What the FDA labels say about taking them together
Digoxin and lonafarnib
Lonafarnib's FDA label of July 2, 2025 names digoxin in its drug interactions section; the digoxin labels PlainMeds reads (3) do not name lonafarnib. The lonafarnib label: “P-gp Substrates Clinical Impact Lonafarnib is a weak P-gp inhibitor. Coadministration of ZOKINVY with a P-gp substrate increases the AUC and C max of the P-gp substrate, which may increase the risk of the P-gp …”
Check it at the source: the digoxin FDA label on DailyMed (effective December 5, 2024, Advanz Pharma (US) Corp.); the lonafarnib FDA label on DailyMed (effective July 2, 2025, Sentynl Therapeutics, Inc.).
What does the digoxin label say about lonafarnib?
Digoxin's label (effective December 5, 2024) and its 2 other brand-application labels do not name lonafarnib 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 lonafarnib label say about digoxin?
Lonafarnib label, drug interactionsP-gp Substrates Clinical Impact Lonafarnib is a weak P-gp inhibitor. Coadministration of ZOKINVY with a P-gp substrate increases the AUC and C max of the P-gp substrate [see Clinical Pharmacology ( 12.3 )], which may increase the risk of the P-gp substrate's adverse reactions. Prevention or Management When ZOKINVY is coadministered with P-gp substrates (e.g., digoxin, dabigatran) where minimal concentration changes may lead to serious or life-threatening toxicities, monitor for adverse reactions and reduce the dosage of the P-gp substrate in accordance with its approved product labeling.
Source: FDA drug label (Zokinvy), Sentynl Therapeutics, Inc., effective July 2, 2025 (SPL set 97391d0c-943e-4c5a-8423-68e163aa7f50), 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 | Lonafarnib | |
|---|---|---|
| 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