Ibrutinib Interactions: — Blood Thinners, Antifungals and Fish Oil

Not without involving your oncology team first. Fluconazole blocks CYP3A4, the enzyme that clears ibrutinib, and can push ibrutinib levels significantly higher than intended. Your team will usually switch you to a topical antifungal — a cream or pessary — that does not absorb into the bloodstream and does not interact. If you have already taken a dose from a pharmacist, call your oncology team the same day and tell them.

Paracetamol at standard doses is generally the safer choice for pain or fever on ibrutinib. It does not meaningfully affect platelets or CYP3A4 the way ibuprofen and other NSAIDs do. Avoid ibuprofen and diclofenac unless your team has specifically said otherwise. Tell your oncology team about any regular paracetamol use, because high doses — particularly with alcohol — carry their own liver risks.

No. Grapefruit and Seville orange contain compounds that block CYP3A4 in the gut, which can raise ibrutinib levels unpredictably. This applies to the fresh fruit and to juice. Sweet orange and most other citrus are not affected in the same way, but if you are unsure about a specific product, ask your pharmacist before drinking it.

Many herbal preparations have not been studied in combination with ibrutinib, and some are known to affect liver enzymes or platelet function. St John's Wort is a clear risk. Several Ayurvedic formulations have not been tested at all. Do not stop anything you have been using for years without discussing it, but bring every supplement, herb and traditional preparation to your next appointment. Your oncology team needs that information to keep you safe — they are not there to judge the choice.

This is a decision your oncologist and cardiologist need to make together — do not stop or continue on your own. Aspirin adds to ibrutinib's effect on platelets and the combination can lead to serious bleeding. At the same time, stopping a cardiac aspirin carries its own risks depending on your heart history. If you have not already told your cardiologist you are starting ibrutinib, that call should happen before your first dose.

Tell your dentist you are on ibrutinib before any extraction, implant or procedure that could cause bleeding. Ibrutinib's effect on platelets is real and dental procedures are one of the situations where it matters most. Your oncology team may advise a short break from ibrutinib before a planned procedure — that timing is for them to decide, not the dentist. Carry a medicines card to every dental appointment, including routine scale-and-polish visits.

Some do and some do not. Diltiazem and verapamil — calcium-channel blockers sometimes used for blood pressure or heart rhythm — are moderate CYP3A4 inhibitors and can raise ibrutinib levels. Amlodipine and ACE inhibitors are generally of lower concern for this interaction. Your oncologist should review your full blood pressure regimen when ibrutinib is started. Bring a complete list of everything you take to that first appointment.

Tell your oncology team immediately — this is an urgent conversation. Rifampicin is one of the most powerful inducers of CYP3A4 and can reduce ibrutinib to levels where it may not control your cancer. Your oncology team will need to work with the TB team to decide whether ibrutinib can continue, whether dose adjustment under close monitoring is possible, or whether TB can be managed with a regimen that does not include rifampicin. Do not start rifampicin before that discussion has happened.