SIDE EFFECTS: Injection site reactions (pain/swelling/redness), headache, tiredness, diarrhea, upset stomach, loss of appetite, back pain, dizziness, dry mouth, taste changes, nausea, or vomiting may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Flu-like symptoms such as fever, chills, and muscle aches may occur, especially when you first start this medication. These symptoms usually last about 1 day after the injection and improve or go away after a few weeks of continued use. You can reduce these side effects by injecting this medicine at bedtime and using a fever reducer/pain reliever such as acetaminophen before each dose. Consult your doctor or pharmacist for more information. 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: feeling too hot or cold (more than others around you), fast/irregular heartbeat, increased thirst/urination, menstrual changes (absent/delayed/irregular periods), numbness/tingling of hands/feet, swelling (especially of face/hands/feet), trouble sleeping, trouble walking, vision changes (such as blurred vision, partial loss of vision), easy bleeding/bruising, persistent nausea/vomiting, signs of infection (e.g., fever, persistent sore throat), stomach/abdominal pain, dark urine, black/tarry stools, yellowing eyes/skin. Get medical help right away if any of these very serious side effects occur: chest pain, seizures, weakness on one side of the body, slurred speech. This drug may cause you to develop serious mental/mood changes that may get worse during treatment or after your last dose. Tell your doctor right away if you have symptoms such as confusion, depression, thoughts of suicide or hurting others, unusual irritability, or aggressive behavior. If this occurs, psychiatric therapy and monitoring is recommended during and after treatment with this medication. 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: See also Warning section. Before using interferon alfa, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as albumin), 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: blood cell disorders (e.g., anemia, neutropenia, thrombocytopenia), blood clots, cancer, diabetes, eye problems, heart disease (e.g., angina, irregular heartbeat), high blood pressure, HIV infection, immune system diseases (e.g., lupus, psoriasis, rheumatoid arthritis), intestinal disease (e.g., colitis), kidney disease, liver disease (e.g., autoimmune hepatitis, decompensated liver disease), lung diseases (e.g., chronic obstructive pulmonary disease-COPD, asthma, pneumonia), mental/mood disorders (e.g., anxiety, depression), high blood triglyceride levels, pancreatitis, seizure disorder, thyroid disease, use/abuse of drugs/alcohol. 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. Do not have immunizations/vaccinations without the consent of your doctor, and avoid contact with people who have recently received oral polio vaccine or flu vaccine inhaled through the nose. Wash your hands well to prevent the spread of infections. To lower your risk of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports. 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). Interferon and ribavirin may also slow down a child's rate of growth. Normal weight gain and rate of growth usually return after treatment is completed but the final adult height may be lower than expected. Monitor your child's height and weight periodically during treatment. Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug, especially dizziness, mental/mood changes, and effects on the heart. Interferon alfa is not recommended for use during pregnancy. It may harm an unborn baby. Consult your doctor for more details and to discuss reliable forms of birth control. Interferon alfa, when used in combination with ribavirin, must not be used during pregnancy by either the pregnant woman or her male partner. The combination may cause harm to an unborn baby. Two reliable forms of birth control (such as condoms, birth control pills) must be used whenever at least one sexual partner is using these medicines together, and for at least 6 months after stopping treatment. If you or your partner become pregnant, or if you think you or your partner may be pregnant, tell your doctor right away. It is not known whether 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: barbiturates (e.g., phenobarbital), colchicine, drugs that may affect your immune system (e.g., cancer chemotherapy, aldesleukin, cyclosporine), hydroxyurea, telbivudine, theophyllines (e.g., aminophylline, theophylline).

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. Symptoms of overdose may include: chest pain, persistent nausea/vomiting, stomach/abdominal pain, dark urine.