NIH Clinical Trial Validates Weekly Injectable Buprenorphine as Superior Treatment for Opioid Use Disorder During Pregnancy

NIH study finds weekly buprenorphine injections more effective than daily pills for treating OUD in pregnant patients. Discover the latest results on safety and abstinence.

By: AXL Media

Published: Mar 16, 2026, 12:15 PM EDT

Source: Information for this report was sourced from NIH/Office of the Director

Addressing the Challenges of Opioid Treatment in Pregnancy

Treating opioid use disorder (OUD) during pregnancy is a critical public health priority, as untreated addiction carries severe risks for both mother and child, including fatal overdose and neonatal opioid withdrawal syndrome (NOWS). While daily sublingual buprenorphine has long been the standard of care, it is often plagued by poor adherence and fluctuating blood levels that can trigger intense cravings. A new multicenter trial supported by the NIH HEAL Initiative has now demonstrated that a weekly subcutaneous injection of extended-release buprenorphine offers a more stable and effective alternative, helping pregnant patients maintain higher rates of abstinence from illicit substances.

The Pharmacological Advantage of Extended-Release Formulations

The primary advantage of the injectable formulation lies in its ability to eliminate the "peak-trough" effects associated with daily oral medication. When buprenorphine is taken under the tongue every 24 hours, the concentration of the drug in the bloodstream can rise and fall sharply, leading to periods of inadequate coverage. In contrast, the weekly extended-release injection provides a steady, continuous dose that mitigates withdrawal symptoms and cravings more reliably. Dr. Nora D. Volkow, director of the National Institute on Drug Abuse, noted that this stability is clinically valuable for ensuring safety and better recovery outcomes in the context of the ongoing overdose crisis.

Comparative Results in Maternal Abstinence and Safety

The randomized trial, which followed 140 pregnant adults, provided the first robust data on the efficacy of extended-release buprenorphine in this specific demographic. Researchers found that urine drug screens showed significantly higher rates of illicit opioid abstinence among those receiving the weekly injections compared to those on daily sublingual therapy. Furthermore, while both groups reported similar rates of non-serious side effects, the extended-release group experienced fewer serious maternal adverse events throughout the trial. These findings suggest that the longer-acting medication is not only more effective at preventing relapse but also carries a favorable safety profile for the mother.