Urolithiasis with topiramate in nonambulatory children and young adults.

Urolithiasis occurs infrequently in the pediatric population, where metabolic factors play a primary role in the pathogenesis of stone formation. Topiramate, an antiepileptic drug, is associated with a kidney stone in 1.5% of patients in published clinical trials. However, this risk may be much higher in certain populations with multiple preexisting risk factors. We performed a retrospective review of all nonambulatory and neurologically impaired individuals in a long-term care facility. Three groups were involved: those with no exposure to antiepileptic drugs, those on antiepileptic drugs other than topiramate, and those who had been treated with topiramate. Thirteen of 24 (54%) individuals on topiramate monotherapy or polytherapy developed clinical evidence of urolithiasis after a mean duration of 36.4 months. Our results suggest that nonambulatory and neurologically impaired individuals in a long-term care facility appear to be at higher risk of developing kidney stones with topiramate than previously reported.