General information on drug use in breastfeeding: introduction

The benefits of breastfeeding are sufficiently important to recommend that it should not be discontinued or discouraged unless there is substantial evidence that the drug taken by the mother will be harmful to the infant, and no alternative treatment can be found.

Most drugs are excreted only to a minimal extent in breast milk and in most cases the dosage to which the infant is ultimately exposed is very low and is well below the therapeutic dose level for infants. For this reason, few drugs are totally contraindicated while breastfeeding. However, women who are known to be HIV-infected should be counselled not to breastfeed or to provide their milk for the nutrition of their own or other infants, except in areas where infectious diseases and malnutrition are major causes of infant mortality and where safe alternatives to breastfeeding are unavailable.

In most situations, drugs cross the placenta more efficiently than into breast milk.

When considering prescribing drugs (particularly longer-term) during breastfeeding, the following checklist may assist in guiding the decision:

Woman's preference for breastfeeding: Most women have a strong preference for breastfeeding. Inability to breastfeed can lead to a sense of failure as a mother, which may predispose to subsequent postnatal depression.

Nonpharmacological treatment: If such a treatment is available and likely to be successful, it may allow the woman to breastfeed, at least until the period of maximum benefit to the infant has passed.

Harm–benefit analysis (see also Box 11.2 for psychotropic drugs): For the infant, there are demonstrable increases in immunocompetence (eg decreased rates of otitis media), and neurodevelopmental advantage (eg possible increased IQ in the older child). For the woman, physiological benefits of breastfeeding include better uterine involution, more delayed ovulation and decreased risk of breast cancer.

Education, documentation and communication: The discussion regarding harm/benefit with the mother and her partner should be properly documented in the patient's notes. Other health professionals involved in postnatal management should be informed of medication changes.

The main consideration overall is that unless there is significant risk to the infant from necessary maternal medication, breastfeeding should be continued.