Tysabri is a brand-name prescription drug. It's used to treat adults with:

  • Relapsing forms of multiple sclerosis (MS). MS is an illness in which your immune system (your body's defense against disease) attacks your central nervous system.
  • Moderately to severely active Crohn's disease if other treatments haven't worked for you. Crohn's disease is a kind of inflammatory bowel disease in which you have swelling in your digestive tract. And "active" means that you currently have symptoms.

Tysabri contains natalizumab. This is a type of biologic drug (made from parts of living organisms) called an integrin receptor antagonist.

A healthcare provider will give you Tysabri as an intravenous infusion in a clinic or your doctor's office. This is an injection into your vein that's slowly dripped in over time. Tysabri infusions usually take an hour.

Effectiveness

Tysabri has been found to be effective (work well) for treating relapsing forms of MS and moderately to severely active Crohn's disease.

One study looked at how Tysabri worked in people with MS. After two years of treatment, people who took Tysabri had a 42% lower risk of worsening of symptoms than people who took a placebo (no treatment). The worsening of symptoms included trouble moving or walking. And 67% of people who took Tysabri didn't relapse (have flare-ups), compared to 41% of people who took a placebo.

A different study looked at people with Crohn's disease who took Tysabri. After 12 weeks of treatment, 60% of people had fewer symptoms. This was compared to 44% of people who took a placebo. And 37% of people were in remission, which means that they had fewer symptoms or none at all. This was compared to 25% of people who took a placebo.

Tysabri is available only as a brand-name medication. Tysabri contains one active drug ingredient: natalizumab.

Tysabri isn't currently available as a biosimilar.

A biosimilar is a drug that's similar to a brand-name medication. A generic drug, on the other hand, is an exact copy of a brand-name medication. Biosimilars are based on biologic drugs, which are made from parts of living organisms. Generics are based on regular drugs made from chemicals.

Both biosimilars and generics are as safe and effective as the brand-name drug they're made to copy. They also tend to cost less than brand-name drugs.

Tysabri can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Tysabri. These lists do not include all possible side effects.

For more information on the possible side effects of Tysabri, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

More common side effects

The more common side effects of Tysabri can include:

  • headaches
  • pain in your arms, legs, joints, or stomach
  • fatigue (lack of energy) or feeling tired
  • diarrhea
  • nausea
  • rash
  • weight loss or weight gain

Most of these side effects may go away within a few days or a couple of weeks. If they're more severe or don't go away, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Tysabri aren't common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you're having a medical emergency.

Serious side effects and their symptoms can include the following:

  • Progressive multifocal leukoencephalopathy (PML),* a type of severe brain infection. Symptoms can include:
    • gradually getting weaker on one side of your body
    • clumsiness
    • vision problems
    • changes in your thinking, memory, or personality
    • confusion
  • Herpes infections, such as encephalitis (brain infection) or meningitis (brain and spinal cord infection). Symptoms can include:
    • sudden fever
    • severe headache
    • vision changes or eye pain
    • confusion
  • Liver damage. Symptoms can include:
    • jaundice (yellowish color of your skin and the whites of your eyes)
    • dark urine
    • nausea or vomiting
    • feeling tired or weak
  • Infections in your urinary tract, vagina, lungs, nose, or throat. General symptoms of an infection can include:
  • Allergic reactions. See "Side effect details" below for possible symptoms.
  • Depression. See "Side effect details" below for possible symptoms.

* Tysabri has a boxed warning for PML. This is the most serious warning from the Food and Drug Administration (FDA). For more information, see "FDA warning" at the beginning of this article.

Side effect details

You may wonder how often certain side effects occur with this drug. Here's some detail on some of the side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Tysabri. One study looked at people with multiple sclerosis (MS). Of those people who received Tysabri, 4% had an allergic reaction within two hours of taking the drug. This was compared to less than 1% of people who took a placebo (no treatment).

In the same study, 5% of people who received Tysabri had an allergic reaction more than two hours after they took the drug. This was compared to 2% of people who took a placebo.

