Monday, March 16, 2026
NIH-supported study shows this treatment resulted in higher rates of illicit opioid abstinence than current standard of care.
In a clinical trial supported by the National Institutes of Health (NIH), a research team found that administering weekly injectable extended-release buprenorphine for treatment of opioid use disorder (OUD) during pregnancy led to higher rates of abstinence from illicit opioids than buprenorphine given daily under the tongue (sublingual), one of the standard methods of treatment. Additionally, serious adverse events were less common in those receiving extended-release treatment. The findings, which support the use of this formulation of buprenorphine for treating OUD during pregnancy, were published in JAMA Internal Medicine.
“These findings are clinically valuable for they show us that this injectable extended-release buprenorphine formulation is safe to use in pregnancy and results in better opioid abstinence outcomes compared to sublingual buprenorphine,” said Nora D. Volkow, M.D., director of NIH’s National Institute on Drug Abuse (NIDA). “This is especially relevant in the context of the ongoing opioid overdose crisis and public health emergency.”
Illicit opioid use and untreated OUD can have dire consequences during pregnancy, including risk of fatal overdose for the mother and the development of neonatal opioid withdrawal syndrome (NOWS) and other adverse consequences for the baby. Treating OUD in pregnancy with sublingual buprenorphine is effective, but it has disadvantages, including risk of misuse, potentially poor adherence, and daily fluctuating blood levels known as peak-trough effects that may inadequately mitigate opioid-related cravings and withdrawal, leading to continued opioid use. The researchers in this study wanted to see if using a weekly formulation of subcutaneous (under-the-skin), extended-release buprenorphine injections during pregnancy—with the option of a monthly formulation for postpartum participants who were not breastfeeding—might promote as good or better opioid abstinence rates and NOWS outcomes.
In the multicenter trial, 140 pregnant adults were randomized to receive either injectable extended-release or sublingual buprenorphine (with or without naloxone). The trial, supported by the NIDA Clinical Trials Network as part of the NIH Helping to End Addiction Long-term ® Initiative (NIH HEAL Initiative®), was the first randomized trial testing extended-release buprenorphine for OUD in pregnancy and postpartum.
The researchers found that rates of illicit opioid abstinence during pregnancy, as measured by urine drug screens, were significantly higher for those receiving weekly extended-release buprenorphine and were non-inferior postpartum compared to participants receiving sublingual buprenorphine. While the percentage of participants experiencing non-serious maternal adverse events did not differ between the types of treatments, they were more commonly rated as medication-related in the extended-release group during pregnancy. Serious maternal adverse events were less common in the extended-release group throughout the trial. NOWS outcomes did not differ between the treatment groups.
“We knew that injectable extended-release buprenorphine leads to superior rates of illicit opioid abstinence in non-pregnant adults, but there had been no completed randomized clinical trial testing its use during pregnancy,” said principal investigator and lead author John Winhusen, Ph.D., professor of Psychiatry and Behavioral Neuroscience at the University of Cincinnati College of Medicine. “It is exciting to share the results of this trial, which have immediate clinical application: this longer-acting medication can safely and more effectively support treatment and recovery in pregnant patients.”
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About the National Institute on Drug Abuse (NIDA): NIDA is a component of the National Institutes of Health, U.S. Department of Health and Human Services. NIDA supports most of the world’s research on the health aspects of drug use and addiction. The Institute carries out a large variety of programs to inform policy, improve practice, and advance addiction science. For more information about NIDA and its programs, visit www.nida.nih.gov.
About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
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Reference
TJ Winhusen, et al. Extended-release versus Sublingual Buprenorphine in Pregnancy through 12-months Postpartum. JAMA Internal Medicine. DOI: 10.1001/jamainternmed.2026.0057
