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Tysabri (Intravenous)

Generic name: natalizumab (intravenous route) [ na-ta-LYE-zoo-mab ]
Drug class: Selective immunosuppressants

Medically reviewed by Last updated on Jan 21, 2022.

Intravenous route(Solution)

Progressive Multifocal LeukoencephalopathyNatalizumab increases the risk of progressive multifocal leukoencephalopathy (PML), an opportunistic viral infection of the brain that usually leads to death or severe disability.Risk factors for PML include the presence of anti-JC virus antibodies, duration of therapy, and prior use of immunosuppressants. These factors should be considered in the context of expected benefit when initiating and continuing treatment with natalizumab.Monitor patients, and withhold natalizumab immediately at the first sign or symptoms suggestive of PML.Because of the risk of PML, natalizumab is available only through a restricted distribution program called the TOUCH(R) Prescribing Program .

Commonly used brand name(s)

In the U.S.

  • Tysabri

Available Dosage Forms:

  • Solution

Therapeutic Class: Immune Suppressant

Pharmacologic Class: Monoclonal Antibody

Uses for Tysabri

Natalizumab injection is used to treat patients with relapsing forms of multiple sclerosis (MS). This medicine will not cure MS, but it may slow some of the disabling effects and decrease the number of flare-ups (relapses) of the disease.

Natalizumab injection is also used to treat moderate to severely active Crohn's disease (CD) when other medicines or treatments did not work well. This medicine will not cure CD, but may prevent it from occurring again.

This medicine is available only under a restricted distribution program called the TOUCH® Prescribing program.

Before using Tysabri

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of natalizumab injection in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of natalizumab injection in the elderly.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Anifrolumab-fnia
  • Infliximab
  • Tofacitinib

Interactions with food/tobacco/alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Herpes infection—Use with caution. May increase the risk for more serious infections (eg, encephalitis, meningitis, retinal necrosis).
  • Liver disease—Use with caution. This medicine may make this condition worse.
  • Progressive multifocal leukoencephalopathy (PML, rare brain infection) or history of—Should not be used in patients with this condition.
  • Weak immune system (caused by HIV infection, AIDS, leukemia, lymphoma, or organ transplant)—Use is not recommended. May increase risk of developing infections, including PML.

Proper use of Tysabri

A nurse or other trained health professional will give you this medicine in a medical facility. It is given through a needle placed into one of your veins. The medicine must be injected slowly, so the needle will have to remain in place for about an hour.

It is very important that you understand the requirements of the TOUCH® Prescribing Program, and become familiar with the medication guide. Read and follow these instructions carefully. Ask your doctor if you have any questions. Ask your pharmacist for the medication guide if you do not have one.

Your doctor may need to check your brain before you start receiving this medicine. To do this, you may need to have a Magnetic Resonance Imaging (MRI) scan.

Precautions while using Tysabri

Your doctor will want to check your progress at 3 months and 6 months after the first injection, then every 6 months after that. Blood and urine tests may be needed to check for unwanted effects.

This medicine may increase your risk of developing infections, including a rare and serious brain infection called progressive multifocal leukoencephalopathy (PML). This is more likely to occur if you have had JCV infection, have been receiving natalizumab for a long time (longer than 2 years), or if you have been using medicine that weakens your immune system (eg, azathioprine, cyclophosphamide, cyclosporine, mercaptopurine, methotrexate, mitoxantrone, mycophenolate mofetil, or steroid medicine) before receiving this medicine. Check with your doctor right away if you have vision changes, loss of coordination, clumsiness, memory loss, difficulty speaking or understanding what others say, or weak legs.

Natalizumab may cause a rare condition called immune reconstitution inflammatory syndrome (IRIS). This may occur after a person stops receiving this medicine after developing PML during treatment. Tell your doctor right away if you have an inflammatory reaction to an infection that includes mild burning, stinging, or tingling of the skin, or a feeling of heat, redness, or swelling of the skin.

Natalizumab may increase the risk of developing encephalitis, meningitis, or acute retinal necrosis caused by herpes and varicella viruses. Check with your doctor if you have a fever, headache, eye pain or redness, sensitivity of the eyes to the sun, or confusion.

Check with your doctor right away if you pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

This medicine may cause serious allergic reactions, including anaphylaxis, which can be life-threatening and require immediate medical attention. Tell your doctor right away if you have a rash, itching, hoarseness, trouble breathing or swallowing, or any swelling of your hands, face, or mouth after receiving this medicine.

This medicine may lower the number of some types of blood cells in your body. Because of this, you may bleed or get infections more easily. To help with these problems, avoid being near people who are sick or have infections. Wash your hands often. Stay away from rough sports or other situations where you could be bruised, cut, or injured. Brush and floss your teeth gently. Be careful when using sharp objects, including razors and fingernail clippers.

Tysabri side effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

  • Bladder pain
  • blistering, crusting, irritation, itching, or reddening of the skin
  • bloody or cloudy urine
  • body produces substance that can bind to drug making it less effective or cause side effects
  • chest tightness
  • cough
  • difficult, burning, or painful urination
  • difficulty with swallowing
  • dizziness
  • fast heartbeat
  • frequent, strong, or increased urge to urinate
  • hives, itching, skin rash
  • itching of the vagina or genital area
  • lower back or side pain
  • pain during sexual intercourse
  • passing urine more often
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • thick, white vaginal discharge with no odor or with a mild odor
  • unusual tiredness or weakness


  • Blurred vision
  • changes in behavior
  • chest pain
  • confusion
  • difficult or labored breathing
  • fainting or lightheadedness when getting up suddenly from a lying or sitting position
  • feeling of warmth
  • feeling unusually cold
  • fever
  • gaseous abdominal or stomach pain
  • nausea
  • redness of the face, neck, arms, and occasionally, upper chest
  • shivering
  • sneezing
  • sore throat
  • stomach fullness
  • sweating
  • thoughts of killing oneself
  • yellow eyes or skin

Incidence not known

  • Back, leg, or stomach pains
  • black, tarry stools
  • bleeding gums
  • chills
  • dark urine
  • drowsiness
  • general body swelling
  • headache
  • heavier menstrual periods
  • loss of appetite
  • nosebleeds
  • pale skin
  • pinpoint red spots on the skin
  • seizures
  • unusual bleeding or bruising
  • vomiting

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Cracked, dry, scaly skin
  • diarrhea
  • difficulty with moving
  • discouragement
  • feeling sad or empty
  • irregular menstruation
  • irritability
  • loss of interest or pleasure
  • muscle pain or stiffness
  • pain, cramps, or heavy bleeding
  • pain in the joints
  • stomach soreness or discomfort
  • swollen glands
  • trouble concentrating
  • trouble sleeping

Less common

  • Absent, missed, or irregular menstrual periods
  • chest discomfort
  • local bleeding
  • shakiness in the legs, arms, hands, or feet
  • stopping of menstrual bleeding
  • trembling or shaking of the hands or feet

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Frequently asked questions

View more FAQ

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.