Serum valproate levels in 6 breastfeeding mother-infant pairs

Background: Women with bipolar disorder are at high risk for recurrence of an affective episode in the postpartum period, and treatment with a mood st abilizer may be indicated. Few data are available to inform the risk-benefi t decision regarding the use of valproate for women with bipolar disorder w ho elect to breast-feed. Method: Serum valproate levels were obtained from 6 breastfeeding mother-in fant pairs. AU mothers had a diagnosis of bipolar disorder (Research Diagno stic Criteria) and were taking divalproex sodium as prophylaxis for or trea tment of a recurrent affective episode. None of the mothers received valpro ate during pregnancy. Results: The mothers had serum valproate levels near or within the therapeu tic range (39.4 to 79.0 mu g/mL). Infant serum levels were low, ranging fro m 0.7 to 1.5 mu g/mL (0.9%-2.3% of maternal serum levels). No adverse clini cal effects were observed in the infants. Conclusion: Serum valproate levels were low in nurslings of mothers treated with valproate. These data can be used to inform clinical decisions regard ing the use of valproate during breastfeeding.