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Avonex Pen

Generic name: interferon beta-1a [in-ter-FEAR-on-BAY-ta]
Brand names: Avonex Pen, Avonex Prefilled Syringe, Rebif, Rebif Rebidose
Drug class: interferons

What is Avonex Pen?

Avonex pen is used for treating relapsing forms of multiple sclerosis (including the clinically isolated syndrome and relapsing remitting diseases, as well as active secondary progressive disease).Avonex Pen does not cure MS. It will reduce the number of symptoms that recur.Avonex Pen can be used in other ways not mentioned in the medication guide.

Side effects of Avonex Pen

If you experience symptoms of an allergy (hives or itching), a skin reaction that is severe (fever or sore throat with burning eyes, skin pain or blistering, or red or purple skin patches), seek emergency medical attention.Avonex Pen may cause dangerous blood clots inside the blood vessels of your organs, such as the brain and kidneys. If you experience symptoms such as fever, fatigue, reduced urination, or nosebleeds, seek medical attention immediately.

Avonex Pen may cause serious side effects. Contact your doctor immediately if:

  • Pain, swelling, bruises, redness, or changes in the skin where the injection has been given
  • A feeling of lightheadedness, as if you could pass out.
  • Unusual changes in behaviour or mood (feeling depressed, hopeless, anxious, or nervous);
  • Thoughts of suicide or harming yourself
  • Easy bruising and unusual bleeding
  • A seizure;
  • Heart problems: swelling, rapid weight gain, shortness of breath, chest pain that spreads to the jaw or shoulder, nausea, and sweating.
  • Liver problems: nausea, fatigue, confusion, easy bleeding or bruising, clay-coloured stools or urine, or jaundice
  • Signs of infection include fever, chills, and a cough that is bloody or has mucus.
  • Thyroid problems include mood swings, difficulty sleeping, fatigue, nausea, weakness of the muscles, diarrhoea, pounding hearts, dry skin and hair, changes in weight, changes to menstrual cycles, swelling on your face or neck, and sensitivity to heat or cold temperatures.

Avonex Pen side effects may include the following:

  • Low blood cell counts
  • Skin changes at the site of the injection
  • Depression;
  • Abnormal liver function tests
  • Stomach pain;
  • Flu symptoms: headache, fever, chills, and chest pain. Back Pain.

There may be other side effects. For medical advice on side effects, call your doctor. Submit adverse events by calling the FDA at 1-800-FDA-1088.


Avonex Pen may harm your liver. If you experience symptoms like nausea, fatigue, confusion, easy bleeding or bruising, dark urine or clay-coloured stool, or yellowing skin or eyes, call your doctor.Avonex Pen can cause suicidal thoughts in some people. Be aware of any changes you may experience in mood or symptoms. Inform your doctor if you experience any changes in symptoms or a new one.

Before you take this drug

Avonex Pen should not be used if allergic to albumin, natural interferon beta (or recombinant), or natural interferon.

If you've ever:

  • Blood clots or bleeding issues;
  • Depression, mental illness, or suicide thoughts or acts;
  • Liver Disease
  • Bleeding problems
  • Low blood cell counts
  • Heart Disease
  • A thyroid condition;
  • A latex allergy
  • An autoimmune disease such as rheumatoid arthritis or lupus.
  • A seizure;
  • If you are a heavy drinker of alcohol,

Some brands of Interferon Beta-1a may contain human plasma that has been donated and could contain viruses or infectious agents. The plasma that is donated is treated and tested to minimise the chance of infection. However, there's still a tiny possibility. You should ask your doctor if there are any risks.Inform your doctor of any pregnancy or breastfeeding plans.Avonex pens are not intended for anyone under the age of 18.

How to take Avonex pens?

Read all the instructions or guides that come with your medication and follow the directions. Sometimes, your doctor will change the dose. You must take the medication exactly as prescribed.Avonex Pen can be administered by injection. You may be taught how to use the Avonex Pen by your healthcare provider.Please read and follow all instructions for use that come with your medication. If you do not understand the instructions, ask your pharmacist or doctor.Avonex injections are usually given once a week at night, on the same day every week.The Rebif injection is given under the skin at the same dose on the day of each dosage.Before using the powder, it must be diluted with liquid. Only prepare an injection when you're ready to administer it. If the colour of your medicine changes or if it contains particles, do not se it. For new medication, call your pharmacist.You will be shown by your care provider where to place the Avonex pen on your body. Each time, inject in a new place. Don't inject in the same spot twice.Check for redness or swelling in the area of your injection about 2 hours later. If you notice a reaction to the skin that doesn't go away in a couple of days, call your doctor.You may experience flu-like symptoms when first using this medicine. Other medications may be prescribed to prevent symptoms. Continue to take these medications as prescribed by your doctor.Medical tests will be required frequently.The prefilled syringes or injection pens are only for one-time use. After one usage, throw it out, even if the medicine is still inside.Keep this medication in the fridge. Do not expose yourself to light.Mix the powdered form of Interferon Beta-1a and a diluteant in the refrigerator. Use the mix within six hours.Remove the Avonex autoinjector from the fridge 30 minutes prior to your injection so that it can reach room temperature. The medicine should not be heated in hot water.

Avonex Pen can be stored for a few hours in a cool, dark room.

  • Avonex autoinjectors or prefilled syringes should not be left out of the refrigerator for more than seven days.
  • The Avonex vial, the Rebif prefilled autoinjector, or the syringe should not be left out of the refrigerator for longer than 30 days.

Avonex Pen should not be frozen. If it is, throw the medication away.Every vial, autoinjector, or syringe is only for one-time use. After one usage, throw it out, even if the medicine is still inside.Only use a needle or syringe once, and place it in the "sharps container" to prevent punctures. Be sure to follow local or state laws on how you should dispose of the container. Protect the health of yourself, pets and children alike with these items by keeping them out of reach of pets or children.

What happens if I miss the dose?

Avonex: Inject the medication as soon as possible, but not for two consecutive days. Never use more than one dose at a time.If you missed a Rebif dose, call your doctor to get instructions.

What happens if I overdose?

Call 1-800-222-1222 for poison help or seek immediate medical attention.

Avoid this

Avonex Pen should not be injected into red or irritated skin.

Interaction with other drug

Avonex Pen may be affected by other drugs, such as prescription or over-the-counter medications, vitamins, and herbal products. Inform your doctor of all the medicines you are currently taking and those that you will begin or stop using.