Drug interactions
Lonafarnib + Tofacitinib
Severity: Major
Lonafarnib and Tofacitinib: major interaction.
Last updated Sources: US FDA label
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
Lonafarnib inhibits CYP3A4 and may increase tofacitinib exposure, since tofacitinib is cleared mainly by CYP3A4 with a smaller CYP2C19 contribution. This may increase infection and cytopenia risk.
What this interaction means in plain words
Lonafarnib 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.
Lonafarnib belongs to Miscellaneous; Tofacitinib belongs to Musculoskeletal.
Why it happens
Lonafarnib inhibits CYP3A4 and to a lesser extent CYP2C19, reducing tofacitinib clearance.
What to do
Reduce the tofacitinib dose as for strong CYP3A4 inhibitors, or use an alternative. 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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Lonafarnib and Tofacitinib, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
Other interactions of Tofacitinib
- Baricitinib + Tofacitinib Contraindicated
- Cladribine + Tofacitinib Contraindicated
- Tofacitinib + Upadacitinib Contraindicated
- Abatacept + Tofacitinib Major
- Anti-thymocyte + Tofacitinib Major
- Antithymocyte globulin equine + Tofacitinib Major
Other interactions of Lonafarnib
- Alfuzosin + Lonafarnib Contraindicated
- Amobarbital + Lonafarnib Contraindicated
- Apalutamide + Lonafarnib Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Carbamazepine + Lonafarnib Contraindicated
- Clarithromycin + Lonafarnib Contraindicated
Frequently asked questions
Can I take Lonafarnib with Tofacitinib?
MediHelp rates the interaction as major. Lonafarnib 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. Lonafarnib inhibits CYP3A4 and may increase tofacitinib exposure, since tofacitinib is cleared mainly by CYP3A4 with a smaller CYP2C19 contribution. This may increase infection and cytopenia risk.
How serious is the interaction between Lonafarnib 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 for strong CYP3A4 inhibitors, or use an alternative. 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
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
