Is carbamazepine associated with NAG elevations suggestive of renal disease?

Elevations of urinary N-acetyl-beta-glucosaminidase (NAG) were found in previous studies of epileptic patients using carbamazepine. Since NAG can be a sensitive indicator of urinary tract problems, it was postulated that carbamazepine could be causing urinary tract damage. To explore this issue further, 27 mood disorder patients who were taking carbamazepine were compared to 171 mood disorder patients who were not using carbamazepine. There were no significant differences in NAG levels between the two groups. A hypothesis is presented which states that the elevated NAG levels found in some seizure patients could be associated with abnormalities of serotonin metabolism.