Key facts about Phenytoin
What dosages is Phenytoin available in?
Phenytoin is available as a 100 mg, 200 mg, and 300 mg extended-release oral capsule, a 50 mg chewable tablet, and a 125 mg/5 ml oral suspension.
What is Phenytoin used for?
Phenytoin is an antiepileptic and is used to treat tonic-clonic (grand mal) seizures, psychomotor (temporal lobe) seizures, and seizures during and following brain surgery.
How does Phenytoin work?
Phenytoin is an antiepileptic medication. It prevents seizures by decreasing abnormal signals between nerve cells in the brain.
How do I take Phenytoin?
Phenytoin is typically taken by mouth with a starting dose of 1 capsule (100 mg) by mouth 3 times a day, slowly increasing up to a maximum of 2 capsules (200 mg) by mouth 3 times a day. Your physician will adjust the dose based on blood levels of this medication.
Is it safe for me to take Phenytoin?
Phenytoin is a safe and effective treatment when used for FDA licensed indications. However, like all medications, they may give you unwanted side effects. You should always discuss potential side effects with your physician to ensure the medication is suitable and right for you. You should not use this medication if you have a known hypersensitivity to Phenytoin, its ingredients, or other hydantoins, a history of prior acute hepatotoxicity attributable to Phenytoin, or are currently taking delavirdine.
Phenytoin Common Side Effects
Common side effects of Phenytoin include:
- Uncontrolled eye movements
- Abnormal/worsening coordination
- Slurred speech
- Sleepiness
- Mental confusion
Phenytoin Serious Side Effects
Serious side effects are rare with Phenytoin. Contact your healthcare provider immediately if you experience any of the following.
- Status epilepticus (seizures lasting longer than 5 minutes or when seizures occur so closely together that the person doesnt’t recover between seizures) due to missed doses or sudden stopping of Phenytoin
- Serious allergic reactions: skin reactions, swelling, trouble breathing
- Serious liver injury: darkened urine, nausea, vomiting, stomach pain, yellowing of your skin or eyes, itching
- Suicidal thoughts or behavior
Effects of other drugs, drug classes and over-the-counter products on Phenytoin
The following medications may interact with Phenytoin:
- Multiple drug interactions because of extensive plasma protein binding, saturable metabolism and potent induction of hepatic enzymes. Interactions can occure with stomach acid reducers, sedatives, antidepressants, estrogen hormone replacement, phenothiazines, disulfiram, methylphenidate, sulfa drugs, carbamazepine, sucralfate, molindone, phenobarbital, valproic acid, divalproex sodium, steroids, antibiotics, digoxin, furosemide, or theophylline
Who makes Phenytoin?
Various FDA-approved generic manufacturers
Is Phenytoin safe in pregnancy?
Phenytoin may cause fetal harm when administered to a pregnant woman. There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed Phenytoin during pregnancy. You can call the tollfree number 1-888-233-2334. Information on the registry can also be found at the AED pregnancy registry
