Introduction

Phenytoin (FEN-i-toin)

Treats different types of seizures (epilepsy). This medicine is an anticonvulsant.

Brand Name(s)

There may be other brand names for this medicine.

When This Medicine Should Not Be Used

You should not receive this medicine if you have had an allergic reaction to phenytoin or fosphenytoin. You should also not receive this medicine if you have certain heart problems. Ask your doctor what these heart problems are, and if you have them.

How to Use This Medicine

Injectable

• Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given through a needle placed in one of your veins. It may also be given as a shot into one of your muscles.
• A nurse or other trained health professional will give you this medicine.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• There are many other drugs that can cause medical problems if you use them together with phenytoin. Tell your doctor about all other medicines you are using.
• Do not drink alcohol while you are using this medicine.

Warnings While Using This Medicine

• Make sure your doctor knows if you are pregnant or breast feeding. Tell your doctor if you have low blood pressure, osteoporosis, or diabetes. This medicine may raise your blood sugar.
• Do not stop using this medicine suddenly without asking your doctor. You may need to slowly decrease your dose before stopping it completely.
• This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

• Blistering, peeling, red skin rash.
• Confusion.
• Dark-colored urine or pale stools.
• Fast, slow, or uneven heartbeats.
• Fever, swelling in your lymph nodes (just under your jaw).
• Lightheadedness or fainting.
• Nausea, vomiting, loss of appetite, pain in your upper stomach.
• Yellowing of your skin or the whites of your eyes.

If you notice these less serious side effects, talk with your doctor:

• Constipation.
• Dizziness.
• Pain, swelling, or tenderness where the needle is placed.
• Trouble sleeping.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088