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fosphenytoin (cont.)

What should I discuss with my healthcare provider before I receive fosphenytoin (Cerebyx)?

You should not receive this medication if you are allergic to fosphenytoin or phenytoin (Dilantin) or if you have certain heart conditions:

  • slow heartbeats;
  • heart block;
  • AV block; or
  • Adams-Stokes syndrome (a heart rhythm disorder).

Before you receive fosphenytoin, tell your doctor if you are allergic to any drugs, or if you have:

If you have any of these conditions, you may need a dose adjustment or special tests to safely receive this medication.

Patients of Asian ancestry may have a higher risk of developing a rare but serious skin reaction to fosphenytoin. Your doctor may recommend a blood test before you start the medication to determine your risk of this skin reaction.

Fosphenytoin can lower your blood sugar. If you are a diabetic, check your blood sugar regularly while you are using this medication.

FDA pregnancy category D. Fosphenytoin may cause harm to an unborn baby, but having a seizure during pregnancy could harm both the mother and the baby. Do not receive fosphenytoin without telling your doctor if you are pregnant. Seizure control is very important during pregnancy and the benefits of preventing seizures may outweigh any risks posed by using fosphenytoin.

If you have received fosphenytoin during pregnancy, be sure to tell the doctor who delivers your baby about your fosphenytoin use. Both you and the baby may need to receive medications to prevent excessive bleeding during delivery and just after birth.

Fosphenytoin can make birth control pills less effective. Avoid pregnancy while receiving fosphenytoin.

It is not known whether fosphenytoin passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How is fosphenytoin given (Cerebyx)?

Fosphenytoin is given as an injection into a muscle or through a needle placed into a vein. You will receive this injection in a clinic or hospital setting. Your doctor, nurse, or other healthcare provider will give you this injection.

Your heart rate will be monitored through electrocardiograph or ECG (sometimes called an EKG) when you are given your first dose of fosphenytoin. This machine measures electrical activity of the heart. This will help your doctor determine whether fosphenytoin is causing any harmful effects on your heart.

To be sure this medication is not causing other harmful effects, your blood may need to be tested at regular intervals.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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