Remdesivir and Breastfeeding

Summary of use during lactation

Information from 5 patients indicate that milk levels of remdesivir and its active metabolite are very low in milk. Additionally, remdesivir is poorly absorbed orally, and the metabolite is only partially absorbed orally, so infants are not likely to absorb clinically important amounts of the drug from milk. Newborn infants have received intravenous remdesivir therapy for Ebola and for COVID-19 with no serious adverse drug reactions and it is FDA approved for use in infants of at least 28 days and weighing 3 kg.[1-3] Infants exposed via breastmilk have also not had any reported adverse reactions. Given this information, mothers receiving remdesivir do not need to avoid nursing, but until more data are available, remdesivir should be used with careful infant monitoring during breastfeeding.[4] The most common adverse effects reported after intravenous infusion include elevated aminotransferase and bilirubin levels and other liver enzyme elevations, diarrhea, rash, renal impairment and hypotension.

Drug levels in milk and infant serum

Maternal Levels. Two days after delivery, a woman was diagnosed with a SARS-CoV-2 infection. She was given 200 mg of remdesivir on the first day of therapy, then 100 mg daily for 4 more days. Although not stated, all doses are presumed to have been given intravenously. On day 5 of therapy, milk was collected just before the dose and 1, 3, 6, and 24 hours after the last dose. Remdesevir and its metabolite GS-441524 were measured in milk. The concentration of remdesivir in milk was 1.29 mcg/L one hour before administration on day 5, but undetectable (<0.5 mcg/L) in the other samples. The concentration of the active metabolite GS-441524 in the milk samples were 13.5 mcg/L before the fifth dose, 285 mcg/L at 3 hours after the dose and 64.3 mcg/L at 24 hours after the dose. The authors estimated the relative infant doses of remdesevir and GS-441524 in breastmilk as 0.007% and 1.6%, respectively. The half-life of GS-441524 in milk was estimated to be 9.3 hours.[5] Four women with COVID-19 who received remdesivir provided 17 milk samples for analysis of remdesivir and its active metabolite GS-441524. All of the milk samples had unquantifiable (<100 mcg/L) concentrations of remdesevir. Eleven of the samples contained unquantifiable (<100 mcg/L) concentrations of GS-441524. The highest concentration of the metabolite in the remaining 6 samples from one woman was 168 mcg/L. Using this “worst-case” value, the infant dose would be 25.2 mcg/kg daily, which would be a relative infant dose of <5%.[6] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

The manufacturer reports that 11 breastfed infants were exposed to remdesevir in breastmilk from pharmacovigilance reports. The reports do not indicate adverse effects on breastfed infants from exposure to remdesivir and its metabolite through breastmilk.

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

Alternative drugs to consider

Nirmatrelvir

References

1. Dörnemann J, Burzio C, Ronsse A, et al. First newborn baby to receive experimental therapies survives Ebola virus disease. J Infect Dis 2017;215:171-4.28073857 PubMed
2. Mulangu S, Dodd LE, Davey RT, Jr, et al. A randomized, controlled trial of Ebola virus disease therapeutics. N Engl J Med 2019;381:2293-303.31774950 PubMed
3. Frauenfelder C, Brierley J, Whittaker E, et al. Infant with SARS-CoV-2 infection causing severe lung disease treated with remdesivir. Pediatrics 2020;146:e20201701.32554811 PubMed
4. Aleissa MM, Silverman EA, Paredes Acosta LM, et al. New perspectives on antimicrobial agents: Remdesivir treatment for COVID-19. Antimicrob Agents Chemother 2021;65:e01814-20.33139290 PubMed
5. Wada YS, Saito J, Hashii Y, et al. Remdesivir and human milk: A case study. J Hum Lact 2022;38:248-51.35189734 PubMed
6. Bertrand K, Sepulveda Y, Spiegel BJ, et al. Concentrations of remdesivir and GS-441524 in human milk from lactating individuals diagnosed with COVID-19. Pediatr Res 2024;96:269-72.38347172 PubMed