Renal tubular dysfunction in epileptic children on valproic acid therapy

To investigate the effects of valproic acid (VPA) on renal tubular function , we examined 15 ambulatory children with epilepsy who received VPA for at least 6 months. None of the patients had mental retardation. Fourteen age- and sex-matched children were used as a control group. No statistically sig nificant differences were. found between patients and control subjects with respect to blood urea nitrogen (BUN), creatinine (Cr), uric acid, creatini ne clearance (C-Cr), tubular reabsorption of phosphorus (TRP), urinary Ca:c reatinine ratio, urinary pH and mean urinary beta (2)-microglobulin concent rations (P>0.05). Protein and glucose in patient urine samples were negativ e. Urine microscopic examinations and amino acid chromatographies of patien ts were also normal. However, significant differences were found between pa tient and control groups with respect to mean urinary N-acetyl-beta-D-gluco samine:creatinine ratio (NAG:Cr) and mean urinary malondialdehyde:creatinin e (MDA:Cr) ratio (P<0.05). In conclusion, ambulatory children with epilepsy taking VPA therapy may develop proximal renal tubular dysfunction. Althoug h this finding is clinically insignificant, it should be kept in mind durin g VPA therapy.