Natalizumab for Multiple Sclerosis

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Natalizumab for Multiple Sclerosis


Generic NameBrand Name

How It Works

Natalizumab stops certain immune system cells from getting into the central nervous system. It blocks the inflammatory response that happens in multiple sclerosis (MS). Natalizumab is given as an injection in a vein (intravenous, or IV).

Why It Is Used

Natalizumab is used to treat people with MS who have relapses followed by periods of recovery (relapsing-remitting MS). This drug is available for treating relapsing forms of MS when other medicines for MS have not worked.

How Well It Works

Natalizumab can decrease relapse rates in people with MS. It can lower the chances that a person with MS will be permanently disabled.1

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

  • Usually the benefits of the medicine are more important than any minor side effects.
  • Side effects may go away after you take the medicine for a while.
  • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Call 911 or other emergency services right away if you have:

  • Trouble breathing.
  • Swelling of your face, lips, tongue, or throat.

Call your doctor right away if you have:

  • Hives.
  • Signs of illness or infection, such as chills, cough, or fever.
  • Chest pain or tightness.
  • A rash on your head, face, or belly.
  • Belly pain or fullness.
  • Lower back or side pain, especially with painful urination.

Common side effects of this medicine include:

  • Stomach pain, nausea, and vomiting.
  • Painful throat.
  • Redness, itching, or swelling at the injection site.
  • Skin problems, such as bleeding, blistering, or crusting.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Drug safety

Warnings about serious side effects of natalizumab have been issued. The U.S. Food and Drug Administration (FDA) and the drug's manufacturers have warned about:

  • An increased risk of a serious infection. Biologics affect the body's ability to fight all infections. So if you get a fever, cold, or the flu while you are taking this medicine, let your doctor know right away.
  • An increased risk of blood or nervous system disorders. Call your doctor if you have symptoms of blood disorders (such as bruising or bleeding) or symptoms of nervous system problems (such as numbness, weakness, tingling, or vision problems).
  • An increased risk of lymphoma (a type of blood cancer) in children and adolescents who take this medicine for longer than 2½ years (30 months). Adults, children, and adolescents who take this medicine also have a higher risk for leukemia and other cancers.
  • An increased risk of liver injuries. Call your doctor if your skin starts to look yellow, if you are very tired, or if you have a fever or dark brown urine.
  • An increased risk of psoriasis.

In very few cases, natalizumab has caused a serious and life-threatening brain infection called PML (progressive multifocal leukoencephalopathy). Natalizumab is tightly controlled because of this. If you take natalizumab, you will be watched closely for signs of any serious side effects.

Your risk for getting PML increases if you have any of these risk factors:

  • You have been taking natalizumab for longer than 2 years.
  • You have taken other immunosuppressant medicines, such as methotrexate or cyclophosphamide.
  • You have ever been infected with the JC virus. There is a test your doctor can do to see if you have antibodies to the JC virus in your blood.

In those who have all three risk factors, about 1 person out of 85 will get PML.2

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Advice for women

If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.


Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.



  1. Goodin DS, et al. (2008). Assessment: The use of natalizumab (Tysabri) for the treatment of multiple sclerosis (an evidence-based review): Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology, 71(10): 766–773.
  2. Fox RJ, Rudick RA (2012). Risk stratification and patient counseling for natalizumab in multiple sclerosis. Neurology, 78(6): 436–437.


ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Primary Medical ReviewerAnne C. Poinier, MD - Internal Medicine
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Primary Medical ReviewerAnne C. Poinier, MD - Internal Medicine
Specialist Medical ReviewerBarrie J. Hurwitz, MD - Neurology
Specialist Medical ReviewerBarrie J. Hurwitz, MD - Neurology
Last RevisedFebruary 15, 2012

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