Groundbreaking study to assess safety of drugs passed through breastmilk

The Pediatric Trials Network (PTN) is undertaking a groundbreaking study to assess the safety of commonly used off-patent medications when they are given to breastfeeding mothers. The study will track how different drugs are passed through breastmilk to determine dosing levels that are safe for both mom and baby.

Although the U.S. Food and Drug Administration (FDA) has implemented a guidance document on conducting lactation studies, off-patent drugs are not included in that rule. The PTN seeks to fill this knowledge gap.

Dr. Kevin Watt

“Although the benefits of breastfeeding are well-documented, we still don’t know enough about the effects of many prescription and over-the-counter off-patent drugs when they are passed to infants through their mother’s breastmilk,” said Dr. Kevin Watt, an assistant professor of pediatrics at Duke University who is leading the study. “As a rule, we discourage unnecessary drug use during lactation, but it’s quite common for new mothers to have symptoms or medical conditions that must be treated with drugs.”

“Many breastfeeding moms struggle with the decision to take medications because of the fear that these drugs will harm their children,” Watt said. “In the end, it often comes down to either stopping breastfeeding or discontinuing needed medications. We want to take the guesswork out of this difficult decision and allow moms to breastfeed without worry.”

The study is expected to begin in April of 2018 and will enroll approximately 50 lactating women, along with their breastfed infants, for each drug studied. Initially 10 off-patent drugs will be studied, including medications used to treat bacterial infections, depression and anxiety, high blood pressure, diabetes, and chronic pain. Mothers will be enrolled in the study only if they are already taking one of the study drugs as part of their routine care.

Mothers who participate in the study will provide samples of breastmilk, their blood, their infants’ blood, or a combination to help researchers measure drug levels and determine the safest dose. Mothers and infants are expected to remain in the study until the infants reach 180 days of age.

The study, supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), will also explore the effects of maternal obesity on drug exposure and long-term outcomes of breastfed infants exposed to drugs in breastmilk.

See the NIH LactMed database for more information on the levels of various substances in breastmilk and infant blood, and possible adverse effects.