[Migraine-induced kidney stones?]

A 42-year old woman was referred for a metabolic evaluation after two episodes of kidney stones. Her laboratory results revealed a normal anion-gap metabolic acidosis, a marked hypocitraturia (0,6 mmol/24h; norm 1,6-4,5) and a urinary pH of 7,0 confirming renal tubular acidosis (RTA). We identified topiramate, our patient's medication for migraine, as the cause of the RTA. Topiramate, a carboanhydrase inhibitor leads to RTA of a mixed (proximal and distal) type and thus significantly increases the risk for kidney stones.