Why Drug Interactions Matter with Eohilia

If you've been prescribed Eohilia (Budesonide oral suspension) for eosinophilic esophagitis (EoE), it's important to know which medications and foods can interact with it. Drug interactions can change how much Budesonide your body absorbs, which can increase your risk of side effects or make the medication less effective.

Eohilia's active ingredient, Budesonide, is processed by a specific enzyme in your liver called CYP3A4. Anything that slows down this enzyme can cause Budesonide to build up in your body to higher-than-intended levels. This article explains the key interactions to know about.

How Budesonide Is Processed in Your Body

When you swallow Eohilia, some of the Budesonide passes through your esophagus (where it does its work) and gets absorbed into your bloodstream. Your liver then breaks down the Budesonide using the CYP3A4 enzyme — a process called metabolism.

This liver breakdown is actually one of the reasons Eohilia has fewer body-wide side effects than systemic steroids. Your liver clears most of the absorbed Budesonide before it can circulate widely. This is called high first-pass metabolism.

The problem is that certain drugs and foods can block or slow down the CYP3A4 enzyme. When that happens, more Budesonide stays in your bloodstream for longer, which increases the risk of corticosteroid side effects like adrenal suppression, immune suppression, and Cushing's syndrome symptoms.

Medications That Interact with Eohilia

The following medications are CYP3A4 inhibitors that can increase Budesonide levels in your body. Tell your doctor if you're taking any of them:

Antifungal Medications

• Ketoconazole — One of the strongest CYP3A4 inhibitors. Studies have shown it can increase Budesonide blood levels by several times.
• Itraconazole — Another potent antifungal that significantly increases Budesonide exposure.

This creates a potential problem: if you develop oral or esophageal candidiasis (thrush) from Eohilia — which is a common side effect — and your doctor prescribes an antifungal, the antifungal might increase your Budesonide levels. Make sure your doctor is aware you're taking Eohilia.

HIV Medications

• Ritonavir
• Indinavir
• Saquinavir

These protease inhibitors are strong CYP3A4 inhibitors. If you're taking any HIV medications, your doctor needs to know before prescribing Eohilia.

Antibiotics

• Erythromycin — A macrolide antibiotic that inhibits CYP3A4. Other macrolides like clarithromycin may also interact, though they aren't specifically listed in Eohilia's labeling.

Immunosuppressants

• Cyclosporine — Used for organ transplant patients and some autoimmune conditions. It inhibits CYP3A4 and can raise Budesonide levels.

Grapefruit Juice: A Surprising Interaction

Grapefruit and grapefruit juice are natural CYP3A4 inhibitors. Drinking grapefruit juice while taking Eohilia can increase the amount of Budesonide in your blood.

The official guidance is simple: avoid grapefruit juice during your 12-week Eohilia treatment. This includes:

• Fresh grapefruit
• Grapefruit juice (fresh or from concentrate)
• Grapefruit-containing drinks or supplements

Other citrus fruits like oranges, lemons, and limes do not have the same effect and are fine to consume.

Other Corticosteroids

If you're using other corticosteroid medications while taking Eohilia, the combined steroid exposure can increase your risk of side effects. Examples include:

• Steroid inhalers for asthma (fluticasone, beclomethasone, other Budesonide inhalers)
• Nasal steroid sprays (Flonase, Rhinocort)
• Steroid creams for eczema or skin conditions
• Oral steroids like Prednisone

None of these are necessarily prohibited with Eohilia, but your doctor should be aware of your total corticosteroid exposure. The risk of adrenal suppression and other steroid side effects increases when you're using multiple corticosteroid products.

Medications That Are Generally Safe with Eohilia

While you should always tell your doctor about every medication you take, these common drug categories do not have known significant interactions with Eohilia:

• Proton pump inhibitors (PPIs) like omeprazole or pantoprazole — Many EoE patients take PPIs alongside Eohilia. There is no known interaction.
• Common pain relievers like acetaminophen (Tylenol)
• Antihistamines like cetirizine (Zyrtec) or loratadine (Claritin)

However, "no known interaction" doesn't mean you shouldn't mention these to your doctor. Always provide a complete medication list.

What to Tell Your Doctor Before Starting Eohilia

Before your first dose of Eohilia, make sure your doctor knows about:

• All prescription medications you take
• Over-the-counter medications including antifungals, antibiotics, and pain relievers
• Herbal supplements — some may affect CYP3A4 (e.g., St. John's Wort can decrease Budesonide levels)
• Other corticosteroids you use (inhalers, nasal sprays, creams)
• Whether you regularly drink grapefruit juice

If you start a new medication during your Eohilia treatment, tell both your prescribing doctor and your pharmacist so they can check for interactions.

What Happens If You Have an Interaction?

If you take a CYP3A4 inhibitor along with Eohilia, you may experience increased corticosteroid effects, including:

• Greater risk of adrenal suppression
• Increased risk of infections due to immune suppression
• Symptoms of hypercorticism (puffy face, weight gain, easy bruising)
• More frequent or severe candidiasis

If you need a medication that interacts with Eohilia, your doctor may:

• Adjust the timing of your medications
• Choose an alternative drug that doesn't inhibit CYP3A4
• Monitor you more closely for side effects
• In some cases, adjust your Eohilia treatment plan

The Bottom Line

The most important Eohilia drug interactions involve CYP3A4 inhibitors — medications and foods that slow down how your liver processes Budesonide. Key culprits include ketoconazole, itraconazole, HIV protease inhibitors, erythromycin, cyclosporine, and grapefruit juice.

Always give your doctor a complete list of everything you take, and avoid grapefruit during treatment. If you have questions about a specific medication, don't guess — ask your doctor or pharmacist.

For more about what to expect during treatment, read our guides on Eohilia side effects and what Eohilia is and how to take it.