In other clinical studies, 2% of people with Crohn's disease had an allergic reaction within two hours of receiving Tysabri. This was compared to less than 1% of people who took a placebo. These studies didn't include information on allergic reactions that occurred more than two hours after taking Tysabri.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing or wheezing
  • chest pain
  • nausea
  • dizziness
  • low blood pressure
  • chills

It's possible to have a serious allergic reaction any time after you receive Tysabri. But these reactions typically occur within two hours of starting the dose. A healthcare provider will monitor you for at least an hour after you receive Tysabri. So if you have an allergic reaction during that time, they can treat it right away.

If you have a severe allergic reaction to Tysabri after you leave the healthcare provider, call your doctor right away. Call 911 if your symptoms feel life-threatening or if you think you're having a medical emergency.

Progressive multifocal leukoencephalopathy (PML)

Taking Tysabri increases your risk for a severe brain infection called progressive multifocal leukoencephalopathy (PML). This is a rare but very serious side effect. PML can lead to severe disability, such as being unable to walk, or death.

In a clinical trial, 2 out of 1,869 people who took Tysabri and Avonex (another MS drug) for MS developed PML. This was compared to zero people who took only Avonex.

In another study, 1 out of 1043 people who took Tysabri for Crohn's disease developed PML. This was compared to zero people who took a placebo (no treatment).

It's possible to develop PML during Tysabri treatment and up to six months after you stop taking the drug.

You're at an increased risk for PML if you:

  • have been taking Tysabri for longer than two years
  • had prior treatment with certain medications that may have weakened your immune system
  • have the John Cunningham virus

While you take Tysabri, your doctor will monitor you for PML. If you have any symptoms of PML, tell your doctor right away. (See "Serious side effects" above for a list of possible symptoms.) Your doctor can decide if you should stop taking Tysabri. Unfortunately, it's not possible to prevent or cure PML.

Skin rash

While you take Tysabri, it's possible that you may have a rash on your skin. In one study, 12% of people who took Tysabri for MS developed a skin rash. This was compared to 9% of people who took a placebo (no treatment).

In another study, 6% of people who took Tysabri for Crohn's disease developed a skin rash. This was compared to 4% of people who took a placebo.

If you're taking Tysabri and develop a skin rash that doesn't go away after a couple of days or gets worse, tell your doctor. They can recommend how to treat it.

Weight loss or weight gain

While you take Tysabri, it's possible that you may lose weight or gain weight. In a clinical trial, 2% of people who took Tysabri for MS lost weight or gained weight. This was compared to less than 1% of people who took a placebo (no treatment).

If you have any concerns about your weight loss or weight gain, talk with your doctor. They may adjust your diet and exercise routine as needed. Your doctor may also refer you to a dietitian to make sure you're getting the proper nutrition.

Headache

While taking Tysabri, it's possible that you may have headaches. In a clinical trial, 38% of people who took Tysabri for MS had headaches. This was compared to 33% of people who took a placebo (no treatment).

In two other clinical trials, 32% and 37% of people who took Tysabri for Crohn's disease had headaches. This was compared to 23% and 31% of people who took a placebo. Headaches are one of the most common side effects of Tysabri.

If you have headaches that don't go away while you take Tysabri, talk with your doctor. They can recommend treatments that may help.

Depression

While taking Tysabri, it's possible that you may have depression. In a clinical trial, 19% of people who took Tysabri for MS developed depression. This was compared to 16% of people who took a placebo (no treatment). In fact, depression is one of the most common side effects of Tysabri.

If you're taking Tysabri and have any symptoms of depression, tell your doctor. Symptoms may include feeling sad, hopeless, or losing interest in activities you usually enjoy. You and your doctor can discuss ways to manage your symptoms and which treatments are available. Your doctor may also have you stop taking Tysabri and use a different medication.

Hair loss (not a side effect)

While taking Tysabri, it's not likely that you'll lose your hair. In clinical trials of Tysabri, hair loss wasn't a side effect.

