Squill and Digoxin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Digoxin
Squill
No brand names on record
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 risk of digoxin toxicity
Interaction Deep Dive
A case of death likely due to cardiac glycoside toxicity following squill ingestion has been reported5. Both squill and digitalis, the source of digoxin, are known to contain cardiac glycosides known as cardenolides 123. Squill contains proscillaridin A as its principal cardiac glycoside 4. At this time, squill is not widely available in the United States.
Why it happens (mechanism)
Additive cardiac glycoside activity
Literature reports
1 report — tap to read
a) A 55 year-old female developed nausea, vomiting, and seizures following ingestion of squill for arthritis. On admission to the hospital 2 hours after ingestion, blood pressure was 110/70 mmHg, pulse was 56 beats/minute, serum potassium was 5.9 millimoles/liter (mmol/L), and a digoxin level was 1.59 nanograms/milliliter (ng/mL). Gastric lavage was performed and activated charcoal 50 grams was administered. Nine hours after ingestion, electrocardiogram showed complete atrioventricular block, and the patient had lost consciousness. Atropine was ineffective, and a temporary cardiac pacemaker was applied at 60 beats/minute. Twenty-four hours after ingestion, ventricular tachycardia occurred and serum potassium was 6.2 mmol/L. Lidocaine injections were ineffective and ventricular fibrillation occurred which was unresponsive to direct-current cardioversion and cardiopulmonary resuscitation. Death occurred 30 hours after ingestion. The patient's medical history included hypothyroidism treated with thyroxine; a TSH level one week prior to squill ingestion was 9.4 milli-international units/milliliter (mIU/mL) (normal 0.25 to 4.3 mIU/mL) and T3 was 61 nanograms/deciliter (ng/dL) (normal 86 to 187 ng/dL). Hypothyroidism may be a risk factor for digoxin toxicity 5.
Common questions
Can I take Squill and Digoxin together?
Increased risk of digoxin toxicity Always confirm with your pharmacist or prescriber before making any change.
How serious is the Squill 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 "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 Squill 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 (5)
- Mashour NH, Lin GI, & Frishman WH: Herbal medicine for the treatment of cardiovascular disease. Arch Intern Med 1998; 158:2225-2234. DOI
- Loew D: Phytotherapy in heart failure. Phytomed 1997; 4:267-271. PubMed
- Krenn L, Schlifelner, Stimpfl T, et al: HPLC separation and quantitative determination of cardenolides in herba convallariae. Planta Med 1992; 58(Suppl 1):A682-684. DOI
- Blumenthal M, Busse WR, Goldberg A, et alBlumenthal M, Busse WR, Goldberg A, et al (Eds): The complete German commission E monographs, 1st. American Botanical Council, Austin, TX, 1998.
- Tuncok Y, Kozan O, Cavdar C, et al: Urginea maritima (squill) toxicity. J Toxicol Clin Toxicol 1995; 33:83-86.
Keep reading about Digoxin
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