Multiple sclerosis image Approximately 300,000 Americans live with multiple sclerosis (MS). MS is a chronic, disabling disease that affects the central nervous system and causes loss of muscle control. The disease causes inflammation, destruction, and scarring of the sheath that covers nerve fibers (called myelin) in the brain and spinal cord. As a result, electrical signals from the brain are slowed or blocked from reaching the eyes, muscles, and other parts of the body.

Currently there are few treatment options for MS. In the way of medications there are four agents that focus on preventing relapse: interferon beta 1a, interferon beta 1b, mitoxantrone, and glatiramer. All are relatively new drugs that are still undergoing post-market testing for dose and comparative effectiveness. This article will focus specifically on Rebif, which is an interferon beta-1a drug that was approved by the U.S. Food and Drug Administration (FDA) in March 2002. Of the “disease modifying” drugs currently available for MS, Rebif is the most expensive with an estimated wholesale cost of over $22,000 yearly. While the National Multiple Sclerosis Society has urged that all medical plans cover this and similar medications, many still do not. The manufacturers of most of the disease modifying drugs have a plan that allows some persons without adequate insurance coverage to receive medication at reduced cost.

The Evidence

The FDA approved Rebif for use against relapsing forms of MS. People with this type of MS experience clearly defined disease relapses, with full recovery or residual deficit upon recovery. The positive results from two major studies of people with relapsing MS prompted the FDA to approve this drug.

Compared to the placebo group, the group of study volunteers taking Rebif had the following:

  • Lower rate of relapse
  • Longer time until first relapse
  • Higher proportion of relapse-free patients
  • Lower number of active lesions, as seen on MRI
  • Delay in progression of disability

A second study compared Rebif with the current drug, Avonex. This 6-month trial involved 677 people with relapsing-remitting MS. Again, the people taking Rebif experienced fewer relapses and less accumulation of lesions in their brains.

Use of Rebif

Rebif is available in two forms: pre-filled syringes for subcutaneous injection, and sterile powder to be mixed with a diluting agent. Your doctor will determine the best dosing schedule for you. Typically, though, Rebif is taken three times per week. Injections are delivered subcutaneously—between the fat layer just under the skin and the muscles beneath. Injections should be given at least 48 hours apart.

Precautions

You should not use Rebif if you are pregnant, breastfeeding, or trying to become pregnant. This drug can also affect liver function. You may need to have regular blood tests to monitor liver function.

Some people have experienced allergic reactions when using Rebif. A reaction can occur after the first dose, but not always; it may also occur after you've taken Rebif several times. Be aware of signs of an allergic reaction.

Signs of a severe reaction (requiring urgent medical attention) include:

  • Difficulty breathing
  • Loss of consciousness

Signs of a less severe reaction include:

  • Itching
  • Flushing
  • Skin bumps

If you think you are having a reaction, stop taking the medication immediately and call your doctor.

Much more common side effects include the following:

  • Flu-like symptoms: fatigue, chills, fever, muscle aches, sweating
  • Injection site reactions: swelling, redness, discoloration, pain
  • Depression

Most of these symptoms disappear over time as your body adjusts to this medicine. Depression can occasionally become severe and may need treatment. Be sure to tell your doctor if you are experiencing mood changes after beginning Rebif.