However, some other MS drugs, such as teriflunomide (Aubagio) and mitoxantrone, may cause hair loss.

And Crohn's disease itself may cause some hair loss. This is because your stomach may not properly absorb the nutrients from your food that help your hair grow.

If you're taking Tysabri and are concerned about hair loss, talk with your doctor. They may test you to see what's causing the hair loss. Your doctor may also give you tips on how to cope with losing your hair.

Cancer (not a side effect)

Tysabri isn't likely to cause you to develop cancer. In clinical trials of Tysabri, cancer wasn't a side effect.

Research has found an increased risk of certain types of cancer in the intestines of people with Crohn's disease.

And there's conflicting information on whether MS increases the risk of cancer. More data is needed to confirm whether there's a link between MS and cancer.

If you're taking Tysabri and are concerned about developing cancer, talk with your doctor.

As with all medications, the cost of Tysabri can vary. To find current prices for Tysabri in your area, check out WellRx.com.

The cost you find on WellRx.com is what you may pay without insurance. The actual price you'll pay depends on your insurance plan and your location.

Financial and insurance assistance

If you need financial support to pay for Tysabri, or if you need help understanding your insurance coverage, help is available.

Biogen, the manufacturer of Tysabri, offers a program called Above MS. This program may be able to help lower the cost of your medication. For more information and to find out if you're eligible for support, call 800-456-2255 or visit the program website.

The Food and Drug Administration (FDA) approves prescription drugs such as Tysabri to treat certain conditions.

Tysabri is FDA-approved to treat relapsing forms of multiple sclerosis (MS) in adults.

MS is an illness in which your immune system (your body's defense against disease) attacks your central nervous system. (Your brain and spinal cord make up your central nervous system.) With MS, your immune system destroys myelin, which is the covering that protects nerve fibers.

Without this covering, your brain has a hard time sending messages to the rest of your body through your nerves. This can lead to permanent nerve damage and trouble moving around.

With relapsing forms of MS, you have times where you have few or no symptoms. This is followed by relapses (flare-ups during which your symptoms get worse). Relapsing forms of MS are the most common types of MS.

Tysabri helps slow down the worsening of MS symptoms. The drug also helps decrease the number of flare-ups you have.

One study looked at how Tysabri worked in people with MS. After two years of treatment, people who took Tysabri had a 42% lower risk of worsening of symptoms than people who took a placebo (no treatment). The worsening of symptoms included trouble moving or walking. And 67% of people who took Tysabri didn't relapse (have flare-ups), compared to 41% of people who took a placebo.

Another study looked at people with MS who took Tysabri and a second MS drug called Avonex. After two years of treatment, people who took Tysabri with Avonex had a 24% lower risk of their symptoms getting worse than people who took only Avonex. The worsening of symptoms included trouble moving or walking. And 54% of people who took both drugs didn't relapse (have flare-ups), compared to 32% of people who took only Avonex.

In addition to multiple sclerosis (MS), the Food and Drug Administration (FDA) has approved Tysabri to treat some forms of Crohn's disease.

Tysabri for Crohn's disease

Tysabri can also be used to treat moderately to severely active Crohn's disease if other treatments haven't worked for you. Crohn's disease is a kind of inflammatory bowel disease in which you have swelling in your digestive tract. And "active" means that you currently have symptoms.

One study looked at people with Crohn's disease who took Tysabri. After 12 weeks of treatment, 60% of people had fewer symptoms (felt better). This was compared to 44% of people who took a placebo. And 37% of people were in remission, which means that they had fewer symptoms or none at all. This was compared to 25% of people who took a placebo.

Other drugs are available that can treat multiple sclerosis (MS) and Crohn's disease. Some may be better suited for you than others. If you're interested in finding an alternative to Tysabri, talk with your doctor. They can tell you about other medications that may work well for you.

