Drug Interaction Report

Digoxin and Kyushin: Interaction Details

A pharmacist-reviewed analysis of the Digoxin and Kyushin 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

Digoxin

Cardoxin® Digitek Digitek® Digox Lanoxicaps® Lanoxin Lanoxin®
+

Kyushin

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
LinkedIn
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 453 documented Digoxin interactions, 359 are 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
rapid
Evidence
probable
Severity
Major

What happens

Increased risk of digoxin toxicity

Interaction Deep Dive

One of the ingredients of kyushin is toad venom toxin. Toad venom toxin, a bufadienolide, is cardioactive with properties similar to digitalis134. Ingestion or dermal absorption of toad venom (from Bufo species) has caused typical digitalis-like poisoning, with dysrhythmias, heart block, hypotension, and vomiting 56718.

Why it happens (mechanism)

Additive digitalis glycoside effect

Literature reports

4 reports — tap to read

a) Six previously healthy males between the ages of 17 and 40 presented with vomiting, bradycardia, and hypotension; several were hyperkalemic and 1 suffered a seizure. All exhibited positive serum digoxin concentrations. The substance they had ingested was an aphrodisiac called "love stone" or "rock hard", which was found to be identical to Chan Su, a Chinese medication made from toad venom. Four of the patients died of cardiac dysrhythmias. Two recovered after administration of digoxin immune Fab (Digibind(R)); one received 10 vials and the other, 10 vials followed by an additional 10 vials 1.

b) A 65-year-old woman developed nausea, vomiting, diarrhea, general malaise, and abdominal pain 5 hours after consuming 50 tablets of kyushin, a traditional Chinese medicine. Upon hospital admission her heart rate was 60 beats/minute, blood pressure was 140/70 mmHg. The electrocardiogram (EKG) showed a second degree Wenckebach AV block and a flat T-wave which normalized the next day. The serum digoxin-like immunoreactive substance (DLIS) was 2.35 ng/mL 24 hours after ingestion (using the Digoxin II kit by Abbott Laboratories, Inc.). Serum electrolytes were normal. With supportive treatment, this gradually declined over 5 days and the patient was released on the eighth day 2.

c) A 34-year-old female developed nausea, vomiting, and general malaise two hours after consuming approximately 50 pills of kyushin during an attempted suicide. On admission to the hospital, her heart rate was 64 beats/minute, blood pressure was 110/70 mmHg. Serum DLIS 10 hours after consuming the drug was 1.84 ng/mL. This diminished to 0.67 ng/mL by the next day with supportive treatment and symptoms also subsided. Serum electrolytes were normal. All EKGs during hospitalization were normal 2.

d) The bufadienolides in toad venom are presumed to be the cardioactive components of kyushin which has proven its ability to inhibit sodium, potassium, and ATPase activity 34.

Common questions

Can I take Digoxin and Kyushin together?

Increased risk of digoxin toxicity Always confirm with your pharmacist or prescriber before making any change.

How serious is the Digoxin and Kyushin 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 "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Digoxin or Kyushin 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 (8)

  1. Brubacher JR, Ravikumar PR, Bania T, et al: Treatment of toad venom poisoning with digoxin-specific fab fragments. Chest 1996; 110(5):1282-1288. DOI
  2. Lin CS, Lin MC, Chen KS, et al: A digoxin-like immunoreactive substance and atrioventricular block induced by a Chinese medicine "Kyushin". Jap Circ J 1989; 53:1077-1080. PubMed
  3. Lichtstein P, Kachalsky S, & Deutsch J: Identification of a ouabain-like compound in toad skin and plasma as a bufodienolide derivative. Life Sci 1986; 38:1261-1270. DOI
  4. Palumbo NE, Perri S, & Read G: Experimental induction and treatment of toad poisoning in the dog. J Am Vet Med Assoc 1975; 167:1000-1005. DOI
  5. Du NT & Due P: Severe toad venom poisoning by dermal absorption (abstract). J Toxicol Clin Toxicol 2001; 39:563.
  6. Chi HT, Hung DZ, & Hu WH: Prognostic implications of hyperkalemia in toad toxin intoxication. Hum Exp Toxicol 1998; 17:343-346. PubMed
  7. Ko RJ, Greenwald MS, & Loscutoff SM: Lethal ingestion of Chinese herbal tea containing Ch'an su. West J Med 1996; 164:71-75.
  8. CDC: Deaths associated with a purported aphrodisiac-- City, February 1993-May 1995. CDC: MMWR 1995; 44:853-861.
Was this write-up helpful?
Digoxin

Keep reading about Digoxin

All Digoxin interactions (453) Digoxin drug information
Also serious with: Levoketoconazole Meclofenamate Mavorixafor Parathyroid Hormone Injection
Kyushin

Keep reading about Kyushin

All Kyushin interactions (1)
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:

Digoxin + Activated Charcoal Aloe Blue Flag Danshen European Buckthorn Foxglove Indian Snakeroot Lily-of-the-valley + 105 more

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

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
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.