Amiloride and Breastfeeding

Summary of use during lactation

Minimal information on the use of amiloride during breastfeeding found a slightly elevated serum potassium and low serum and urinary magnesium levels in one breastfed infant, suggested a systemic effect. An alternate drug may be preferred.

Drug levels in milk and infant serum

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

Effects in breastfed infants

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

Effects on lactation and breastmilk

Intense diuresis can suppress lactation;[1,2] however, it is unlikely that amiloride alone is sufficiently potent to cause this effect. A woman with Gitelman syndrome was prescribed amiloride 5 mg daily. She became pregnant and delivered a healthy infant. Amiloride was initially discontinued during breastfeeding, but restarted at 6 weeks postpartum. While on amiloride, the baby’s laboratory values showed a serum potassium of 5.8 mmol/L and a serum magnesium of 2.3 mg/dL. Spot urine concentrations of magnesium were < 1.4 mg/dL, urine creatinine was 5 mg/dL, and urine potassium was 5 mmol/L. Amiloride was stopped for one week and laboratory tests were repeated. Serum potassium was 4.8 mmol/L, magnesium was 2.2 mg/dL and a urine magnesium concentration was 1.7 mg/dL. Urine creatinine was 8 mg/dL, and urine potassium was 6 mmol/L.[3]

Alternative drugs to consider

Spironolactone

References

1. Healy M. Suppressing lactation with oral diuretics. Lancet 1961;277:1353-4. doi:10.1016/S0140-6736(61)90289-6
2. Cominos DC, Van Der Walt A, Van Rooyen AJ. Suppression of postpartum lactation with furosemide. S Afr Med J 1976;50:251-2.3858
3. Ibrahim A, Rodan AR, Westenfelder C, et al. Gitelman syndrome patient managed with amiloride during pregnancy and lactation. BMC Nephrol 2024;25:403.39521975 PubMed