Prescription onlyNo lower cost generic available

Avonex

(Interferon Beta-1A)

Prescription onlyNo lower cost generic available
  • Injection
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Lowers the frequency of multiple sclerosis exacerbations.

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Our bottom line

Avonex (Interferon Beta-1A) is an injectable medicine effective for relapsing, remitting MS and has manageable side effects and weekly dosing.

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Upsides

  • One of the main treatments for relapsing MS that has been around for many years.
  • Injections are given weekly, and not daily like other MS medications.
  • Helps reduce the frequency of MS relapse episodes.
  • Flu-like reactions are the most common side effects and usually go away with continued treatment or can be avoided by using over-the-counter pain and fever-reducing medicines before the injection (like acetaminophen or ibuprofen).
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Downsides

  • Injection site reactions are common, ranging from localized pain, redness, and swelling to severe skin dryness.
  • Flu-like symptoms are common after interferon injections.
  • It's not clear what type of problems occur if taken during pregnancy.
  • Blood testing is required before and during use of Avonex (Interferon Beta-1A).
  • May not be as effective as other interferons.
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Side effect rates for Avonex (Interferon Beta-1A)

684 From clinical trials of Avonex / Multiple sclerosis (relapsing) (30 mcg)
  • Headache
  • Flu-like symptoms
  • Muscle pain
  • Muscle weakness
  • Nausea
  • Pain
  • Fever
  • Chills
  • Low mood disorder
  • Urinary tract infection

Risks and Warnings for Avonex (Interferon Beta-1A)

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    • Higher risk if:
    • History of depression or mental illness

    Avonex (Interferon Beta-1A) may increase the risk of suicidal thoughts or behavior. Watch for new or worsening depression or any unusual changes in mood or behavior, especially during the first few months of treatment or when the dose changes. Tell your doctor right away if you have any of these symptoms.

Common concerns from people taking Avonex (Interferon Beta-1A)

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Pregnancy
Interactions
  • Avonex (Interferon Beta-1A) can cause flu-like symptoms (headache, fever, muscle pain) right after injections, lasting minutes or hours.
  • Avonex (Interferon Beta-1A) may increase the risk of suicidal thoughts or behavior. Watch for new or worsening depression or any unusual changes in mood or behavior, especially during the first few months of treatment or when the dose changes. Tell your doctor right away if you have any of these symptoms.
  • Avonex (Interferon Beta-1A) has been reported to cause hypersensitivity reactions (severe rash, trouble breathing) and angioedema (life-threatening condition with swelling with or without hives). Get emergency care right away.
  • Avonex (Interferon Beta-1A) can cause serious liver injury with the risk increasing during the first 6 months after you start. You'll need to have your liver enzymes tested at 1, 3, and 6 months. If liver enzymes are significantly elevated and you have appetite/weight loss, stomach discomfort, vomiting, and notice dark urine, yellowing of skin/eyes, change in stool color, and skin rash, you should stop taking Avonex (Interferon Beta-1A) until your doctor decides if it's safe to re-start.
  • Avonex (Interferon Beta-1A) is not thought to cause adverse effects on the heart, but a small number of people with no history of heart problems developed heart failure and heart muscle weakness. Your doctor should watch you carefully especially when you start Avonex (Interferon Beta-1A) then as long as you continue to take it.
  • Because Avonex (Interferon Beta-1A) vial contains albumin, made from human blood, there’s an extremely low risk of transmitting a fatal brain disorder called Creutzfeldt-Jakob disease (CJD) or other viral disease. People who have allergies to albumin shouldn't use the vial formulation of Avonex (Interferon Beta-1A). The prefilled syringe doesn't contain albumin and may be a better choice for albumin-sensitive people. Make sure you talk to your doctor first.
  • Avonex (Interferon Beta-1A) hasn’t been studied in pregnant women, so the effects on your unborn baby are unknown. If you take it during pregnancy or breastfeed, it’s possible that some medicine may get into your baby’s blood. Talk to your doctor first and if you get pregnant while taking Avonex (Interferon Beta-1A), you'll need to enroll in the Avonex (Interferon Beta-1A) pregnancy registry.
  • Avonex (Interferon Beta-1A) can affect the bone marrow and lower your red and white blood cells and platelets to very low levels. When your blood cells and platelets levels drop too low, you are at more risk for infections, bleeding and bruising and will have to stop taking Avonex (Interferon Beta-1A) until levels correct. You'll have to get your blood tested regularly at least every 6 months.
Kidneys and liver
  • Avonex (Interferon Beta-1A) can cause serious liver injury with the risk increasing during the first 6 months after you start. You'll need to have your liver enzymes tested at 1, 3, and 6 months. If liver enzymes are significantly elevated and you have appetite/weight loss, stomach discomfort, vomiting, and notice dark urine, yellowing of skin/eyes, change in stool color, and skin rash, you should stop taking Avonex (Interferon Beta-1A) until your doctor decides if it's safe to re-start.
Pain
  • Flu-like reactions are the most common side effects and usually go away with continued treatment or can be avoided by using over-the-counter pain and fever-reducing medicines before the injection (like acetaminophen or ibuprofen).
  • Injection site reactions are common, ranging from localized pain, redness, and swelling to severe skin dryness.
  • Injection site reactions can be severe and include pain, redness, swelling, infection, and rarely, tissue death. In some cases, these reactions happened more than 2 years after starting Avonex (Interferon Beta-1A). They usually get better, but may need antibiotics or in severe cases, surgical treatment. It’s important that you follow instructions carefully and learn how to inject Avonex (Interferon Beta-1A) correctly.