Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes Unitron Peg (Peginterferon-alfa-2b). If you are concerned about side effects, discuss the risks and benefits of Unitron Peg (Peginterferon-alfa-2b) with your doctor.

The following side effects have been reported by at least 1% of people taking Unitron Peg (Peginterferon-alfa-2b). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• decreased desire for sexual activities
• drowsiness
• Dry Mouth
• dry skin
• flu-like symptoms (unusual tiredness, Fever, chills, muscle aches, joint pain and Headaches)
• flushing of the skin
• indigestion
• loss of appetite
• nausea
• pain in bones, joints, or muscles
• redness, swelling, bruising, irritation, or itching at place of injection
• temporary hair loss
• trouble sleeping
• vomiting
• weight changes (loss or gain)

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal pain or swelling
• Anemia (paleness, tiredness, shortness of breath)
• changes in mood (e.g., irritability, Depression, anxiety, aggression)
• confusion
• dizziness
• eye pain or swelling of the eye
• high blood sugar (increased thirst, hunger, weakness, drowsiness, blurred vision, weight loss)
• low blood sugar (headache, hunger, weakness, irritability, trouble concentrating)
• lower back or side pain
• signs of infection (e.g., chills, fever, cough, sore throat, difficulty or painful urination, difficulty breathing)
• tingling or burning sensation in arms or legs
• ulcers or sores in the mouth or throat
• unusual bruising or bleeding (e.g., bleeding gums, nosebleeds, blood in the urine, pinpoint-sized red spots on skin)
• vision changes (e.g., blurred vision, vision loss)
• worsening psoriasis

Stop taking the medication and seek immediate medical attention if any of the following occur:

• fast or irregular heartbeat (palpitations)
• severe skin rash (blistering, peeling, and spreading)
• suicidal feelings or suicide attempt(s)
• symptoms of a Heart Attack (e.g., severe chest pain or pressure, pain in the arm or shoulder, nausea, sweating)
• symptoms of a Anaphylaxis (severe allergic reaction) (e.g., Hives; difficulty breathing; swelling of the face, mouth, throat, or tongue)
• symptoms of a Stroke (e.g., sudden and severe headache, sudden weakness or numbness in the arms or legs, sudden vision changes, sudden dizziness)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Unitron Peg (Peginterferon-alfa-2b).

Peginterferon alfa-2b should not be used by anyone who:

• is allergic to peginterferon alfa-2b, any other interferon, or to any of the ingredients of the medication
• has decompensated liver disease
• has Epilepsy (seizures)
• has or has had autoimmune diseases (including autoimmune hepatitis)
• has or has had severe psychiatric conditions
• has severely reduced kidney function
• has Thyroid disease, when medication cannot bring thyroid function into the normal range

There may be an interaction between peginterferon alfa-2b and any of the following:

• Aldesleukin
• telbivudine
• Theophylline

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Unitron Peg (Peginterferon-alfa-2b). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Unitron Peg (Peginterferon-alfa-2b).

Allergic reactions: In rare cases, Unitron Peg (Peginterferon-alfa-2b) may cause severe allergic reactions. If you notice hives, swelling of the face or throat, or difficulty breathing, stop using Unitron Peg (Peginterferon-alfa-2b) and get medical help immediately.

Autoimmune conditions: Unitron Peg (Peginterferon-alfa-2b) may cause or worsen autoimmune conditions including myositis, hepatitis, immune thrombocytopenic purpura (ITP), Rheumatoid Arthritis, interstitial nephritis, thyroiditis, and systemic Lupus erythematosus. If psoriasis appears, the medication may need to be discontinued.

Blood glucose (sugar): Unitron Peg (Peginterferon-alfa-2b) can cause low or high blood sugar. People with Diabetes should discuss with their doctor how Unitron Peg (Peginterferon-alfa-2b) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Unitron Peg (Peginterferon-alfa-2b), and whether any special monitoring is needed. If you experience high blood sugar (increased thirst, hunger, weakness, drowsiness, blurred vision, weight loss) or low blood sugar (headache, hunger, weakness, irritability, trouble concentrating) while taking Unitron Peg (Peginterferon-alfa-2b), contact your doctor.

Blood problems: Unitron Peg (Peginterferon-alfa-2b) may suppress bone marrow function and cause blood problems such as low platelet counts, low white blood cell counts, and anemia. Your doctor will monitor you for these problems with blood tests. If you experience persistent fever and chills, tiredness, shortness of breath, or easy bruising or bleeding, contact your doctor.

Colon disorders: Unitron Peg (Peginterferon-alfa-2b) may cause certain types of colitis. Report any stomach or abdominal pain, bloody Diarrhea, or fever to your doctor immediately.

Depression and other psychiatric disorders: Unitron Peg (Peginterferon-alfa-2b) can cause depression and other psychiatric conditions. People with psychiatric conditions should be closely monitored by their doctor while using Unitron Peg (Peginterferon-alfa-2b), as it may worsen these conditions. If you have or had a severe psychiatric condition, you should not take Unitron Peg (Peginterferon-alfa-2b). If you feel unusual sadness or hopelessness, or experience other behaviour or mood changes, contact your doctor immediately.