Alternatives for multiple sclerosis

Examples of other drugs that may be used to treat MS include:

  • interferon beta-1a (Avonex)
  • interferon beta-1b (Betaseron)
  • glatiramer acetate (Copaxone, Glatopa)
  • fingolimod (Gilenya)
  • alemtuzumab (Lemtrada)
  • dimethyl fumarate (Tecfidera)
  • teriflunomide (Aubagio)
  • ocrelizumab (Ocrevus)

Alternatives for Crohn's disease

Examples of other drugs that may be used to treat Crohn's disease include:

  • azathioprine (Azasan, Imuran)
  • 6-mercaptopurine (Purinethol)
  • budesonide (Entocort EC, Uceris)
  • methotrexate (Trexall)
  • infliximab (Remicade, Inflectra, Renflexis)
  • adalimumab (Humira, Amjevita, Cyltezo)
  • vedolizumab (Entyvio)
  • ustekinumab (Stelara)

You may wonder how Tysabri compares to other medications that are prescribed for similar uses. Here we look at how Tysabri and Ocrevus are alike and different.

Uses

The Food and Drug Administration (FDA) has approved both Tysabri and Ocrevus to treat relapsing forms of multiple sclerosis (MS) in adults.

Tysabri is also approved to treat moderately to severely active Crohn's disease in adults if other treatments haven't worked. Crohn's disease is a kind of inflammatory bowel disease in which you have swelling in your digestive tract. And "active" means that you currently have symptoms.

Ocrevus is also approved to treat progressive (worsening) forms of MS in adults.

Tysabri contains the active drug natalizumab. Ocrevus contains the active drug ocrelizumab.

Drug forms and administration

Tysabri and Ocrevus are both given as an intravenous infusion in a clinic or your doctor's office. This is an injection into your vein that's slowly dripped in over time. A healthcare provider will monitor you for at least one hour after the treatment in case you have an allergic reaction.

Side effects and risks

Tysabri and Ocrevus contain different drugs but are in a similar drug class. (A class of drugs is a group of medications that work in a similar way.) Therefore, both medications can cause very similar side effects. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Tysabri, with Ocrevus, or with both drugs (when taken individually).

  • Can occur with Tysabri:
    • pain in your arms, legs, joints, or stomach
    • diarrhea
    • weight loss or weight gain
    • nausea
    • rash
    • fatigue (lack of energy) or feeling tired
  • Can occur with Ocrevus:
    • fever
    • faster heart rate
  • Can occur with both Tysabri and Ocrevus:

Serious side effects

These lists contain examples of serious side effects that can occur with Tysabri, with Ocrevus, or with both drugs (when taken individually).

  • Can occur with Tysabri:
  • Can occur with Ocrevus:
  • Can occur with both Tysabri and Ocrevus:
    • progressive multifocal leukoencephalopathy (PML),* a type of severe brain infection
    • infections in your urinary tract, vagina, lungs, nose, or throat
    • severe allergic reactions

* Tysabri has a boxed warning for PML. This is the most serious warning from the Food and Drug Administration (FDA). For more information, see "FDA warning" at the beginning of this article.

Effectiveness

Tysabri and Ocrevus have some different FDA-approved uses, but they're both used to treat relapsing forms of MS in adults.

Separate studies of the two drugs were compared in a larger review of studies. Researchers found both Tysabri and Ocrevus to be effective for treating relapsing forms of MS.

Costs

Tysabri and Ocrevus are both brand-name drugs. There are currently no biosimilars of either drug.

A biosimilar is a drug that's similar to a brand-name medication. A generic drug, on the other hand, is an exact copy of a brand-name medication. Biosimilars are based on biologic drugs, which are made from parts of living organisms. Generics are based on regular drugs made from chemicals. Both biosimilars and generics are as safe and effective as the brand-name drug they're trying to copy. They also tend to cost less than brand-name drugs.

According to estimates on WellRx.com, Tysabri generally costs less than Ocrevus. The actual price you'll pay for either drug will depend on your insurance plan and your location.

In addition to Ocrevus (see above), other medications similar to Tysabri are also available. Here we look at how Tysabri and Humira are alike and different.

