Maternal, fetal, neonatal and breastmilk flecainide concentration during maternal therapy and lactation: A case report

Abstract

Abstract Background: Mothers requiring the antiarrhythmic agent flecainide are often advised not to breastfeed, because of the lack of data concercing neonatal effects and flecainide plasma concentrations following maternal exposure as well as via lactation. This is the first report on combined maternal, fetal, neonatal and breastmilk flecainide concentrations in a breastfed infant of a mother requiring flecainide treatment. Case presentation: All maternal flecainide concentrations fell within the therapeutic range. The fetal to maternal flecainide ratio was 0.72 and the milk to maternal ratio was 2.5. The relative infant dose received via breastmilk compared to maternal dose was 5.6%. Neonatal plasma concentrations were not detectable, despite the flecainide accumulation in breastmilk. All electrocardiograms to assess the neonatal antiarrhytmic effect were normal. Conclusions: Our results assume that flecainide can be prescribed safely to lactating mothers. Quantification of drug concentrations in neonatal blood in addition to measurements in maternal and fetal blood, and breastmilk, are helpful to evaluate the effects and safety of maternal medication use during pregnancy and lactation.