Ethosuximide (Zarontin) is an expensive drug used to control seizures in certain types of epilepsy. This drug is less popular than comparable drugs. It is available in brand and generic form. Generic zarontin is covered by most Medicare and insurance plans, but some pharmacy coupons or cash prices may be lower. Get Ethosuximide for as low as $33.68, which is 87% off the average retail price of $252.45 for the most common version, by using a GoodRx coupon.