Can Angiotensin Receptor Blockers (ARBs) be given to a nursing mother?

ARBs Should Be Avoided During Breastfeeding

ARBs (Angiotensin Receptor Blockers) should be avoided in nursing mothers due to limited safety data and potential risks to the breastfed infant, with safer alternatives readily available. 1, 2

Guideline Recommendations Against ARB Use

The major cardiovascular guidelines consistently recommend against ARB use during lactation:

• The American Heart Association explicitly states that ARBs should be avoided during lactation based on limited safety data. 1
• The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends that ARBs should be avoided during lactation due to reports of adverse fetal and neonatal renal effects. 2
• The 2017 ACC/AHA Hypertension Guidelines note that ACE inhibitors and ARBs are fetotoxic and contraindicated during pregnancy, though specific lactation guidance is less detailed in this document. 3

Safer Alternative Antihypertensive Options

First-line antihypertensive medications for breastfeeding mothers include:

• Methyldopa, labetalol, propranolol, and enalapril are the most suitable options, with enalapril being the preferred ACE inhibitor due to its safety profile and favorable pharmacokinetics. 1
• Beta-blockers such as propranolol and labetalol are preferred if a beta-blocker is indicated, due to their high protein binding and minimal transfer into breast milk. 1
• Nifedipine (long-acting calcium channel blocker) is considered safe for breastfeeding mothers. 2
• Methyldopa has a well-established safety record with no short-term adverse effects reported in breastfed infants. 1

Clinical Decision Algorithm

For mild hypertension (Stage 1):

• Consider withholding antihypertensive medication with close blood pressure monitoring if the mother wishes to breastfeed for only a few months. 1
• Home blood pressure monitoring is suggested for breastfeeding mothers. 1

For moderate to severe hypertension requiring treatment:

• First-line options: methyldopa, labetalol, or propranolol. 1, 2
• Second-line options: enalapril (preferred ACE inhibitor) unless the neonate is premature or has renal failure. 1
• Nifedipine and amlodipine are also appropriate first-line agents for postpartum hypertension. 4

Important Caveats and Monitoring

Key considerations when managing hypertension in nursing mothers:

• Closely monitor breastfed infants of mothers taking any antihypertensive agents for potential adverse effects such as changes in heart rate, weight, hypotension, hyperkalemia, and renal impairment. 1, 2
• Diuretics may reduce milk production and suppress lactation, making them less desirable during breastfeeding. 1, 2, 4
• ACE inhibitors are generally not recommended for women breastfeeding infants during the infant's first month of life due to concerns about neonatal hypotension, though enalapril specifically has very low levels in breast milk. 3
• Antihypertensive medication is usually continued until blood pressure has normalized, which may take days to several weeks postpartum. 1

Evidence Quality Note

The evidence base for ARB safety during lactation is notably limited compared to other antihypertensive classes. 1 A systematic review found that ACE inhibitors, methyldopa, beta-blockers with high protein binding, and some calcium channel blockers all appear to be safe treatments, but ARBs were not included in the safe category due to insufficient data. 5