August 10, 2025

Which kidney medications are safe while breastfeeding?

A new review of existing studies offers insights into which medications taken by breastfeeding mothers with kidney disease are safe for their infants. 

When mothers breastfeed their infants, small amounts of the medications they take can sometimes pass into breast milk. Unfortunately, few studies have been able to assess the degree to which this happens, since people who are pregnant or breastfeeding have traditionally been excluded from clinical research for safety reasons.  

To help address this gap, Paula Parnizari and colleagues reviewed 81 published studies, most of which were reports of small case studies.  

The review suggests that, among renin-angiotensin system inhibitors, enalapril and captopril are safe during breastfeeding. Although evidence is very limited, quinapril, benazepril, candesartan, and valsartan also appear to be acceptable. SGLT2 inhibitors are not recommended while breastfeeding due to lack of human safety data and concerns about how these drugs may affect the infant’s developing kidneys.  

For immunosuppressive drugs, the evidence indicates that azathioprine, cyclosporine, tacrolimus, budesonide, rituximab, and eculizumab are acceptable for use while breastfeeding. Belimumab also appears likely to be safe, though data are limited.  

No studies were found on the safety of the newer complement inhibitors (avacopan, ravulizumab, iptacopan, and pegcetacoplan), and the authors say these drugs should be used with caution while breastfeeding until more data become available.  

NOTE: Anyone taking medications should always speak with their doctor before breastfeeding, as changes to treatment may be necessary.