What the FDA labels say about taking them together
Allopurinol and aminophylline
Aminophylline's FDA label of May 22, 2026 names allopurinol in its drug interactions section; the allopurinol labels PlainMeds reads (4) do not name aminophylline. The aminophylline label: “30% increase Allopurinol Decreases theophylline clearance at allopurinol doses ≥600 mg/day.”
Check it at the source: the allopurinol FDA label on DailyMed (effective May 21, 2026, Rising Pharma Holdings, Inc.); the aminophylline FDA label on DailyMed (effective May 22, 2026, Hospira, Inc.).
What does the allopurinol label say about aminophylline?
Allopurinol's label (effective May 21, 2026) and its 3 other brand-application labels do not name aminophylline in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Allopurinol), Rising Pharma Holdings, Inc., effective May 21, 2026 (SPL set 30ad5ba2-1cef-4933-b104-0597f6a2aaa2), via openFDA; the full label on DailyMed
What does the aminophylline label say about allopurinol?
Aminophylline label, drug interactions30% increase Allopurinol Decreases theophylline clearance at allopurinol doses ≥600 mg/day.
Source: FDA drug label (Aminophylline), Hospira, Inc., effective May 22, 2026 (SPL set 9a663ef3-881f-48bd-2689-3713b24545c2), 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
| Allopurinol | Aminophylline | |
|---|---|---|
| Labeled for | Gout | Asthma |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0315 per tablet 100 mg tablet | n/a |
| 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