Important Safety Information About AVONEX

Wht is the indication?

AVONEX® (Interferon beta-1a) is approved by the FDA to treat relapsing forms of MS to decrease the number of flare-ups and slow the occurrence of some of the disability that is common in people with MS.


What is the most important safety information I should know about AVONEX?

AVONEX can cause serious side effects, so before you start taking AVONEX, you should talk with your doctor about the possible benefits of AVONEX and its possible side effects to decide if AVONEX is right for you.

  • Sometimes interferons, including AVONEX, make people feel sad. If you are taking AVONEX, and feel unusually sad, you should tell a family member or friend right away and call your doctor as soon as possible.
  • Your liver may be affected by taking AVONEX and a few patients have developed severe liver injury. Your healthcare provider may ask you to have regular blood tests to make sure that your liver is working properly. If your skin or the whites of your eyes become yellow or if you are bruising easily you should call your doctor immediately.
  • Some people have had severe allergic reactions, a drop in their red or white blood cell levels, heart problems, changes in their thyroid function, or seizures.

AVONEX has not been studied in pregnant women. If you become pregnant while taking AVONEX, you should stop taking AVONEX immediately, tell your doctor, and consider enrolling in the AVONEX Pregnancy Registry by calling 1-800-456-2255.

Most people who take AVONEX have flu-like symptoms (fever, chills, sweating, muscle aches, and tiredness) early during the course of therapy. For many people, these symptoms lessen or go away over time. Talk to your doctor if these symptoms continue longer than the first few months of therapy, or if they are difficult to manage.

Who should not take AVONEX?

Do not take AVONEX if you have had an allergic reaction (difficulty breathing, itching, flushing or skin bumps spread widely over the body) to interferon beta.

You should tell your doctor if you are taking any other prescription or nonprescription medicines. This includes any vitamin or mineral supplements, or herbal products.

You should tell your doctor if you have had a natural rubber sensitivity since the AVONEX prefilled syringe cap contains dry natural rubber, which may cause allergic reactions.

Where can I get more information?

This information is not intended to replace discussions with a healthcare provider. Please see the patient Medication Guide and full Prescribing Information at the bottom of this page for additional information.