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Drug interactions

Idelalisib + Tofacitinib

Severity: Major

Idelalisib and Tofacitinib: major interaction.

Last updated

For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.

Summary

Idelalisib is a strong CYP3A inhibitor and may raise tofacitinib concentrations. It is also immunosuppressive and associated with serious infections, so risk is compounded.

What this interaction means in plain words

Idelalisib and Tofacitinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.

Idelalisib belongs to Oncology; Tofacitinib belongs to Musculoskeletal.

Evidence level: Moderate

Why it happens

CYP3A4 inhibition reduces tofacitinib clearance, combined with additive immunosuppression from PI3K delta inhibition.

What to do

Avoid the combination if possible; otherwise reduce tofacitinib per strong CYP3A4 inhibitor labeling. Monitor closely for infection and cytopenias.

What to ask your pharmacist

  • Does the benefit of taking both outweigh the risk in my case?
  • Do I need any blood test, ECG or other check while on both?
  • What early warning signs should I watch for, and what should I do if they appear?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Idelalisib with Tofacitinib?

MediHelp rates the interaction as major. Idelalisib and Tofacitinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Idelalisib is a strong CYP3A inhibitor and may raise tofacitinib concentrations. It is also immunosuppressive and associated with serious infections, so risk is compounded.

How serious is the interaction between Idelalisib and Tofacitinib?

MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination if possible; otherwise reduce tofacitinib per strong CYP3A4 inhibitor labeling. Monitor closely for infection and cytopenias.

What other medicines interact with Tofacitinib?

MediHelp also lists interactions of Tofacitinib with, for example, Baricitinib, Cladribine, Upadacitinib. The full list is on the Tofacitinib page.

Full monographs, dosing and an interaction checker in the MediHelp app

Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.

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