Uses

The Food and Drug Administration (FDA) has approved both Tysabri and Humira to treat moderately to severely active Crohn's disease in adults if other treatments haven't worked. Crohn's disease is a kind of inflammatory bowel disease in which you have swelling in your digestive tract. And "active" means that you currently have symptoms.

Tysabri is also approved to treat relapsing forms of multiple sclerosis (MS) in adults.

Humira is also approved to treat:

  • Crohn's disease in children ages 6 years and older if other drugs haven't worked
  • rheumatoid arthritis
  • psoriatic arthritis
  • moderate to severe juvenile idiopathic arthritis in those ages 2 years and older
  • ankylosing spondylitis (arthritis of the spine)
  • moderate to severe plaque psoriasis
  • moderate to severely active ulcerative colitis if other drugs haven't worked
  • some types of noninfectious uveitis, including intermediate uveitis, posterior uveitis, and panuveitis in those ages 2 years and older
  • hidradenitis suppurativa in those ages 12 years and older

Tysabri contains the active drug natalizumab. Humira contains the active drug adalimumab.

Drug forms and administration

Tysabri is given as an intravenous infusion in a clinic or your doctor's office. This is an injection into your vein that's slowly dripped in over time. A healthcare provider will monitor you for at least one hour after the treatment in case you have an allergic reaction.

Humira is given as an injection just under your skin (subcutaneous).

Side effects and risks

Tysabri and Humira contain different drugs but are in a similar drug class. (A class of drugs is a group of medications that work in a similar way.) Therefore, both medications can cause very similar side effects. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Tysabri, with Humira, or with both drugs (when taken individually).

  • Can occur with Tysabri:
    • pain in your arms, legs, joints, or stomach
    • diarrhea
    • fatigue (lack of energy) or feeling tired
    • weight loss or weight gain
  • Can occur with Humira:
    • few unique common side effects
  • Can occur with both Tysabri and Humira:

Serious side effects

These lists contain examples of serious side effects that can occur with Tysabri, with Humira, or with both drugs (when taken individually).

  • Can occur with Tysabri:
    • progressive multifocal leukoencephalopathy (PML),* a type of severe brain infection
    • herpes infections, such as encephalitis (brain infection) or meningitis (brain and spinal cord infection)
    • depression
    • infections in your vagina, nose, or throat
  • Can occur with Humira:
    • lupus-like syndrome, an immune system reaction
    • hepatitis B, if you've had it in the past
    • psoriasis, new or worsening
    • heart failure
  • Can occur with both Tysabri and Humira:
    • severe allergic reactions
    • infections in your urinary tract or lungs
    • liver damage

* Tysabri has a boxed warning for PML. This is the most serious warning from the Food and Drug Administration (FDA). For more information, see "FDA warning" at the beginning of this article.

Effectiveness

Tysabri and Humira have some different FDA-approved uses, but they're both used to treat Crohn's disease.

These drugs haven't been directly compared in clinical studies. However, studies have found both Tysabri and Humira to be effective for treating Crohn's disease.

Costs

Tysabri and Humira are both brand-name drugs. There are currently no biosimilars for Tysabri. There are three biosimilars for Humira: Hyrimoz, Cyltezo, and Amjevita. They may cost less than Humira and Tysabri.

A biosimilar is a drug that's similar to a brand-name medication. A generic drug, on the other hand, is an exact copy of a brand-name medication. Biosimilars are based on biologic drugs, which are made from parts of living organisms. Generics are based on regular drugs made from chemicals.

Both biosimilars and generics are as safe and effective as the brand-name drug they're trying to copy. They also tend to cost less than brand-name drugs.

According to estimates on WellRx.com, Tysabri generally costs more than Humira. The actual price you'll pay for either drug will depend on your insurance plan and your location.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to suit your needs.

Drug forms and strengths

Tysabri comes in a 15-mL single-dose vial. Each vial contains 300 mg of the drug.

A healthcare provider will give you Tysabri as an intravenous infusion in a clinic or your doctor's office. This is an injection into your vein that's slowly dripped in over time. Tysabri infusions usually take an hour.

