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.
Relapsing forms of multiple sclerosis (MS)
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.
Source: FDA
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
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
mood changes, especially with thoughts of suicide
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
speech problems
stomach pain
swelling of the face, lips, or eyelids
Rare
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
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
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:
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.
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
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
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.
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.
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.
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.
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).
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).
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).
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.
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.
Relapsing forms of multiple sclerosis (MS)
Relapsing forms of multiple sclerosis (MS)
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