Phenytoin
- TRADE NAMES: Di-Hydran; Dilantin (Pfizer); Diphenylan; Epanutin; Fenytoin; Phenhydan; Phenytek; Pyoredol; Zentropil
- INDICATIONS: Grand mal seizures
- SYNONYM: diphenylhydantoin; DPH; phenytoin sodium
- CLASS: Antiarrhythmic class Ib, Anticonvulsant, Antiepileptic; hydantoin, CYP3A4 inducer
- HALF-LIFE: 7–42 hours (dose dependent)
Abacavir, Abiraterone, Acitretin, Afatinib, Amiodarone, Amitriptyline, Amlodipine, Amprenavir, Apixaban, Apremilast, Aprepitant, Artemether/Lumefantrine, Beclomethasone, Bictegravir/Emtricitabine/Tenofovir Alafenamide, Boceprevir, Brigatinib, Brivaracetam, Buprenorphine, Cabazitaxel, Cabozantinib, Caffeine, Calcium, Capecitabine, Caspofungin, Cefazolin, Cenobamate, Ceritinib, Chloramphenicol, Cimetidine, Ciprofloxacin, Citalopram, Clobazam, Clorazepate, Cobicistat/Elvitegravir/Emtricitabine/Tenofovir Disoproxil, Cobimetinib, Colesevelam, Copanlisib, Crizotinib, Cyclosporine, Cyproterone, Dabigatran, Daclatasvir, Darunavir, Dasatinib, Deferasirox, Deflazacort, Delavirdine, Dexamethasone, Diazoxide, Disulfiram, Dopamine, Doravirine, Doravirine/Lamiduvine/Tenofovir Disoproxil, Doxycycline, Dronedarone, Efavirenz, Elbasvir & Grazoprevir, Eliglustat, Emtricitabine/Rilpivirine/Tenofovir Alafenamide, Enzalutamide, Erlotinib, Eslicarbazepine, Ethosuximide, Etravirine, Everolimus, Ezogabine, Fesoterodine, Flibanserin, Floxuridine, Fluconazole, Flunisolide, Fluoxetine, Fosamprenavir, Fostemsavir, Gefitinib, Gold & Gold Compounds, Hydrocortisone, Ibrexafungerp, Ibrexafungerp, Ibrutinib, Idelalisib, Imatinib, Indinavir, Influenza Vaccine, Isoniazid, Isotretinoin, Isradipine, Itraconazole, Ivabradine, Ixabepilone, Ixazomib, Lacosamide, Lapatinib, Ledipasvir & Sofosbuvir, Leflunomide, Letermovir, Levodopa, Levomepromazine, Levonorgestrel, Lisdexamfetamine, Lomustine, Lopinavir, Lumateperone, Meperidine, Metformin, Methsuximide, Methylprednisolone, Metronidazole, Midazolam, Midostaurin, Mifepristone, Mivacurium, Naldemedine, Nelfinavir, Neratinib, Nifedipine, Nilotinib, Nilutamide, Nintedanib, Olaparib, Oliceridine, Ombitasvir/Paritaprevir/Ritonavir, Ombitasvir/Paritaprevir/Ritonavir and Dasabuvir, Omeprazole, Ondansetron, Osimertinib, Oxcarbazepine, Oxtriphylline, Palbociclib, Paroxetine Hydrochloride, Pemetrexed, Perampanel, Phenylbutazone, Pimavanserin, Piracetam, Ponatinib, Ponesimod, Ponesimod, Posaconazole, Prednisolone, Prednisone, Propranolol, Regorafenib, Rifapentine, Rilpivirine, Riociguat, Risperidone, Ritonavir, Rivaroxaban, Roflumilast, Romidepsin, Saquinavir, Simeprevir, Sofosbuvir, Sofosbuvir & Velpatasvir, Sofosbuvir/Velpatasvir/Voxilaprevir, Solifenacin, Sonidegib, Sorafenib, St John's Wort, Sucralfate, Sunitinib, Tegafur/Gimeracil/Oteracil, Telaprevir, Telithromycin, Temsirolimus, Teniposide, Tenofovir Alafenamide, Tezacaftor/Ivacaftor, Thalidomide, Tiagabine, Ticagrelor, Ticlopidine, Tinidazole, Tipranavir, Tizanidine, Tolvaptan, Triamcinolone, Trimethoprim, Ubrogepant, Ulipristal, Uracil/Tegafur, Valbenazine, Vandetanib, Vemurafenib, Venetoclax, Vigabatrin, Vorapaxar, Voriconazole, Vortioxetine, Zidovudine, Zuclopenthixol
PREGNANCY CATEGORY: D
Aromatic antiepileptic drugs, phenytoin, phenobarbital, carbamazepine and primidone, are a frequent cause of severe cutaneous adverse reactions. A strong genetic association between HLA-B*1502 and phenytoin-induced Stevens-Johnson syndrome and toxic epidermal necrolysis has been shown in Han Chinese patients.
Children whose mothers receive phenytoin during pregnancy are born with fetal hydantoin syndrome. The main features of this syndrome are mental and growth retardation, unusual facies, digital and nail hypoplasia, and coarse scalp hair. Occasionally neonatal acne will be present.
Please login to see the rest of this drug profile
Click on the DRUG REVIEW ARTICLE tab (above) to see a review of phenytoin in the Taylor & Francis journal Expert Opinion on Drug Safety. (Note that non-subscribers to the journal will only be able to see an abstract of the article.)
Page last updated 08/31/2023
Symbol key
Incidence 
- <1%
- 1-5%
- 5-10%
- 10-15%
- 15-20%
- 20-30%
- >30%
Seriousness
- Hospitalization possible
- Life threatening
- Fatal
Warnings in other populations
- Breast feeding
- Geriatric
- Pediatric
