Objective The aim of the study was to investigate renal glomerular and tubular side effects of valproate and carbamazepine if exists, in children who are on these antiepileptic drugs between 6 months and two years of time.

Method A prospective study was performed on epileptic children (primary generalized and partial epilepsy) under valproate (n:30), carbamazepine (n:24) treatments and healty control group (n:26). The serum creatinine, Cystatin C levels and urinary excretion of N-acetyl-β-D-glucosaminidase levels were taken at the beginning of the study and after 6 months of therapy. Three Glomerular filtration rate formulae with creatinine, Cystatin C and combined of all of were used to determine glomerular filtration functions.

Results Serum creatinine, Cystatin C levels of patients and glomerular filtration rate values were in the normal range according to patient ages and healthy control group. However urinary N-acety-β-D-glucosaminidase/creatinine levels were higher in both groups (valproate 6.1±5) (carbamazepine 3.14±1.97) when compared to the levels of the control group (2.6±1.3) (p<0.05)Although this is a preliminary study; bearing in mind that patients on both antiepileptic drugs may have a tubulotoxicity risk; renal function test should also be checked in during the treatment of all patients with special emphasis when there is a renal or systemic disease co-existing.