• Renal tubular function;
  • Epilepsy;
  • Valproate;
  • Carbamazepine;
  • Phenobarbital

Summary: Purpose: The goal of the study was to evaluate the tubular renal function in children and adolescents who are undergoing monotherapy with sodium valproate (VPA), carbamazepine (CBZ), and phenobarbital (PB).

Methods: The urinary excretion of N-acetyl-β-glucosaminidase (NAG), β-galactosidase (β-Gal), alanine-amino-peptidase (AAP), and α1-microglobulin (α1M) was measured in 58 epileptic patients (29 girls and 29 boys), aged 12.6 ± 3.9 years, who were subdivided into three groups according to their therapy. Fifty healthy sex- and age-matched children served as controls. The measurements were taken before the beginning of therapy and after 6 months, 1 year, and 2 years of therapy.

Results: Before the beginning of therapy, there were no significant differences in NAG, β-Gal, AAP, and α1M values between the control group and the three groups of epileptic children. After 6 months of therapy, patients treated with VPA and CBZ showed a significant increase in the urinary excretion of NAG and β-Gal compared with baseline data and control values. After 1 and 2 years, these patients showed a persistence of the changes found after 6 months of therapy. In patients treated with PB, we did not find any significant variation in NAG, β-Gal, AAP, and α1M urinary excretion.

Conclusions: Our study demonstrates that in patients treated with VPA and CBZ, an impairment of tubular function can be present, whereas PB does not cause any significant change.