What is interferon beta-1a (Rebif), and how does it work (mechanism of action)?

Interferon beta-1a (Rebif) is a protein produced by recombinant DNA technology using genetically engineered Chinese Hamster Ovary Cells into which the human interferon beta genes have been introduced. It is used for treating multiple sclerosis (MS). Interferon beta-1a is designed to be identical to interferon beta that is naturally produced by various cells in the body. Interferon beta has antiviral properties and plays a role in regulating the immune response. The exact mechanism by which interferon beta-1a works in the body to treat MS is not known. Interferon beta-1a does not cure MS. Rather, it helps to decrease the number of flare-ups and slows the occurrence of some of the physical disability that commonly occurs in the disease. Rebif was first approved by the FDA in 1996.

What brand names are available for interferon beta-1a (Rebif)?


Is interferon beta-1a (Rebif) available as a generic drug?


Do I need a prescription for interferon beta-1a (Rebif)?


What are the side effects of interferon beta-1a (Rebif)?

The most common side effects of interferon beta-1a are:

Flu-like symptoms are commonly experienced when patients first start taking interferon beta-1a. These symptoms can be managed with over-the-counter pain and fever reducers, and usually decrease or go away over time.

Stomach pain, an increase in liver enzymes, and blood disorders including a drop in the number of red blood cells, white blood cells, and platelets also may occur.

Interferon beta-1a may also cause other serious side effects including seizures, suicidal thoughts or actions, liver disease, and serious allergic and skin reactions.


Multiple Sclerosis (MS) Symptoms and Treatment See Slideshow

What is the dosage for interferon beta-1a (Rebif)?

The recommended dose of Rebif is either 22 mcg or 44 mcg injected subcutaneously three times per week. It should be administered around the same time each week on the same three days of the week at least 48 hours apart.

The best sites to inject are the areas of the body that usually have more fatty tissue like the thigh, the outer surface of the upper arm, stomach, or buttocks. Avoid injecting around the waistlines or within 2 inches of the navel. To prevent injury, patients who are very thin should only inject the thigh or the outer surface of the arm.

Which drugs or supplements interact with interferon beta-1a (Rebif)?

Combining interferon beta-1a with zidovudine (Retrovir) or hydroxyurea (Hydrea) may increase the risk of bone marrow suppression.

Is interferon beta-1a (Rebif) safe to take if I'm pregnant or breastfeeding?

Use of interferon beta-1a has not been adequately evaluated in pregnant women. Due to the lack of conclusive safety data, interferon beta-1a should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Interferon beta-1a is classified as FDA pregnancy risk category C (animal studies show an adverse effect on the fetus).

It is not known if interferon beta-1a is excreted in breast milk. As many drugs enter breast milk and can potentially cause harm to the nursing infant, interferon beta-1a should be used cautiously in nursing mothers. 

What else should I know about interferon beta-1a (Rebif)?

What preparations of interferon beta-1a (Rebif) are available?

Injection: 8.8 mcg/0.2 ml, 22 mcg/0.5 ml, and 44 mcg/0.5 ml in single-dose prefilled syringe or single-dose autoinjector.

How should I keep interferon beta-1a (Rebif) stored?

Preferably interferon beta-1a should be stored refrigerated between 2 C to 8 C (36 F to 46 F). If needed, interferon beta-1a can be stored between 2 C to 25 C (36 F to 77 F) for up to 30 days.


What kind of disease is multiple sclerosis? See Answer


Interferon beta-1a (Rebif) is a synthetic protein the is typically made naturally in the body and is used to treat relapsing multiple sclerosis in adults. Side effects, drug interactions, and pregnancy safety should be reviewed prior to taking this medication.

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Medically Reviewed on 8/5/2019
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