Phenytoin is a prescription anticonvulsant medication indicated to control complex partial or grand mal seizures. This medication can also be used to prevent or treat seizures that arise during or following brain surgery. Phenytoin works by lowering the amount of unusual electrical activity within a patient's brain. Despite the beneficial aspects of phenytoin, certain patients should not take this medication. Patients should be aware of the contraindications for phenytoin prior to beginning treatment.
Phenytoin Hypersensitivity
Patients who are allergic or hypersensitive to phenytoin or other medications that contain hydantoins should not take this drug, RxList warns. Improper use of phenytoin by hypersensitive patients can result in a severe allergic reaction called anaphylaxis. Anaphylaxis can cause life-threatening symptoms, including heart rate abnormalities, breathing difficulties and facial or body swelling. Allergic patients who take phenytoin require immediate medical intervention to prevent additional complications.
Pregnant or Breastfeeding
Phenytoin has been assigned to pregnancy category D by the U.S. Food and Drug Administration. Expectant mothers who use this medication are at risk of experiencing recurrent seizures during pregnancy. Treatment with phenytoin during pregnancy can also elevate the risk of fetal development problems, such as growth or mental deficiencies. Fetal exposure to phenytoin can also increase an infant's risk of developing a severe bleeding disorder that can result in life-threatening medical complications. Women who are breastfeeding should avoid using phenytoin to limit the risk of exposing a nursing infant to this medication.
Petit Mal Seizures
This medication is not effective in the treatment or prevention of petit mal seizures, the FDA warns. A petit mal seizure, also called an absence seizure, is milder than grand mal seizures and typically lasts for a few seconds, MayoClinic.com reports. Patients who experience both grand mal and petit mal seizures require combination drug treatment to control seizure symptoms.
