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Drug interactions

Saquinavir + Tofacitinib

Severity: Major

Saquinavir 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

Saquinavir, usually given with ritonavir, inhibits CYP3A4 and can increase tofacitinib levels. This increases the risk of infection and hematologic toxicity.

What this interaction means in plain words

Saquinavir 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.

Evidence level: Moderate

Why it happens

Inhibition of CYP3A4-mediated tofacitinib metabolism.

What to do

Reduce the tofacitinib dose as labeled for potent CYP3A4 inhibitors. Monitor 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 Saquinavir with Tofacitinib?

MediHelp rates the interaction as major. Saquinavir 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. Saquinavir, usually given with ritonavir, inhibits CYP3A4 and can increase tofacitinib levels. This increases the risk of infection and hematologic toxicity.

How serious is the interaction between Saquinavir 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: Reduce the tofacitinib dose as labeled for potent CYP3A4 inhibitors. Monitor 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

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