Relative to other drugs transported from plasma to breast milk in nursing mothers, escitalopram eventuates in infant exposures during breastfeeding that are among the lowest observed among selective serotonin reuptake inibitors, according to the physiologically based pharmacokinetic modeling of a University of Toronto group (S.R. Delaney and colleagues, Clinical Pharmacokinetics, published on the Web, ahead of print on April 12, 2018 (doi:1007/s40262-018-0657-2).
The authors measured breast milk concentrations in 18 escitalopram-treated mothers (mean = 50 ng/ml after attainment of steady-state plasma escitalopram concentrations) and applied them, along with average infant feeding frequencies, feeding volumes, and a calculated infant daily dose, to their model. Extrapolating their results to 1600 infants nursed by mothers receiving escitalopram at a dosage of 20 milligrams per day, the authors observed an infant escitalopram exposure only 1.7 percent that of their mothers (as area under plasma concentration-time curve)–a level deemed “no substantial exposure” by the authors.
The authors’ work suggests that escitalopram may be as safe or safer than sertraline (the only other selective serotonin reuptake inhibitor that has received substantial study with respect to safety during breastfeeding).