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TYSABRI Indication and
Important Safety Information


TYSABRI® (natalizumab) is a prescription medicine used to treat adults with relapsing forms of Multiple Sclerosis (MS). TYSABRI can slow the worsening of symptoms common in people with MS and can decrease the number of flare-ups (relapses). TYSABRI increases the risk of PML. When starting and continuing treatment with TYSABRI, it is important that you discuss with your doctor whether the expected benefit of TYSABRI is enough to outweigh this risk.


  • TYSABRI increases your risk of getting a rare brain infection—called progressive multifocal leukoencephalopathy (PML)—that usually leads to death or severe disability. If PML occurs, it usually occurs in people with weakened immune systems. There is no known treatment, prevention, or cure for PML.
  • Your risk of getting PML may be higher if you are also being treated with other medicines that can weaken your immune system, including other treatments for MS. You should not take certain medicines that weaken your immune system at the same time you are taking TYSABRI. Even if you use TYSABRI alone to treat your MS, you can still get PML.
  • Your risk of getting PML is higher if you:
    • have received TYSABRI for a long time, especially longer than 2 years
    • have received certain medicines that can weaken your immune system before you start receiving TYSABRI
    • have been exposed to John Cunningham Virus (JCV). JCV is a common virus that is harmless in most people but can cause PML in people who have weakened immune systems, such as people taking TYSABRI. Most people who are exposed to JCV do not know it or do not have any symptoms. This exposure usually happens in childhood. Before you start receiving TYSABRI or during your treatment, your doctor may do a blood test to check if you have been exposed to JCV.
    • Your risk of getting PML is greatest if you have all 3 risk factors listed above. There may be other risk factors for getting PML during TYSABRI treatment that we do not know about yet. Before you decide to receive TYSABRI, your doctor should discuss the risks and benefits of TYSABRI treatment with you.
  • While you receive TYSABRI, and for 6 months after you stop receiving TYSABRI, it is important that you call your doctor right away if you have any new or worsening medical problems (such as problems with your thinking, eyesight, balance, or strength; weakness on 1 side of your body; and using your arms and legs) that have lasted several days. Tell all of your doctors that you are getting treatment with TYSABRI.
  • Because of your risk of getting PML while you receive TYSABRI, TYSABRI is available only through a restricted distribution program called the TOUCH® Prescribing Program. To receive TYSABRI, you must talk with your doctor, understand the risks and benefits of TYSABRI, and agree to follow all of the instructions in the TOUCH® Prescribing Program. Only prescribers, infusion centers, and patients enrolled in TOUCH can, respectively, prescribe, infuse, and receive TYSABRI.
  • If you have PML or are allergic to TYSABRI or any of its ingredients, you should not receive TYSABRI.
  • Before you receive TYSABRI, tell your doctor if you have a medical condition that can weaken your immune system, such as HIV infection or AIDS, leukemia or lymphoma, organ transplant, or others, or if you have any new or worsening medical problems that have lasted several days.
  • If you are pregnant or plan to become pregnant or if you are breastfeeding or plan to breastfeed, tell your doctor. It is not known if TYSABRI can harm your unborn baby or if the TYSABRI that passes into your breast milk can harm your baby. To learn about the best way to feed your baby while you receive TYSABRI, talk with your doctor.
  • Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Especially tell your doctor if you take medicines that can weaken your immune system. If you are not sure, ask your doctor.
  • TYSABRI may increase your risk of getting an infection of the brain or the covering of your brain and spinal cord (encephalitis or meningitis) caused by herpes viruses that may lead to death. If you have sudden fever, if you have severe headache, or if you feel confused after receiving TYSABRI, call your doctor right away.
  • TYSABRI may cause liver damage. Symptoms of liver damage include yellowing of the skin and eyes (jaundice), unusual darkening of the urine, nausea, feeling tired or weak, or vomiting. Blood tests can be done to check for liver damage. If you experience any symptoms of liver damage, call your doctor right away.
  • Other serious side effects with TYSABRI include allergic reactions (e.g., hives, itching, trouble breathing, chest pain, dizziness, wheezing, chills, rash, nausea, flushing of skin, low blood pressure), including serious allergic reactions (e.g., anaphylaxis) and infections. Serious allergic reactions usually happen within 2 hours of the start of the infusion, but they can happen any time after receiving TYSABRI. If you have any symptom of an allergic reaction, tell your doctor or nurse right away. If you are having an allergic reaction, you may need treatment.
  • Because TYSABRI can weaken your immune system, TYSABRI may increase your risk of getting an unusual or serious infection. If you also take other medicines that can weaken your immune system, you have a higher risk of getting infections.
  • Common side effects include headache, urinary tract infection, lung infection, pain in your arms and legs, vaginitis, stomach-area pain, feeling tired, joint pain, depression, diarrhea, rash, and nausea. If you experience any side effect that bothers you or does not go away, tell your doctor.
  • These are not all of the possible side effects of TYSABRI. For more information, ask your doctor.
  • For medical advice about side effects, call your doctor. To report side effects, call FDA at 1-800-FDA-1088.
Important Safety Information

Please see full Prescribing Information (PDF) , including Boxed Warning and
Patient Medication Guide (PDF) .

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