Dilantin (injection)

Phenytoin injection is a medicine that helps control seizures, specifically in cases of prolonged seizures (status epilepticus). Phenytoin injection is also used to stop seizures from happening during surgery.

Phenytoin injection may also be used for other reasons that are not mentioned in this medication guide.

A phenytoin injection may cause serious heart problems that can be life-threatening. This medicine is usually given by injection only if you cannot take the medicine by mouth.

If possible, before you receive a phenytoin injection, inform your caregivers if you have ever had serious heart problems or slow heartbeats that have caused you to faint.

Your heart rate, breathing, blood pressure, and other vital signs will be monitored closely. Tell your caregiver if you feel weak, light-headed, or short of breath during or after an injection.

If you can, before you get a phenytoin injection, let your caregivers know if you have ever had:

• a heart condition called 2nd or 3rd degree "AV block";
• slow heartbeats that caused you to faint;
• liver problems caused by phenytoin; or
• if you currently take delavirdine (Rescriptor).

Inform your doctor if you have ever had:

• liver or kidney disease;
• diabetes;
• porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system); or
• if you are of Asian ancestry (you may need a special blood test to check your risk of having a skin reaction to phenytoin).

Tell your doctor if you are pregnant. Phenytoin may harm an unborn baby, but having a seizure during pregnancy could harm both you and the baby. The benefit of preventing seizures may be greater than any risks to the baby.

If you have had a phenytoin injection during pregnancy, be sure to inform the doctor who delivers your baby about your phenytoin use. Both you and the baby may need medications to prevent excessive bleeding during delivery and shortly after birth.

If you are pregnant, your name may be included in a pregnancy registry to monitor the effects of phenytoin on the baby.

Phenytoin can make birth control pills less effective. Ask your doctor about using a non-hormonal birth control method (condom, diaphragm with spermicide) to avoid pregnancy.

It may not be safe to breast-feed while using this medicine. Consult your doctor about any risks.

In an emergency, you might not be able to inform caregivers if you are pregnant or breast-feeding. Ensure that any doctor caring for your pregnancy or your baby is aware that you received this medicine.

Get emergency medical help if you notice any signs of an allergic reaction, such as hives, difficulty breathing, or swelling in your face or throat, or if you have a severe skin reaction, which may include fever, sore throat, burning in your eyes, skin pain, or a red or purple skin rash that spreads and causes blistering and peeling.

Seek medical treatment if you experience a serious drug reaction that can affect many parts of your body. Symptoms may include skin rash, fever, swollen glands, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.

A phenytoin injection may cause life-threatening heart problems. Inform your caregiver if you feel weak, light-headed, or short of breath during or after an injection.

Dilantin may cause serious side effects. Contact your doctor immediately if you have:

• a light-headed feeling, as if you might pass out;
• confusion, unusual thoughts, or behavior;
• fever, chills, sore throat, swollen glands;
• red or swollen gums, mouth sores;
• easy bruising or unusual bleeding;
• pain, swelling, bruising, or other irritation where the injection was given;
• purple discoloration of your skin around the IV needle, or spreading away from where the medicine was injected (this may occur several days after an injection);
• increased thirst or increased urination; or
• liver problems, such as loss of appetite, upper stomach pain, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Common side effects of Dilantin may include:

• drowsiness or confusion;
• slurred speech;
• abnormal eye movement; or
• problems with balance or muscle movement.

This is not a complete list of side effects, and others may occur. Contact your doctor for medical advice regarding side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Phenytoin is injected into a muscle, or given as an infusion into a vein. A healthcare provider will give you this injection if you are unable to take the medicine by mouth.

Your breathing, blood pressure, oxygen levels, and other vital signs will be watched closely.

Tell your caregivers if you feel any burning, pain, or swelling around the IV needle when phenytoin is injected.

While receiving phenytoin, you may need frequent blood tests. You may also need a blood test when switching from the injection form to the oral form of phenytoin.

You should not stop using phenytoin suddenly, even if you feel fine. Stopping suddenly may cause increased seizures. Follow your doctor's instructions about tapering your dose.

Phenytoin can cause swelling in your gums. Pay special attention to your dental hygiene while receiving this medicine. Brush and floss your teeth regularly.

Because you will receive phenytoin (injection) in a clinical setting, you are not likely to miss a dose.

Seek emergency medical help or call the Poison Help line at 1-800-222-1222. An overdose of phenytoin can be deadly. Symptoms of an overdose may include twitching eye movements, slurred speech, loss of balance, tremor, muscle stiffness or weakness, nausea, vomiting, feeling light-headed, fainting, and slow or shallow breathing.

Do not drive or engage in hazardous activities until you know how this medicine will affect you. Your reactions may be affected.

Do not drink alcohol while taking phenytoin. Alcohol can raise your blood levels of phenytoin and may increase side effects. Daily alcohol consumption can lower your blood levels of phenytoin, which can raise your risk of seizures.

Ask your doctor or pharmacist before using over-the-counter medicines like cimetidine, omeprazole, St. John's wort, or vitamins and mineral supplements that contain folic acid.

Sometimes, it is not safe to use certain medications together. Some drugs can change the levels of other drugs in your blood, which may increase side effects or make the medications work less effectively.

Many drugs can interact with phenytoin. Not all possible interactions are mentioned here. TELL YOUR DOCTOR ABOUT ALL OTHER MEDICINES YOU USE, and any that you begin or stop using while being treated with phenytoin. This includes prescription and over-the-counter medicines, vitamins, and herbal products.