Leflunomide and Rifampin interaction
Leflunomide and Rifampin: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Leflunomide (Arava) label · effective 2025-06-04
Concomitant use of ARAVA and rifampin, a potent inducer of CYP and transporters, increased the plasma concentration of teriflunomide by 40%.
Because of the potential for ARAVA concentrations to continue to increase with multiple dosing, caution should be used if patients are to be receiving both ARAVA and rifampin [see Clinical Pharmacology (12.3) ] .
For other substrates of BCRP (e.g., mitoxantrone) and drugs in the OATP family (e.g., methotrexate, rifampin), especially HMG-Co reductase inhibitors (e.g., atorvastatin, nateglinide, pravastatin, repaglinide, and simvastatin), consider reducing the dose of these drugs and monitor patients closely for signs and symptoms of increased exposures to the drugs while…
However, when coadministered with the metabolite, teriflunomide, rifampin did not affect its pharmacokinetics.
No dosage adjustment is recommended for ARAVA when coadministered with rifampin.
From the Rifampin (Rifadin IV) label · effective 2026-05-27
Glipizide Decrease exposure Immunosuppressive Agents Cyclosporine Decrease exposure Tacrolimus Prevention or Management: Monitoring of whole blood concentrations and appropriate dosage adjustments of tacrolimus are recommended when rifampin and tacrolimus are used concomitantly.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.