DrugindexOnline^{2nd edition}

Generic Name: Interferon Beta-1a Intramuscular Injection (Prefilled Syringes) (in-ter-FEER-on BAY-tah)
Brand Name: Avonex

Avonex Prefilled Syringes is used for:

Treating relapsing forms of multiple sclerosis (MS) to reduce the number of flare-ups and slow down the development of physical disability associated with MS.

Avonex Prefilled Syringes is a protein identical to one found in the body. How Avonex Prefilled Syringes works is not fully understood. It is thought to interfere with other chemicals in the body that cause flare-ups of MS.

Do NOT use Avonex Prefilled Syringes if:

• you are allergic to any ingredient in Avonex Prefilled Syringes

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

Before using Avonex Prefilled Syringes:

Some medical conditions may interact with Avonex Prefilled Syringes. 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 a history of liver problems or high liver enzyme levels, blood problems (eg, anemia), thyroid problems, bone marrow depression, heart disease, seizures, alcohol abuse or dependence, depression, or suicidal thoughts or behaviors

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

• Medicines that may harm the liver (eg, acetaminophen, methotrexate, ketoconazole, isoniazid, certain medicines for HIV infection) because the risk of side effects on the liver may be increased. Ask your doctor if you are unsure if any of your medicines might harm the liver.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Avonex Prefilled Syringes 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 Avonex Prefilled Syringes:

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

• Avonex Prefilled Syringes comes with an additional patient information sheet called a Medication Guide. Read it carefully and reread it each time you get Avonex Prefilled Syringes refilled.
• Avonex Prefilled Syringes may be administered as an injection at your doctor's office, hospital, or clinic. If you are using Avonex Prefilled Syringes at home, carefully follow the injection procedures taught to you by your health care provider.
• If Avonex Prefilled Syringes contains particles or is discolored, or if the vial is cracked or damaged in any way, do not use it.
• Use the proper technique taught to you by your doctor. Inject Avonex Prefilled Syringes into a muscle.
• Keep this product, as well as syringes and needles, out of the reach of children and away from pets. Do not reuse needles, syringes, or other materials. Dispose of properly after use. Ask your doctor or pharmacist to explain local regulations for proper disposal.
• If you miss a dose of Avonex Prefilled Syringes, use it as soon as possible and skip your dose the following day. Do not take Avonex Prefilled Syringes on 2 consecutive days. Return to your regular dosing schedule the following week. If you accidentally take Avonex Prefilled Syringes on 2 consecutive days or use more than your prescribed dose, contact your doctor immediately.

Ask your health care provider any questions you may have about how to use Avonex Prefilled Syringes.

Important safety information:

• Some patients become depressed or suicidal while taking Avonex Prefilled Syringes. If you begin to feel depressed or suicidal, contact your doctor.
• Drinking alcohol may increase the risk of side effects on the liver from Avonex Prefilled Syringes. Talk to your doctor before drinking alcohol while you are using Avonex Prefilled Syringes.
• Avonex Prefilled Syringes commonly causes flu-like symptoms. Talk to your doctor about whether you should take a nonprescription medicine for pain or fever reduction before or after taking Avonex Prefilled Syringes.
• LAB TESTS, including blood cell counts, liver function tests, and thyroid function tests, may be performed to monitor your progress or to check for side effects. Be sure to keep all doctor and lab appointments.
• Use Avonex Prefilled Syringes with caution in the ELDERLY because they may be more sensitive to its effects.
• Use Avonex Prefilled Syringes with extreme caution in CHILDREN. Safety and effectiveness have not been confirmed.
• PREGNANCY and BREAST-FEEDING: Avonex Prefilled Syringes may cause harm to the fetus. If you think you may be pregnant, discuss with your doctor the benefits and risks of using Avonex Prefilled Syringes during pregnancy. It is unknown if Avonex Prefilled Syringes is excreted in breast milk. If you are or will be breast-feeding while you are using Avonex Prefilled Syringes, check with your doctor or pharmacist to discuss the risks to your baby.

Possible side effects of Avonex Prefilled Syringes:

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:

Drowsiness; flu-like symptoms (eg, headache, tiredness, fever, chills, back pain, muscle aches, weakness); pain, redness, or swelling at the injection site; stomach pain.

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); change in vision; chest pain; dark urine; depression; easy bruising or bleeding; extreme tiredness or weakness; fast or irregular heartbeat; feeling cold or hot all the time; increased urination at night; infection at the injection site; seizures; shortness of breath; suicidal thoughts or behaviors; swollen ankles; unexplained change in weight; yellowing of the eyes or skin.

This is not a complete list of all side effects that may occur. If you have questions or need medical advice about side effects, contact your doctor or health care provider. You may report side effects to the FDA at 1-800-FDA-1088 (1-800-332-1088) or 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/findyour.htm), or emergency room immediately.

Proper storage of Avonex Prefilled Syringes:

Store Avonex Prefilled Syringes in the refrigerator, between 36 and 46 degrees F (2 and 8 degrees C). Do not freeze. Protect from light. Keep Avonex Prefilled Syringes, as well as needles and syringes, out of the reach of children and away from pets.

General information:

• If you have any questions about Avonex Prefilled Syringes, please talk with your doctor, pharmacist, or other health care provider.
• Avonex Prefilled Syringes 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 Avonex Prefilled Syringes. 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.