Welcome! You’re in GoodRx for healthcare professionals. Now, you’ll enjoy a streamlined experience created specifically for healthcare professionals.

Are you a healthcare professional? Join GoodRx for HCPs

HomeDrugsAvonex (interferon beta-1a) Prices

Avonex

interferon beta-1a

Used for Multiple Sclerosis

Avonex (interferon beta-1a) is an injectable biologic used for the treatment of relapsing multiple sclerosis (MS). However, it can cause uncomfortable flu-like symptoms as a side effect.

Reviewed by:

Hope Chang, PharmD, AAHIVP

Michelle Nguyen, PharmD

Last reviewed on August 24, 2021

Basics Side effects Pros & cons Pharmacist tips FAQs Warnings Dosage Interactions Cost Alternatives Latest news Images Prices Medicare

What is Avonex (interferon beta-1a)?

What is Avonex (interferon beta-1a) used for?

Relapsing forms of multiple sclerosis (MS)

How Avonex (interferon beta-1a) works

Avonex (interferon beta-1a) is a biologic medication. Interferons typically attach to certain proteins and affect cell processes. It's not known exacty how Avonex (interferon beta-1a) helps treat multiple sclerosis.

Are you looking for information on Rebif (interferon beta-1a) subcutaneous injection instead?

Drug Facts

Common BrandsAvonex

Drug ClassBiologic

Controlled Substance ClassificationNot a controlled medication

Generic StatusNo lower-cost generic available

AvailabilityPrescription only

Get your GoodRx coupon

Avg retail price

$13423.27(save 37.54%)

GoodRx discount

$8384.45

See prices

What are the side effects of Avonex (interferon beta-1a)?

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

Headache (58%)
Flu-like symptoms (49%)
Weakness, fatigue (24%)
Muscle pain (29%)
Fever (20%)
Chills (19%)
Depression (18%)
Urinary tract infection (UTI) (17%)
Dizziness (14%)

Other Side Effects

Stomach pain
Injection site reaction
Infection
Toothache
Joint pain
Hair loss
Eye problems
Migraine

Serious Side Effects

Contact your healthcare provider immediately if you experience any of the following.

Liver damage: severe stomach pain, pale stools, dark urine, or yellowing of your skin or eyes
Chest pain
Abnormal bleeding
Seizures

Source: FDA

The following side effects have also been reported

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Black, tarry stools

chills

flu-like symptoms

headache

joint pain

muscle aches

nausea

pain

painful or difficult urination

sores, ulcers, or white spots on the lips or in the mouth

swollen glands

trouble breathing

unusual bleeding or bruising

unusual tiredness or weakness

Less common

Clumsiness or unsteadiness

decreased hearing

difficulty with swallowing

dizziness

fainting

feeling of warmth

hives or itching

mood changes, especially with thoughts of suicide

muscle spasms

pain or discharge from the vagina

pelvic discomfort, aching, or heaviness

redness of the face, neck, arms, and occasionally, upper chest

redness, swelling, or tenderness at the injection site

runny or stuffy nose

seizures

skin lesions

sneezing

sore throat

speech problems

stomach pain

swelling of the face, lips, or eyelids

Rare

Earache

general feeling of discomfort or illness

loss of appetite

painful blisters on trunk of the body

painful cold sores or blisters on the lips, nose, eyes, or genitals

Incidence not known

Bleeding gums

blood in the urine or stools

bloody nose

chest discomfort

confusion

constipation

dark urine

decreased urine output

depressed mood

dilated neck veins

dry skin and hair

extreme fatigue

fast, irregular, or pounding heartbeat

feeling cold

general tiredness and weakness

hair loss

heavier menstrual periods

high fever

irregular breathing

light-colored stools

loss of bladder control

mental depression

mood or other mental changes

muscle cramps and stiffness

nausea or vomiting

nervousness

pale skin

persistent loss of appetite

pinpoint red spots on the skin

puffiness or swelling of the eyelids, or around the eyes, face, lips, or tongue

redness, blistering, peeling, or loosening of the skin

sensitivity to heat

skin rash

slowed heartbeat

sudden loss of consciousness

sweating

swelling of the face, fingers, feet, or lower legs

swelling of the mouth or throat

tightness in the chest

tightness in the throat

upper right stomach pain or tenderness

weight gain or loss

yellow eyes and skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Heartburn

indigestion

sour stomach

Less common

Hair loss

trouble sleeping

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Pros and cons of Avonex (interferon beta-1a)

Pros

A disease-modifying therapy (DMT) that prevents worsening MS

One of the first DMTs approved for MS, so there's a lot of research and experience

Comes as an autoinjector pen and prefilled syringe for easy at-home injections

Can be stored at room temperature for up to 7 days

Cons

Not a first-choice treatment option for relapsing MS

Needs to be injected every week

Has many unpleasant side effects

Might not be a good option for people with a history of mental health conditions

Pharmacist tips for Avonex (interferon beta-1a)

Avonex (interferon beta-1a) is a once-weekly injection. Pick a day of the week that is convenient for you and typically works well with your schedule.

Your healthcare provider will show you how to properly inject the medication. They might watch you when you do your first injection to make sure that you're administering it properly.

