• Seizure disorders

Phenytek Generic Name & Formulations

General Description

Phenytoin sodium, ext-rel 200mg, 300mg; caps.

Pharmacological Class


How Supplied

Caps—30, 100


Phenytek Indications


Tonic-clonic, psychomotor and neurosurgically induced seizures.

Phenytek Dosage and Administration


Initially: 100mg 3 times daily. Increase weekly if needed; max 200mg 3 times daily. Once-a-day dosing only with 300mg caps for patients controlled on 300mg daily.


Initially 5mg/kg per day in 2–3 equally divided doses. Increase weekly if needed. Usual maintenance: 4–8mg/kg per day; max 300mg daily.

Phenytek Contraindications

Not Applicable

Phenytek Boxed Warnings

Not Applicable

Phenytek Warnings/Precautions


Diabetes. Impaired liver function. Change dose gradually. Discontinue if rash develops. Monitor serum levels. Use proper dental hygiene. Hormonal contraception. Porphyria. Elderly. Debilitated. Pregnancy. Nursing mothers: not recommended.

Phenytek Pharmacokinetics

See Literature

Phenytek Interactions


Potentiated by acute alcohol ingestion, amiodarone, benzodiazepines (eg, diazepam), chloramphenicol, dicumarol, disulfiram, estrogens, halothane, H2 blockers, isoniazid, methylphenidate, phenothiazines, phenylbutazone, salicylates, succinamides (eg, ethosuximide), sulfonamides, tolbutamide, trazodone, others. Antagonized by chronic alcohol ingestion, carbamazepine, reserpine, others. Antagonizes tricyclic antidepressants, oral anticoagulants, oral contraceptives, estrogens, corticosteroids, doxycycline, digitoxin, furosemide, theophylline, rifampin, quinidine, vitamins D and K, others. Variable effects with phenobarbital, valproic acid, divalproex, others. Absorption decreased by calcium, antacids.

Phenytek Adverse Reactions

Adverse Reactions

Nystagmus, ataxia, slurred speech, decreased coordination, dizziness, GI disturbances, gingival hyperplasia, osteomalacia, blood dyscrasias, lymphadenopathy, hepatic disease, rash, hyperglycemia, SLE, hypertrichosis.

Phenytek Clinical Trials

See Literature

Phenytek Note

Not Applicable

Phenytek Patient Counseling

See Literature