Evaluating strength of recommendations for commonly administered medications in lactating women

To characterize the data on medications for lactating people in the LactMed database and evaluate the strength of the data for the most commonly administered medications in lactating women.

A retrospective analysis of all medications in the LactMed database in 12/2020 was performed. Each medication was classified into one of three categories: absent data, minimal-moderate data, strong data pertaining to safety in lactation. No data was defined as no available research studies associated with the medication. Minimal-moderate data was defined as absent research studies in one or more of the four LactMed categories: maternal drug levels, infant drug levels, effects on infants, effects on lactation, or if data was limited to a case report or observational study. Strong data was classified as availability of research studies in all four LactMed categories with data derived from pharmacokinetic/pharmacodynamic, cohort, case control, or randomized control studies. Additionally, the most commonly used medications in lactating women as defined by prior literature were analyzed for strength of data.

1408 medications were evaluated: 714 (51%) had no associated data, 664 (47%) had minimal-moderate data, and 30 (2%) had strong data. Maternal drug level category had the highest proportion of rigorous supportive data while the effect on lactation category had the least supportive data. Of the most common mediations used in lactating women, sex hormones (contraception) and the nervous system medication classes had the most robust supportive data while respiratory, blood forming organs, and galactogogues had the weakest supportive data.

There is significant variability and dearth in the quality of data guiding recommendations for use of medications in lactation providing numerous opportunities for research.