Medicine Identification Chart

Dilantin^®

generic name: phenytoin -- FENY-toy-n

Manufacturer:Pfizer (Read Recent Statement From Pfizer)

Dilantin(Di-LAN-tin) was developed in 1938 as the first modern antiepileptic drug and has been used ever since as first line therapy for partial and generalized tonic clonic seizures. It is not effective against myoclonic, atonic (drop attacks) and absence seizures. Dilantin is generally given as capsules or chewable tablets, usually once or twice a day. A related product (Cerebyx - fosphenytoin) is available for intramuscular and intravenous use against status epilepticus (non-stop seizures), replacing the previous formulation.

Dilantin is metabolized (processed) in the liver. It interacts with a number of other antiepileptic drugs and other drugs, including oral contraceptives, Coumadin, quinidine, vitamin D and folic acid. At high doses, a small additional dose or slightly lower dose produces disproportionately large changes in blood levels, with consequent seizures (when levels drop) or increased side effects (when levels rise abruptly). At high levels, short term side effects such as difficulty in concentration, slow motor speed, unsteadiness, double vision, nausea and drowsiness may occur. Seizures may also increase. Longer term side effects include gum overgrowth (gingival hyperplasia), excessive hairiness (hirsutism), thickening of facial features, nystagmus, rash and folate deficiency. Rare reactions include serious rash, bone marrow suppression and effects on the lymph system and a lupus like syndrome. Safety in pregnancy has not been established. Women who are taking this medication and who wish to become pregnant should discuss treatment options with their physicians before the pregnancy begins.

Not everyone experiences side effects. There may be other side effects not appearing above. For a complete list, consult your doctor, nurse, or pharmacist. More detailed sources of information on side effects include the drug's prescribing information sheet, the Physician's Desk Reference, or pharmaceutical company which produces the drug.

RECENT PFIZER STATEMENT ON DILANTIN:

“Last fall, Pfizer sent a letter to health care professionals informing them that the FDA had approved manufacturing changes for Dilantin® (phenytoin sodium). Because Dilantin® has been continuously produced since 1938, some aspects of its manufacture did not reflect the latest technological advances. The FDA requested that Pfizer update its manufacturing processes and make procedures consistent, and Pfizer agreed with that request.

“As a result of this updated manufacturing method, Pfizer discontinued manufacturing Dilantin® Kapseals® (extended phenytoin sodium, USP) 100 mg capsules and began manufacturing and distributing Dilantin® 100 mg Extended Oral Capsules. It’s important to note that Dilantin® Capsules contain the same active (100 mg extended phenytoin sodium) and inactive ingredients (lactose monohydrate, NF; confectioner’s sugar, NF; talc, USP; and magnesium stearate, NF) as Dilantin® Kapseals® .

“Pfizer conducted two bioequivalence studies comparing the rate and extent of absorption of Dilantin® Kapseals® and Dilantin® Capsules. Bioequivalence is recognized by the FDA and is considered worldwide to be a valid substitute for therapeutic equivalence. The bioequivalence studies conducted by Pfizer showed that the Dilantin® Capsules met FDA standards for bioequivalence to the Dilantin Kapseals®, and FDA granted Pfizer the authorization to market Dilantin® Capsules.

“While the products are ‘pharmaceutical equivalents,’ phenytoin sodium is a drug product that has a narrow therapeutic index (NTI). Due to the NTI, therapeutic drug monitoring is essential for any patient during treatment with phenytoin sodium. For this reason, patients transitioning to Dilantin® Capsules should continue to have therapeutic drug monitoring. This monitoring should be done according to the judgment of the physician. Patients taking phenytoin should be advised to inform their physician of any change in seizure control, any new clinical condition or any new medication.

“Dilantin is an important medicine that helps patients with a serious medical condition. Pfizer is committed to ensuring the availability of a product that is safe and efficacious for patients and that complies with FDA’s current Good Manufacturing Practices standards.”