Scroll for Important Safety Information and Indications

DILANTIN is available in 30-mg and 100-mg capsules.

Important Safety Information

DILANTIN is contraindicated in patients with:

  • A history of hypersensitivity to phenytoin, its inactive ingredients, or other hydantoins
  • A history of prior acute hepatotoxicity attributable to phenytoin
  • Coadministration with delavirdine because of the potential for loss of virologic response and possible resistance to delavirdine or to the class of non-nucleoside reverse transcriptase inhibitors

Abrupt withdrawal of phenytoin in epileptic patients may precipitate status epilepticus.

When a change in the dosage form or brand is prescribed, careful monitoring of phenytoin serum levels should be carried out.

Antiepileptic drugs, including DILANTIN, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any antiepileptic drug should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior.

Patients should be instructed to call their physician if a skin rash or any of the symptoms listed below appear.

Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS), have been reported with phenytoin treatment. DILANTIN should be discontinued at first sign of a rash. If the rash is exfoliative, purpuric, or bullous or if lupus erythematosus, Stevens-Johnson syndrome, or toxic epidermal necrolysis is suspected, use of this drug should not be resumed and alternative therapy should be considered. If a rash occurs, the patient should also be evaluated for signs and symptoms of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). Some of these events have been fatal or life-threatening.

Cases of acute hepatotoxicity, including infrequent cases of acute hepatic failure, have been reported with DILANTIN. In these patients with acute hepatotoxicity, DILANTIN should be immediately discontinued and not re-administered.

Hematopoietic complications, some fatal, have occasionally been reported in association with administration of DILANTIN. These have included thrombocytopenia, leukopenia, granulocytopenia, agranulocytosis, and pancytopenia with or without bone marrow suppression. There have been reports suggesting a relationship between phenytoin and the development of lymphadenopathy, including benign lymph node hyperplasia, pseudolymphoma, lymphoma, and Hodgkin's disease.

The chronic use of DILANTIN in patients with epilepsy has been associated with decreased bone mineral density and bone fractures and is considered to be due to phenytoin's interference with vitamin D metabolism.

Because the fraction of unbound phenytoin is increased in patients with renal or hepatic disease, or in those with hypoalbuminemia, the monitoring of phenytoin serum levels should be based on the unbound fraction in those patients.

Caution should be exercised in using this medication in patients suffering from porphyria.

DILANTIN may cause fetal harm when administered to a pregnant woman. Prenatal exposure to phenytoin may increase the risks for congenital malformations and other adverse development outcomes. A potentially life-threatening bleeding disorder related to decreased levels of vitamin K-dependent clotting factors may occur in newborns exposed to phenytoin in utero. Infant breastfeeding is not recommended for women taking this drug because phenytoin appears to be secreted in low concentrations in human milk.

Patients taking DILANTIN should be advised of the importance of informing the physician of any clinical condition. Patients with impaired liver function, elderly patients, or those who are gravely ill may show early signs of toxicity.

Hyperglycemia, resulting from the drug's inhibitory effects on insulin release, has been reported. Phenytoin may also raise the serum glucose level in diabetic patients.

The importance of good dental hygiene should be stressed in order to minimize the development of gingival hyperplasia and its complications.

Multiple drug interactions exist with phenytoin because of extensive plasma protein binding, saturable metabolism and potent induction of hepatic enzymes.

The most common side effects encountered with phenytoin therapy are nervous system reactions and are usually dose-related. They include nystagmus, ataxia, slurred speech, decreased coordination, somnolence and mental confusion.


Phenytoin is indicated for the treatment of tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery.

Phenytoin serum level determinations may be necessary for optimal dosage adjustments.

Terms and Conditions

By using the DILANTIN Savings Card, you acknowledge that you currently meet the eligibility criteria and will comply with the following terms and conditions.

  • The Card is not valid for prescriptions that are eligible to be reimbursed, in whole or in part, by Medicaid, Medicare, or other federal or state health care programs (including any state prescription drug assistance programs and the Government Health Insurance Plan available in Puerto Rico [formerly known as “La Reforma De Salud”])
  • The Card is not valid for prescriptions that are eligible to be reimbursed by private insurance plans or other health or pharmacy benefit programs that reimburse you for the entire cost of your prescription drugs
  • You must be 18 years or older
  • By using the Card, you will receive savings of up to $20 off per fill, for a maximum savings of $240 per card
  • You must deduct the value received under this program from any reimbursement request submitted to your insurance plan, either directly by you or on your behalf
  • The Card is not valid for Massachusetts residents whose prescriptions are covered in whole or in part by third-party insurance, or where otherwise prohibited by law
  • The Card cannot be combined with any other rebate or coupon, free trial, or similar offer for the specified prescription
  • The Card will be accepted only at participating pharmacies
  • The Card is not health insurance
  • This offer is good only in the United States and Puerto Rico
  • The Card is limited to one per person during this offering period and is not transferable
  • Pfizer reserves the right to rescind, revoke, or amend the Card without notice
  • Offer expires 12/31/18

No membership fees apply. For help with the DILANTIN Savings Card, call 1-866-590-9400, visit DILANTIN.com, or write: Attn: DILANTIN, PO Box 4937, Warren, NJ 07059-6600.

Please see Full Prescribing Information and Medication Guide.

Are your patients in need of prescription assistance?

Pfizer RxPathways® connects eligible patients to assistance programs that offer insurance support, co-pay assistance, and medicines for free or at a savings.

Learn more by visiting
www.PfizerRxPathways.com or
calling 1-844-989-PATH (7284)

Clinical Information