Drug Interaction Report

Digitoxin and Furosemide Injection: Interaction Details

A pharmacist-reviewed analysis of the Digitoxin and Furosemide Injection interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Furosemide Injection

Disal Furoscix Furoscix® Lasix Lasix® Salix - substance
+

Digitoxin

No brand names on record
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
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.

Of 14 documented Digitoxin interactions, 1 is rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
delayed
Evidence
probable
Severity
Major

What happens

Digitoxin toxicity (nausea, vomiting, cardiac arrhythmias)

Interaction Deep Dive

Concomitant loop diuretic and digitalis therapy can result in digitalis toxicity secondary to hypokalemia and possibly hypomagnesemia1234567.

Why it happens (mechanism)

Diuretic-induced hypokalemia and hypomagnesemia enhance Na-K-ATPase inhibition by cardiac glycosides

Common questions

Can I take Digitoxin and Furosemide Injection together?

Digitoxin toxicity (nausea, vomiting, cardiac arrhythmias) Always confirm with your pharmacist or prescriber before making any change.

How serious is the Digitoxin and Furosemide Injection interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

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 Digitoxin or Furosemide Injection 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 (7)

  1. Tannen RL: Diuretic-induced hypokalemia (clinical conference). Kidney Int 1985; 28:988-1000. DOI
  2. Whang R, Oei TO, & Watanabe A: Frequency of hypomagnesemia in hospitalized patients receiving digitalis. Arch Intern Med 1985; 145:655-656. DOI
  3. Knochel JP: Diuretic-induced hypokalemia. Am J Med 1984; 77:18-27. PubMed
  4. Sandor FF, Pickens PT, & Crallan J: Variations of plasma potassium concentrations during long-term treatment of hypertension with diuretics without potassium supplements. Br Med J 1982; 284:711-715. DOI
  5. Iseri LT, Freed J, & Bures AR: Magnesium deficiency and cardiac disorders. Am J Med 1975; 58:837-846. DOI
  6. Steiness E & Olesen KH: Cardiac arrhythmias induced by hypokalemia and potassium loss during maintenance digoxin therapy. Br Heart J 1976; 38:167-172.
  7. Shapiro S, Slone D, Lewis GP, et al: The epidemiology of digoxin. A study in three Boston hospitals. J Chron Dis 1969; 22:361-371. DOI
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Furosemide Injection

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Beyond drug–drug

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:

Digitoxin + Activated Charcoal Coffee Charcoal European Mandrake Glucomannan Guar Gum Gum Arabic Slippery Elm Tragacanth + 9 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.