What the FDA labels say about taking them together
Leflunomide and rifampin
Leflunomide's FDA label of June 4, 2025 names rifampin in its drug interactions section; the rifampin label PlainMeds reads does not name leflunomide. The leflunomide label: “Concomitant use of ARAVA and rifampin, a potent inducer of CYP and transporters, increased the plasma concentration of teriflunomide by 40%.”
Check it at the source: the leflunomide FDA label on DailyMed (effective June 4, 2025, sanofi-aventis U.S. LLC); the rifampin FDA label on DailyMed (effective February 11, 2026, Lupin Pharmaceuticals, Inc.).
What does the leflunomide label say about rifampin?
Leflunomide label, drug interactionsConcomitant use of ARAVA and rifampin, a potent inducer of CYP and transporters, increased the plasma concentration of teriflunomide by 40%.
Source: FDA drug label (Arava), sanofi-aventis U.S. LLC, effective June 4, 2025 (SPL set 320f63f2-fac3-4aee-aff8-85724e00ef52), via openFDA; the full label on DailyMed
What does the rifampin label say about leflunomide?
Rifampin's label (effective February 11, 2026) does not name leflunomide in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (rifampin), Lupin Pharmaceuticals, Inc., effective February 11, 2026 (SPL set b56004f0-f23d-47f6-80c7-39884fccbccc), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Leflunomide | Rifampin | |
|---|---|---|
| Labeled for | Rheumatoid arthritis | n/a |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.324 per tablet 10 mg tablet | $0.679 per capsule 300 mg capsule |
| Shortage now | A presentation being discontinued | In shortage |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once