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
Adults
- Tiredness/fatigue (56%)
- Headache (54%)
- Muscle pain (37%)
- Fever (37%)
- Chills (35%)
- Joint pain (28%)
- Nausea/vomiting (24%)
- Hair loss (23%)
- Pain, swelling, or redness at injection site (22%)
- Anxious/nervousness (19%)
- Difficulty sleeping (19%)
- Depression (18%)
- Loss of appetite (17%)
- Diarrhea (16%)
- Dizziness (16%)
- Stomach pain (15%)
- Itching (12%)
- Pain (11%)
Children
- Flu-like symptoms (fever, cough, short of breath) (81%)
- Stomach problems (nausea, vomiting, diarrhea, stomach pain) (44%)
- Pain, swelling, or redness at injection site (42%)
- Headache (39%)
- Muscle pain (29%)
- Tiredness/weakness (20%)
- Irritated/angry feeling (14%)
- Itching (12%)
- Difficulty sleeping (12%)
- Rash (10%)
Less Common Side Effects
Adults
- Back pain
- Difficulty concentrating
- Skin irritation
- Sweating
- Impaired memory
- Rash
- Low platelet count
- Dry skin
- Blurry vision
- Weight loss
- Shortness of breath
- Cough
Children
- Lack of energy/strength
- Bloody nose
- Nausea
- Upper respiratory infection
- Hair loss
- Low appetite
- Dizziness
- Common cold
Pegasys serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Serious allergic reactions: hives, itching, swelling of face or tongue, difficulty breathing
- Bleeding that's difficult to stop
- Depression and thoughts of self-harm
- Heart problems: high blood pressure, fast and irregular heart beat, chest pain, heart attacks
- Severe skin reactions: blisters or sores on skin, painful rash, redness over large parts of the body
- Autoimmune disorders
- Stroke or brain bleed: facial drooping on one side, slurred speech, weakness, dizziness, headache, confusion, vision loss
- Severe or fatal infections: fever, difficulty breathing, diarrhea, weakness
- Worsening liver problems or liver failure: swelling of your stomach, yellowing of your skin or the whites of your eyes, confusion
- Lung problems: lung infection, shortness of breath, high blood pressure in the lung, lung failure
- Inflamed intestines and pancreas: stomach or back pain, bloody diarrhea, fever, sweating, loss of appetite, nausea, vomiting
Source: DailyMed
The following Pegasys 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
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.
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