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PEG-Intron (Subcutaneous)

Generic Name: peginterferon alfa-2b (Subcutaneous route)

peg-in-ter-FEER-on AL-fa-2b

Subcutaneous route(Powder for Solution)

PegIntron(R) may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Monitor closely and withdraw therapy with persistently severe or worsening signs or symptoms of these conditions. Use with ribavirin: Ribavirin may cause birth defects and fetal death, and extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Ribavirin causes hemolytic anemia, which may result in a worsening of cardiac disease .

Subcutaneous route(Powder for Solution)

Sylatron(TM): The risk of serious depression, with suicidal ideation and completed suicides, and other serious neuropsychiatric disorders are increased with alpha interferons, including peginterferon alfa-2b. Permanently discontinue peginterferon alfa-2b in patients with persistently severe or worsening signs or symptoms of depression, psychosis, or encephalopathy. These disorders may not resolve after stopping peginterferon alfa-2b .

Commonly used brand name(s)

In the U.S.

  • PEG-Intron
  • Peg Intron RP
  • Sylatron

Available Dosage Forms:

  • Powder for Solution
  • Kit

Therapeutic Class: Antineoplastic Agent

Pharmacologic Class: Interferon, Alfa (class)

Uses For PEG-Intron

Peginterferon alfa-2b injection is a synthetic (man-made) version of substances normally produced in the body to fight infection. Peginterferon alfa-2b injection is used alone or together with ribavirin and another drug called a hepatitic C virus (HCV) NS3/4A protease inhibitor (such as telaprevir or boceprevir) to treat chronic hepatitis C infection. It is used for patients who have never been treated by alpha interferons. The combination treatment of peginterferon alfa-2b and ribavirin is used to treat adults and children 3 years of age and older who show symptoms of liver damage.

Peginterferon alfa-2b injection is also used to prevent malignant melanoma (a type of skin cancer) from coming back after it has been removed by surgery. This medicine should be started within 84 days of surgery to remove lymph nodes containing cancer.

This medicine is available only with your doctor's prescription.

Before Using PEG-Intron

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of Pegintron® in children younger than 3 years of age. Safety and efficacy have not been established.

Appropriate studies have not been performed on the relationship of age to the effects of Sylatron™ in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of peginterferon alfa-2b injection in the elderly. However, elderly patients are likely to be more sensitive to the effects of this medicine, and are more likely to have age-related kidney problems, which may require caution in patients receiving this medicine.


Pregnancy Category Explanation
All Trimesters C Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

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.

  • Thioridazine

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.

  • Aminophylline
  • Amitriptyline
  • Anagrelide
  • Caffeine Citrate
  • Clomipramine
  • Desipramine
  • Donepezil
  • Doxepin
  • Doxorubicin
  • Eliglustat
  • Flecainide
  • Imipramine
  • Methadone
  • Nortriptyline
  • Perphenazine
  • Pirfenidone
  • Propranolol
  • Rasagiline
  • Ropivacaine
  • Theophylline
  • Tizanidine
  • Tramadol
  • Trimipramine
  • Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Allergic reactions (eg, anaphylaxis, bronchoconstriction, Stevens-Johnson syndrome) or
  • Autoimmune hepatitis (liver inflammation) or
  • Decompensated liver disease—Should not be used in patients with these conditions.
  • Angina (severe chest pain) or
  • Heart attack, history of or
  • Heart or blood vessel disease or
  • Heart rhythm problems (eg, arrhythmia , tachycardia), history of or
  • Hypotension (low blood pressure)—Use with caution. Patients with these conditions should be closely monitored while using this medicine.
  • Bone marrow problems (eg, aplastic anemia) or
  • Brain disease (eg, encephalopathy) or
  • Breathing problems or other lung diseases (eg, chronic obstructive pulmonary disease or COPD, pneumonia, pulmonary infiltrates, sarcoidosis), or history of or
  • Depression or mental illness, history of or
  • Diabetes mellitus (sugar diabetes) or
  • Diabetic retinopathy (eye problem caused by diabetes) or
  • Eye or vision problems (eg, retinopathy, optic neuritis) or
  • Hyperglycemia (high blood sugar level) or
  • Hypertensive retinopathy (eye problem caused by hypertension or high blood pressure) or
  • Hypertriglyceridemia (high triglyceride levels or fats in the blood) or
  • Kidney disease or
  • Liver disease (including cirrhosis), severe or
  • Psoriasis or
  • Psychiatric problems, history of or
  • Rheumatoid arthritis or
  • Systemic lupus erythematosus or
  • Thyroid disease or
  • Type 1 diabetes—Use with caution. May make these conditions worse.
  • Colitis (inflammation of the bowel) or
  • Pancreatitis (inflammation of the pancreas)—Peginterferon alfa-2b should be stopped in patients with these conditions.
  • Heart disease (severe and unstable), or history of or
  • Kidney disease, severe or
  • Sickle cell anemia (red blood cell disorder) or
  • Thalassemia major (genetic blood disorder)—Peginterferon alfa-2b together with ribavirin should not be used in patients with these conditions.
  • Organ transplant (eg, liver)—Use of peginterferon alfa-2b alone or in combination with ribavirin have not been studied in patients with this condition.

