breastfeeding and beta blockers

Last edited 06/2023 and last reviewed 06/2023

Breastfeeding and beta blockers

  • labetalol, metoprolol, and propranolol are the beta-blockers of choice during breastfeeding (1)
    • very small amounts get into breast milk, and they have shorter half-lives leading to a lower risk of accumulation in a breastfed infant. Labetalol and metoprolol also do not rely on excretion in the urine, again leading to less risk of accumulation
    • amount of beta-blockers found in breastmilk varies depending on the exact medication (2)
      • atenolol, acebutolol, and nadolol are present in high amounts in breast milk and may not be recommended while breastfeeding
      • propranolol, labetalol, and metoprolol have been found in small amounts in breastmilk and are considered compatible with breastfeeding.
    • labetalol and propranolol are used therapeutically in neonates, and metoprolol in infants from one month of age
      • however, any beta-blocker may be used during breastfeeding if clinically appropriate, although more careful monitoring may be required
    • labetalol
      • infant monitoring whilst using labetalol whilst breastfeeding (1)
        • as a precaution, monitor infants for signs of bradycardia or hypoglycaemia including drowsiness, lethargy, and poor feeding and inadequate weight gain
        • hypoglycaemia may also manifest as jitteriness/ tremors, sweating, irritability, fast breathing, looking pale, and unusual cry
        • notes on labetalol
          • limited evidence indicates that levels in breast milk are generally very small
            • most breastfed infants are likely to get less than 1% of maternal weight-adjusted dose via breast milk
          • labetalol is mostly metabolised in the liver, and its half-life in adults is 6-8 hours
            • risk of accumulation in a breastfed infant is therefore low
          • most studies have not reported any adverse effects in breastfed infants
            • one premature infant developed sinus bradycardia when exposed to labetalol via breast milk, suggesting additional caution is needed in very young or premature infants
    • metoprolol
      • infant monitoring whilst using metoprolol whilst breastfeeding (1)
        • as a precaution, monitor infants for signs of bradycardia or hypoglycaemia including drowsiness, lethargy, and poor feeding and inadequate weight gain
        • hypoglycaemia may also manifest as jitteriness/tremors, sweating, irritability, fast breathing, looking pale, and unusual cry
        • notes on metoprolol
          • limited evidence indicates that amounts in breast milk are generally very small
            • most breastfed infants are likely to get less than 2% of the weight-adjusted maternal dose of metoprolol via breast milk
          • metoprolol is mostly metabolised in the liver, and its half-life in most adults is 3-7 hours, and 5-10 hours in neonates
            • note though that, metoprolol is metabolised by the hepatic cytochrome P450 2D6 enzyme
              • some individuals do not have effective levels of this enzyme ("poor metabolisers"), resulting in slower metabolism and a half-life of 7-9 hours in adults, and presumably longer in neonates
              • s may increase the risk of infant side effects
              • risk of significant accumulation in a breastfed infant is therefore relatively low, but not impossible, especially in very young infants
    • propranolol
      • infant monitoring whilst using propranolol whilst breastfeeding (1)
        • as a precaution, monitor infants for signs of bradycardia or hypoglycaemia including drowsiness, lethargy, and poor feeding and inadequate weight gain
        • hypoglycaemia may also manifest as jitteriness/tremors, sweating, irritability, fast breathing, looking pale, and unusual cry
        • notes on propranolol
          • limited evidence indicates the amounts in breast milk are very small
            • most breastfed infants are likely to get less than 1% of the weight-adjusted maternal daily dose of propranolol via breast milk
            • despite propranolol almost being completely excreted in the urine, it is highly lipid soluble and highly protein bound, and has a half-life of 3-6 hours
              • accumulation in a breastfed infant is therefore unlikely
          • have been no reported side effects in infants clearly attributed to exposure to propranolol via breast milk
          • is used therapeutically in infants from birth

  • Effect on breastfeeding
    • beta-blockers are not known to have an effect on breastfeeding (1)
      • however, non-selective beta-blockers (especially labetalol) have been reported to cause nipple pain or Raynaud’s phenomenon of the nipple

Reference:

Related pages:

breastfeeding and hypertension