Peginterferon Alfa-2a (Subcutaneous)

Peginterferon alfa-2a is a medication that is injected into the patient. This medicine is often used as a solo, or primary drug, but can also be used with other medicines for treatment purposes. This medication is used for patients who are struggling with hepatitis B or C.


Peginterferon alfa-2a injection can be used alone with medication like ribavirin (Copegus, Rebetol), boceprevir (Victrelis), and telaprevir (Incivek). Its use both alone and with these medications in addition is to treat patient who are suffering chronic hepatitis infection, either hepatitis B or C.

Peginterferon alfa-2a is a man-made medication solution, which can supplement and replace a substance that is usually found within the human body. This synthetic solution can help the patient's immune system to fight off the hepatitis infection more effectively.

This medication is solely available by prescription from a relevant doctor or medical professional.

Conditions Treated

Type Of Medicine

  • Solution (for injection)

Side Effects

There are several required effects of Peginterferon alfa-2a, that allows this medication to work with a patient's immune system to achieve the best possible results when it comes to fighting both hepatitis B and C. As well as these needed and required effects of Peginterferon alfa-2a, using this medicine can also lead to unexpected, unwanted or unneeded side effects when it is used. It is unlikely that any patient experiences every side effect listed or recorded.

However, should you find yourself experiencing any of the effects that are, even if it is just a single one, it's important that you talk to your doctor as soon as you can.

Should any of the below listed side effects occur during the time or following the time you have taken Peginterferon alfa-2a , it's important that you inform a relevant medical professional or doctor as soon as possible, who can provide you with help and assistance:

  • Black, tarry stools
  • Bone pain
  • Chest pain or discomfort
  • Chills
  • Confusion
  • Constipation
  • Cough
  • Depressed mood
  • Discouragement
  • Dizziness
  • Dry skin and hair
  • Fainting
  • Fast heartbeat
  • Feeling cold
  • Feeling sad or empty
  • Fever
  • Hair loss
  • Headache
  • Heart murmur
  • Hives
  • Hoarseness or husky voice
  • Irritability
  • Lack of appetite
  • Lightheadedness
  • Loss of interest or pleasure
  • Lower back or side pain
  • Muscle cramps and stiffness
  • Painful or difficult urination
  • Pale skin
  • Pale skin
  • Rapid, shallow breathing
  • Shortness of breath
  • Slowed heartbeat
  • Sneezing
  • Sore throat
  • Stomach pain
  • Tightness in the chest
  • Tiredness
  • Trouble sleeping
  • Trouble with concentrating
  • Troubled breathing with exertion
  • Ulcers, sores, or white spots in the mouth
  • Unusual bleeding or bruising
  • Unusual tiredness or weakness
  • Weight gain

In addition to the side effects that may be caused by Peginterferon alfa-2a that are listed above, this medication may also cause other, more minor side effects during your treatment with this medicine. Often, these side effects will fade or reduce over time as your body becomes more used to this medication being within your body. If you require additional support for any of the below side effects, your doctor should be able to support you in reducing or altering any side effects that are problematic or continue to worsen over time.

Check with a medical professional as soon as you can if any of the below listed side effects continue for longer than expected, are troublesome or if you have any questions about them:

  • Acid or sour stomach
  • Back pain
  • Belching
  • Blistering, crusting, irritation, itching, or reddening of the skin
  • Blurred vision
  • Change of hearing
  • Cracked, dry, scaly skin
  • Diarrhea
  • Dry mouth
  • Fear
  • Feeling unusually cold, shivering
  • Hair loss or thinning of the hair
  • Heartburn
  • Indigestion
  • Loss of hearing
  • Memory problems
  • Muscle or joint pain
  • Nervousness
  • Numbness
  • Pain
  • Rash
  • Redness
  • Scarring
  • Soreness
  • Stinging
  • Stomach discomfort or upset
  • Stomach pain
  • Swelling
  • Tenderness
  • Tingling
  • Ulceration
  • Vomiting
  • Warmth

As well as the above listed side effects of Peginterferon alfa-2a, you may also experience other effects that are not included. These may be due to your combination of medication, or any other variability of factors. If you experience other side effects, consult with your doctor on the cause and they will be able to advise you of what to do next, and potentially how to avoid these effects

The primary person you should inform regarding any side effects should be your doctor or a relevant trained medical professional, who will be best placed to help you with any issues or conditions you may be experiencing. In addition, you can report your side effects directly to the FDA on the number 1-800-FDA-1088.


The correct dosage of Peginterferon alfa-2a will vary depending on each individual patient. The listed information hear provides the average dosage for this medication and should not be taken as a guideline. It is important that when taking this medicine, you follow your orders of prescription, and the directions on your prescription itself. Should your dose be different, do not alter it to match the below.

The amount of Peginterferon alfa-2a you take depends upon the strength of the medicine itself that is prescribed. It will also vary depending on the number or doses you take each day, the time that there is between each dose, and the amount of time that you are prescribed Peginterferon alfa-2a as a treatment.

