Are diuretics, such as furosemide (Lasix) and hydrochlorothiazide (HCTZ), safe to use during breastfeeding?

Safety of Diuretics During Breastfeeding

Diuretics should be used with caution during breastfeeding as they may reduce milk volume and potentially suppress lactation, particularly at higher doses. 1

Types of Diuretics and Their Safety Profiles

Loop Diuretics (Furosemide/Lasix)

• Furosemide is excreted into breast milk, requiring careful monitoring of the nursing infant 2
• The FDA label for furosemide specifically states that it "may inhibit lactation" 2
• Should be used with caution in breastfeeding mothers, especially when higher doses are required 1

Thiazide Diuretics (Hydrochlorothiazide/HCTZ)

• Thiazides are excreted in breast milk according to the FDA drug label 3
• The FDA notes: "Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue hydrochlorothiazide, taking into account the importance of the drug to the mother" 3
• May reduce milk volume, particularly at higher doses 1

Clinical Decision-Making Algorithm

For Mothers with Stage 1 Hypertension

• Consider withholding antihypertensive medication during breastfeeding period if clinically appropriate 1
• Monitor blood pressure closely 1
• Reinstitute antihypertensive therapy after discontinuation of nursing 1

For Mothers Requiring Antihypertensive Therapy

• First-line agents for postpartum hypertension regardless of breastfeeding status include 1:

  • Nifedipine
  • Amlodipine
  • Enalapril
  • Labetalol

• Diuretics should be considered alternative agents rather than first-line therapy 1

• If diuretics are necessary, use the lowest effective dose to minimize impact on milk production 1

Monitoring Recommendations

• When a breastfeeding mother is taking diuretics: 1
  • Monitor the infant closely for potential adverse effects
  • Watch for signs of dehydration in the infant
  • Monitor milk production and infant weight gain
  • Consider supplemental feeding if milk production appears affected

Important Considerations and Caveats

• The benefits of breastfeeding generally outweigh the risks of most medications, including carefully managed diuretic therapy 4, 5
• Most medications can be used safely during breastfeeding at recommended doses, but diuretics require special consideration due to their potential effect on milk production 6
• The amount of medication transferred to the infant via breast milk is typically small and often does not lead to clinically significant effects 5
• When diuretics are necessary for maternal health, consider:
  • Using the lowest effective dose 1
  • Timing administration immediately after breastfeeding to minimize concentration in milk 7
  • Monitoring infant weight gain and hydration status 1

Alternative Approaches

• For hypertension management during breastfeeding, consider other antihypertensive medications with better safety profiles 1:
  • ACE inhibitors like benazepril, captopril, or enalapril have been sufficiently tested in breastfeeding women 1
  • Beta-blockers like propranolol and labetalol are preferred if beta-blockade is indicated 1
  • Avoid ACEIs and ARBs if there are concerns about adverse renal effects 1