Brief Reports Serum Sertraline and N-Desmethylsertraline Levels in Breast-Feeding Mother-Infant Pairs

Objective: The authors’ goal was to study the serum sertraline levels of breast-feeding mothers and their infants. Method: They obtained serum levels of sertraline and N-desmethylsertraline in nine mother-infant pairs. Results: Sertraline levels were very low (less than 2 ng/ml) in seven of the nine infants and low (3 ng/ml) in one. N-Desmethylsertraline levels were also low (6 ng/ml or less) in seven of the nine infants. One infant had a high level of N-desmethylsertraline, and one infant had unusual serum sertraline and N-desmethylsertraline values (half of its mother’s levels). All infants were thriving. Conclusions: Most breast-feeding infants whose mothers were taking sertraline had very low serum levels of both sertraline and N-desmethylsertraline, consistent with published reports. The authors discuss in detail the one infant with unusually high levels. (Am J Psychiatry 1998; 155:690–692)