Diazoxide (Eudaxen) can lower the amount of phenytoin in your body when the two are taken together. Your doctor may need to check your phenytoin blood levels and may have to increase your phenytoin dose. Do not change the dose yourself.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.