Adalimumab and Leflunomide interaction

Adalimumab and Leflunomide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Adalimumab label · effective 2026-01-12

Major

It is uncertain whether the occurrence of HSTCL is related to use of a TNF blocker or a TNF blocker in combination with these other immunosuppressants [see Warnings and Precautions (5.2) ] .

Boxed warningby drug classView label on DailyMed

From the Leflunomide (Arava) label · effective 2025-06-04

Moderate

If used with concomitant methotrexate and/or other potential immunosuppressive agents, chronic monitoring should be monthly.

Warnings and precautionsby drug classView label on DailyMed
Minor

These events have been reported most frequently in patients who received concomitant treatment with methotrexate or other immunosuppressive agents, or who had recently discontinued these therapies; in some cases, patients had a prior history of a significant hematologic abnormality.

Warnings and precautionsby drug classView label on DailyMed

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Not 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.