ACE Inhibitors During Lactation
Specific ACE inhibitors—benazepril, captopril, and enalapril—are safe to use during lactation. 1
Recommended ACE Inhibitors for Breastfeeding
The 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA guidelines explicitly state that benazepril, captopril, and enalapril are safe during lactation. 1 These three agents have been specifically studied and demonstrate:
- Very low milk-to-plasma ratios, resulting in minimal infant exposure 2, 3
- High protein binding (particularly relevant for enalapril), which limits transfer into breast milk 3
- Established safety profiles with no documented adverse effects in breastfed infants 2
Enalapril is particularly well-supported as the preferred ACE inhibitor during lactation, with endorsement from both the European Society of Cardiology and American Heart Association guidelines. 4, 2
Important Caveats and Monitoring
Timing Considerations
- Exercise caution during the infant's first month of life due to theoretical concerns about neonatal hypotension, especially in premature infants 4, 2
- Avoid use in infants with renal failure 4
Clinical Monitoring
Monitor breastfed infants for: 4
- Changes in heart rate
- Weight gain patterns (particularly during first 4 weeks as an indicator of kidney function)
- Feeding patterns
Neonates with In Utero ACE Inhibitor Exposure
If the infant had in utero exposure to ACE inhibitors, closely observe for: 5
- Hypotension
- Oliguria
- Hyperkalemia
Medications to Avoid During Lactation
Aldosterone antagonists are contraindicated during lactation due to their anti-androgen effects. 1
Angiotensin receptor-neprilysin inhibitors (ARNIs) should be avoided based on their mechanism of renal toxicity and potential for serious complications in nursing infants. 4
Diuretics may suppress lactation and reduce milk production. 4
Alternative Antihypertensive Options
If ACE inhibitors are not suitable, safe alternatives include: 4
- Methyldopa: Well-established safety record with no short-term adverse effects in breastfed infants
- Labetalol or propranolol: Preferred beta-blockers due to high protein binding and minimal milk transfer
- Long-acting nifedipine: Safe calcium channel blocker option
Risk-Benefit Framework
Do not withhold necessary antihypertensive therapy in breastfeeding mothers with moderate to severe hypertension. 4, 2 The risks of untreated maternal cardiovascular disease (including stroke, heart failure, and death) far outweigh the minimal infant exposure from appropriate medication choices like enalapril, captopril, or benazepril. 4, 2
Practical Algorithm
- If ACE inhibitor therapy is required during lactation: Switch to or continue benazepril, captopril, or enalapril 1
- If the infant is less than 1 month old or premature: Consider alternative agents (methyldopa, labetalol) or use enalapril with enhanced monitoring 4, 2
- Monitor infant weight gain during the first 4 weeks as a surrogate for kidney function 4
- Avoid lisinopril and other non-specified ACE inhibitors as they lack specific safety data for lactation 5