What the FDA labels say about taking them together
Nilutamide and theophylline
Nilutamide's FDA label of June 26, 2026 names theophylline in its drug interactions section; the theophylline label PlainMeds reads does not name nilutamide. The nilutamide label: “Consequently, drugs with a low therapeutic margin, such as vitamin K antagonists, phenytoin, and theophylline, could have a delayed elimination and increases in their serum half-life leading to a toxic level.”
Check it at the source: the nilutamide FDA label on DailyMed (effective June 26, 2026, ANI Pharmaceuticals, Inc.); the theophylline FDA label on DailyMed (effective March 10, 2026, Strides Pharma Science Limited).
What does the nilutamide label say about theophylline?
Nilutamide label, drug interactionsConsequently, drugs with a low therapeutic margin, such as vitamin K antagonists, phenytoin, and theophylline, could have a delayed elimination and increases in their serum half-life leading to a toxic level.
Source: FDA drug label (Nilutamide), ANDA207631 (Ani Pharms), as published by ANI Pharmaceuticals, Inc., effective June 26, 2026 (SPL set d5740b8f-fbb3-4023-9133-9e359a9ab980), via openFDA; the full label on DailyMed
What does the theophylline label say about nilutamide?
Theophylline's label (effective March 10, 2026) does not name nilutamide 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
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
| Nilutamide | Theophylline | |
|---|---|---|
| Labeled for | Prostate cancer | Asthma |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $0.330 per tablet 300 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