Tysabri (natalizumab) is a prescription drug that’s used to treat multiple sclerosis and Crohn’s disease. This drug can interact with other medications. For example, Tysabri can interact with medications that suppress immune system activity.
Tysabri is used in adults to treat:
- multiple sclerosis
- Crohn’s disease after previous medications that weren’t effective or tolerated
The active ingredient in Tysabri is natalizumab. Tysabri comes in a solution for intravenous (IV) infusion into a vein.
An interaction can occur because one substance causes . substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Tysabri’s possible interactions. And for more information about Tysabri, including details about its uses, see this article.
Before you start using Tysabri, tell your doctor and pharmacist about any prescription, over-the-counter (OTC), or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Tysabri interacts with herbs or vitamins and supplements, see the “Are there other interactions with Tysabri?” section below.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Tysabri. Keep in mind that this table does not include all drugs that may interact with Tysabri. For more information about these interactions, see the “Drug interactions explained” section below.
| Drug group | Drug examples | What can happen |
|---|---|---|
| immunosuppressants, which are drugs that suppress immune system activity | • azathioprine (Azasan, Imuran) • methotrexate (Trexall) • 6-mercaptopurine (Purinethol) • etanercept (Enbrel) • adalimumab (Humira) • infliximab (Remicade) | can increase the risk of PML and other infections |
| corticosteroids | • prednisone (Rayos) • methylprednisolone (Medrol) • budesonide (Entocort EC, others) | can increase the risk of PML and other infections |
Certain health conditions or other factors could raise your risk of harm if you use Tysabri. In such cases, your doctor may not prescribe Tysabri for you. These are known as contraindications. The list below includes contraindications of Tysabri.
If you have or ever had PML: Tysabri has a boxed warning for the risk of developing PML, which is a severe brain infection. PML can lead to serious complications and possibly death. If you have or ever had PML, Tysabri may not be right for you. Talk with your doctor about other treatment options for your condition.
For more information about the risk of developing PML, see the “Boxed warning” section near the beginning of this article.
If you’ve had an allergic reaction: If you’ve had an allergic reaction to Tysabri or any of its ingredients, your doctor likely won’t prescribe Tysabri for you. This is because using the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.
Before you start using Tysabri, talk with your doctor if any of the factors above apply to you. Your doctor can determine whether Tysabri is safe for you to use.
Tysabri is not known to interact with alcohol, but you still may want to avoid alcohol use during Tysabri treatment. This is because alcohol may worsen some of your symptoms. In the following articles, you can learn more about the effects of alcohol on your condition during Tysabri treatment:
If you have questions about consuming alcohol while using Tysabri, talk with your doctor or pharmacist.
Learn more about certain drug interactions that can occur with Tysabri.
Interaction with immunosuppressants
Tysabri can interact with immunosuppressants (medications that weaken or suppress your immune system activity). These drugs treat a variety of health conditions, including multiple sclerosis and Crohn’s disease.
Examples of immunosuppressant drugs include:
- azathioprine (Azasan, Imuran)
- methotrexate (Trexall)
- 6-mercaptopurine (Purinethol)
- etanercept (Enbrel)
- adalimumab (Humira)
- infliximab (Remicade)
What could happen
Using Tysabri with immunosuppressants can raise your risk of developing PML and other serious infections.
What you can do
If you have multiple sclerosis or Crohn’s disease, you may already be taking an immunosuppressant. Before starting Tysabri, talk with your doctor about all the medications you are taking, including OTC medications. They can check whether any of these medications interact with Tysabri.
Typically, if you have Crohn’s disease, you should not be using Tysabri along with other immunosuppressants.
If you have questions about using Tysabri with immunosuppressants, talk with your doctor or pharmacist.
Interaction with corticosteroids
Tysabri can interact with corticosteroids used long term to treat a variety of health conditions. These include multiple sclerosis, asthma, gout, and lupus.
