From the Guidelines
Both diphenhydramine and hydrocortisone can pass into breast milk, but the amount is typically below the therapeutic level for the drug, as stated in the 2020 guideline from the Association of Anaesthetists 1. When considering the use of these medications in breastfeeding mothers, it's essential to weigh the potential benefits against the risks.
- Diphenhydramine does transfer into breast milk in small amounts and may cause drowsiness or irritability in nursing infants, as well as potentially reduce milk supply in some women.
- Hydrocortisone, particularly in topical applications, is considered compatible with breastfeeding due to minimal systemic absorption, while oral hydrocortisone passes into breast milk in small amounts but is generally acceptable for short-term use at typical therapeutic doses. Key considerations for breastfeeding mothers taking these medications include:
- Timing doses right after nursing to minimize infant exposure
- Consulting with a healthcare provider for longer-term use to assess benefits and risks and explore alternative treatments if necessary Given the information from the 2020 guideline 1, the primary concern is the therapeutic range of the drug in the infant, which is typically not reached due to the small amounts of the drug passing through breast milk.
From the FDA Drug Label
If pregnant or breast-feeding, ask a healthcare professional before use The FDA drug label does not answer the question.
From the Research
Drug Transfer into Breast Milk
- Diphenhydramine is an antihistamine, and according to a systematic literature review 2, the relative infant dose of antihistamines is below 5%, indicating that the amount of diphenhydramine that passes into breast milk is likely to be small.
- The study found that the relative infant dose for various antihistamines ranged from 0.3% to 4.5%, suggesting that diphenhydramine is unlikely to reach therapeutic levels in infant serum.
- Another study 3 discussed the disposition of maternal drugs in breast milk, including the concept of relative infant dose (RID) and milk-to-plasma drug concentration ratio (MP ratio), which can be used to estimate the amount of drug that passes into breast milk.
Corticosteroids in Breast Milk
- Hydrocortisone is a corticosteroid, and according to a study on corticosteroids during pregnancy 4, very little corticosteroid ingested by the mother enters her breast milk.
- This suggests that the amount of hydrocortisone that passes into breast milk is likely to be minimal.
- However, it is worth noting that the study 4 focused on systemic corticosteroids, and the transfer of topical hydrocortisone into breast milk may be different.
- A study on the effect of human milk and topical hydrocortisone 1% on diaper dermatitis 5 did not address the transfer of hydrocortisone into breast milk, but rather its use as a treatment for diaper dermatitis.