You have accessJournal of UrologyStone Disease: Epidemiology & Evaluation II (MP54)1 Sep 2021MP54-13 METABOLIC DISTURBANCES DURING TOPIRAMATE USE AND THEIR REVERSIBILITY FOLLOWING DRUG CESSATION Daniel Pelzman, Eman Kazi, and Michelle Semins Daniel PelzmanDaniel Pelzman More articles by this author , Eman KaziEman Kazi More articles by this author , and Michelle SeminsMichelle Semins More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002084.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Topiramate is a commonly used medication which inhibits carbonic anhydrase, causing renal tubular acidosis and hypocitraturia, thereby increasing the risk for kidney stone formation. Despite the strong association between topiramate use and kidney stone formation, few studies have examined the characteristics of stone formers taking topiramate. Additionally, the reversibility of the metabolic disturbances with cessation of the medication has not been previously studied. To fill this knowledge gap, we investigated the stone composition and 24-hour urine samples of a large cohort of stone formers taking topiramate. METHODS: All progress notes written by 5 endourologists from a single academic center were retrospectively reviewed from January 2010 to July 2020 containing the words “topiramate” or “topamax.” Inclusion criteria were age >18 and presence of either a 24-hour urine sample or stone analysis while on topiramate. In addition, a subgroup of 17 patients with 24-hour urine samples before and after stopping topiramate were identified. RESULTS: A total of 93 patients were identified and included for final analysis. Twenty-four hour urine samples were available in 65 patients and showed mean citrate excretion of 333 mg/day (95% confidence interval (CI) [254-412]), mean pH of 6.54 (95% CI [6.41-6.68]), and mean calcium phosphate supersaturation of 1.8 (95% CI [1.6-2.1]). In the subgroup analysis, mean urinary citrate excretion increased from 233 mg/day (95% CI [135-330]) to 633 mg/day (95% CI [471-796], p<0.01), and pH decreased from 6.61 (95% CI [6.34-6.89]) to 6.34 (95% CI [6.12-6.56], p=0.06) after stopping topiramate (Figure 1). 114 stone events occurred in 73 distinct patients with 50% either pure or majority (≥50%) calcium phosphate by composition. CONCLUSIONS: Hypocitraturia and elevated pH is seen during topiramate use with resultant higher rate of calcium phosphate stone formation compared to the general population. Stopping topiramate leads to significant increase in citrate excretion and normalization of pH. Patients and providers should be aware of this risk when starting topiramate therapy. These metabolic disturbances appear to be reversible with medication cessation. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e954-e954 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Pelzman More articles by this author Eman Kazi More articles by this author Michelle Semins More articles by this author Expand All Advertisement Loading ...