Store Avonex (interferon beta-1a) in the refrigerator; don't freeze it. If you're traveling or don't have access to a refrigerator, Avonex (interferon beta-1a) can be stored at room temperature for up to 7 days. Don't put medication back in the refrigerator after it has reached room temperature.

Keep the syringes or injection pens in their original container. This will protect the medication from light.

When you're ready for your injection, take Avonex (interferon beta-1a) out of the refrigerator and let it warm up to room temperature. This can take about 30 minutes and can help with injection discomfort.

Always check that the medication is clear, colorless, and free of particles. Don't use the medication if it's cloudy, colored, or has lumps or particles in it. Contact your provider or pharmacy about a replacement medication.

Flu-like symptoms are a common side effect. It's usually worse in the beginning and should get better with time. Make sure you stay hydrated. Using over-the-counter cold and flu medications, like acetaminophen (Tylenol) and ibuprofen (Advil, Motrin), can help with the symptoms.

Let your provider know if you have a latex allergy. The cap for the syringe and pen both contain natural latex.

Frequently asked questions about Avonex (interferon beta-1a)

How effective is Avonex (interferon beta-1a)?

Sometimes it's hard to know if disease-modifying therapies (DMTs) are working. They prevent your MS from getting worse, but you might not feel the effects right away. In clinical trials, 78% of people taking Avonex (interferon beta-1a) did not have worsening of their MS for at least 2 years.

Does Avonex (interferon beta-1a) suppress the immune system?

Avonex (interferon beta-1a) can lower the number of white blood cells that you have. White blood cells are responsible for fighting off infections. Low white blood cells can mean a weaker immune system.

How is Avonex (interferon beta-1a) administered?

Avonex (interferon beta-1a) must be injected into your muscle. It can't be taken orally or injected into the fatty tissue under your skin. Once you've chosen your injection site, use one hand to stretch out the skin around the injection site.

Where can I inject Avonex (interferon beta-1a)?

Avonex (interferon beta-1a) can be injected into your thigh or upper arm. Remember to rotate your injection sites to decrease soreness and irritation.

Is Avonex (interferon beta-1a) the same as Rebif?

Avonex (interferon beta-1a) is very similar to Rebif and they both have the same active ingredient. Avonex (interferon beta-1a) is injected into your muscle (intramuscular) once weekly, which is less frequent than Rebif, which is injected 3 times a week under the skin (subcutaneous). See the bottom of this page for a side-by-side comparison.

How to save using GoodRx

1. Compare PricesSpecify your dosage and quantity to find out exactly how much you can save.

2. Select your free couponYou can use the displayed coupon, or compare prices at other pharmacies near you.

3. Show coupon to your pharmacistPresent your printed or electronic coupon when you pick up your prescription.

Get free coupon Learn more

What are the risks and warnings for Avonex (interferon beta-1a)?

Avonex (interferon beta-1a) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Mental health

Risk factors: History of mental health conditions

Interferons, such as Avonex (interferon beta-1a), can affect your mental health. This can include depression, aggressive behavior, and in severe cases, thoughts about harming yourself or others. Avonex (interferon beta-1a) might not be a good option for people who have a history of violent behavior or certain mental health conditions. Let your provider know if you notice a change in mood while taking Avonex (interferon beta-1a). If it's caused by the medication, it will usually go away once the medication is stopped.

Liver damage

Risk factors: Taking other medications that harm the liver | Chronic heavy alcohol consumption

Avonex (interferon beta-1a) can cause liver damage and in some cases, lead to serious liver problems. Your provider will monitor your blood tests closely to check your liver function and might stop the medication if your liver tests get too high. Let your provider know if you have severe stomach pain, pale stools, dark urine, or yellowing of your skin or eyes. These can be signs of a liver problem.

Congestive heart failure

Risk factors: History of heart conditions

Some people taking Avonex (interferon beta-1a) experienced heart problems. Let your provider know if you have a history of heart conditions. They may monitor your heart more closely. If you have a cardiologist, let them know you're taking Avonex (interferon beta-1a).

Lower blood cell counts

Risk factors: Taking other medications that lower blood cell counts

Avonex (interferon beta-1a) can affect the way your cells work and result in decreased blood cell counts. Having fewer red and white blood cells can raise your risk of bleeding, infection, and anemia. Your provider will monitor your labs and might stop or pause the medication if your cell counts become too low. Let your provider know if you have an infection or notice any abnormal bleeding (like bleeding gums when you brush your teeth, a cut that won't stop bleeding, or a bruise that gets larger with time).

Seizures

Risk factors: History of seizure

It's rare, but using Avonex (interferon beta-1a) has been associated with seizures. Let your provider know if you have a history of seizures before starting Avonex (interferon beta-1a).

Avonex (interferon beta-1a) dosage forms

Typical dosing for Avonex (interferon beta-1a)

The recommended dose is 30 mcg by intramuscular (IM) injection (into the muscle) once weekly. To help with flu-like side effects you can start at 7.5 mcg for the first week, then 15 mcg on week 2, 22.5 mcg on week 3, and then 30 mcg every week thereafter.

Interactions between Avonex (interferon beta-1a) and other drugs

Avonex (interferon beta-1a) may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking. The list below does not include all possible drug interactions with Avonex (interferon beta-1a). Please note that only the generic name of each medication is listed below.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.