Is it safe to use Angiotensin-Converting Enzyme (ACE) inhibitors during lactation?

ARNI Use During Lactation

ARNIs (Angiotensin Receptor-Neprilysin Inhibitors) are contraindicated during lactation and should not be used in breastfeeding mothers. 1

Evidence-Based Recommendation

The 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA guidelines explicitly state that angiotensin receptor-neprilysin inhibitors can cause serious fetal and neonatal complications including renal dysgenesis, oligohydramnios, neonatal anuric renal failure, intrauterine growth retardation, and pulmonary hypoplasia. 1 While these data primarily reference pregnancy, the same mechanism of action that causes renal toxicity in utero poses theoretical risks to nursing infants through breast milk exposure. 1

Safe Alternative Antihypertensive Options During Lactation

If you need to treat hypertension or heart failure in a lactating mother, switch to enalapril, which is the preferred ACE inhibitor during lactation due to its established safety profile and favorable pharmacokinetics. 2, 3

First-Line Agents for Lactation:

• Enalapril: Most widely studied ACE inhibitor with very low breast milk concentrations and explicit ESC endorsement as safe for breastfeeding 2, 3
• Methyldopa: Well-established safety record with no short-term adverse effects reported in breastfed infants 2, 1
• Labetalol or Propranolol: Preferred beta-blockers due to high protein binding and minimal milk transfer 2, 1

Medications to Avoid:

• ARBs (like valsartan): Should be avoided due to limited safety data during lactation 2
• Diuretics: May reduce milk production and suppress lactation 1, 2
• ARNIs: Contraindicated based on mechanism of renal toxicity 1

Clinical Management Algorithm

1. Immediately discontinue ARNI if patient is breastfeeding or planning to breastfeed 1

2. Transition to enalapril at standard therapeutic doses without dose adjustment, monitoring infant weight during the first 4 weeks as an indicator of kidney function 3

3. Alternative regimens if ACE inhibitor contraindicated:

   • Methyldopa as first-line monotherapy 2
   • Add labetalol or propranolol if additional BP control needed 2
   • Consider nifedipine-retard or amlodipine as third-line options 4

4. Monitor the breastfed infant closely for changes in heart rate, weight gain, and feeding patterns 2, 1

5. Use home BP monitoring to titrate therapy, continuing antihypertensive medication until BP normalizes (may take days to several weeks postpartum) 1, 2

Important Caveats

Avoid enalapril in premature neonates or those with renal failure, as theoretical concerns about neonatal hypotension exist during the infant's first month of life, though actual risk appears minimal. 3 In these specific cases, methyldopa becomes the preferred alternative. 2

The FDA's conservative labeling of many antihypertensive agents as contraindicated during lactation often reflects insufficient testing rather than proven harm. 3 International guidelines from the ESC and AHA provide more nuanced, evidence-based recommendations supporting the use of specific agents like enalapril. 2, 3

Do not withhold necessary antihypertensive therapy in breastfeeding mothers with moderate to severe hypertension, as maternal cardiovascular complications pose greater risks than the minimal infant drug exposure from appropriate medication choices. 2, 1