American Board of Internal Medicine (ABIM) Certification Practice Exam

What common risk should patients starting topiramate be counseled about?

1. Weight gain

2. Kidney stones

3. Heart palpitations

4. Gastrointestinal bleeding

The correct answer is: Kidney stones

Patients starting topiramate should be counseled about the risk of developing kidney stones. Topiramate is an anticonvulsant and is also used for migraine prophylaxis. One of its known side effects is the increased excretion of calcium and phosphate in urine, which can lead to the formation of calcium phosphate or calcium oxalate stones in susceptible individuals. Importantly, the likelihood of kidney stone formation increases with higher doses of the medication and is particularly relevant in patients who may have other risk factors for stone formation. When initiating topiramate therapy, it is prudent to inform patients about the importance of staying well-hydrated to reduce the risk of stone formation, alongside monitoring for any symptoms suggestive of renal lithiasis, such as flank pain, hematuria, or urinary obstruction. This proactive counseling can help mitigate potential complications associated with its use. The other options listed—weight gain, heart palpitations, and gastrointestinal bleeding—are not typically associated with topiramate therapy. In fact, topiramate is more commonly linked to weight loss rather than gain. Heart palpitations are not a prevalent side effect of topiramate, and while gastrointestinal side effects can occur, significant gastrointestinal bleeding is not commonly reported with this