For injection dosage form:

For hepatitis B and hepatitis C:

Adult dosage is based on the body weight of the patient and must be determined by your doctor. An average dose for Peginterferon alfa-2a is 180 micrograms (mcg) injected under the skin every week for 48 weeks. The medicine should be taken on the same day every week and at around the same time.

For children, the dosage of this medication should be decided by a medical professional.

For hepatitis C infection, in combination with ribavirin:

Adult dosage is based on body weight and should be determined by a doctor. The average dose of this medication is 180 micrograms (mcg) injected under the skin once a week (same time and day every week), alongside oral ribavirin twice daily for between 24 to 48 weeks. The length of time you take this treatment will be determined by your doctor.

For children and adolescents that are five years of age or older, their dosage must be determined by a trained medical professional. The dosage given is usually determined by the body size and weight of the child, and the average amount given is 180 mcg injected under the skin once every week (same time/day each week) alongside oral ribavirin, which is taken twice daily for 24 to 48 weeks. The time your child is prescribed this treatment is decided by your doctor.

If you miss a dose or forget to take your medication and you are between 1 to 2 days late, take your prescribed dose as soon as you can. If it has been longer than 2 days since you were prescribed to use Peginterferon alfa-2a, call your doctor for instructions.


Although certain medications can generally not be used at the same time, in some cases two potentially conflicting medicines can be taken together even if it is likely that an interaction will occur, as this may be preferable to not taking them. When this happens, your doctor may decide to alter the dose, or take any other precautions necessary. When you're prescribed Peginterferon alfa-2a, it is especially important that your doctor is aware if you are prescribed or have taken any of the drugs listed below. The following potential interactions are selected based on their potential significance, and are not all-inclusive.

Taking Peginterferon alfa-2a with any of the following medications is not usually recommended. A medical professional should take the decision whether or not to treat you with this medication, or to change some of the other medications you are prescribed.

  • Telbivudine

Taking Peginterferon alfa-2a with the following drugs is usually not the best course of action but may be necessary in certain cases despite the chance of interaction. If both types of medicine are prescribed at the same time, a doctor may choose to alter the dose or how regularly you take one or both of the drugs.

  • Theophylline

Using Peginterferon alfa-2a alongside any of the below medicines will likely cause an increased potential of effects but taking both of the medicines together may be the right form of treatment for you. If both medicines are prescribed to be taken at the same time, a doctor may decide to change either dose or how frequently you use one or each of the drugs.

  • Methadone

Certain medicines cannot be taken at or with any food, or even when eating specific types or groups of food as interactions can happen. Using tobacco or alcohol with medicines that interact can also cause effects to occur. There are no known direct interactions with Peginterferon alfa-2a as a result of alcohol, food or tobacco. However, it is important to discuss this with your healthcare professional.

As well as drug and other forms of interaction, taking Peginterferon alfa-2a when suffering from certain illnesses or conditions may result in interactions or problems occurring during your time taking this medication. Inform your doctor if you have, or have had, any of the following:


In deciding to use Peginterferon alfa-2a, the risks of taking this medicine should be weighed against the good it will do for treating your medical condition. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Inform your doctor if you have had any allergic reaction or unusual physical response to this type of medicine or any other medicines. You should also inform a doctor if you have any other types of allergies, including those to dyes, foods, preservatives, or animals. For non-prescription products or over the counter medicines, read the label and ingredients in your medicine carefully before taking any medication.

For children under five years old, appropriate studies have not been performed on the relationship of age to the effects of this medication. As such, prescribing this medication to children below this age may hold more risk.

Appropriate studies performed using Peginterferon alfa-2a have not shown any geriatric-specific problems that could limit the usefulness of this medication in the elderly. However, elderly patients are more likely to suffer from age-related kidney problems, which may require care and adjustment in the dose for patients receiving peginterferon alfa-2a.

Peginterferon alfa-2a is FDA pregnancy category C, which suggests that there are no adequate studies of this medication to determine if it can cause harm to unborn babies. Due to this, it's important to weight up the risks and benefits of taking Peginterferon alfa-2a. The same is true for breastfeeding during the time you are taking Peginterferon alfa-2a.

A nurse or trained medical professional is likely to give you this medication in a controlled medical environment. Peginterferon alfa-2a is generally given as a shot under the skin, generally in the stomach or the thighs. If you do not wish to take your medication in this environment, you can be shown how to properly take this medication from home by a trained professional. Only use this medication as prescribed by your doctor.

Every container of Peginterferon alfa-2a medication contains a comprehensive Medication Guide. Be sure to read the instructions through, and ensure you understand the below listed:

  • How to prepare your injection.
  • Proper use of disposable syringes.
  • Giving the injection.
  • How long each injection is stable.

Peginterferon alfa-2a comes in three forms of dosage - a vial, a prefilled and prepared syringe, or a disposable auto injector. It is possible to switch between dosage types, but should you do so it if important this ensure you are still taking the right amount of medicine.

Use each form of dosage, whether it's a syringe, vial or auto injector, only a single time. Do not use unused medicine at a later date, and do not save any medication that you have not taken. If the medicine in the syringe or vial has changed in color, or if you see any particles in the solution do not use it.

