Leflunomide and Teriflunomide interaction
Leflunomide and Teriflunomide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Leflunomide (Arava) label · effective 2025-06-04
Patients being treated with teriflunomide [see Drug Interactions (7) ] .
After stopping ARAVA, it is recommended that an accelerated drug elimination procedure be used to reduce the plasma concentrations of the active metabolite, teriflunomide.
If a woman becomes pregnant while taking ARAVA, stop treatment with ARAVA, apprise the patient of the potential risk to a fetus, and perform an accelerated drug elimination procedure to achieve nondetectable plasma concentrations of teriflunomide, the active metabolite of leflunomide [see Warnings and Precautions (5.3) ] .
Based on animal data, human plasma concentrations of teriflunomide of less than 0.02 mg/L (0.02 mcg/mL) are expected to have minimal embryo-fetal risk [see Contraindications (4) , Warnings and Precautions (5.3) , and Use in Specific Populations (8.1) ] .
From the Teriflunomide (Aubagio) label · effective 2026-02-20
Patients with a history of a hypersensitivity reaction to teriflunomide, leflunomide, or to any of the inactive ingredients in AUBAGIO.
Coadministration with leflunomide [see Clinical Pharmacology (12.3) ].
Fatal infections have been reported in the postmarketing setting in patients receiving leflunomide, especially Pneumocystis jirovecii pneumonia and aspergillosis.
No cases of serious pancytopenia were reported in premarketing clinical trials of AUBAGIO but rare cases of pancytopenia and agranulocytosis have been reported in the postmarketing setting with leflunomide.
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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.