After your infusion is complete, your healthcare provider will monitor you for at least one hour in case you have an allergic reaction.

Dosage for multiple sclerosis (MS)

For multiple sclerosis (MS), the typical dose of Tysabri is 300 mg every four weeks.

Dosage for Crohn's disease

For Crohn's disease, the typical dose of Tysabri is 300 mg every four weeks.

What if I miss a dose?

If you miss an appointment to have an infusion, call your doctor right away. They can schedule a new visit and adjust the timing of other appointments if needed.

Will I need to use this drug long term?

Tysabri is meant to be used as a long-term treatment. If you and your doctor determine that Tysabri is safe and effective for you, you'll likely take it long term.

There isn't enough data to know whether it's safe to take Tysabri during pregnancy. Some animal studies have shown that the drug harmed the fetus. However, other animal studies showed that Tysabri didn't cause any harm to the mother or fetus. Keep in mind that animal studies don't always predict what will happen in humans.

If you're pregnant or want to become pregnant, tell your doctor before you start taking Tysabri. They can discuss the pros and cons with you.

Studies show that Tysabri passes into human breast milk. However, there haven't been any studies on whether Tysabri affects breastfed children whose mothers took the drug.

If you want to breastfeed while taking Tysabri, talk with your doctor. They can discuss the possible risks and benefits with you.

Here are answers to some frequently asked questions about Tysabri.

Will I have withdrawal symptoms if I stop using Tysabri?

It's not likely. There haven't been any reports of withdrawal symptoms in people who stopped taking Tysabri.

Your symptoms of multiple sclerosis (MS) or Crohn's disease may get worse after stopping Tysabri. However, that is likely because the medication was working when you were taking it and it no longer works once you stop taking it.

If you'd like to stop taking Tysabri, first talk with your doctor. They can discuss with you how to best end your treatment. Your doctor can also recommend other ways to help manage your symptoms of MS or Crohn's disease.

Where can I get Tysabri infusions?

You'll have to go to your doctor's office or a clinic to receive Tysabri. A healthcare provider will give you the drug as an intravenous infusion. This is an injection into your vein that's slowly dripped in over time. Tysabri infusions usually take an hour.

Does taking Tysabri weaken my immune system?

It can. Tysabri may weaken your immune system (your body's defense against disease). When your immune system isn't strong, it has a hard time fighting germs. So Tysabri may also increase your risk of getting infections. These include:

  • Progressive multifocal leukoencephalopathy (PML), a type of severe brain infection. Tysabri has a boxed warning for PML. This is the most serious warning from the Food and Drug Administration (FDA). For more information, see "FDA warning" at the beginning of this article.
  • Infections caused by the herpes virus, such as encephalitis (brain infection) or meningitis (brain and spinal cord infection).
  • Infections in your urinary tract, vagina, lungs, nose, or throat.

To help prevent infections while you're taking Tysabri, be sure to wash your hands often. Also, limit contact with anyone who's sick. And avoid sharing personal items such as toothbrushes, drinking glasses, and towels with others.

If you develop an infection while taking Tysabri, tell your doctor right away. They can help treat it so it doesn't get worse.

Can Tysabri be used to treat progressive MS?

No. For MS, The Food and Drug Administration (FDA) has only approved Tysabri to treat relapsing forms of MS in adults.

With relapsing forms of MS, you may have times when you have few or no symptoms (remission). This is followed by times when you have relapses (flare-ups during which your symptoms get worse). But with progressive MS, you'll generally always have symptoms. Your MS tends to get worse and leads to more disability, such as having trouble moving or walking.

One clinical study looked at people with progressive MS. Researchers found that Tysabri didn't help prevent symptoms from getting worse any better than a placebo (no treatment) did. More long-term data is needed to see whether Tysabri can treat progressive MS.

If you have progressive MS, talk with your doctor. They can recommend the best treatment options for you.

Can I take Tysabri with steroids?

