Which side effect is associated with Zonisamide (Zonegran)?

Zonisamide, a medication used primarily for the treatment of epilepsy, has several potential side effects, one of which is the formation of kidney stones. This side effect is particularly important to monitor because zonisamide causes an increase in urinary calcium excretion and may lead to metabolic changes that promote stone formation. Patients on zonisamide should be aware of the symptoms of kidney stones, such as severe flank pain, hematuria, or urinary obstruction, and should stay hydrated to help reduce the risk of this side effect.

The other options are less commonly associated with zonisamide. While constipation can occur with certain medications, it is not a well-documented side effect of zonisamide. Increased appetite is not typical either; in fact, some anticonvulsants may lead to weight loss rather than weight gain. Acne is not particularly linked to zonisamide use, as dermatological side effects are not common with this drug. Thus, among the options provided, kidney stones stand out as a key side effect of zonisamide that clinicians and patients need to be mindful of.