Interferon Beta-1A
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Rebif (Interferon)

What is Rebif (Interferon)?

Rebif (interferon beta-1a) is a subcutaneous medication that is injected by patients with multiple sclerosis that is frequently relapsing. It is most commonly used in those with active secondary progressive disease, relapsing-remitting disease, and clinically isolated syndrome. This medication is not a cure for multiple sclerosis and is prescribed only for managing relapse symptoms of the disease and reducing the frequency of such episodes.

Rebif is not a cure for multiple sclerosis but assists in the reduction of flare-ups and symptoms of the condition, reducing the frequency of hospitalizations, the use of additional medication for patients to manage their symptoms, and also encouraging a decrease in brain lesions and progression of the disease.

How is Rebif Used?

Rebif is a subcutaneous medication to be injected under the patient’s skin approximately three times per week. Patients prescribed Rebif should follow their prescribing physician’s instructions regarding the frequency of injection. Most commonly, patients using Rebif will be instructed to inject the medication with a minimum of 48 hours between doses. A Monday-Wednesday-Friday injection schedule is often recommended for the sake of simplicity. Injecting the medication close to the patient’s bedtime is also recommended to reduce experiencing any unpleasant side effects.

When using this medication, patients may choose to allow the solution to sit outside of the refrigerator for approximately thirty minutes to warm up before use, as using it directly after removing it from refrigeration is often uncomfortable when the medication is injected under the skin. Rebif should not be heated to room temperature before injection by any other means. This medication should not be placed in hot or warm water, and it should not be microwaved.

This medication should not be injected into any areas of the skin that appear sore, red, infected, or scarred. The location of the injection site should also be changed for each dose to lessen the likelihood of skin damage or injury. Rebif should be injected under the skin in any of the following areas of the patient’s body: the buttocks, abdomen, thighs, or backside of their upper arms. Patients using this medication should follow their prescribing physician’s specific instructions regarding the frequency and location of the injections.

Before injecting this medication, patients should first sterilize the injection site with rubbing alcohol to reduce the chances of infection.

Patients using Rebif for the treatment of their condition should ensure that they use the medication regularly, as instructed by their physician, to gain the most benefits from the medication. If you are using this medication as instructed and experience a worsening of your condition, please contact your doctor.

It is normal for patients to experience some redness or irritation at the site of injection. However, this should subside within a few hours. If you have injected Rebif and experience swelling, redness, or pain that worsens in intensity or does not fade away after the time you inject your next dose of medication, contact your doctor.


Rebif should be stored in the refrigerator at temperatures within the range of 36°F (2°C) to 46°F (8°C) and should never be frozen. Rebif may safely reach a high temperature of 77°F (25°C) for a span of thirty days but will need to be disposed of after this time period has ended.

This medication should also be protected from exposure to light.

Keep this medication out of the reach of pets and children at all times.

Patients should not use their medication if it appears to have particles in it or has changed colors. If your solution of Rebif has changed in color or consistency, please contact your pharmacist for additional assistance.

When disposing of a Rebif prefilled syringe or autoinjector, these items should not be thrown into the patient’s household trash. These items should be disposed of in an FDA-approved sharps disposal container, but for patients who are unable to acquire this type of container, a heavy-duty plastic container with a puncture-resistant and tight-fitting lid will suffice. Please label any such homemade sharps disposal container appropriately to warn others of the risks posed by both the used needles as well as the hazards of medical waste from both the used medication and the items having made physical contact beneath the patient’s skin. When your Rebif sharps disposal container has become full, please contact your physician or local pharmacist for proper disposal instructions.


Rebif is prescribed for the following variations of multiple sclerosis:

  • active secondary progressive multiple sclerosis
  • clinically isolated syndrome (CIS)
  • relapsing multiple sclerosis
  • relapsing-remitting multiple sclerosis

How Does Rebif Work?

The active ingredient in Rebif, interferon beta, is an immunomodulator. This type of chemical assists in regulating the immune system. As multiple sclerosis in all of its forms involve the patient’s immune system attacking the body itself, balancing and regulating the immune system of these individuals is the ideal treatment tactic for managing the symptoms of such an autoimmune disorder.

When used for the treatment of various types of multiple sclerosis, this medication functions by inhibiting the overactivity of the cells within the patient’s body that are actively attacking the individual’s nervous system.


Rebif is available in two dosages:

  • 22 mcg
  • 44 mcg

This medication is also available in three different injection options:

  • Rebif Rebidose (interferon beta-1a) autoinjector
  • Rebiject II autoinjector
  • Rebif prefilled syringe

A patient’s prescribed dosage of this medication may vary depending upon the specific condition for which it has been prescribed as well as how well they respond to the use of Rebif for treatment. Some patients may have their doctor initially prescribe lower doses of Rebif at the beginning of treatment with the medication to reduce the likelihood of experiencing adverse side effects, increasing the dose over time as the patient becomes more tolerant.


If you have intentionally or accidentally injected too much Rebif, seek emergency medical attention immediately.