Proper Use of peginterferon alfa-2b

This section provides information on the proper use of a number of products that contain peginterferon alfa-2b. It may not be specific to PEG-Intron. Please read with care.

A nurse or other trained health professional may give you or your child this medicine. This medicine is given as a shot under your skin. You may be taught how to give this medicine at home. Make sure you understand all of the instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to.

Each package of peginterferon alfa-2b contains a Medication Guide and a patient instruction sheet. Read this sheet carefully and make sure you understand:

  • How to prepare the injection.
  • How to give the injection.
  • How long the injection is stable.

If you have any questions about any of this, check with your doctor.

Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.

If you are using this medicine at home, your doctor may tell you to inject the medicine at bedtime and to take medicines (eg, acetaminophen, Tylenol®) 30 minutes before the injection. This helps prevent common "flu-like" symptoms such as fever, chills, headaches, muscle or joint pain, or tiredness. Also, drinking extra fluids may help if you experience these unwanted effects.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For injection dosage form:
    • For hepatitis C virus infection:
      • Adults—Dose is based on body weight and must be determined by your doctor. It is usually between 40 and 150 micrograms (mcg) injected under the skin once a week (same time and day each week).
      • Children 3 years of age and older—Dose is based on body weight and must be determined by your doctor.
      • Children younger than 3 years of age—Use and dose must be determined by your doctor.
    • For hepatitis C virus infection, in combination with ribavirin:
      • Adults—Dose is based on body weight and must be determined by your doctor. It is usually between 50 and 150 micrograms (mcg) injected under the skin once a week (same time and day each week) and should be taken together with ribavirin capsules or solution twice daily.
      • Children 3 years of age and older—Dose is based on body surface area and must be determined by your doctor. The dose is usually 60 micrograms per square meter (mcg/m[2]) of body surface area injected under the skin once a week (same time and day each week) and should be taken together with ribavirin capsules or solution twice daily.
      • Children younger than 3 years of age—Use and dose must be determined by your doctor.
    • For treatment of melanoma:
      • Adults—Dose is based on body weight and must be determined by your doctor. It is usually 6 micrograms (mcg) per kilogram (kg) of body weight injected under the skin once a week for 8 doses. This should be followed by a dose of 3 mcg/kg of body weight injected under the skin once a week for up to 5 years.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

This medicine needs to be given on a fixed schedule. If you miss a dose or forget to use your medicine, call your doctor or pharmacist for instructions.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Store unopened vials of this medicine at room temperature, away from heat and direct light. Do not freeze. An open vial of medicine must be used right away.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

After mixing the medicine, use it right away. If you are unable to do this, the mixture may be stored in the refrigerator for 24 hours. Throw away any mixed medicine that has not been used within this time. Do not freeze the solution.

Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.

Precautions While Using PEG-Intron

It is very important that your doctor check the progress of you or your child at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Using peginterferon alfa-2b together with ribavirin while you are pregnant can harm your unborn baby. These medicines may also cause birth defects if the father is using it when his sexual partner becomes pregnant. If a pregnancy occurs while you are using these medicines, tell your doctor right away.

A negative pregnancy test is needed in women who are of childbearing age before starting treatment with this medicine and ribavirin. Female patients and female partners of male patients must use 2 forms of birth control during therapy and for 6 months after therapy ends. Female patients must have regular pregnancy tests during combination therapy.

