What the FDA labels say about taking them together
Digoxin and ritonavir
Digoxin's FDA label (Lanoxin) of October 17, 2025 names ritonavir in its drug interactions section, and ritonavir's label names digoxin too. The ritonavir label: “Concomitant administration of ritonavir with digoxin may increase digoxin levels. Caution should be exercised when co-administering ritonavir with digoxin, with appropriate monitoring of serum digoxin levels.”
Check it at the source: the digoxin FDA label on DailyMed (effective December 5, 2024, Advanz Pharma (US) Corp.); the ritonavir FDA label on DailyMed (effective July 23, 2026, AbbVie Inc.).
What does the digoxin label say about ritonavir?
Lanoxin label (Covis Pharma US, Inc, October 17, 2025), drug interactionsRitonavir NA 86% Digoxin concentrations increased less than 50% Amiodarone 17% 40% Measure serum digoxin concentrations before initiating concomitant drugs.
Source: FDA drug label (Lanoxin, NDA009330), Covis Pharma US, Inc, effective October 17, 2025 (SPL set 9ec84cac-6ecc-43dc-8006-6ccc029e2707), via openFDA
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 ritonavir label say about digoxin?
Ritonavir label, drug interactionsConcomitant Drug Class/Drug Name: Digoxin; Effect on Concentration of Ritonavir or Concomitant Drug: ↑ digoxin; Clinical Comment: Concomitant administration of ritonavir with digoxin may increase digoxin levels. Caution should be exercised when co-administering ritonavir with digoxin, with appropriate monitoring of serum digoxin levels.
Ritonavir label, warnings and precautionsThe impact on the PR interval of co-administration of ritonavir with other drugs that prolong the PR interval (including calcium channel blockers, beta-adrenergic blockers, digoxin and atazanavir) has not been evaluated.
Source: FDA drug label (Norvir), AbbVie Inc., effective July 23, 2026 (SPL set 2849298e-de6e-47bb-8194-56e075b33fc3), 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 | Ritonavir | |
|---|---|---|
| Labeled for | Heart failure, Atrial fibrillation | HIV |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.133 per tablet 125 mcg tablet | $0.607 per tablet 100 mg tablet |
| Shortage now | No current entry | A presentation being discontinued |
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