What the FDA labels say about taking them together
Leflunomide and tizanidine
Leflunomide's FDA label of June 4, 2025 names tizanidine in its drug interactions section; the tizanidine labels PlainMeds reads (3) do not name leflunomide. The leflunomide label: “In patients taking ARAVA, exposure of drugs metabolized by CYP1A2 may be reduced.”
Check it at the source: the leflunomide FDA label on DailyMed (effective June 4, 2025, sanofi-aventis U.S. LLC); the tizanidine FDA label on DailyMed (effective January 2, 2026, Legacy Pharma USA, Inc.).
What does the leflunomide label say about tizanidine?
Leflunomide label, drug interactionsIn patients taking ARAVA, exposure of drugs metabolized by CYP1A2 (e.g., alosetron, duloxetine, theophylline, tizanidine) may be reduced.
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 tizanidine label say about leflunomide?
Tizanidine's label (effective January 2, 2026) and its 2 other brand-application labels do 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 (Zanaflex), Legacy Pharma USA, Inc., effective January 2, 2026 (SPL set 60c27d35-7349-4fc6-86ad-70fffdbe3e08), 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 | Tizanidine | |
|---|---|---|
| Labeled for | Rheumatoid arthritis | Muscle spasms and spasticity |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.324 per tablet 10 mg tablet | $0.0331 per tablet 4 mg tablet |
| Shortage now | A presentation being discontinued | No current entry |
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