INFLUENCE OF ADDITIONAL THERAPY WITH ZONISAMIDE (EXCEGRAN) ON PROTEIN-BINDING AND METABOLISM OF CARBAMAZEPINE

The influence of comedication with zonisamide (ZNS) on protein binding and carbamazepine (CBZ) metabolism was studied in 16 pediatric epilep tic patients. Correlations were evaluated between ZNS daily dose and i ndividual change of level per dose ratio (L/D ratio), free fraction, a nd carbamazepine-10,11-epoxide/CBZ level ratio (CBZE/CBZ). Statistical significant negative correlation was observed between LID ratio and Z NS daily dose. Despite alteration in the L/D ratio, the free fraction of CBZ was unaltered in combination with ZNS. To assess the effect of addition of ZNS on CBZ metabolism, the CBZE/CBZ level ratio was compar ed; this ratio showed a tendency to increase with increase in ZNS dose . Consequently, ZNS is considered to have a significant effect on CBZ metabolism but not on protein binding.