Generic Name: Fosphenytoin (fos-FEN-i-toin)Brand Name: Cerebyx

Cerebyx is used for:

Treating certain types of severe seizures (eg, status epilepticus). It is also used to prevent and treat seizures that may occur during or after brain or nervous system surgery. It may also be used for other conditions as determined by your doctor.

Cerebyx is an anticonvulsant. It works in the brain to block the spread of seizure activity.

Do NOT use Cerebyx if:

  • you are allergic to any ingredient in Cerebyx or to other hydantoins (eg, fosphenytoin)
  • you have certain types of heart problems (eg, very slow heartbeat, certain types of heart block, or Adams-Stokes syndrome)

Contact your doctor or health care provider right away if any of these apply to you.

Before using Cerebyx :

Some medical conditions may interact with Cerebyx . Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have heart problems (eg, heart block), low blood pressure, a blood disease (eg, porphyria), liver or kidney disease, low blood albumin levels, diabetes, or a history of lymph gland problems
  • if you are in very poor health
  • if you drink alcohol or have a history of alcohol abuse
  • if you have been tested and know whether or not you have a gene type called HLA-B*1502
  • if you are taking a barbiturate (eg, phenobarbital) or a succinimide (eg, methsuximide)

Some MEDICINES MAY INTERACT with Cerebyx . Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Many other prescription and nonprescription medicines (eg, used for asthma, blood thinning, diabetes, infections, inflammation, aches and pains, high blood pressure, heart problems, high cholesterol, birth control, hormone replacement, mental or mood problems, sleep, seizures), multivitamin products, and herbal or dietary supplements (eg, herbal teas, coenzyme Q10, garlic, ginseng, ginkgo, St. John's wort) may interact with Cerebyx . Ask your doctor or pharmacist if you are unsure if any of your medicines might interfere with Cerebyx

This may not be a complete list of all interactions that may occur. Ask your health care provider if Cerebyx may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Cerebyx :

Use Cerebyx as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Cerebyx is usually given as an injection at your doctor's office, hospital, or clinic. If you will be using Cerebyx at home, a health care provider will teach you how to use it. Be sure you understand how to use Cerebyx . Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.
  • Do not use Cerebyx if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.
  • Do not suddenly stop taking Cerebyx . You may have an increased risk of side effects (eg, seizures). If you need to stop Cerebyx or add a new medicine, your doctor will gradually lower your dose.
  • Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.
  • If you miss a dose of Cerebyx , contact your doctor right away.

Ask your health care provider any questions you may have about how to use Cerebyx .

Important safety information:

  • Cerebyx may cause dizziness or drowsiness. These effects may be worse if you take it with alcohol or certain medicines. Use Cerebyx with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Check with your doctor before you drink alcohol while you are taking Cerebyx . Alcohol may increase or decrease the amount of medicine in your blood.
  • Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.
  • Proper dental care is important while you are taking Cerebyx . Brush and floss your teeth and visit the dentist regularly.
  • Cerebyx may raise your blood sugar. High blood sugar may make you feel confused, drowsy, or thirsty. It can also make you flush, breathe faster, or have a fruit-like breath odor. If these symptoms occur, tell your doctor right away.
  • There have been reports of lymph node problems, including cancer, in patients who take Cerebyx . It is not known if Cerebyx may be the cause. Contact your doctor right away if you develop swollen lymph nodes, fever, rash, dark urine, stomach pain, or yellowing of the eyes or skin.
  • Tell your doctor or dentist that you take Cerebyx before you receive any medical or dental care, emergency care, or surgery.
  • Hormonal birth control (eg, birth control pills) may not work as well while you are using Cerebyx . To prevent pregnancy, use an extra form of birth control (eg, condoms).
  • Patients who have a certain gene type called HLA-B*1502 may have an increased risk for serious skin reactions from Cerebyx . This gene type is found most commonly in Asian patients. Tell your doctor if you have been tested and know whether or not you have the HLA-B*1502 gene type. Discuss any questions or concerns with your doctor.
  • Cerebyx may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Cerebyx .
  • Lab tests, including blood phenytoin levels and heart function, may be performed while you use Cerebyx . These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • Use Cerebyx with caution in the ELDERLY; they may be more sensitive to its effects.
  • Cerebyx should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.
  • Women who take Cerebyx may experience an increase in seizure activity if they become pregnant. Discuss any questions or concerns with your doctor. If you think you may be pregnant, contact your doctor.
  • PREGNANCY and BREAST-FEEDING: Cerebyx may cause harm to the fetus. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Cerebyx while you are pregnant. Cerebyx is found in breast milk. Do not breast-feed while taking Cerebyx .

Possible side effects of Cerebyx :

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Burning, numbness, or tingling; dizziness; drowsiness; headache; nausea; pelvic pain; taste changes; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bone pain; butterfly-shaped rash on the face; clumsiness or unsteadiness; confusion; dark urine; delirium; fast, slow, or irregular heartbeat; fever; hearing problems (eg, ringing in the ears, hearing loss); high blood sugar (increased thirst, hunger, or urination; rapid breathing; flushing; fruit-like breath odor); mental or mood changes; muscle weakness or cramping; pain, swelling, or redness at the injection site; red, swollen, blistered, or peeling skin; severe or persistent dizziness or drowsiness; signs of infection (eg, fever, chills, sore throat); slurred speech; stomach pain; swollen lymph nodes; swollen or tender gums; tremor; unusual bruising or bleeding; unusual eye movements; unusual muscle movements; vision changes; yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center (http://www.aapcc.org), or emergency room immediately. Symptoms may include confusion; decreased coordination; fainting; fast, slow, or irregular heartbeat; joint pain; loss of consciousness; severe dizziness or headache; severe or persistent nausea or vomiting; slow or difficult breathing; slurred speech; tremor; unusual eye movements.

Proper storage of Cerebyx :

Cerebyx is usually handled and stored by a health care provider. If you are using Cerebyx at home, store Cerebyx as directed by your pharmacist or health care provider. Keep Cerebyx out of the reach of children and away from pets.

General information:

  • If you have any questions about Cerebyx , please talk with your doctor, pharmacist, or other health care provider.
  • Cerebyx is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.

This information is a summary only. It does not contain all information about Cerebyx . If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

  • Cerebyx Prescribing Information (FDA)
  • Cerebyx Advanced Consumer (Micromedex) - Includes Dosage Information
  • Cerebyx Concise Consumer Information (Cerner Multum)
  • Fosphenytoin Prescribing Information (FDA)
  • Fosphenytoin Professional Patient Advice (Wolters Kluwer)