Avonex IM

Avonex IM Side Effects

Pain, swelling, or redness at the injection site may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

Flu-like symptoms such as headache, fatigue, fever, chills, and muscle aches may occur when you first start this medication. These symptoms usually last about a day after the shot and improve or go away after a few months of continued use. You can minimize these side effects by injecting this medicine at bedtime and using fever reducers/pain relievers such as acetaminophen or ibuprofen before each dose. Consult your doctor or pharmacist for more information.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur:

• mental/mood changes (e.g., depression, thoughts of suicide, new or worsening psychiatric symptoms)
• hair loss
• vision changes
• persistent fatigue
• numbness/tingling/swelling of the hands/ankles/feet
• muscle weakness
• trouble breathing
• sudden weight gain
• gradual change in weight (without a change in diet or exercise)
• cold or heat intolerance
• slow/fast/irregular heartbeat

Tell your doctor immediately if any of these rare but very serious side effects occur:

• easy bleeding or bruising
• signs of infection (e.g., fever, persistent sore throat)
• yellowing eyes or skin
• persistent nausea/vomiting
• stomach/abdominal pain
• dark urine

Seek immediate medical attention if any of these rare but very serious side effects occur:

• chest pain
• seizures

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

Call your doctor for medical advice about side effects. In the US, you may report side effects to the Food and Drug Administration (FDA) at 1-800-FDA-1088.

In Canada, you may report side effects to Health Canada at 1-866-234-2345.

Avonex IM Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA) or 1-800-668-1507 (Canada).