Digoxin and Felodipine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Digoxin
Felodipine
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased digoxin exposure and an increased risk of bradycardia and advanced complete heart block
Interaction Deep Dive
Coadministration of digoxin and felodipine (P-gp inhibitor and calcium channel blocker) may increase digoxin exposure, may also cause additive effects on AV node conduction which may result in bradycardia and advanced or complete heart block. Measure digoxin exposure before initiating concomitant drugs. Also, monitor potential signs and symptoms of clinical toxicity1234. In 12 patients with left ventricular failure on long-term digoxin treatment, administration of felodipine increased digoxin Cmax but not AUC or urinary excretion 5.
Why it happens (mechanism)
Inhibition of P-gp-mediated efflux transport of digoxin; additive effects on AV node conduction
Literature reports
1 report — tap to read
a) Concomitant felodipine and digoxin administration produces only transient increases in plasma digoxin concentrations which are not sustained with continued administration. Twelve patients with left ventricular failure who were on stable, long-term digoxin treatment received felodipine 2.5 mg or 5 mg twice daily for seven days, followed by seven days of washout and a further week of felodipine 10 mg twice daily. Following the first doses of felodipine 2.5 mg, 5 mg, and 10 mg, mean Cmax of digoxin was significantly increased by 35% to 39%. Digoxin AUC for 24 hours was not different from pretreatment values and no change in 24 hour urinary excretion of digoxin was observed. This interaction may be of clinical relevance only in patients whose plasma digoxin concentration is in the upper portion of the therapeutic range or in patients with pre-existing renal insufficiency. Impaired renal clearance may be the explanation for the increased peak plasma levels of digoxin seen in this study 5.
Common questions
Can I take Digoxin and Felodipine together?
Increased digoxin exposure and an increased risk of bradycardia and advanced complete heart block Always confirm with your pharmacist or prescriber before making any change.
How serious is the Digoxin and Felodipine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Digoxin or Felodipine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (5)
- Product Information: LANOXIN(R) oral tablets, digoxin oral tablets. Concordia Pharmaceuticals Inc (per FDA), Kansas City, MO, 2019. DailyMed
- Product Information: DIGOXIN oral tablets, digoxin oral tablets. Aurobindo Pharma USA, Inc. (per Dailymed), East Windsor, NJ, May. DailyMed
- Product Information: LANOXIN® intravenous, intramuscular injection, digoxin intravenous, intramuscular injection. Covis Pharma (per FDA), King of Prussia, PA, 2025. DailyMed
- Product Information: DIGOXIN intravenous injection, digoxin intravenous injection. Hikma Pharmaceuticals USA Inc. (per Dailymed), Berkeley Heights, NJ, 2023. DailyMed
- Rehnqvist N, Billing E, Moberg L, et al: Pharmacokinetics of felodipine and effect on digoxin plasma levels in patients with heart failure. Drugs 1987; 34(suppl 3):33-42. PubMed
Keep reading about Digoxin
Keep reading about Felodipine
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