Drowsiness/reduced alertness: Unitron Peg (Peginterferon-alfa-2b) may cause drowsiness or confusion. If the medication affects you in this way, avoid driving, operating machinery, or other tasks that require alertness.

Ear disorders: Certain ear disorders and hearing loss have been observed in people treated with Unitron Peg (Peginterferon-alfa-2b). If you experience any changes in your hearing while taking Unitron Peg (Peginterferon-alfa-2b), contact your doctor.

Eye disorders: Certain eye disorders have been observed in people treated with Unitron Peg (Peginterferon-alfa-2b). If you experience any changes in vision while taking Unitron Peg (Peginterferon-alfa-2b), contact your doctor.

Fertility: Unitron Peg (Peginterferon-alfa-2b) may affect fertility. Some women have reported changes in their menstrual cycle when using Unitron Peg (Peginterferon-alfa-2b). If you experience any changes in your menstrual cycle while using Unitron Peg (Peginterferon-alfa-2b), contact your doctor.

Flu-like symptoms: Unitron Peg (Peginterferon-alfa-2b) may cause a flu-like reaction, with aching muscles, fever, chills, and headache. Your doctor may prescribe Acetaminophen before each dose of Unitron Peg (Peginterferon-alfa-2b) and as needed to help reduce these symptoms.

Fluids: Unitron Peg (Peginterferon-alfa-2b) may cause dehydration. People taking Unitron Peg (Peginterferon-alfa-2b) should drink adequate fluids, especially on hot days or when exercising.

HCV/HIV/HBV: The safety and effectiveness of Unitron Peg (Peginterferon-alfa-2b) have not been established for people with hepatitis C (HCV), who are also infected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV).

Heart disease: Unitron Peg (Peginterferon-alfa-2b) as well as others like it can cause heart problems such as high blood pressure, chest pain, heart attack, abnormal heart rhythms, and heart failure. People who have had a heart attack, heart failure, or changes in heart rhythm (Arrhythmias) should discuss with their doctor how Unitron Peg (Peginterferon-alfa-2b) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Unitron Peg (Peginterferon-alfa-2b), and whether any special monitoring is needed. People who have had severe, unstable, or uncontrolled heart disease within the past 6 months should not use Unitron Peg (Peginterferon-alfa-2b).

Kidney Disease: People with kidney disease should have their kidney function assessed regularly while taking Unitron Peg (Peginterferon-alfa-2b). For people with reduced kidney function, their doctor may prescribe a lower dose. People who have severely reduced kidney function should not take Unitron Peg (Peginterferon-alfa-2b).

Liver function: People who are taking Unitron Peg (Peginterferon-alfa-2b) will need frequent checkups to test their liver function. People with severely reduced liver function should not take Unitron Peg (Peginterferon-alfa-2b).

Lung disorders: Certain lung disorders may occur in people using Unitron Peg (Peginterferon-alfa-2b). If you experience fever, cough, or shortness of breath, contact your doctor. People who have chronic obstructive pulmonary disease- COPD (Chronic Obstructive Pulmonary Disease) (e.g., emphysema, chronic Bronchitis) should not take Unitron Peg (Peginterferon-alfa-2b).

Pancreatitis: Unitron Peg (Peginterferon-alfa-2b) may cause pancreatitis, which may be fatal. If you develop symptoms of pancreatitis (e.g., severe abdominal with or without vomiting), get immediate medical attention.

Thyroid disorders: Unitron Peg (Peginterferon-alfa-2b) can cause or worsen Hypothyroidism (low thyroid) or Hyperthyroidism (high thyroid). People with thyroid conditions should discuss with their doctor how Unitron Peg (Peginterferon-alfa-2b) may affect their medical condition, how their medical condition may affect the dosing and effectiveness of Unitron Peg (Peginterferon-alfa-2b), and whether any special monitoring is needed.

Transplants: The safety and effectiveness of using Unitron Peg (Peginterferon-alfa-2b) have not been established for people who have had a liver or other organ transplant.

Triglycerides: Unitron Peg (Peginterferon-alfa-2b) can cause or increase high triglyceride levels in the blood. Your doctor will check your triglyceride levels while you are taking Unitron Peg (Peginterferon-alfa-2b).

Pregnancy: Unitron Peg (Peginterferon-alfa-2b) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Unitron Peg (Peginterferon-alfa-2b), contact your doctor immediately. Women who may become pregnant should use an effective method of birth control while using peginterferon alfa-2b.

Breast-feeding: It is not known if peginterferon alfa-2b passes into breast milk. Breast-feeding must be stopped before starting Unitron Peg (Peginterferon-alfa-2b)..

Children and adolescents: The safety and effectiveness of using Unitron Peg (Peginterferon-alfa-2b) have not been established for children less than 18 years of age.