The reported symptoms of a patient who overdosed on this medication include redness of the skin and a rise in body temperature.

Patients with significant mental health concerns, especially a preexisting diagnosis of depression, are at an increased risk of suicidal ideation and suicide attempts when using Rebif. These individuals should disclose any relevant psychological diagnoses to their prescribing physician before beginning treatment with this medication.

Side Effects

It is normal for patients to experience irritation, swelling, or redness at the site of injection when using Rebif. However, there are also additional side effects that have been reported with the use of this medication.

The most common side effects of taking Rebif are as follows:

  • chills
  • fatigue
  • fever
  • flu-like symptoms
  • headache
  • muscle aches
  • stomach pain

Most of the common side effects pass soon after the first few days after an injection has been administered. Patients may use over-the-counter medications to manage these symptoms (e.g., ibuprofen, acetaminophen).

Some of the following side effects may occur and should be discussed with your doctor if they remain persistent or increase in severity while taking Rebif:

  • abdominal pain
  • behavioral changes
  • blue toes or fingers
  • changes in urine output
  • changes in skin color occurring at the injection site
  • dark-colored urine
  • depression that is new or worsening
  • difficulty regulating body temperature
  • easy bruising or bleeding
  • fatigue
  • heart failure symptoms that are new or worsening
  • jaundice (yellowing of the skin or eyes)
  • joint swelling or pain
  • loss of appetite
  • mood changes
  • nausea that doesn’t stop
  • psychological changes
  • psychosis
  • pus at the injection site
  • shortness of breath
  • sudden or unusual weight gain
  • swelling of the ankles or feet
  • symptoms of kidney trouble
  • symptoms of liver trouble
  • suicidal ideation
  • vomiting that doesn’t stop

Please seek immediate emergency medical assistance if you experience seizures while taking this medication. Patients should also seek out emergency medical attention if they experience any symptoms of an allergic reaction while taking Rebif:

  • difficulty breathing
  • dizziness that is severe or may indicate fainting
  • itchiness
  • rash
  • swelling of the throat, tongue, or face

Due to Rebif’s ability to lower a patient’s immune response, individuals taking this medication are at a higher risk of infection during treatment. Please contact your physician if you experience any of the following symptoms of infection while using this medication:

  • chills
  • cough
  • fever
  • persistent sore throat

Warnings & Precautions

Rebif is associated with a number of significant side effects that have been reported from patients using the medication for the treatment of their relapsing form of multiple sclerosis. Please inform your doctor of any preexisting health conditions as well as any family history of applicable conditions before beginning treatment with this medication.

Blood-Related Conditions

Rebif is capable of affecting a patient’s platelet and blood cell counts as well as impacting their bone marrow. This medication may result in low levels of white and red blood cells to the extent that the condition becomes hazardous. Patients taking Rebif for treatment will typically have regular blood tests performed to monitor their platelet and blood cell counts to avoid an increased risk of bleeding issues, bruising, and infections.

Psychological Changes

Rebif has been linked to an increased risk of behavioral and psychological changes in patients using the medication for treatment. Patients taking Rebif that begin to experience new or worsening depression, significant changes in mood and behavior, or suicidal ideation should contact their prescribing physician immediately and seek emergency medical attention if needed. If you are experiencing suicidal thoughts or impulses, please contact the Suicide Prevention Lifeline by dialing 988 or visiting the Suicide Prevention Lifeline website and using their online chat option.

Liver Risks

This medication can result in changes to the liver that may impact its function and worsen preexisting liver conditions. Patients taking Rebif for treatment will have their condition monitored throughout the duration of treatment to manage symptoms of liver impairment. If you are taking Rebif, inform your doctor if you experience any of the following symptoms of liver failure or impairment: confusion, dark-colored urine, easy bleeding or bruising, fatigue, jaundice (yellowing of the eyes or skin), loss of appetite, nausea, or pale-colored stools.

Pregnancy and Breastfeeding

Rebif should not be used by patients who are currently pregnant or breastfeeding. Individuals using this medication for treatment that become pregnant or believe they may be pregnant should consult their physician immediately. If you are currently using Rebif and would like to breastfeed, please consult with your doctor before doing so, as Rebif may be passed through a patient’s breastmilk.

Additional Medical Conditions

If you have any of the following medical conditions, exercise caution when taking Rebif and discuss your medical history with your doctor before beginning this medication:

  • any mental health conditions
  • bleeding issues
  • blood clots (risk or history)
  • depression
  • epilepsy or other seizure-related conditions
  • liver disease
  • low blood cell counts
  • regular alcohol consumption
  • suicidal ideation or behavior
  • thyroid issues

Drug Interactions

Speak to your doctor about any medications or herbal supplements you are currently taking before beginning treatment with Rebif. Discuss any concerns you may have with your doctor or a trusted pharmacist.

