Is Amiloride safe while breastfeeding?

Summary of use during breastfeeding

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.

Effects on the breastfed infant

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

Effects on milk supply

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]

Levels in milk

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

Alternatives LactMed lists

• Spironolactone