In Reply We thank Drs Hayes and Puusepp-Benazzouz for their comments and interest in our article1 describing antiepileptic drug (AED) exposure to infants who were breastfed by mothers with epilepsy. Although lamotrigine is comparatively more lipophilic than other AEDs, it is highly soluble in acidic pH (Biopharmaceutics Classification System class IIb) and has high oral bioavailability.2,3 In addition, to our knowledge, there is no evidence from previous studies that establishes an association between lamotrigine disposition in the body and body fat content measured as patient weight.4