Possible Drug-Associated Sialolithiasis From the Bicarbonate Anhydrase Inhibitor Topiramate: A Case Report and Literature Review

Topiramate is an antiepileptic drug indicated for the treatment of seizure disorders, migraine prophylaxis, and, more recently, weight loss. This new indication will likely increase the use of this agent significantly. As a carbonic anhydrase inhibitor, topiramate can affect the pH of bodily fluids and is known to increase the risk of nephrolithiasis. However, as discussed in the present report, these properties also result in an as yet unaddressed risk of the development of sialoliths, calcified stones formed in the salivary duct or glands. The physiologic mechanisms for stone development in the salivary gland are reviewed and the pharmacologic effects of topiramate on sialolith formation discussed. The present report describes a female patient treated with topiramate for migraine prophylaxis who subsequently presented with a sialolith in the left submandibular duct.