detoxification and choose naltrexone should be encouraged to start the combination therapy instead.