Phenytoin is used to prevent and control seizures (also called an anticonvulsant or antiepileptic drug). It works by reducing the spread of seizure activity in the brain.
Read the Medication Guide provided by your pharmacist before you start taking phenytoin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth usually once a day or in divided doses as directed by your doctor. You may take it with food if stomach upset occurs. Take this medication with a full glass (8 ounces or 240 milliliters) of water unless your doctor directs you otherwise.
Swallow the capsules whole. Do not use the capsules if discolored.
Use this medication regularly in order to get the most benefit from it. It is important to take all doses on time to keep the amount of medicine in your body at a constant level. Remember to use it at the same time(s) each day. Dosage is based on your medical condition and response to therapy.
Products that contain calcium (e.g., antacids, calcium supplements) and nutritional tube-feeding (enteral) products may decrease the absorption of phenytoin. Do not take these products at the same time as your phenytoin dose. Separate liquid nutritional products at least 1 hour before and 1 hour after your phenytoin dose, or as directed by your doctor.
Do not stop taking this medication without consulting your doctor. Seizures may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.