SIDE EFFECTS: See also Warning section. Flu-like symptoms (such as fever, chills, muscle/joint aches, fatigue, headache, nausea, stomach pain) may occur. If instructed to do so, taking pain/fever-reducing medications (such as acetaminophen) or injecting this medication at bedtime may help reduce some of these flu-like symptoms. Dry mouth, bad taste in mouth, increased sweating, loss of appetite, weight loss, trouble sleeping, dizziness, diarrhea, vomiting, dry skin, or redness/swelling at the injection site may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Tooth and gum problems may sometimes occur during treatment. Having a dry mouth can worsen this side effect. Prevent dry mouth by drinking plenty of water or using a saliva substitute. Brush your teeth well at least twice a day and have regular dental exams. If you experience vomiting during treatment, rinse your mouth afterwards to lessen the chance of tooth and gum problems. Temporary hair loss may occur. Normal hair growth should return after treatment has ended. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including: persistent sore throat or fever, easy or unusual bleeding/bruising, unusually severe fatigue, increased thirst/urination, severe stomach pain with nausea/vomiting, bloody diarrhea. Get medical help right away if you have any serious side effects, including: chest/jaw/left arm pain, unusually slow/fast/pounding heartbeat, vision changes (such as blurred vision, partial loss of vision). A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before using peginterferon alfa-2b, tell your doctor or pharmacist if you are allergic to it; or to polyethylene glycol (PEG); or to other interferons; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney disease, liver disease, mental/mood disorders (such as depression), history of drug/alcohol abuse, thyroid disease, diabetes, eye problems, inflammation of the bowels (such as colitis), pancreatitis, high blood triglyceride levels. This drug may make you dizzy. Alcohol or marijuana can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Children may be more sensitive to the side effects of this drug, especially mental mood changes (such as severe depression, thoughts/attempts of suicide). This medication is not recommended for use during pregnancy because of possible serious harm to the unborn baby. Consult your doctor for more details and to discuss reliable forms of birth control. If you become pregnant or think you may be pregnant, inform your doctor right away. It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug include: hydroxyurea, telbivudine.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.