What the FDA labels say about taking them together
Digoxin and fostamatinib
Fostamatinib's FDA label of November 5, 2025 names digoxin in its drug interactions section; the digoxin labels PlainMeds reads (3) do not name fostamatinib. The fostamatinib label: “P-Glycoprotein (P-gp) Substrates Concomitant use of TAVALISSE may increase concentrations of P-gp substrates (e.g., digoxin).”
Check it at the source: the digoxin FDA label on DailyMed (effective December 5, 2024, Advanz Pharma (US) Corp.); the fostamatinib FDA label on DailyMed (effective November 5, 2025, Rigel Pharmaceuticals, Inc.).
What does the digoxin label say about fostamatinib?
Digoxin's label (effective December 5, 2024) and its 2 other brand-application labels do not name fostamatinib in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (LANOXIN), Advanz Pharma (US) Corp., effective December 5, 2024 (SPL set d91e3646-4c63-4512-ab22-db39c085c4dc), via openFDA; the full label on DailyMed
What does the fostamatinib label say about digoxin?
Fostamatinib label, drug interactionsP-Glycoprotein (P-gp) Substrates Concomitant use of TAVALISSE may increase concentrations of P-gp substrates (e.g., digoxin).
Source: FDA drug label (TAVALISSE), Rigel Pharmaceuticals, Inc., effective November 5, 2025 (SPL set 21149cc3-049b-43e2-b141-c9499160556c), 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
| Digoxin | Fostamatinib | |
|---|---|---|
| Labeled for | Heart failure, Atrial fibrillation | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.133 per tablet 125 mcg tablet | n/a |
| 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