Topiramate may not increase risk of urolithiasis: A nationwide population-based cohort study

PURPOSE Topiramate is an effective anti-epileptic drug and can be associated with increased risk for urolithiasis because of its effects on acid-base profile. Evidences that supported an association of topiramate and urolithiasis were limited to case reports or series. We investigated the association of topiramate and urolithiasis in a nationwide population-based cohort study. METHODS We analyzed 1377 patients receiving topiramate and 1377 age- and gender-matched control patients (not receiving topiramate) between 1997 and 2008. The risk of urolithiasis was analyzed using Kaplan-Meier analysis, followed by Cox proportional hazard regression. RESULTS Of the 2754 patients, 79 (2.9%) patients developed urolithiasis in two (interquartile range: 1.2-4.2) years. The proportion of patients who developed urolithiasis in the patients receiving topiramate was not different from that of the control patients (p=0.138, χ(2) test). The urolithiasis free survival was not different between the patients receiving topiramate and the control patients (p=0.168) in Cox proportional hazard regression. The duration and total dosage of topiramate were not associated with risk of urolithiasis in patients receiving topiramate (p=0.482 and p=0.751). CONCLUSION Topiramate may not increase the risk of urolithiasis. The duration and the total dosage of topiramate were not associated with urolithiasis risks.