Medicines safety in breastfeeding

breast-fed infants

Pharmacists play an important role in advising parents and carers of breast-fed infants about their safe use of medicines.

The benefits of breastfeeding are widely recognised, and breastfeeding should be promoted whenever possible. The risks and benefits of using medicines while breastfeeding should be assessed, weighing the need to treat the lactating mother for a medical condition against the risks to the infant from exposure to medicines. Medicines used while breastfeeding should be at the lowest appropriate dose.

Medicines compatible with breastfeeding

Medicines that are considered safe for infants can usually be safely used by a lactating mother. Medicines that have been widely used in breastfeeding women, with clinical experience and evidence-based data to support their safety, are generally preferred over newer medicines. Topical or local treatments (e.g. inhalers, creams, eye drops) are generally considered safe to use during breastfeeding and may be preferred over systemic agents.1,4

The pharmacokinetic properties of a medicine influence its safety in breastfeeding. Infant exposure to medicines through breast milk can be minimised by using medicines with short half-lives, high protein binding, low oral bioavailability or high molecular weight.4

Medicines to avoid

Medicines are generally contraindicated or recommended not to be used during breastfeeding if they are likely to1,2,3:

  • cause unacceptable adverse effects in the breastfed infant (e.g. antineoplastic agents, amiodarone, oral retinoids, methotrexate, radiopharmaceuticals)
  • reduce maternal milk supply (e.g. tamoxifen, estrogen5).

In some cases, these recommendations may need to be considered in the context of the specific patient. For example, the use of a combined oral contraceptive containing estrogen may be acceptable if other contraceptive methods are not suitable and lactation is well established.5,6

In the absence of extensive clinical studies in lactating women and breastfed infants, many manufacturers are required to state that their medicine is not recommended for use in breastfeeding. In some cases, the recommendation to avoid a certain medicine during breastfeeding is based on limited data or the use of higher-than-usual doses. Before making recommendations to breastfeeding women, health professionals should thoroughly review current, reliable, evidence-based resources.7

Limited data are available to support the safety of most complementary and alternative medicines in breastfeeding.1

Further information

This article is reproduced from the Australian Pharmaceutical Formulary and Handbook: The everyday guide to pharmacy practice.



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