Maybe. If you have MS or Crohn's disease, you may already be taking a steroid as part of your treatment. Your doctor may prescribe Tysabri in addition to the steroid. In some cases, you can keep taking the steroid during your Tysabri treatment.

However, taking Tysabri with certain steroids may increase your risk for serious infections. (To learn more about possible infections, see the "Tysabri side effects" section above.) So if you're taking one of these steroids, your doctor will slowly taper your dosage within six months of you starting to take Tysabri. This means that you'll take less and less of the steroid until you stop taking it completely. Some of these steroids include oral (taken by mouth) forms you use long term — for example, budesonide (Entocort EC, Uceris).

If you're taking a steroid, talk with your doctor before you start taking Tysabri. They can go over your medications with you and recommend the best dosages.

Clinical studies haven't shown that alcohol interacts with Tysabri.

However, if you drink alcohol, talk with your doctor. They can tell you how much alcohol is safe for you during your Tysabri treatment.

Tysabri can interact with several other medications.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Tysabri and other medications

Below is a list of medications that can interact with Tysabri. This list does not contain all drugs that may interact with Tysabri.

Before taking Tysabri, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Tysabri and immunosuppressants

Taking Tysabri with an immunosuppressant may increase your risk for serious infections. Immunosuppressants are a type of drug that weakens your immune system. (Your immune system helps your body fight disease.) If you have multiple sclerosis (MS) or Crohn's disease, you already may be taking an immunosuppressant.

Tysabri may also weaken your immune system. When your immune system isn't strong, it has a hard time fighting germs. So taking Tysabri and immunosuppressants together may make you more likely to develop an infection. (To learn more about possible infections, see the "Tysabri side effects" section above.)

Examples of immunosuppressant drugs that may increase your risk for infections include:

  • methotrexate (Trexall)
  • 6-mercaptopurine (Purinethol)
  • azathioprine (Azasan, Imuran)
  • adalimumab (Humira, biosimilars)
  • infliximab (Remicade, biosimilars)
  • etanercept (Enbrel)
  • golimumab (Simponi)

If you're taking an immunosuppressant, talk with your doctor before you start receiving Tysabri. Your doctor may have you stop taking the immunosuppressant.

Tysabri and certain steroids

Taking Tysabri with certain oral (taken by mouth) steroids long term may increase your risk for infections. Both Tysabri and certain steroids may weaken your immune system (your body's defense against disease). When your immune system isn't strong, it has a hard time fighting germs. So taking these drugs together may make you more likely to develop an infection. (To learn more about possible infections, see the "Tysabri side effects" section above.)

An example of a steroid that may increase your risk for infections is budesonide (Entocort EC, Uceris).

If you're using a steroid, talk with your doctor before you start receiving Tysabri. They may have you take less and less of the steroid until you stop using it completely. They can also recommend other ways to help manage your symptoms.

Tysabri and herbs and supplements

No herbs or supplements have been reported to interact with Tysabri. However, you should still check with your doctor or pharmacist before using any of these products.

A healthcare provider will give you Tysabri as an intravenous infusion in a clinic or your doctor's office. This is an injection into your vein that's slowly dripped in over time.

The healthcare provider will first put a needle into one of your veins. Then they'll connect a bag that contains Tysabri to the needle. The drug will flow from the bag to your body. Tysabri infusions usually take an hour.

After your infusion is complete, the healthcare provider will monitor you for at least one hour in case you have an allergic reaction.

When to take

For both multiple sclerosis (MS) and Crohn's disease, you'll receive infusions of Tysabri every four weeks.

To help you remember when you have an appointment for an infusion, put your treatment schedule on a calendar. Also, set a reminder in your phone so that you don't miss getting a dose of Tysabri.

Tysabri is approved to treat certain forms of multiple sclerosis (MS) and Crohn's disease.

Multiple sclerosis (MS)

Multiple sclerosis (MS) is an illness in which your immune system (your body's defense against disease) attacks your central nervous system. (Your brain and spinal cord make up your central nervous system.) With MS, your immune system destroys myelin, which is the covering that protects nerve fibers. Without this covering, your brain has a hard time sending messages to the rest of your body through your nerves. This can lead to permanent nerve damage and trouble moving around.

