Xolair (omalizumab) is a prescription drug that’s used to treat asthma and certain other conditions. This drug can interact with certain vaccines and health conditions.

Xolair is used to treat:

  • moderate to severe asthma caused by allergens and symptoms that aren’t managed by treatment with an inhaled corticosteroid, in adults and certain children
  • chronic rhinosinusitis with nasal polyps that don’t respond to nasal corticosteroids, as an add-on medication in adults
  • chronic spontaneous urticaria, a type of hives, that continues causing symptoms despite treatment with an H1 antihistamine such as cetirizine, in adults and certain children
  • food allergy caused by a certain allergen called immunoglobulin E (IgE), in adults and certain children

Xolair contains the active ingredient (what makes a drug work) omalizumab. It’s a type of biologic drug.

It comes as a liquid solution for subcutaneous injection inside single-dose, pre-filled syringes and pens. It’s also available in a single-dose vial for use by a healthcare professional to give injections.

An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.

Keep reading to learn about Xolair’s possible interactions. And for more information about Xolair, including details about its uses, see this article.

Certain health conditions or other factors could raise your risk of harm if you take Xolair. In such cases, your doctor may not prescribe Xolair for you. These are known as contraindications.

If you’ve had an allergic reaction: If you’ve had an allergic reaction to Xolair or any of its ingredients, your doctor likely won’t prescribe Xolair 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 taking Xolair, talk with your doctor if the factor above applies to you. Your doctor can determine whether Xolair is safe for you to take.

Xolair isn’t known to interact with other drugs based on Xolair’s studies and reports since it was approved for use. But this doesn’t mean interactions with other medications can’t occur or won’t be discovered later.

Before you start using Xolair, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take before you start taking Xolair. Sharing this information with them may help prevent possible interactions that could be identified during your treatment.

(To learn whether Xolair interacts with herbs or vitamins and supplements, see the “Are there other interactions with Xolair?” section below.)

If you have questions about this, talk with your doctor or pharmacist.

Xolair isn’t known to interact with alcohol. But Xolair and alcohol can cause some similar side effects, such as abdominal pain and headache. So you may be more likely to experience these side effects if you drink alcohol during your Xolair treatment.

If you have questions about consuming alcohol while using Xolair, talk with your doctor or pharmacist.

Xolair may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below doesn’t include all other possible interactions with Xolair.

Does Xolair interact with supplements?

Before you start using Xolair, 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.

Xolair interactions with herbs

There are currently no reports of Xolair 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 Xolair.

Xolair interactions with vitamins

There are currently no reports of Xolair 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 Xolair.

Does Xolair interact with food?

There are currently no reports of Xolair interacting with food. If you have questions about eating certain foods during your treatment with Xolair, talk with your doctor.

Does Xolair interact with vaccines?

There are currently no reports of Xolair interacting with vaccines. If you have questions about getting certain vaccines during your Xolair treatment, talk with your doctor.

Does Xolair interact with lab tests?

There are currently no reports of Xolair interacting with lab tests. If you have questions about having certain lab tests during your treatment with Xolair, talk with the healthcare professional ordering the test.

Note: Xolair will elevate the level of an immune system protein called IgE. This elevation can persist for up to 1 year after you’ve ended treatment with Xolair. This isn’t technically an interaction with the lab test. But it’s important to let your doctor know that you’re taking Xolair if they order a test to check your IgE level.

Does Xolair interact with cannabis or CBD?

There are currently no reports of Xolair 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 Xolair.

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 Xolair. Before using Xolair, talk with your doctor about your health history. They’ll determine whether Xolair is right for you.

Health conditions or other factors that might interact with Xolair include:

Current or past parasitic infection: Treatment with Xolair can increase your risk of developing a parasitic infection. If you have a current parasitic infection, taking Xolair may worsen your infection. Your doctor may want to treat your infection first before prescribing Xolair to you.

Current or past cancer: People with current or past cancer were excluded from participating in studies on Xolair. New cancer was a very rare side effect reported by people treated with Xolair in these studies. It’s not known if Xolair will worsen an existing cancer, or if it could cause a previous cancer to come back. You can discuss the pros and cons of using Xolair with your doctor if this applies to you.

Pregnancy: If you’re pregnant or planning a pregnancy, talk with your doctor before using Xolair. Studies after Xolair was approved don’t show a risk of major complications if the drug is used during pregnancy. But it may cause low birth weight in the newborn. However, having untreated asthma is known to raise the risk of pregnancy complications.

Breastfeeding: It’s not known whether it’s safe to use Xolair 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 Xolair or any of its ingredients, your doctor will likely not prescribe Xolair. 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.

Latex allergy: The needle cap on Xolair prefilled syringes contains latex. Be sure to let your doctor know if you have a latex allergy before you start treatment with Xolair. They may suggest a treatment other than Xolair for you.

Find answers to some frequently asked questions about Xolair and possible interactions.

Can you take Xolair and prednisone together?

Yes, if your doctor prescribes both medications to you. Xolair and prednisone aren’t known to directly interact.

Both Xolair and prednisone are prescribed to treat asthma in certain situations. Prednisone is also used to treat many other conditions, such as multiple sclerosis.

Both Xolair and prednisone suppress activity in your immune system. This effect can be additive, meaning the effects of both drugs are greater than the effects of each drug. However, this will vary based on your health history.

Is it safe to take Xolair if I’m also taking Advair?

Yes, it should be safe to take Xolair with Advair. There is no known interaction between these drugs.

Xolair is used to treat asthma in certain situations in adults and certain children. Advair is also used to treat adults in adults and certain children. Advair is a type of drug called an inhaled corticosteroid (ICS). In studies for treating asthma, Xolair was used with ICS drugs.

If you have other questions about taking Xolair and Advair together, talk with your doctor or pharmacist.

Taking certain steps can help you avoid interactions with Xolair. 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. Your doctor or pharmacist can help you fill out a medication list.
  • What to do if you start taking a new drug during your Xolair treatment.

It’s also important to understand Xolair’s label and other paperwork that may come with the drug. Colored stickers that describe interactions may be on the label. And the paperwork (sometimes called the patient package insert or medication guide) may have other details about interactions.

(If you did not get paperwork with Xolair, ask your pharmacist to print a copy for you.)

If you have trouble reading or understanding this information, your doctor or pharmacist can help.

Using Xolair exactly as prescribed can also help prevent interactions.

If you still have questions about Xolair and its possible interactions, talk with your doctor.

Questions you may want to ask your doctor include:

  • Could I still take Xolair even if it interacts with a health condition I have?
  • If I take Xolair and have certain health conditions, will I be monitored more closely during treatment?
  • Should I let you know if I make lifestyle changes, such as to my diet or exercise routine?

To learn more about Xolair, see these articles:

To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.

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.