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How long can Avonex be unrefrigerated?

Medically reviewed by Carmen Pope, BPharm. Last updated on May 8, 2023.

Official answer

  • Avonex may be kept unrefrigerated for up to 7 days as long as the room temperature is not more than 25°C (77°F).
  • Avonex is a brand of interferon beta-1a. Interferons are cytokines, which are proteins that cells use to communicate with each other to trigger the protective defenses of the immune system.
  • Interferons also “interfere” with viral replication by protecting cells from viral infections.

Avonex prefilled syringes and autoinjectors should be stored at 2°C to 8°C (36°F to 46°F) in their original packaging to protect from light. They should not be frozen. Do not use Avonex that has exceeded its expiry date.

Before use, Avonex should be removed from the refrigerator and allowed to warm naturally to room temperature for 30 minutes before administering. Do not use external heat sources such as a microwave or hot water.

Allowing the injection to warm to room temperature makes the injection procedure more comfortable for the person being administered it.

If refrigeration is unavailable, Avonex may be kept unrefrigerated, at room temperature (below 25°C [77°F]) for 7 days. Do not put Avonex back into the refrigerator if it has been left out of the refrigerator for more than a few minutes.

Avonex should not be exposed to high temperatures greater than 25°C (77°F). Do not use Avonex if it has been kept at room temperature for longer than 7 days, or exposed to temperatures other than those recommended. Do not use beyond its expiration date.

What is Avonex?

What is Avonex? Avonex is a brand of interferon beta-1a that may be used to treat relapsing forms of multiple sclerosis (MS) in adults, such as clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.

How does Avonex work?

Interferon beta-1a, the active ingredient in Avonex is, a 186 amino acid glycoprotein. There are several different types of interferons produced by the body to fight viral infections and other foreign invaders. Although the interferon in Avonex is man-made, it contains all of the same basic components as the interferon beta that occurs naturally in the human body.

Interferons help control immune system activities. Avonex helps to inhibit inflammation that can cause MS flare-ups. Avonex may help slow the progression of physical disability associated with Multiple sclerosis (MS) in people with MRI results that contain features consistent with MS lesions

How is Avonex given?

Avonex is administered by injection directly into the muscle (intramuscular) and comes in several forms:

  • A powdered form which requires reconstitution
  • Single-use prefilled syringe (30 micrograms)
  • Autoinjector, single-use (30 micrograms)
  • Avostart Grip titration kit to use with prefilled syringes.

The recommended dose is 30 micrograms once a week; however, smaller dosages (for example 7.5 micrograms) may be given initially to reduce the incidence and severity of flu-like symptoms that may occur when initiating Avonex therapy at a dose of 30 micrograms.

The dose may be increased by 7.5 micrograms each week for the next three weeks until the recommended dose of 30 micrograms is achieved.


Avonex (Interferon beta-1a) Biogen Inc., Cambridge, MA

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