Serum concentrations of antidepressants and benzodiazepines in nursing infants: A case series

Objective. The relative risk of psychotropic medication use in women with p uerperal psychiatric illness who are breastfeeding has yet to be quantified adequately. Although the emotional and medical benefits of breastfeeding a nd adverse effects of maternal depression on infant development are well de scribed, how these absolute benefits weigh against the potential effects of psychotropic drug use during lactation to ultimately guide clinical decisi ons is still unclear. The objective of this report was to evaluate the exte nt that psychotropic medications were present in the serum of infants breas tfed by mothers treated with antidepressants and benzodiazepines. Design. Serum samples were obtained from 35 nursing infants whose mothers w ere treated with psychotropic medications while breastfeeding. When a detec table concentration of medication was reported, information regarding infan t behavior was obtained by maternal report. Setting. The Perinatal and Reproductive Psychiatry Program at Massachusetts General Hospital serves as a regional consultation center for the treatmen t of psychiatric disorders during pregnancy;md the postpartum period. Patients. Subjects were mothers referred to the Perinatal Psychiatry Progra m for consultation regarding the relative safety of psychotropic medication use while breastfeeding. Primary Outcome Measures. Presence of detectable levels of medication in infants whose mothers breastfed while taking psycho tropic medications during pregnancy and/or during the puerperium and the we ll-being (based on maternal report) of infants who had detectable serum con centrations of medication. Results. Seventy-four percent (n = 26) of infants had serum medication conc entrations below the laboratory limit of detection (assay sensitivity 5-50 ng/mL). In the remaining 26% of the sample (n = 9), serum concentrations of psychotropic medications and/or active metabolites were detected. In each of these cases, infants had been exposed to the medication during pregnancy . Medications were not detected in infant serum when mothers had taken thes e agents solely during the postpartum period. No readily apparent difficult ies with the infants were reported by mothers. Conclusions. These data support the low incidence of infant toxicity and ad verse effects associated with antidepressant and benzodiazepine use during breastfeeding. These data also suggest that infant serum monitoring is help ful in the assessment of medication exposure in children of mothers who bre astfeed while using psychotropic medications. Given the limited accumulated data regarding serum concentrations of psychotropic medications in breastf eeding infants, no single agent seems to be safer than another. Therefore, choice of pharmacologic treatment should be guided by the likelihood that i t will result in restoration of maternal psychiatric well-being.