Introduction: Remdesivir was originally developed to treat Ebola hemorrhagic fever, and its efficacy in treating coronavirus disease 2019 was detected during a preliminary analysis of a randomized controlled trial. It is known that Severe Acute Respiratory Syndrome Coronavirus 2 is not transmitted through human milk, but data about the presence of remdesivir in human milk have been lacking.
Main issue: In this case study, we determined the human milk-to-serum drug concentration ratio and the relative dose of Remdesivir in one participant.
Management: The participant, a 28-year-old primipara, was found to have Coronavirus 2 infection in 2019, 2 days after delivery. She was given Remdesivir. The Remdesivir concentration in maternal serum and human milk was measured, and the milk-to-serum drug concentration ratio was found to be low (0.089), as was the relative infant dose (0.0070). The participant could not breastfeed her infant during her Coronavirus 2 infection treatment because in Japan anyone with COVID-19 was completely quarantined. However, she was able to resume breastfeeding after discharge and breastfed her infant for 6 months with supplements.
Conclusion: Given the low amount of Remdesivir in the participant's milk, the inclusion of antibodies to Severe Acute Respiratory Syndrome Coronavirus 2, which can be expected to protect the infant from infection, and various other benefits of human milk, suggests that breastfeeding is safe during treatment with Remdesivir.
Keywords: COVID-19; SARS-CoV-2; breastfeeding; case study; human milk; relative infant dose; remdesivir.