Extended-Release Buprenorphine Shows Promise to Support Breastfeeding Parents with Opioid Use Disorder

Researchers at Boston Medical Center (BMC) have promising new data that suggests extended-release buprenorphine could be used to treat parents with opioid use disorder while breastfeeding, without passing the chemicals to their infants. The once-monthly dose is effective at mitigating risks of relapse and overdose, and for new parents, it is often more manageable than sublingual buprenorphine, which patients need to take multiple times a day, likely decreasing medication adherence.  

However, the chemical solvent that allows for sustained release, N-Methyl-2-pyrrolidone (NMP), is a known developmental toxicant at high levels, based on animal studies. The concern is that it could pose a threat to infants if transferred from their birthing parent while pregnant or breastfeeding—however, the safety of longer-acting medications to treat opioid use disorder (OUD) during pregnancy, post-partum, and breastfeeding has been understudied. In this new research, BMC teams sought to address that gap and better understand if and how NMP can be transferred through breastmilk. 

Their findings, published recently in Breastfeeding Medicine, showed that neither buprenorphine nor NMP were detected in blood samples from three parents’ breastfed infants. 

“Birthing parents’ access to evidence-based treatments like extended-release buprenorphine will not only support recovery but also help families thrive from the very beginning,” said Elisha Wachman, MD, neonatologist and Vice Chair for Research in the Department of Pediatrics at BMC.  

“Preliminary Results are Reassuring”  

In the study, Wachman and colleagues collected milk and blood samples from three lactating parents who received 300 milligrams of extended-release buprenorphine monthly. The team also analyzed buprenorphine and NMP concentrations in the blood samples of their infants.  

The researchers found that the three lactating parents had buprenorphine levels in their blood similar to those reported in non-pregnant individuals taking extended-release buprenorphine. The team also found that buprenorphine and NMP were at low concentrations in parents’ breastmilk—similar to levels previously reported for buprenorphine in parents taking medication sublingually. Yet neither chemical was at detectable levels in their infants’ blood.  

 “Ultimately, our goal is to generate robust evidence that informs care and improves outcomes, not only for individuals with opioid use disorder, but also for their children and families.”  

Elisha Wachman, MD, neonatologist and Vice Chair for Research in the Department of Pediatrics at BMC

These early findings suggest that parents taking a typical, effective dose of extended-release buprenorphine did not pass the medication or chemical to their babies through breastfeeding. 

“Our preliminary results are reassuring and suggest that it is likely safe to use extended-release buprenorphine in lactating individuals with opioid use disorder. These findings add to the growing evidence that effective treatment can continue during breastfeeding, benefiting both parent and child,” says Wachman, who is also a professor of pediatrics at the Boston University Chobanian & Avedisian School of Medicine. 

The Future of Research into OUD treatment when Pregnant or Breastfeeding 

About 7% of women reported taking prescription opioids during pregnancy in 2019, and 1 in 5 of those women reported misuse according to the U.S. Centers for Disease Control and Prevention. BMC’s study results offer early promise for being able to continue evidence-based treatment for opioid use disorder while pregnant or breastfeeding, but there is still much more discovery to do to better assist this population.  

The team is now seeking to conduct larger studies that would enroll additional participants to be able to look at the transfer of NMP through breastmilk over time, as well as to study extended-release buprenorphine in pregnant patients to ensure safety and efficacy. 

“Ultimately, our goal is to generate robust evidence that informs care and improves outcomes,” Wachman says, “not only for individuals with opioid use disorder, but also for their children and families.”