Tysabri works by binding (attaching) to the cells in your immune system that are attacking your central nervous system. The drug helps prevent the cells from moving to your brain and spinal cord, where they can cause nerve damage.

Crohn's disease

Crohn's disease is a kind of inflammatory bowel disease that causes inflammation (swelling) in your digestive tract. Cells in your immune system that normally fight disease mistakenly attack your digestive tract. This causes the inflammation.

Tysabri works by binding to these cells. The drug helps prevent the cells from moving to your digestive tract, where they can cause inflammation.

How long does it take to work?

For MS, it's hard to say how quickly Tysabri starts to work. This is because the drug is meant to help prevent relapses (flare-ups) and keep MS from getting worse.

For Crohn's disease, you can expect to see your symptoms improve within the first eight weeks of taking Tysabri. In a clinical study, after eight weeks of treatment, Crohn's disease symptoms eased significantly in more than half of the people who took Tysabri. And nearly a third of people who took the drug were in remission (free from symptoms).

This drug comes with several precautions.

FDA warning: Progressive multifocal leukoencephalopathy (PML)

This drug has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

Taking Tysabri increases your risk for a severe brain infection called progressive multifocal leukoencephalopathy (PML). PML can lead to severe disability, such as not being able to walk, or death. While you take Tysabri, your doctor will monitor you. If you have any signs or symptoms of the infection, your doctor may have you stop taking Tysabri. You also shouldn't take Tysabri if you've had PML in the past.

Due to the risk of PML, you can get Tysabri only from your doctor through a drug safety program. It's called REMS (Risk Evaluation and Mitigation Strategies). The REMS program for Tysabri is called the TOUCH Prescribing Program. The program helps make sure that you know about possible side effects of the drug. If you have questions about the program, ask your doctor.

Other warnings

Before taking Tysabri, talk with your doctor about your health history. Tysabri may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Conditions that can weaken your immune system. Tysabri can weaken your immune system (your body's defense against disease). So if your immune system is already weak because of lymphoma, leukemia, or HIV, for example, your body may be less able to fight germs. If you have lymphoma, leukemia, or HIV, your doctor may prescribe a drug other than Tysabri.
  • Allergic reactions. Tysabri may cause mild or severe allergic reactions. If you have an allergic reaction to Tysabri, your doctor may have you stop taking the drug. They can also recommend a different treatment.
  • Pregnancy. It's not known whether Tysabri is safe for you and your baby during pregnancy. For more information, see the "Tysabri and pregnancy" section above.

Note: For more information about the potential negative effects of Tysabri, see the "Tysabri side effects" section above.

The following information is provided for clinicians and other healthcare professionals.

Indications

Tysabri is indicated to treat relapsing forms of multiple sclerosis (MS). It is also indicated to treat Crohn's disease and maintain remission when traditional therapies do not work.

Mechanism of action

Tysabri contains natalizumab, which is a monoclonal antibody that binds to alpha-4 integrin. In MS, it prevents the movement of T-lymphocytes into the central nervous system to reduce relapse frequency. In Crohn's disease, Tysabri prevents leukocytes from migrating into the gut, thereby reducing inflammation.

Pharmacokinetics and metabolism

Tysabri contains natalizumab, which is a monoclonal antibody. The half-life is 7 to 15 days for MS, and 3 to 17 days for Crohn's disease.

After every four weeks of dosing, it takes about 24 weeks for MS and 16 to 24 weeks for Crohn's disease to reach steady state.

Contraindications

Tysabri is contraindicated in people who have previously had:

  • progressive multifocal leukoencephalopathy (PML)
  • hypersensitivity reactions to Tysabri

Storage

Store Tysabri (single-dose vials and diluted solution) in the refrigerator between 36°F to 46°F (2°C to 8°C) and do not freeze. Protect from light and do not shake.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.