Fosphenytoin (Injection)


Fosphenytoin (fos-FEN-i-toin)
Treats different types of seizures (epilepsy). Belongs to a class of drugs called anticonvulsants.

Brand Name(s)

There may be other brand names for this medicine.

When This Medicine Should Not Be Used

You should not use this medicine if you have had an allergic reaction to fosphenytoin or phenytoin in the past.

How to Use This Medicine

  • Fosphenytoin is given only for a short time when you cannot take other forms of anticonvulsant medicine, such as when you are in the hospital or having surgery.
  • An IM injection is a shot given in your muscle (upper arm, thigh, buttocks). An IV infusion is a bag of medicine connected to a long tube with a needle on the end of it. The needle is placed in your vein, usually on the back of your hand or wrist, or inside your elbow. The medicine slowly drips from the bag through the tube and into your vein.
  • Your doctor will prescribe the amount of medicine you should have and when it will be given.
  • A nurse or other caregiver will give you the injections.
  • Sometimes you or a family member may be trained to give your shots at home.
If a dose is missed:
  • Take the missed dose as soon as possible.
  • If it is almost time for your next regular dose, wait until then to take your medicine and skip the missed dose.
  • You should not use two doses at the same time, unless directed by your doctor.
  • If you miss two or more doses, call your doctor.

How to Store and Dispose of This Medicine

  • If you use this medicine at home, store it in the refrigerator.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
  • Avoid drinking alcohol.
  • Talk to your doctor if you are also taking birth control pills. Your dose may need to be changed or you may need to use another kind of birth control.
  • Make sure your doctor knows if you are also taking any of these medicines: cimetidine (Tagamet®); Cordarone®, disulfiram (Antabuse®); Coumadin®, Prozac® or other medicine for depression; diabetes medicine (pills, not insulin); other seizure medicine such as Tegretol®, phenobarbital, or Klonopin®.

Warnings While Using This Medicine

  • Check with your doctor before using fosphenytoin if you are pregnant or breastfeeding, or if you have heart problems, high blood pressure, liver or kidney disease, or a blood disorder.
  • Because of the risk of increased seizures, do not suddenly stop taking this medicine without first checking with your doctor.
  • This medicine may cause drowsiness. Be careful when driving or using dangerous machinery.
  • Brush your teeth, use dental floss, and see a dentist on a regular basis. All of these things can help avoid gum bleeding or enlargement.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:
  • Dizziness or lightheadedness
  • Fever, sore throat, unusual bleeding or bruising
  • Loss of seizure control
  • Rash, hives, or blisters
  • Severe burning, itching, or tingling
  • Severe confusion or unsteadiness
  • Slurred speech
  • Uncontrolled eye or body movements
  • Yellowing of the skin or eyes
If you notice these less serious side effects, talk with your doctor:
  • Constipation
  • Drowsiness
  • Nausea or vomiting
  • Nervousness
  • Ringing in the ears
  • Thickening of the gums
  • Trouble seeing

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
Review Date: 2011-02-04 Reviewed By: Keywords: ,
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