What the FDA labels say about taking them together
Digoxin and lapatinib ditosylate
Lapatinib ditosylate's FDA label of November 30, 2023 names digoxin in its drug interactions section; the digoxin labels PlainMeds reads (3) do not name lapatinib ditosylate. The lapatinib ditosylate label: “Following coadministration of TYKERB and digoxin (P-gp substrate), systemic AUC of an oral digoxin dose increased approximately 2.8-fold.”
Check it at the source: the digoxin FDA label on DailyMed (effective December 5, 2024, Advanz Pharma (US) Corp.); the lapatinib ditosylate FDA label on DailyMed (effective November 30, 2023, Teva Pharmaceuticals, Inc.).
What does the digoxin label say about lapatinib ditosylate?
Digoxin's label (effective December 5, 2024) and its 2 other brand-application labels do not name lapatinib ditosylate 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 lapatinib ditosylate label say about digoxin?
Lapatinib ditosylate label, drug interactionsFollowing coadministration of lapatinib and digoxin (P-gp substrate), systemic AUC of an oral digoxin dose increased approximately 2.8-fold.
Source: FDA drug label (Tykerb, NDA022059), Novartis Pharmaceuticals Corporation, effective January 27, 2026 (SPL set eee37f88-ec6a-4c30-b8aa-e2c71f93088c), via openFDA
Source: FDA drug label (Lapatinib), Teva Pharmaceuticals, Inc., effective November 30, 2023 (SPL set b09abf73-1eef-4e12-b400-c030d546d223), 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 | Lapatinib ditosylate | |
|---|---|---|
| Labeled for | Heart failure, Atrial fibrillation | Breast cancer |
| Boxed warning | No | Yes |
| 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