Pegasys (peginterferon alfa-2a) is an interferon alpha. It's used to treat chronic (long-term) hepatitis B and hepatitis C in children and adults, sometimes in combination with other antivirals. Pegasys (peginterferon alfa-2a) is injected under the skin, typically once per week. The most common side effects of this medication include tiredness, headache, and fever.
Pegasys (peginterferon alfa-2a) is an interferon alpha. It's not completely clear how Pegasys (peginterferon alfa-2a) works, but it's thought to activate proteins of your immune system to attack hepatitis B and hepatitis C viruses and stop them from growing.
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.
Adults
Children
Adults
Children
Contact your healthcare provider immediately if you experience any of the following.
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
discouragement
feeling sad or empty
irritability
lack of appetite
loss of interest or pleasure
lower back or side pain
painful or difficult urination
pale skin
tiredness
trouble sleeping
trouble concentrating
ulcers, sores, or white spots in the mouth
unusual bleeding or bruising
unusual tiredness or weakness
Less common
Bone pain
chest pain or discomfort
confusion
depressed mood
dizziness
dry skin and hair
fainting
fast heartbeat
feeling cold
headache
heart murmur
hoarseness or husky voice
lightheadedness
muscle cramps and stiffness
pale skin
rapid, shallow breathing
slowed heartbeat
stomach pain
tightness in the chest
troubled breathing with exertion
Incidence not known
Accumulation of pus in the arms or legs
blistering, peeling, loosening of the skin
decreased urination
increase in heart rate
joint or muscle pain
red, irritated eyes
red skin lesions, often with a purple center
seizures
sunken eyes
swollen, red, tender area of infection in the arms or legs
thirst
wrinkled 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
Back pain
cracked, dry, scaly skin
crusting, irritation, itching, or reddening of the skin
fear
feeling unusually cold, shivering
hair loss or thinning of the hair
muscle or joint pain
nervousness
numbness
rash
redness
soreness
stinging
swelling
tenderness
tingling
ulceration
vomiting
warmth
Incidence not known
Change of hearing
loss of hearing
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.
More tips for how to inject Pegasys (peginterferon alfa-2a) under the skin at home:
No, Pegasys (peginterferon alfa-2a) isn't chemotherapy. Rather, it's an interferon alpha. Chemotherapies are medications typically used to treat cancer; they work by killing fast-growing cells, such as cancer cells. Interferons are similar to immune proteins that your body makes and they work by helping you fight off foreign attackers, like viruses. While Pegasys (peginterferon alfa-2a) isn't FDA-approved for cancer, other interferons are used in cancer treatment. Talk with your provider if you've more questions about interferon therapy.
No, Pegasys (peginterferon alfa-2a) isn't an immunosuppressant. Immunosuppressants lower the activity of your immune system, but Pegasys (peginterferon alfa-2a) does the opposite. It raises the activity of immune proteins in your body to help fight off hepatitis B and C viruses.
Research shows Pegasys (peginterferon alfa-2a) can cure hepatitis C. But studies show that Pegasys (peginterferon alfa-2a) can only functionally cure hepatitis b, meaning it keeps the virus inactive so it's less likely to cause harm. Keep in mind everyone responds differently to medications. Your provider will monitor you by measuring the amount of the virus in your body to see how well you're responding to Pegasys (peginterferon alfa-2a).
Pegasys (peginterferon alfa-2a) is given as an injection under the skin, either into your thigh or stomach. Never inject it into your muscle or vein. Ask your provider or pharmacist if you're not sure how to correctly administer Pegasys (peginterferon alfa-2a).
Pegasys (peginterferon alfa-2a) 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.
Animal studies have shown that Pegasys (peginterferon alfa-2a) can cause harm to unborn babies and has potential to cause an abortion or miscarriage. Additionally, ribavirin (Rebetol), a medication commonly used together with Pegasys (peginterferon alfa-2a), must be avoided in pregnant women and in men whose partners are pregnant because it can cause harm to an unborn baby, including death. If using Pegasys (peginterferon alfa-2a) and ribavirin (Rebetol) together, women of childbearing age, including those who are partners of men who take these medications, must have a negative pregnancy test before starting treatment. They must also complete monthly pregnancy tests and use two forms of birth control during treatment and for at least 6 months after stopping ribavirin (Rebetol). If you or your female partner becomes pregnant while taking Pegasys (peginterferon alfa-2a) and ribavirin (Rebetol) or within 6 months after you finish treatment, let your provider know right away. It's also encouraged that you contact the Ribavirin Pregnancy Registry, which will monitor the health of you and your baby, by calling 1-800-593-2214.
Talk to your provider about family planning before starting Pegasys (peginterferon alfa-2a) with or without ribavirin (Rebetol).
Pegasys (peginterferon alfa-2a) can cause serious, life-threatening mental health problems. Symptoms include thoughts of harming yourself or others, depression, aggressive behavior, and seeing things that aren't real. This can happen to anyone taking Pegasys (peginterferon alfa-2a), but the risk is higher if you have a history of depression. Let your provider know if you or your loved ones notice a change in your mood or behavior, or if you have thoughts of hurting yourself while you're taking Pegasys (peginterferon alfa-2a). Depending on how severe your symptoms are, your provider might have you stop taking the medication.
