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Interferon beta-1b (Subcutaneous)

Generic name: interferon beta-1b (in-ter-FEER-on BAY-ta-1b)
Drug class: Interferons

Medically reviewed by Last updated on Sep 2, 2021.

Commonly used brand name(s)

In the U.S.

  • Betaseron
  • Extavia

Available Dosage Forms:

  • Powder for Solution

Therapeutic Class: Immunological Agent

Pharmacologic Class: Interferon, Beta (class)

Uses for interferon beta-1b

Interferon beta-1b injection is used to treat the relapsing-remitting forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease. Interferon beta-1b will not cure MS, but it may slow some disabling effects or decrease the number of relapses of the disease.

Interferon beta-1b is available only with your doctor's prescription.

Before using interferon beta-1b

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 interferon beta-1b, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to interferon beta-1b 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 interferon beta-1b injection 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 interferon beta-1b injection in the elderly.


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. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

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. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of interferon beta-1b. Make sure you tell your doctor if you have any other medical problems, especially:

  • Blood or bone marrow problems (eg, anemia, low white blood cells) or
  • Congestive heart failure or
  • Depression, or history of or
  • Liver problems or
  • Seizures, or history of or
  • Thyroid problems, history of—Use with caution. May make these conditions worse.
  • Infections—May decrease your body's ability to fight infections.

Proper use of interferon beta-1b

A nurse or other trained health professional may give you interferon beta-1b. You may also be taught how to give your medicine at home. Interferon beta-1b is given as a shot under your skin.

If you are injecting interferon beta-1b yourself, use it exactly as directed by your doctor in order to help your condition as much as possible. Do not use more or less of it, and do not use it more often than your doctor ordered. Do not change your dose or dosing schedule without checking first with your doctor. The exact amount of medicine you need has been carefully worked out. Using too much will increase the risk of side effects, while using too little may not improve your condition.

Using interferon beta-1b at bedtime may help lessen the flu-like symptoms. Your doctor may want you to take medicines to prevent flu-like symptoms.

Interferon beta-1b comes with a Medication Guide and patient directions. Read and follow the instructions carefully. Ask your doctor if you have any questions.

It is important to follow several steps to prepare your interferon beta-1b injection correctly. Before injecting the medicine, you need to:

  • Collect the items you will need before you begin.
  • Wash your hands thoroughly with soap and water. Do not touch your hair or skin afterwards.
  • Make sure the needle guards are on the needles tightly.
  • Remove the plastic cap from the interferon beta-1b and the diluent vial. Use an alcohol wipe to clean the tops of the vials. Move the alcohol wipe in one direction and use one wipe per vial. Leave the alcohol wipe on top of each vial until you are ready to use it.

In order to keep everything sterile, it is important that you do not touch the tops of the vials or the needles. If you do touch a stopper, clean it with a fresh alcohol wipe. If you touch a needle, or if the needle touches any surface, throw away the entire syringe and start over with a new syringe. Also, use only the diluent (sodium chloride 0.54%) provided with the interferon beta-1b to dilute the medicine for injection.

To mix the contents of one vial:

  • Resting your hands on a stable surface, remove the needle cover on the 3-mL syringe by pulling the cover straight off the needle. Do not touch the needle itself.
  • Pull back the plunger of the syringe back to the 1.2-mL mark.
  • Holding the vial of diluent for interferon beta-1b on a stable surface, slowly insert the needle straight through the stopper into the top of the vial.
  • Push in the plunger all the way to gently inject 1.2 mL of air into the vial. Leave the needle in the vial of diluent.
  • Turn the vial upside down using one hand and make sure the tip of the needle is covered by solution. With your other hand, slowly pull back the plunger of the syringe to withdraw 1.2 mL of diluent into the syringe. Do not shake.
  • Keeping the vial upside down, gently tap the syringe until any air bubbles that formed rise to the top of the barrel of the syringe.
  • Carefully push in the plunger to eject only the air through the needle. Remove the needle/syringe from the vial of diluent.
  • Holding the interferon beta-1b vial on a stable surface, slowly insert the needle of the syringe (containing 1.2 mL of diluent) all the way through the stopper of the vial.
  • Push the plunger down slowly, directing the needle toward the side of the vial to allow the diluent to run down the inside wall. Injecting the diluent directly onto the white cake of medicine will cause excess foaming.
  • Remove the needle/syringe from the vial of interferon beta-1b.
  • Roll the vial between your hands gently to completely dissolve the white cake of medicine.
  • Check the solution to make sure it is clear. If you can see anything solid in the solution or if the solution is discolored, discard it and start again.

To prepare the injection syringe:

  • Remove the needle guard from the 1-mL syringe and pull back the plunger to the 1-mL mark.
  • Insert the needle of the 1-mL syringe through the stopper of the vial of interferon beta-1b solution.
  • Gently push the plunger all the way down to inject air into the vial.
  • Turn the vial of interferon beta-1b solution upside down, keeping the needle tip in the liquid.
  • Pull back the plunger of the syringe to withdraw 1 mL of liquid into the syringe.
  • Hold the syringe with the needle pointing upward. Tap the syringe gently until any air bubbles that formed rise to the top of the barrel of the syringe.
  • Carefully push in the plunger to eject only the air through the needle.
  • Remove the needle/syringe from the vial. Replace the needle guard on the syringe.
  • Throw away the unused portion of the solution remaining in the vial.

The injection should be administered immediately after mixing. If the injection is delayed, refrigerate the mixed solution and inject it within 3 hours. Do not freeze.

