phenytoin (generic name)

Phenytek (brand name)

It is used to control seizures in certain types of epilepsy
(FEN i toyn)
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What is this medicine?

PHENYTOIN (FEN i toyn) is used to control seizures in certain types of epilepsy. It is also used to prevent seizures during or after surgery.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:
  • an alcohol abuse problem
  • Asian ancestry
  • blood disorders or disease
  • diabetes
  • heart problems
  • kidney disease
  • liver disease
  • porphyria
  • receiving radiation therapy
  • suicidal thoughts, plans, or attempt; a previous suicide attempt by you or a family member
  • thyroid disease
  • an unusual or allergic reaction to phenytoin, other medicines, foods, dyes, or preservatives
  • pregnant or trying to get pregnant
  • breast-feeding

How should I use this medicine?

Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. If you are taking extended-release capsules, swallow them whole. Do not crush or chew. Take this medicine with food if it upsets your stomach. It may be best to take your medicine consistently with or without food. Take your doses at regular intervals. Do not take your medicine more often than directed. Do not stop taking this medicine suddenly. This increases the risk of seizures. Your doctor will tell you how much medicine to take. If your doctor wants you to stop the medicine, the dose will be slowly lowered over time to avoid any side effects.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:
  • delavirdine

This medicine may also interact with the following medications:

  • alcohol
  • aspirin and aspirin-like medicines
  • barbiturate medicines for inducing sleep or treating seizures
  • calcium supplements
  • carbamazepine
  • chloramphenicol
  • chlordiazepoxide
  • cimetidine or other medicines for heartburn or stomach ulcers
  • corticosteroid hormones such as prednisone or cortisone
  • diazepam
  • disulfiram
  • doxycycline
  • enteral feedings (liquid nutritional drinks or tube feeding liquids)
  • ethosuximide
  • female hormones, including contraceptive or birth control pills
  • furosemide
  • halothane
  • isoniazid
  • medicines for mental depression, anxiety or other mood problems
  • medicines to control heart rhythm
  • methsuximide
  • methylphenidate
  • molindone
  • phenylbutazone
  • reserpine
  • rifampin, rifabutin or rifapentine
  • sucralfate
  • sulfonamides like Azulfidine or Bactrim
  • theophylline
  • ticlopidine
  • tolbutamide
  • valproic acid
  • vitamin D
  • warfarin

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Last Updated: July 21, 2009
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