It's important to drink more fluids when you are taking Peginterferon alfa-2a. This will ensure you are kept hydrated, especially in the early phase of your treatment - which may result in loss of hydration.

It is critical that that your doctor is able check your progress at regular intervals to make sure that this medicine is working properly. Blood tests may be required to check for unwanted effects.

Using this medicine in combination with ribavirin during pregnancy can harm your unborn baby. These medicines together can also result in birth defects if the father of the child is using it if his sexual partner becomes pregnant during this time. If a pregnancy occurs while you are using these medicines, tell your doctor right away.

A negative pregnancy test is required for women who are of childbearing age prior to starting treatment with this medicine and ribavirin together. Effective birth control must be used by both male and female patients during the course of treatment and for 6 months following the last dose. Female patients will need to take pregnancy tests every month during treatment and for 6 months after the last dose, to ensure they are not pregnant

You should not use Peginterferon alfa-2a together with ribavirin medicine if you are also taking didanosine (Videx, Videx EC). Using these medicines together can result in serious problems.

Peginterferon alfa-2a can cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to feel that they have suicidal thoughts and tendencies to become more depressive. If you, your child, or your caregiver notice any of these effects, it is important to tell your doctor right away.

Certain serious skin reactions can occur when you are using this medicine. Check with your doctor right away if you experience blistering, a severe skin rash or acne, fever or chills, hives or welts, peeling, or loosening of the skin, red skin lesions, or sores or ulcers on the skin when you are using this medicine.

Peginterferon alfa-2a treats the condition associated with hepatitis B or C. However, this medicine will not stop you from giving hepatitis B or hepatitis C to other people. Ensure that you are taking the correct precautions when taking this medication to avoid infecting others.

Taking Peginterferon alfa-2a combined with ribavirin can cause a temporary reduction in the number of white blood cells in your blood, which can then increase the chance of you getting an infection. It can also lower the number of platelets in the blood too, which are required for proper blood clotting. If this occurs, there are certain precautions you can follow, especially when your blood count is low, to reduce the risk of contracting an infection or bleeding:

  • Avoid anyone who has signs of infection. Check with a doctor as soon as possible if you feel that you are getting an infection or if you suffer from a sudden fever, chills, lower back or side pain, a cough or hoarseness, or painful/difficult urination.
  • Check with a doctor straight away should you notice any bleeding or bruising that is unusual. This can also include blood in the urine or stools, black, tarry stools, or even pinpoint red spots on the skin.
  • Be very careful when you use a toothbrush, floss, or toothpick, that can potentially cause wounds or infections. Your doctor may be able to tell you other, less risky ways to care for your teeth during this time.
  • Never the inside of your nose or your eyes unless you have just washed your hands and have not touched anything else in the meantime.
  • Be careful to not cut yourself when you are using any sharp tools such as a safety razor or fingernail/toenail cutters.
  • Try to avoid contact sports of any kind, or other situations where bruising or injury are likely occur.

Check with your doctor right away if you or your child experience any of the following symptoms, as they could be indicative of a condition called hemolytic anemia:

  • Yellowing of the eyes or skin
  • Unusual tiredness or weakness
  • Sore throat
  • Pale skin
  • Nosebleeds
  • Nausea or vomiting
  • Loss of appetite
  • Headache
  • General body swelling
  • Fever
  • Difficulty breathing
  • Dark urine
  • Chills
  • Bleeding gums
  • Back, leg, or stomach pains

If you experience sudden and lightheadedness, chills, nausea, vomiting, constipation, fever, or severe stomach pain, speak to your doctor immediately. These can be symptoms of pancreatitis.

Peginterferon alfa-2a when used with ribavirin can directly impact the growth of children. A doctor is likely to require frequent appointments in order to confirm your child's growth in weight and height during and following using with these medicines.

Peginterferon alfa-2a causes some people to become dizzy, feel drowsy or be less present than they generally feel. Before you drive, use machines, ensure you are aware of how this medication makes you feel.

Do not take different medicines in addition to Peginterferon alfa-2a if they have not been discussed with, or prescribed by, your doctor. This includes but is not limited to any and all prescription or over-the-counter medications as well as vitamin supplements or herbal medicines.x


Keep Peginterferon alfa-2a out of the reach of children as all times.

Never keep any outdated medicine or other drugs when they are no longer needed.

Ask your doctor the proper way to dispose of any medicine you do not use.

Store Peginterferon alfa-2a in the refrigerator prior to use. Never freeze this medication.

Never leave Peginterferon alfa-2a out of the refrigerator for a period longer than 24 hours. Protect this medicine from light at all times.


Peginterferon alfa-2a injection is a form of medication that is used for the treatment of both hepatitis B and C. This medication can be used alone, but is often used with medication like ribavirin (Copegus, Rebetol), boceprevir (Victrelis), and telaprevir (Incivek) to provide an effective form of treatment.

Peginterferon alfa-2a is a man-made solution, created specifically to replace a substance that is usually found within the human body that can be ineffective or reduced due to hepatitis. This synthetic solution helps the patient's immune system to fight off infection more effectively, as their body is unable to.

This medication is only available via prescription from a relevant doctor or medical professional.