Examples of corticosteroid medications include:
- prednisone (Rayos)
- methylprednisolone (Medrol)
- budesonide (Entocort EC, others)
What could happen
Using Tysabri with corticosteroids long term can raise your risk of developing PML and other serious infections.
What you can do
If you’re using corticosteroids long term, talk with your doctor before starting Tysabri. Your doctor may lower the dosage of your corticosteroid until you stop taking it. Then, they’ll likely recommend other medications to manage your symptoms instead.
Ask your doctor or pharmacist if you have other questions about using Tysabri with corticosteroids.
Tysabri may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below does not include all other interactions possible with Tysabri.
Does Tysabri interact with supplements?
Before you start using Tysabri, talk with your doctor and pharmacist about any herbs or vitamins and supplements you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Tysabri interactions and herbs
Tysabri currently has no reports of interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while using Tysabri.
Tysabri interactions and vitamins
Tysabri currently has no reports of interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while using Tysabri.
Does Tysabri interact with food?
Tysabri currently has no reports of interacting with food. If you have questions about eating certain foods during your treatment with Tysabri, talk with your doctor.
Does Tysabri interact with vaccines?
Tysabri currently has no reports of interacting with vaccines. But Tysabri can weaken your immune system activity. And because of this, you may not want to receive live vaccines during your treatment. (Live vaccines contain weakened versions of the bacteria or virus against which they’re meant to protect.) Getting a live vaccine while you’re using Tysabri increases your risk of infection. Examples of live vaccines include measles, mumps, rubella (MMR), rotavirus, and chickenpox. If you need to receive a vaccine, talk with your doctor first to make sure it’s safe.
Does Tysabri interact with lab tests?
Tysabri currently has no reports of interacting with lab tests. If you have questions about having certain lab tests during your treatment with Tysabri, talk with the healthcare professional ordering the test.
Does Tysabri interact with cannabis or CBD?Tysabri currently has no reports of interacting with cannabis (commonly called marijuana) or cannabis products such as cannabidiol (CBD). But as with any drug or supplement, talk with your doctor before using cannabis with Tysabri.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Tysabri. Before using Tysabri, talk with your doctor about your health history. They’ll determine whether Tysabri is right for you.
Health conditions or other factors that might interact with Tysabri include:
PML: Tysabri has a boxed warning for PML. This is a severe brain infection caused by a virus that can lead to serious side effects and possibly death. Talk with your doctor about your health conditions before starting Tysabri. Please see the “When should I avoid Tysabri?” or “Boxed warning” sections above for more details about PML.
Suppressed immune system activity: Tysabri can weaken or suppress your immune system activity, which can increase your risk of infection. Some other health conditions, such as HIV and AIDS or leukemia, can weaken your immune system. If you already have a weakened immune system from another condition, Tysabri may not be right for you. Talk with your doctor about your health conditions before starting Tysabri.
Pregnancy: The drugmaker of Tysabri notes that information on the use of the drug in pregnant people is limited. But it also warns that Tysabri may cause fetal harm when used during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before using Tysabri.
Breastfeeding: It’s not known whether it’s safe to use Tysabri while breastfeeding. The drug passes into breast milk, but it isn’t known whether the drug may cause side effects in a child who’s breastfed. If you’re breastfeeding or planning to breastfeed, talk with your doctor about your options.
Allergic reaction: If you’ve had an allergic reaction to Tysabri or any of its ingredients, your doctor likely won’t prescribe Tysabri. This is because using the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Taking certain steps can help you avoid interactions with Tysabri. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- whether you drink alcohol or use cannabis
- other medications you take, as well as any vitamins, supplements, and herbs (they can also help you fill out a medication list)
- what to do if you start taking a new drug during your Tysabri treatment
It’s also important to understand Tysabri’s
If you have difficulty reading or understanding this information, your doctor or pharmacist can help.
Using Tysabri exactly as prescribed also can help prevent interactions.
Disclaimer: Healthline 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 another 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.