Evaluation of the Safety of Taking Brexpiprazole During the Lactation Period.

Introduction: Brexpiprazole (BPZ), an antipsychotic drug introduced in 2018, is often used to manage psychiatric conditions. However, the effect of its use on infants whose mothers are receiving BPZ during lactation remains uncertain. Given the limited data on its effects on infants, this study evaluated the safety of its use by mothers during lactation.

Materials and methods: Three mother-infant pairs were assessed between 2018 and 2023 at Tohoku University Hospital. Each mother continued BPZ monotherapy (1-2 mg/day) during pregnancy and lactation within the first month postpartum, and data on maternal and infant health, as well as withdrawal symptoms or adverse events in newborns and infants, were collected from medical records.

Results: No withdrawal symptoms or severe adverse events were noted in any of the three newborns or infants. Mild cases of neonatal jaundice and acne were observed in all three newborns and infants; however, they were considered unrelated to BPZ exposure. Nonetheless, it appears that the drug might have decreased milk supply, as supplemental formula feeding was occasionally necessary.

Conclusion: This study suggests that BPZ monotherapy (1-2 mg/day) during lactation does not lead to withdrawal symptoms or serious adverse events in newborns or infants within the first month postpartum. This initial evidence may help inform breastfeeding decisions among mothers receiving BPZ monotherapy.