What the FDA labels say about taking them together
Digoxin and primaquine
Primaquine's FDA label of February 11, 2026 names digoxin in its drug interactions section; the digoxin labels PlainMeds reads (3) do not name primaquine. The primaquine label: “P-gp Substrates Refer to the Prescribing Information for a P-gp substrate where minimal concentration changes may lead to serious adverse reactions for the recommended dosage modification and/or monitoring.”
Check it at the source: the digoxin FDA label on DailyMed (effective December 5, 2024, Advanz Pharma (US) Corp.); the primaquine FDA label on DailyMed (effective February 11, 2026, Sanofi-Aventis U.S. LLC).
What does the digoxin label say about primaquine?
Digoxin's label (effective December 5, 2024) and its 2 other brand-application labels do not name primaquine 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 primaquine label say about digoxin?
Primaquine label, drug interactionsP-gp Substrates Refer to the Prescribing Information for a P-gp substrate where minimal concentration changes may lead to serious adverse reactions (e.g., digoxin and dabigatran) for the recommended dosage modification and/or monitoring.
Source: FDA drug label (Primaquine Phosphate), Sanofi-Aventis U.S. LLC, effective February 11, 2026 (SPL set 1bfbf4ae-81b8-4160-a00d-6322aadd4b59), 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 | Primaquine | |
|---|---|---|
| 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