breastfeeding and calcium channel blockers

Last edited 06/2023 and last reviewed 07/2023

Breastfeeding and calcium channel blockers

  • there are two sub-classes of calcium-channel blockers-dihydropyridines and rate-limiting-which are not generally interchangeable therapeutically (1)
    • nifedipine is the preferred dihydropyridine during breastfeeding
      • note that nifedipine has been used therapeutically in infants
    • verapamil is the preferred rate-limiting calcium channel blocker during breastfeeding
    • a previous review noted that nformation regarding the safety of calcium channel blockers during lactation is limited, although they are not likely to pose a risk to the nursing infant (2)
  • nifedipine
    • infant monitoring whilst on nifedipine (1)
      • as a precaution, monitor the infant for hypotension which may manifest as drowsiness, lethargy, looking pale, poor feeding and inadequate weight gain
      • notes
        • published evidence shows that nifedipine passes into breast milk in very small amounts (1.6% to 3.4% of the maternal weight-adjusted dose) after daily doses of 20 to 90mg
          • amounts are significantly lower than doses used therapeutically in infants from birth
          • no side effects have been reported in breastfed infants
  • verapamil
    • infant monitoring whilst on verapamil (1)
      • as a precaution, monitor the infant for hypotension which may manifest as drowsiness, lethargy, looking pale, poor feeding and inadequate weight gain
      • notes
        • published case reports have shown variable levels of verapamil in breast milk, although amounts are still negligible
          • infant would ingest an estimated 0.01% to 0.98% of the maternal weight-adjusted dose.
          • in the published cases, infant plasma levels were negligible or undetectable
          • no side effects have been reported in breastfed infants

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