Captopril and Digoxin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Digoxin
Captopril
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
Interaction Deep Dive
Coadministration of digoxin and captopril (P-gp inhibitor) may increase digoxin exposure. Drugs that affect renal function, like captopril (ACE inhibitor), may impair the excretion of digoxin. Measure digoxin exposure before initiating concomitant drugs. Reduce digoxin concentrations by decreasing dose by approximately 30-50% or by modifying the dosing frequency and continue monitoring. Also, monitor potential signs and symptoms of clinical toxicity is necessary when initiating, adjusting, or discontinuing captopril2.
Why it happens (mechanism)
Inhibition of P-gp mediated efflux transport of digoxin; reduced GFR or tubular secretion; impaired secretion of digoxin
Literature reports
1 report — tap to read
a) During pharmacokinetic studies, coadministration of captopril and oral digoxin resulted in a 58% increase in digoxin serum concentrations and a 39% increase in digoxin AUC 1.
Common questions
Can I take Captopril and Digoxin together?
Increased digoxin exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Captopril and Digoxin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
Questions for your pharmacist
- Does my dose of Captopril or Digoxin 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 (2)
- Product Information: DIGOXIN oral tablets, digoxin oral tablets. Aurobindo Pharma USA, Inc. (per Dailymed), East Windsor, NJ, May. DailyMed
- Product Information: DIGOXIN intravenous injection, digoxin intravenous injection. Hikma Pharmaceuticals USA Inc. (per Dailymed), Berkeley Heights, NJ, 2023. DailyMed
Keep reading about Digoxin
Keep reading about Captopril
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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