What the FDA labels say about taking them together
Theophylline and zileuton
Zileuton's FDA label of July 29, 2022 names theophylline in its drug interactions section; the theophylline label PlainMeds reads does not name zileuton. The zileuton label: “Reduce theophylline dose and monitor levels. Zileuton increases warfarin levels.”
Check it at the source: the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited); the zileuton FDA label on DailyMed (effective July 29, 2022, Strides Pharma Science Limited).
What does the theophylline label say about zileuton?
Theophylline's label (effective March 10, 2026) does not name zileuton in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Theophylline), Strides Pharma Science Limited, effective March 10, 2026 (SPL set b7a90ccf-9c32-40cc-9008-7e55b3da4dfd), via openFDA; the full label on DailyMed
What does the zileuton label say about theophylline?
Zileuton label, drug interactionsReduce theophylline dose and monitor levels. (7.1) Zileuton increases warfarin levels.
Source: FDA drug label (Zileuton), Strides Pharma Science Limited, effective July 29, 2022 (SPL set a826d16f-df07-447b-b050-b9a02ea1f89e), 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
| Theophylline | Zileuton | |
|---|---|---|
| Labeled for | Asthma | Asthma |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.330 per tablet 300 mg tablet | $2.05 per tablet 600 mg tablet |
| Shortage now | No current entry | 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