Topiramate-Induced Fanconi Syndrome: A Case Report

Topiramate (TPM), originally approved in 1996 for epilepsy, is now widely administered to prevent migraines, induce weight loss, and suppress alcohol cravings. Common renal adverse side effects include metabolic acidosis and nephrolithiasis; however, acute kidney injury (AKI) is uncommon or under-reported. In this report, we present a case of a 41-year-old male with a history of hypertension, obesity, tonic-clonic seizures, and migraines who developed AKI associated with Fanconi syndrome while administered TPM 100 mg daily for migraine prevention. The Naranjo Adverse Drug Reaction Probability Scale, a measure of the likelihood that a drug is causing an adverse reaction, indicated that TPM "probably" (score of 8) caused AKI with Fanconi syndrome. After supportive therapy and drug cessation the patient's kidney function normalized and the Fanconi syndrome resolved. This case is important for several reasons: (1) this is the third case of AKI and second case associated with Fanconi syndrome, which implies a relationship with TPM, (2) the cases illustrate that early recognition and discontinuation of TPM resolves AKI, and (3) common elements between the cases relay plausible risk factors. Thus, clinicians who prescribe TPM should consider monitoring patients for AKI and electrolyte abnormalities.