Is buprenorphine or methadone better for opioid use disorder in pregnancy?

Researchers of a new study published in the New England Journal of Medicine compared outcomes in pregnant patients with opioid use disorder based on whether they received opioid agonist therapy with buprenorphine as opposed to methadone.

The dataset included more than 2.5 million pregnancies in the Medicaid population that resulted in live births during 2000 to 2018, and it found a similar risk for unfavorable outcomes in the mothers regardless of treatment agent received. However, the risk for adverse outcomes in the newborn babies—including neonatal abstinence syndrome, preterm birth, low birth weight, and small size for gestational age—was lower with buprenorphine than with methadone.

The study authors acknowledge that they do not yet know the biologic mechanism underlying the differences between the treatment options, but they suspect that “differences in the pharmacologic mechanism of action” between the partial agonist buprenorphine and the full agonist methadone may come into play.

The National Institute on Drug Abuse sponsored the study.