Pegasys (peginterferon alfa-2a) can cause autoimmune conditions, such as myositis (inflamed muscles), hepatitis, psoriasis (inflamed skin), rheumatoid arthritis (inflamed joints), interstitial nephritis (inflamed kidneys), or make them worse. Some of these can be life-threatening. Make sure you have routine tests and office visits so your provider can monitor your health.
Strokes and brain bleeds have been reported in people taking Pegasys (peginterferon alfa-2a), including in people who have little to no risk factors for stroke. It's not known how frequently these events have occurred. Call 911 right away if you experience facial drooping on one side, slurred speech, weakness, dizziness, headache, confusion, or vision loss.
Severe, life-threatening infections have been reported in people taking Pegasys (peginterferon alfa-2a). Fever is a common side effect of Pegasys (peginterferon alfa-2a), but it can also be a sign of an infection. If you develop a fever or any other signs of an infection (e.g., cough, shortness of breath, weakness, chills, sweating), contact your provider so you can be tested for an infection.
Using Pegasys (peginterferon alfa-2a) and telbivudine (Tyzeka) together can cause or worsen peripheral neuropathy (damage to the nerves causing numbness and pain in your hands and feet). Let your provider know if you're taking telbivudine (Tyzeka) before starting Pegasys (peginterferon alfa-2a).
Pegasys (peginterferon alfa-2a) can cause serious liver problems that can lead to liver failure or death. Your risk might be higher if you're also taking certain HIV NRTIs (e.g., abacavir (Ziagen), zidovudine, lamivudine (Epivir), etc.). You might need to get regular blood tests done to make sure your liver is working properly. Seek medical attention right away if you notice swelling of your stomach, yellowing of your skin or the whites of your eyes, stool changes (black, tarry, or bloody stools), coughing or vomiting up blood, confusion, slurred speech, mood swings, or changes in personality.
High blood pressure, fast and irregular heartbeat, chest pain, and heart attacks have been reported in people taking Pegasys (peginterferon alfa-2a). If you have a history of heart problems, talk to your provider to see if Pegasys (peginterferon alfa-2a) is right for you.
Pegasys (peginterferon alfa-2a) can affect the way your cells work, which can lead to low blood cell counts. This can raise your risk of serious infections, bleeding, and anemia (low red blood cells). Your risk is higher if you have HIV, or if you're taking Pegasys (peginterferon alfa-2a) with ribavirin (Rebetol) and azathioprine (Imuran). You'll need to have lab tests done before and during treatment with Pegasys (peginterferon alfa-2a) so your provider can make sure your blood cell counts are in the normal range. If your blood counts drop too low, you'll likely need to stop taking Pegasys (peginterferon alfa-2a). If you develop any signs of infection (e.g., fever, tiredness, chills, cough, trouble breathing) or signs of bleeding (pale skin, fast heart rate, lightheadedness, blood in your urine or stool), contact your provider right away.
Pegasys (peginterferon alfa-2a) can cause or worsen diabetes and thyroid problems. Let your provider know if you're taking medications for diabetes or thyroid disease before you start taking Pegasys (peginterferon alfa-2a) because it might not be the best option for you until your conditions are stable.
Pegasys (peginterferon alfa-2a) can cause serious eye and vision problems, including retinal detachment and blindness. You'll need an eye exam before starting Pegasys (peginterferon alfa-2a) and occasional exams during treatment if you have a history of eye problems. Let your provider know if you have any changes in your vision while taking Pegasys (peginterferon alfa-2a).
Pegasys (peginterferon alfa-2a) can cause or worsen breathing and lung problems, such as lung infections (pneumonia) or high blood pressure in the lungs (pulmonary hypertension). In severe cases, lung problems can lead to death. Let your provider know if you have shortness of breath or breathing problems. Your provider can order a chest X-ray to check on your lung health.
Pegasys (peginterferon alfa-2a) can cause inflammation of the intestines or pancreas, and can sometimes be life-threatening. If you experience bloody diarrhea, fever, nausea, vomiting, or abdominal pain, contact your provider right away.
Children can experience a delay in growth (both height and weight) during treatment with Pegasys (peginterferon alfa-2a) with or without ribavirin (Rebetol). Children might be able to catch-up in growth after they stop taking Pegasys (peginterferon alfa-2a), but there isn't enough information available to know what the long-term effects of the medication are on children's growth.
Pegasys (peginterferon alfa-2a) can cause severe allergic and skin reactions. Get medical help right away if you experience hives, blisters, swelling or redness in any of your body parts, tightening of your chest, or trouble breathing.
Hepatitis C
The length of treatment with Pegasys (peginterferon alfa-2a) depends on your age, if you have HIV, the type of hepatitis C virus you have, and if you're taking other hepatitis C medications.
Hepatitis B
Your dose might differ if you have kidney problems. Your provider might change your dose based on your lab results or if you develop side effects from Pegasys (peginterferon alfa-2a).
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
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.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Pegasys (peginterferon alfa-2a) will not be safe for you to take.