Uses

Phenytoin helps to reduce seizure activity by acting on sodium channels in neurons within the brain. It is different than drugs like carbamazapine or gabapentin. It is commonly used to treat seizures and other conditions.

How to Use

Take this medication by mouth with water, it can be taken with or without food. Take it consistently with or without food.

If stomach upset occurs, you can take it with food or milk to decrease this effect.

If you are taking the extended release capsules, do not crush or chew the capsules.

Take exactly as directed, do not take more than directed.

Do not stop taking this medicine suddenly, this can increase your risk of seizures.

If you miss a dose, take it as soon as you can. If it is already almost time for your next dose, take only that next dose. Do not double up on any dose.

Important Information

Do not stop taking this medication suddenly, without consulting with your doctor. This can increase your risk of getting a seizure.

Be sure to have regular check ups with your doctor while on this medication. Keep record of your response to the medication and go over it with your doctor at each visit. Regular blood tests may be necessary.

It is important to wear a bracelet or chain that notifies others that you have seizures, and to carry a card that lists your medications and dose schedule.

Do not change the brand or dosage form without consulting with your doctor first.

This medicine may cause drowsiness or dizziness, do not operate heavy machinery, drive a car, or engage in other activity that requires fine motor skills until you are sure of how this medication affects you.

Stand and sit slowly when first starting this medication to avoid dizziness.

Avoid alcohol consumption, alcohol can increase chances of dizziness or drowsiness.

This medicine can decrease the effectiveness of birth control, talk with your doctor about whether or not you should use more than one form of birth control.

Avoid inflicting damage on your gums or teeth while brushing and flossing. This medicine can cause growth of the gum tissue. Visit your dentist regular.

Do not take antacids such as tums at the same time that you take phenytoin. If you need to take an antacid, take it 2-3 hours before or after taking phenytoin. Antacids such as calcium carbonate products strongly decrease the absorption of phenytoin.

Monitor yourself for mood changes or development of depression or suicidal thoughts while taking this medication. Report effects like these to your healthcare provider right away.

Women who become pregnant can enroll in the North American Antiepileptic Drug Pregnancy Registry by calling 1 888 233 2334. This agency collects information regarding the use of this medication during pregnancy.

Be sure that your prescribing doctor is aware if you have any of the the following conditions before taking this medication

Alcohol consumption, blood disorders, heart conditions, diabetes, kidney disease, liver disease, porphyria, currently receive radiation treatments, thyroid disease, previous suicidal thoughts or actions (or a family history of suicide), allergic reaction history, pregnancy, breastfeeding, trying to become pregnant.

Side effects that should be immediately reported to your healthcare provider

Allergic reactions(hives, rashes, itching, swelling of the face or mouth), trouble breathing, yellowing of the skin or eyes, depression or mood changes, thoughts of suicide or suicidal actions, unusual bleeding or bruising, tiny red spots on the skin, vomiting, difficulty walking or loss of coordination, headache, fever, sore throat, heartbeat changes(fast heart rate), dark urine, chest pain, vision changes, skin that is red, loosening or peeling.

Other Side Effects

Constipation, sleep changes, unusual hair growth of any kind, nausea.

Adult Dose

Seizures during and after neurosurgery(prophylaxis and treatment)

Tablets(Infatabs®): 100 mg (2 tablets) by mouth 3 times per day. The usual maintenance dose is 300-400 mg per day.

Generalized Tonic Clonic and Complex Partial Seizures

Tablets(Infatabs®): 100 mg (2 tablets) by mouth 3 times per day. The usual maintenance dose is 300-400 mg per day.

Oral Suspension: 125 mg (5ml) by mouth 3 times per day. The dose is adjusted ever 7-10 days if needed.

Sources

1. Dilantin-125 (R) oral suspension, phenytoin oral suspension[package insert]. Parke-Davis, New York, NY, 2009.

2. Dilantin infatabs ® oral tablets, phenytoin oral tablets[package insert]. Parke-Davis, New York, NY, 2006.