Health Library

Interferon Beta-1a (By injection)

Interferon Beta-1a (in-ter-FEER-on BAY-ta-1a)

Treats relapsing forms of multiple sclerosis (MS).

Brand Name(s):

Avonex, Avonex Administration Dose Pack, Avonex Pen, Rebif, Rebif Rebidose, Rebif Rebidose Titration Pack

When This Medicine Should Not Be Used:

How to Use This Medicine:

Injectable

• Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given as a shot under your skin or into a muscle.
• A nurse or other health provider will give you this medicine.
• You may be taught how to give your medicine at home. Make sure you understand all instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to. A nurse or other trained health professional should watch the first Avonex® injection you give yourself.
• Rebif® comes as an autoinjector pen or a prefilled syringe. It works best if you use it at the same time on the same 3 days each week, at least 48 hours apart.
• Avonex® comes as a prefilled autoinjector pen, a prefilled syringe, or a powder. The powder must be mixed with sterile water before it is given. Follow instructions to mix. Use the medicine as soon as possible after you mix it. If you cannot give your shot right away, you can keep the syringe in the refrigerator for up to 6 hours. After 6 hours, throw the medicine away and mix another dose.
• You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas. Do not inject into an area of the body where the skin is irritated, red, bruised, infected, or scarred. Most people will inject the medicine into the stomach, back of the upper arm, or thigh.
• Check the injection site after 2 hours for redness, swelling, and tenderness.
• You may also receive medicine to help prevent flu-like symptoms.
• Use a new needle and syringe each time you inject your medicine. Do not use any other needle for the prefilled autoinjector pen.
• After you have used a dose of the prefilled syringe or Rebif® Rebidose® autoinjector, throw away any medicine that is leftover. Do not reuse needles or syringes.
• This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
• Missed dose:
  • Avonex®: Give the dose as soon as you remember. Go back to your regular schedule the following week. Do not use extra medicine to make up for a missed dose. Do not use this medicine 2 days in a row.
  • Rebif®: Give the dose as soon as you remember. Skip the next day and give your next regular dose 48 hours later. Go back to your regular schedule the following week. Do not use extra medicine to make up for a missed dose. Do not use this medicine 2 days in a row.
• Keep this medicine in the refrigerator if you store it at home. Do not freeze. You may allow the prefilled autoinjector pens and prefilled syringes to warm to room temperature for 30 minutes before injection. Do not heat in a microwave oven or in hot water.
• If refrigeration is not available, Rebif® prefilled syringes may be kept for up to 30 days at room temperature, away from heat and direct light. Avonex® prefilled autoinjector pens and prefilled syringes may be stored for up to 7 days at room temperature, away from heat and direct light.
• Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease, bone marrow or bleeding problems, heart disease, heart failure, heart rhythm problems, or thyroid problems. Tell your doctor if you have a history of alcohol abuse, depression, thoughts of suicide, or seizures. Tell your doctor if you have a latex allergy.
• This medicine may increase depression or thoughts of suicide. Tell your doctor right away if you start to feel more depressed or think about hurting yourself.
• This medicine may cause the following problems:
  • Liver problems
  • Congestive heart failure
  • Depression or suicidal thoughts
  • Pulmonary arterial hypertension (high blood pressure in the lungs)
  • Seizures
  • Injection site reactions, including serious skin infection or damage (necrosis)
• This medicine may make you bleed, bruise, or get infections more easily. Take precautions to prevent illness and injury. Wash your hands often.
• Some forms of this medicine are made from donated human blood. All donated blood is tested for certain viruses. Although your risk for getting a virus from the medicine is very low, talk with your doctor if you have concerns.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Change in how much or how often you urinate, difficult or painful urination
• Chest pain, trouble breathing, uneven heartbeat
• Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes
• Depression, thoughts of hurting yourself or others
• Fever, chills, cough, sore throat, body aches
• Pain, burning, redness, swelling, or blue or black skin where the shot was given
• Seizures
• Severe or ongoing skin problem where the shot was given
• Swollen or tender glands in the neck, armpit, or groin
• Unusual bleeding, bruising, or weakness

If you notice these less serious side effects, talk with your doctor:

• Muscle or joint pain

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

Last Updated: 9/6/2024