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Generic drug name:
(FEN i toyn)
Brand name(s): DILANTIN, PHENYTEK
GENERIC: available FAMILY: Drugs for Epilepsy
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Pregnancy and Breast-feeding Warnings [top]
Phenytoin has caused serious harm to human infants born to mothers taking this drug during pregnancy. Such infants have been born with cleft palate, damage to the heart, a small head, and mental deficiency. There have been reports of cancer in children whose mothers took phenytoin during pregnancy. Because of the potential for serious adverse effects to the fetus, this drug should not be used by pregnant women.
Phenytoin is excreted in human milk. Because of the potential for serious adverse effects in nursing infants, you should not take this drug while nursing.
Facts About This Drug [top]
Phenytoin (DILANTIN) is approved by the Food and Drug Administration (FDA) to treat most forms of epilepsy. Patients taking phenytoin should adhere strictly to the prescribed dosing schedule and inform the prescribing physician of any situation in which it is not possible to take the drug as prescribed (for example, before, during or after surgery). Sudden discontinuation of the drug or rapid dosage reduction can result in status epilepticus, a medical emergency characterized by prolonged...
Phenytoin (DILANTIN) is approved by the Food and Drug Administration (FDA) to treat most forms of epilepsy. Patients taking phenytoin should adhere strictly to the prescribed dosing schedule and inform the prescribing physician of any situation in which it is not possible to take the drug as prescribed (for example, before, during or after surgery). Sudden discontinuation of the drug or rapid dosage reduction can result in status epilepticus, a medical emergency characterized by prolonged seizures.
Phenytoin can cause severe, sometimes fatal skin adverse reactions (including Stevens-Johnson syndrome and toxic epidermal necrolysis). Certain patients of Asian ancestry are at greatest risk of these adverse events. Patients should notify their physicians immediately if a skin rash develops while taking phenytoin.
Epilepsy drugs, including phenytoin, increase the risk of suicidal thoughts or behavior. Patients using these drugs should be monitored for new onset or worsening of depression, suicidal thoughts or behavior, or any unusual changes in mood or behavior.
A condition known as Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) has been reported in patients using phenytoin. DRESS is also known as multi-organ hypersensitivity and in some cases has been fatal. Symptoms of DRESS include fever, rash, swollen lymph nodes and facial swelling. The disorder can cause inflammation of the liver, kidneys, heart and muscles.
Cases of abnormally slow heart rate and cardiac arrest have been reported in patients treated with phenytoin. Most of the cases of cardiac arrest occurred in patients who already had heart disease.
Chronic use of phenytoin has been associated with decreased bone mineral density (osteopenia, osteoporosis and osteomalacia) and bone fractures. Importantly, the drug can decrease vitamin D levels, which may lead to vitamin D deficiency.
Before You Use This Drug [top]
Do not use if you have or have had:
Tell your doctor if you have or have had:
Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.
When You Use This Drug [top]
How to Use This Drug [top]
Interactions with Other Drugs [top]
The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:
8-MOP, ADALAT, ADALAT CC, ADVIL, AGENERASE, alcohol, ALERMINE, allopurinol, amiodarone, amprenavir, ANTABUSE, azapropazone, BICNU, CALCIFEROL, CAMPTOSAR, CARAFATE, carmustine, charcoal, chloramphenicol, CHLOROMYCETIN, chlorpheniramine, CHLOR-TRIMETON, cimetidine, CIPRO, ciprofloxacin, clopidogrel, CORDARONE, cyclosporine, DECADRON, delavirdine, DEPAKENE/DEPAKOTE, dexamethasone, diazoxide, dicumarol, DIFLUCAN, digitalis, digoxin, disopyramide, disulfiram, divalproex/valproic acid, dopamine, doxycycline, DURAQUIN, ELIXOPHYLLIN, ergocalciferol, felbamate, FELBATOL, fluconazole, fluoxetine, folic acid, FOLICET, FOLVITE, FORTOVASE, GABITRIL, GANTANOL, GLUCOPHAGE, HEXADROL, ibuprofen, INH, INTROPIN, INVIRASE, irinotecan, isoniazid, ketorolac, LANOXICAPS, LANOXIN, metformin, methotrexate, methoxsalen, miconazole, MONISTAT-DERM, MONISTAT 7, MOTRIN, MYSOLINE, nelfinavir, NEORAL, nifedipine, NORPACE, NORVIR, omeprazole, oral contraceptives, OXSORALEN, oxcarbazepine, PLAVIX, PRIFTIN, PRILOSEC, primidone, PROCARDIA, PROCARDIA XL, PROGLYCEM, PROLOPRIM, PROZAC, quetiapine, QUINAGLUTE DURA-TABS, QUINIDEX, quinidine, RESCRIPTOR, RIFADIN, rifampin, RIMACTANE, rifapentine, ritonavir, SANDIMMUNE, saquinavir, SEROQUEL, sertindole, SLO-BID, sucralfate, sulfamethizole, sulfamethoxazole, TAGAMET, THEO-24, theophylline, THIOSULFIL, tiagabine, ticlodipine, TICLID, TOPAMAX, topiramate, TORADOL, TRILEPTAL, trimethoprim, TRIMPEX, valproic acid, VELBAN, VIBRAMYCIN, vinblastine, VIRACEPT, vitamin D, ZYLOPRIM.
Adverse Effects [top]
Call your doctor immediately if you experience:
Call your doctor if these symptoms continue:
Signs of overdose:
If you suspect an overdose, call this number to contact your poison control center: (800) 222-1222.
Ask your doctor which of these tests should be done periodically while you are taking this drug:
last reviewed December 31, 2022