Medication used for treatment of Herpes zoster infection. At latest update, relevant published data on excretion into breast milk were not found. Because a high distribution volume (DV) and high protein-binding capacity, excretion into breast milk in significant amount is very unlikely. A low oral bioavailability impairs the pass of it from the mother's milk to the infant's plasma, except in prematures or in the early neonatal period, when a higher intestinal absorption may occur. Until more data on this medication is available, safer alternative drugs are preferred, especially in such critical age periods.