Does Xolair Interact with Other Medications?

One of the advantages of Xolair (Omalizumab) is that it has fewer drug interactions than many other medications. Because it's a monoclonal antibody that specifically targets IgE rather than being processed through the liver like most pills, it doesn't interfere with the same metabolic pathways that cause most drug-drug interactions.

That said, there are still important interactions and precautions you need to know about. This guide covers what to avoid, what to use with caution, and what to tell your doctor before starting Xolair.

Medications to Use with Caution While on Xolair

Corticosteroids (Prednisone, Prednisolone, etc.)

Many patients starting Xolair are already taking corticosteroids for asthma or other allergic conditions. Here's the critical point: do not abruptly stop corticosteroids when you start Xolair.

Stopping corticosteroids too quickly can cause:

• Rebound worsening of asthma or allergic symptoms
• Adrenal insufficiency (your body may not be producing enough natural cortisol)
• Unmasking of eosinophilic conditions like Churg-Strauss syndrome

Your doctor will gradually taper your corticosteroid dose over time as Xolair takes effect. Never adjust corticosteroid doses on your own.

Other Biologic Therapies

Avoid using Xolair at the same time as other monoclonal antibodies targeting similar immune pathways. These include:

• Dupixent (Dupilumab)
• Nucala (Mepolizumab)
• Fasenra (Benralizumab)
• Tezspire (Tezepelumab)

Combining biologics hasn't been well studied and could increase the risk of immune suppression or unexpected side effects. If your doctor is switching you from one biologic to another, they'll typically stop one before starting the other.

Other Immunosuppressants

While there are no well-established drug-drug interactions, caution is advised when using Xolair alongside other immunosuppressive medications, such as:

• Methotrexate
• Cyclosporine
• Azathioprine
• Mycophenolate

Xolair modifies the immune response, and combining it with other immunosuppressants could theoretically increase infection risk. Your doctor will weigh the benefits and risks.

Allergen Immunotherapy (Allergy Shots)

Xolair and allergen immunotherapy (allergy shots or sublingual immunotherapy) can be used together, and some studies suggest Xolair may actually reduce the risk of allergic reactions during immunotherapy. However, your doctor should monitor you closely, as both treatments affect the immune system.

Vaccines and Xolair

Live Vaccines

There is a theoretical concern that Xolair could alter the immune response to live vaccines, since it modifies IgE-mediated immunity. Live vaccines include:

• MMR (measles, mumps, rubella)
• Varicella (chickenpox)
• Yellow fever
• Nasal flu spray (FluMist)

Talk to your doctor about timing if you need a live vaccine while on Xolair. They may recommend scheduling the vaccine at a specific time relative to your Xolair injections.

Inactivated Vaccines

Inactivated vaccines — including flu shots, COVID-19 vaccines, tetanus, and most other routine vaccines — are generally considered safe to receive while on Xolair. There's no evidence that Xolair reduces their effectiveness.

Food and Dietary Interactions

Xolair has no known food interactions. You don't need to change your diet or avoid specific foods because of Xolair itself.

However, if you're taking Xolair for the food allergy indication, remember:

• You must continue avoiding your trigger foods even while on Xolair
• Xolair reduces the severity of reactions from accidental exposure but does not eliminate your food allergy
• Do not intentionally eat trigger foods to "test" your tolerance without medical supervision

Over-the-Counter Medications

Most OTC medications are safe to take with Xolair, including:

• Antihistamines (Zyrtec, Claritin, Benadryl) — safe and often still used alongside Xolair for chronic hives
• Pain relievers (Tylenol, Advil, Aleve) — no known interactions
• Decongestants — no known interactions
• Inhalers — continue using your prescribed asthma inhalers

Always tell your doctor about all medications you take, including OTC products and supplements, but there are no major red flags with common OTC medications.

Supplements and Herbal Products

There are no well-documented interactions between Xolair and supplements or herbal products. However, some supplements can affect the immune system, so it's worth mentioning to your doctor if you take:

• Echinacea or other immune-boosting supplements
• High-dose vitamin D
• Fish oil (high doses may have mild immune effects)
• Turmeric/curcumin supplements

What to Tell Your Doctor Before Starting Xolair

Before your first Xolair injection, make sure your doctor knows about:

• All medications you take — prescription, OTC, and supplements
• Other biologic medications you're currently on or recently stopped
• Corticosteroid use — type, dose, and how long you've been taking them
• Allergy history — especially latex allergy (the needle cap contains natural rubber latex)
• Pregnancy or breastfeeding — Xolair is Pregnancy Category B, meaning animal studies haven't shown harm, but there's limited human data
• Travel plans — especially to areas where parasitic infections are common, since Xolair may reduce your body's ability to fight parasites
• Upcoming vaccinations — particularly live vaccines
• History of anaphylaxis — from any cause

Can You Drink Alcohol While Taking Xolair?

There is no known interaction between Xolair and alcohol. Moderate alcohol consumption is generally fine while on Xolair. However, if you notice that alcohol worsens your allergic symptoms (which some people report), discuss it with your doctor.

Special Situations

Surgery

If you're planning surgery, tell your surgeon and anesthesiologist that you're taking Xolair. While there are no specific surgical contraindications, your medical team should be aware of all your medications.

Dental Procedures

Xolair does not typically affect dental care. No special precautions are needed for routine dental work.

Starting New Medications

If any doctor prescribes a new medication while you're on Xolair, remind them about your Xolair treatment. This is especially important if the new medication is a biologic or immunosuppressant.

Final Thoughts

Xolair has a relatively clean interaction profile compared to many medications. The most important precautions involve corticosteroid tapering, avoiding concurrent biologics, and being thoughtful about live vaccines. Beyond that, most patients can continue their normal medications and supplements without concern.

The key is communication: make sure every doctor you see knows you're on Xolair. For more about Xolair, read our guides on how Xolair works, side effects to watch for, and how to save money on your prescription.