Approximately 13% of new mothers develop postpartum depression. Postpartum depression is often treated with antidepressants. Many women desire treatment as well as the option to breastfeed their infant. Breastfeeding is beneficial to the child and improves cognitive development, decreases the incidence of infections, allergies, eczema, childhood and adult obesity, diabetes, autoimmune diseases and establishes an emotional bond with the mother. Breastfeeding mothers also benefit as indicated by lower rates of breast and ovarian cancer and faster weight loss following pregnancy.

This study was conducted to identify the antidepressants that lead to minimal infant exposure. Minimal infant exposure was selected to assure infants were exposed to the minimal amount of drug. In addition, infants exposed to drugs need to be able to metabolize the drug with no residual effects. This investigation was accomplished by determining antidepressant levels in nursing mother/infant pairs. The investigator's unpublished data and a comprehensive literature search (years searched were1966 through August 2001) provided the available data.

Statistical meta-analysis of the data indicates that fluoxetine and dothiepin produce the highest infant drug blood concentrations. The infant levels were elevated above the maternal levels by more than 10%. Nortriptyline and paroxetine produced infant levels that were usually undetectable. Elevated infant levels were found with sertraline (7.6%) and citalopram (16.7%). Prenatal exposure to fluoxetine resulted in persistently elevated levels that often lasted beyond six weeks of age.

An additional finding is that the mother's plasma or breast milk levels of drug do not correlate with the infant's blood drug concentration. Hence, there is no way to accurately predict the infant's level of drug.

Dr. Weissman concluded that nortriptyline and paroxetine are the preferred drugs of choice for breastfeeding mothers. Sertraline was the second drug of choice. Drugs to avoid for the treatment of depression in breastfeeding mothers are fluoxetine and citralopram.

(abstract Session 31 No. 91)