This medicine can increase thoughts of suicide in people with or without a history of a mental illness. This medicine may also cause relapse in people with a history of substance abuse. Tell your doctor right away if you start to feel more depressed or exhibit aggressive behavior. Also tell your doctor right away if you have thoughts of hurting yourself. Report any unusual thoughts or behaviors that trouble you, especially if they are new or get worse quickly. Make sure your caregiver knows if you have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell your doctor if you have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. If you, your child, or your caregiver notice any of these side effects during treatment and up to 6 months after treatment, tell your doctor or your child's doctor right away.

This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have itching, hives, hoarseness, trouble with breathing, trouble with swallowing, or any swelling of the hands, face, or mouth while you or your child are using this medicine.

Serious allergic reactions can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loose skin, fever or chills, hives or welts, red skin lesions, severe acne or skin rash, or sores or ulcers on the skin while you or your child are using this medicine.

Check with your doctor right away if blurred vision, difficulty in reading, eye pain, or any other change in vision occurs during or after treatment. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).

Peginterferon alfa-2b injection combined with ribavirin can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets in the blood, which are necessary for proper blood clotting. If this occurs, there are certain precautions you or your child can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

  • If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
  • Check with your doctor immediately if you notice any unusual bleeding or bruising, black, tarry stools, blood in the urine or stools, or pinpoint red spots on your skin.
  • Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
  • Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
  • Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
  • Avoid contact sports or other situations where bruising or injury could occur.

Check with your doctor right away if you or your child have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Peginterferon alfa-2b injection when used together with ribavirin may cause teeth and gum problems. These medicines may cause dryness of the mouth, and a dry mouth may damage your teeth and gums if you take these medicines for a long time. To help prevent this condition, carefully brush your teeth at least two times a day and have regular visits with your dentist. For temporary relief of mouth dryness, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute.

Check with your doctor right away if you or your child have symptoms that could lead to pancreatitis. This includes sudden and severe stomach pain, chills, constipation, nausea, vomiting, fever, or lightheadedness.

Children who use peginterferon alfa-2b and ribavirin combination may have weight loss and slowed growth. Most children have a growth spurt and gain weight after therapy ends. If you have questions about this, talk to your doctor.

Peripheral neuropathy may occur if you use this medicine together with telbivudine (Tyzeka®). Check with your doctor right away if you or your child are having burning, numbness, tingling, or painful sensations in the arms, hands, legs, or feet.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

PEG-Intron Side Effects

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
  • Abdominal or stomach pain
  • anxiety
  • black, tarry stools
  • blood in the urine or stools
  • bloody diarrhea
  • chills
  • cloudy urine
  • cough or hoarseness
  • depression
  • difficult or labored breathing
  • fever
  • irritability
  • lower back or side pain
  • mood swings
  • nausea
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on the skin
  • tightness in the chest
  • trouble sleeping
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting
Less common
  • Changes in menstrual cycle
  • constipation
  • drowsiness
  • dry hair and skin
  • sensitivity to cold
  • weight gain
  • Aching, pain, or stiffness in the joints
  • aggressive behavior
  • attempt to kill yourself
  • backache
  • chest pain (severe)
  • cool, pale skin
  • decrease in vision
  • diarrhea
  • difficulty with speaking
  • dizziness
  • drug addiction or overdose
  • eye pain
  • fast or irregular heartbeat
  • feeling of constant movement of self or surroundings
  • headache
  • loss of appetite
  • muscle weakness
  • nervousness
  • numbness or loss of feeling in one or both limbs on the same side of the body
  • palpitations
  • paralysis
  • possible decrease in the amount of urine
  • rash, hives, or itching
  • restlessness
  • sensation of spinning
  • sensitivity to heat
  • sensitivity to sunlight
  • sweating (excessive)
  • thick, scaly skin
  • thoughts of killing someone
  • thoughts of killing yourself
  • warm, smooth, or moist skin
  • weight loss

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
  • Aching, fullness, or tension in the sinuses
  • bruising, irritation, or itching at the injection site
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • change in taste
  • difficulty with moving
  • flushing of the skin
  • hair loss
  • indigestion
  • loss of taste
  • muscle pain or stiffness
  • pain in the bones or muscles
  • runny nose
  • sneezing
  • sore throat
  • thinning of the hair
Less common
  • Muscle rigidity or stiffness

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.

See also: Side effects (in more detail)

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