To give yourself the injection:

  • Before you self-inject the interferon beta-1b dose, decide where you will inject yourself. There are 8 areas for injection, and each area has an upper, a middle, and a lower injection site. To help prevent injection site reactions, select a site in an area different from the area where you last injected yourself. You should not choose the same area for two injections in a row. Keeping a record of your injections will help make sure you rotate areas.
  • Do not self-inject into any area in which you feel lumps, bumps, firm knots, or pain. Do not use any area in which the skin is discolored, depressed, red, scabbed, tender, or has broken open. Talk to your doctor or other health care professional about these or any other unusual conditions that you find. If you experience a break in the skin or drainage of fluid from the injection site, contact your doctor before continuing injections with interferon beta-1b.
  • Clean the injection site with a fresh alcohol wipe, and let it air dry.
  • Pick up the 1-mL syringe you already filled with interferon beta-1b. Hold the syringe as you would a pencil or dart. Remove the needle guard from the needle, but do not touch the needle itself.
  • Gently pinch the skin together around the site, to lift it up a bit.
  • Resting your wrist on the skin near the site, stick the needle straight into the skin at a 90° angle with a quick, firm motion.
  • Using a slow steady push, inject the medicine by pushing the plunger all the way in until the syringe is empty.
  • Hold a swab on the injection site. Remove the needle by pulling straight out.
  • Gently massage the injection site with a dry cotton ball or gauze.
  • Needles, syringes, and vials should be used for only one injection. Place all used syringes, needles, and vials in a syringe disposal unit or in a hard-walled plastic container, such as a liquid laundry detergent container. Keep the cover closed tightly, and keep the container out of the reach of children. When the container is full, check with your physician or nurse about proper disposal, as laws vary from state to state.


The dose of interferon beta-1b 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 interferon beta-1b. 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 multiple sclerosis (MS):
      • Adults—At first, 0.0625 milligram (mg) (0.25 mL) injected under your skin every other day. Over 6 weeks, your doctor may gradually increase your dose to 0.25 mg (1 mL) every other day.
      • Children—Use and dose must be determined by your doctor.

Missed dose

If you miss a dose of interferon beta-1b, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

The next injection should be scheduled about 48 hours later.


Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Store in the refrigerator. Do not freeze.

If refrigeration is not available, vials may be kept for up to 3 months at room temperature, as long as the temperature does not go above 86 °F.

Precautions while using interferon beta-1b

It is very important that your doctor check your progress at regular visits to make sure that interferon beta-1b is working properly. Blood tests may be needed to check for unwanted effects.

Check with your doctor right away if you have dark urine, persistent loss of appetite, flu-like symptoms, headache, continuing vomiting, general feeling of tiredness or weakness, light-colored stools, right upper stomach pain or tenderness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Interferon beta-1b may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using interferon beta-1b.

Interferon beta-1b may cause some people to be anxious, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these side effects, tell your doctor right away.

Interferon beta-1b may cause redness, pain, or swelling at the injection site. Some patients have developed skin infections or a permanent depression (necrosis) under the skin at the injection site. Contact your doctor right away if you notice any of these side effects at the injection site: depressed or indented skin, blue-green to black skin discoloration, or pain, redness, or sloughing (peeling) of the skin.

Check with your doctor if you notice any signs of fever, chills, or sore throat. These could be symptoms of an infection resulting from low white blood cell counts.

Thrombotic microangiopathy, including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome may occur while you are using interferon beta-1b. Tell your doctor right away if you have black, tarry stools, blood in the urine, difficulty with speaking, fever, pinpoint red spots on the skin, seizures, stomach pain, unusual bleeding or bruising, or yellow eyes or skin.

Check with your doctor right away if you have a rash, bloody or cloudy urine, drowsiness, headache, paleness or cold feeling in fingertips and toes, tingling or pain in fingers or toes when exposed to cold, swelling of the face, feet, or lower legs, trouble breathing, or unusual weight gain. These may be symptoms of a drug-induced lupus erythematosus.

Interferon beta-1b is made from donated human blood. Some human blood products have transmitted certain viruses to people who have received them, although the risk is low. Human donors and donated blood are both tested for viruses to keep the transmission risk low. Talk with your doctor about this risk if you are concerned.

The removable rubber cap of the prefilled syringe contains natural rubber latex, which may cause allergic reactions in people who are sensitive to latex. Tell your doctor if you have a latex allergy before you start using interferon beta-1b.

Interferon beta-1b 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
  • break in the skin at the injection site, with blue-black discoloration, swelling, or drainage of fluid
  • flu-like symptoms including chills, fever, generalized feeling of discomfort or illness, increased sweating, and muscle pain
  • headache or migraine
  • hives, itching, or swelling at the injection site
  • irregular or pounding heartbeat
  • redness, pain, or feeling of heat at the injection site
  • stuffy nose

Less common

  • Bloody or cloudy urine
  • breast pain
  • changes in vision
  • cold hands and feet
  • difficult, burning, or painful urination
  • fast or racing heartbeat
  • frequent urge to urinate
  • pain
  • pelvic pain
  • swollen glands
  • troubled breathing
  • unusual weight gain


  • Abnormal growth in the breast
  • benign lumps in the breast
  • bleeding problems
  • bloating or swelling
  • changes in menstrual periods
  • confusion
  • convulsions (seizures)
  • cyst (abnormal growth filled with fluid or semisolid material)
  • decreased sexual ability in males
  • dry, puffy skin
  • feeling cold
  • hyperactivity
  • increased muscle tone
  • increased urge to urinate
  • loss of memory
  • mental depression with thoughts of suicide
  • problems with speaking
  • red, itching, or swollen eyes
  • swelling of the front part of the neck
  • unusual 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

  • Constipation
  • diarrhea
  • dizziness
  • loss of voice
  • menstrual pain or other changes
  • unusual tiredness or weakness

Less common

  • Anxiety
  • drowsiness
  • hair loss
  • vomiting

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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.