Why Drug Interactions Matter with Yervoy

Yervoy (ipilimumab) is an immunotherapy that works by boosting your immune system's ability to fight cancer. Because it fundamentally changes how your immune system behaves, certain medications can interfere with its effectiveness or increase the risk of dangerous side effects.

Unlike many drugs that are processed through the liver (where most traditional drug interactions occur), Yervoy's interactions are primarily about immune system dynamics. Understanding these interactions can help you and your doctor make the safest choices during treatment.

For background on how Yervoy works, see our guide on Yervoy's mechanism of action.

Major Drug Interactions

Systemic Corticosteroids

This is the most important interaction to understand. Corticosteroids — such as prednisone, dexamethasone, and methylprednisolone — suppress the immune system. Since Yervoy works by activating the immune system, taking corticosteroids at baseline can reduce its effectiveness.

The nuance: Corticosteroids are actually the primary treatment for Yervoy's immune-mediated side effects. If you develop severe colitis, hepatitis, or other immune reactions, your doctor will prescribe high-dose steroids to calm the response. This use is considered necessary and appropriate.

The concern is using corticosteroids at the start of treatment or throughout treatment for other conditions, as this may blunt Yervoy's anti-cancer effect.

What to do: Tell your oncologist about any corticosteroids you're currently taking, including:

• Prednisone or prednisolone
• Dexamethasone
• Methylprednisolone
• Hydrocortisone (systemic, not topical)
• Budesonide (oral)

Your doctor will decide whether to taper you off steroids before starting Yervoy or adjust your treatment plan.

Other Immunosuppressants

Medications that suppress the immune system can reduce Yervoy's effectiveness. These include:

• Methotrexate — Used for autoimmune conditions like rheumatoid arthritis.
• Azathioprine (Imuran) — An immunosuppressant for autoimmune diseases and transplant patients.
• Cyclosporine and tacrolimus — Anti-rejection drugs for organ transplant recipients.
• Mycophenolate (CellCept) — Another anti-rejection and autoimmune medication.
• TNF inhibitors — Such as infliximab (Remicade) or adalimumab (Humira), sometimes used to treat immune-mediated colitis from Yervoy itself.

If you have an autoimmune condition requiring immunosuppressive therapy, your oncologist will carefully weigh the risks and benefits of starting Yervoy.

Live Vaccines

Avoid live vaccines while receiving Yervoy. Because Yervoy alters your immune response, live vaccines may pose unpredictable risks. Examples of live vaccines include:

• MMR (measles, mumps, rubella)
• Varicella (chickenpox)
• Yellow fever
• Nasal flu vaccine (FluMist)
• Rotavirus
• BCG (tuberculosis)

Inactivated vaccines (like the flu shot, COVID-19 vaccines, and pneumococcal vaccine) are generally considered safe. However, their effectiveness may be altered during Yervoy treatment. Talk to your oncologist before getting any vaccine.

Anticoagulants (Blood Thinners)

If you're taking blood thinners such as warfarin, apixaban (Eliquis), rivaroxaban (Xarelto), or enoxaparin (Lovenox), tell your oncologist. Yervoy can cause immune-mediated colitis, which involves inflammation of the intestinal lining. Anticoagulants can increase the risk of gastrointestinal bleeding if colitis develops.

Your doctor likely won't stop your blood thinner unless medically appropriate, but they will monitor you more closely for signs of GI bleeding, such as bloody or dark stools.

Moderate Drug Interactions

Other Checkpoint Inhibitors

Yervoy is frequently combined with nivolumab (Opdivo), which is an FDA-approved combination for several cancers. However, using two checkpoint inhibitors together significantly increases the risk and severity of immune-mediated side effects. Up to 60% of patients on the combination experience severe (grade 3-4) adverse events.

This combination is only used under careful medical supervision with specific approved protocols. Never take checkpoint inhibitors from different prescribers without each doctor being fully aware.

Hepatotoxic Drugs

Yervoy can cause immune-mediated hepatitis (liver inflammation). If you're taking other medications known to stress the liver, the combined effect could increase your risk. Examples include:

• Acetaminophen (Tylenol) in high doses
• Statins (cholesterol medications)
• Certain antibiotics and antifungals
• Alcohol (not a drug interaction per se, but adds liver stress)

Your oncologist will monitor your liver enzymes before each infusion. Report any symptoms like yellowing skin, dark urine, or right-sided abdominal pain immediately.

Food and Supplement Interactions

Yervoy is administered intravenously, so there are no direct food interactions. You don't need to eat or fast before an infusion. However, some supplements may affect your immune system:

• Immune-boosting supplements (echinacea, elderberry, astragalus) — These could theoretically over-stimulate your immune system alongside Yervoy. Discuss any supplements with your oncologist.
• High-dose antioxidants — Some researchers question whether megadoses of vitamins C or E could interfere with cancer treatment. The evidence is unclear, but it's worth mentioning to your doctor.
• Turmeric/curcumin — Has anti-inflammatory properties that could theoretically interact with immune modulation. Tell your doctor if you take it regularly.

What to Tell Your Doctor Before Starting Yervoy

Bring a complete list of everything you take, including:

• All prescription medications
• Over-the-counter drugs (pain relievers, antacids, allergy medications)
• Vitamins and supplements
• Herbal remedies
• Any recent vaccinations

Also inform your doctor about:

• Any autoimmune conditions (rheumatoid arthritis, lupus, Crohn's disease, ulcerative colitis, psoriasis, etc.)
• History of organ transplant
• History of liver disease
• Pregnancy or plans to become pregnant

Can You Take Pain Medication During Yervoy Treatment?

This is a common question. Here's a general guide:

• Acetaminophen (Tylenol) — Generally safe in recommended doses, but avoid excessive use due to liver concerns. Your doctor will monitor liver function.
• NSAIDs (ibuprofen, naproxen) — Use with caution. These may mask fever (an important symptom to monitor) and can irritate the GI tract.
• Opioids — If prescribed for cancer pain, these don't directly interact with Yervoy, but they can cause constipation, which may complicate monitoring for GI side effects.

Always check with your oncology team before taking any new medication, even over-the-counter ones.

The Bottom Line

Yervoy's drug interactions are mostly about protecting its immune-boosting mechanism and managing the risks that come with an activated immune system. The most important thing you can do is maintain open communication with your oncologist about every medication, supplement, and health condition.

For more about Yervoy, read our guides on side effects, uses and dosage, and finding a prescribing doctor.