The following medications may potentially interact with Rebif and increase your chances of experiencing adverse side effects:

  • baricitinib
  • cladribine
  • clozapine
  • corticosteroids
  • deferiprone
  • fingolimod
  • filgotinib
  • inebilizumab
  • leflunomide
  • natalizumab
  • ozanimod
  • ponesimod
  • sarilumab
  • sodium iodide 131
  • siponimod
  • talimogene laherparepvec
  • theophylline-derived CYP1A2 inhibitors
  • tocilizumab
  • upadacitinib
  • ustekinumab
  • zidovudine

Rebif may also potentially interact with other medications used for chemotherapy or that impact the patient’s immune system. Patients using Rebif should consult with their physician before receiving any live vaccines or other immunizations.

Other Substances That May Interact with Rebif

Patients using Rebif are also advised to limit their consumption of alcohol while using this medication for treatment. Although alcohol does not directly interact with Rebif or affect its efficacy, both alcohol and Rebif negatively impact a person’s liver function. Using both of these in conjunction places the patient at a higher risk of liver damage and worsening of any preexisting liver conditions.

Alternative Medications

For patients who are unable to take Rebif or experiencing significant adverse side effects, alternative medications may be used to treat some of the associated conditions for which this medication is commonly prescribed:

  • cladribine (Mavenclad)
  • fingolimod (Gilenya)
  • glatiramer acetate (Copaxone)
  • interferon beta-1a (Avonex)
  • interferon beta-1b (Betaseron)
  • interferon beta-1b (Extavia)
  • ocrelizumab (Ocrevus)
  • peginterferon beta-1a (Plegridy)
  • siponimod (Mayzent)
  • teriflunomide (Aubagio)

Frequently Asked Questions

If a patient has missed a dose of Rebif, they should contact their prescribing physician for instructions on when and how to safely take their next dose.

Yes. Rebif functions by suppressing a patient’s immune response to regulate nerve cell activity that contributes to the symptoms and damage of multiple sclerosis.

Rebif has been approved for use in the United States since 2002 and has been approved for use in Europe as of 1998. It is currently registered worldwide in over 90 different countries for the treatment of multiple sclerosis.

Rebif has not been reported to cause changes in weight; patients have not reported side effects of weight loss or weight gain from using the medication. However, liver damage can result in weight changes, and Rebif places patients using the medication at an increased risk of experiencing liver-related health concerns. If you are taking Rebif and experience unexplained weight gain or weight loss, you should report these symptoms to your prescribing physician.

The safety and efficacy of Rebif have not been determined in individuals below the age of 18 years. This medication is currently approved and used in adult patients only.

The results of clinical trials have shown that Rebif resulted in an average of 30% fewer relapses of MS symptoms in patients using the medication compared to those who only received a placebo for the duration of the trial.

Rebif should be injected just underneath the patient’s skin. This is most commonly done on the patient’s upper thigh, buttocks, the back of their upper arm, or in the meaty portions of their abdomen.

Patients are advised to limit or avoid alcohol consumption while using Rebif for treatment due to the increased risk of damage and other problems occurring in the individual’s liver.

Rebif works by helping to regulate a patient’s immune system. It functions by inhibiting some of the cell activity that contributes to the autoimmune disorder’s main feature of the body attacking its own nervous system.

Rebif works by helping to regulate a patient’s immune system. It functions by inhibiting some of the cell activity that contributes to the autoimmune disorder’s main feature of the body attacking its own nervous system.

Rebif has not been reported to cause insomnia. However, the medication may cause fatigue or sleepiness in some patients due to the effects it may have on the individual’s liver. Please discuss any changes in your sleep quality or energy level with your prescribing physician.

Some patients will have their doctors start them out on a lower dose of Rebif to more easily adjust to the side effects of the medication. Within five weeks, patients using this medication should be at their primary maintenance dose for the duration of treatment unless otherwise instructed by their prescribing physician.

In clinical trials, Rebif was shown to delay the progression of disability associated with multiple sclerosis by nearly twice as long compared to the individuals in the study who were only provided a placebo medication.

Yes, this medication is considered an immunosuppressant due to its ability to inhibit a patient’s immune system to prevent the symptoms of a flare-up of multiple sclerosis.

Although the specific levels of each of the ingredients will vary depending upon which type of syringe or autoinjector a patient is using, the ingredients in Rebif are as follows: interferon beta-1a, human albumin, sodium acetate, mannitol, and water.

Most patients that have used this medication for treatment have reported that the side effects of Rebif will typically lessen in intensity or completely go away within a few months of using the drug. If you are experiencing significant side effects or have any questions, please consult your prescribing physician for more information on how to manage any adverse effects from using Rebif.

Although rare, there have been reports of patients that have used Rebif developing blood clots within the body, resulting in a significant spike in blood pressure attributed to two different clotting conditions occurring simultaneously: thrombotic thrombocytopenic purpura and hemolytic-uremic syndrome. Any patients experiencing sudden or significant changes in blood pressure while using Rebif or having received treatment with the medication in the past should inform their doctor immediately.