Question 1

How does Scilla squill work as a cardiac glycoside?

Accepted Answer

Scilla squill contains cardiac glycosides, primarily scillaren A and proscillaridin A, which work by inhibiting the sodium-potassium ATPase pump in cardiac cells. This inhibition increases intracellular calcium concentration, strengthening cardiac muscle contraction and improving cardiac output. Unlike digitalis, Scilla glycosides have a shorter half-life and are primarily eliminated through the liver rather than kidneys (Evidence Level B). This mechanism produces positive inotropic effects, making it historically useful for heart failure, though pharmaceutical preparations have largely replaced its medicinal use due to narrow therapeutic margins.

Question 2

What drug interactions occur with Scilla squill?

Accepted Answer

Scilla squill carries significant drug interaction risks due to its cardiac glycoside content. Concurrent use with other cardiac glycosides (digoxin, digitoxin) increases toxicity risk. Potassium-depleting diuretics (furosemide, hydrochlorothiazide) enhance glycoside toxicity by causing hypokalemia. Quinidine, verapamil, and amiodarone can increase plasma glycoside levels. Calcium supplements may precipitate arrhythmias when combined with cardiac glycosides. Beta-blockers may potentiate bradycardia. Due to these serious interactions and narrow therapeutic index, Scilla squill should only be used under physician supervision with standardized pharmaceutical preparations (Evidence Level B).

Question 3

What is the proper dosage of Scilla squill?

Accepted Answer

There is no safe home dosage for Scilla squill due to its extremely narrow therapeutic index and potential for fatal toxicity. The active compounds, particularly scillaren A and proscillaridin A, vary significantly in unstandardized preparations. Historically, pharmaceutical preparations were standardized and dosed by physicians based on individual patient response and cardiac status. Modern practice has largely abandoned Scilla squill in favor of safer, well-studied alternatives like digoxin. Self-medication with any unstandardized preparation is contraindicated (Evidence Level B).

Question 4

Is Scilla squill safe during pregnancy and breastfeeding?

Accepted Answer

Scilla squill is unsafe during pregnancy and breastfeeding. The cardiac glycosides present in this herb, including scillaren A and proscillaridin A, can cross the placenta and may affect fetal cardiac development and rhythm. These compounds may also be excreted in breast milk, potentially causing toxicity in nursing infants. Historical use never included pregnancy applications, and modern assessment classifies it as contraindicated (Evidence Level B). Women who are pregnant, planning pregnancy, or breastfeeding should avoid all Scilla squill preparations.

Question 5

What is Scilla squill used for in herbal medicine?

Accepted Answer

Scilla squill (Drimia maritima) has been used historically for cardiac insufficiency and as an expectorant for chronic coughs. Ancient Egyptian, Greek, and Roman physicians employed it for heart conditions and edema. The bulb contains cardiac glycosides that strengthen heart contractions, similar to digitalis but with a shorter duration of action. Red squill varieties have been used as rodenticides due to their toxicity. Modern herbal medicine rarely uses Scilla squill due to safety concerns, and it has largely been replaced by pharmaceutical cardiac glycosides (Evidence Level B, Traditional use).

Question 6

What are the side effects and toxicity of Scilla squill?

Accepted Answer

Scilla squill has a narrow therapeutic window with potentially fatal toxicity. Common side effects include nausea, vomiting, abdominal pain, and diarrhea due to GI irritation. Cardiac toxicity manifests as arrhythmias, including bradycardia, atrioventricular block, and ventricular fibrillation. Neurological symptoms may include headache, fatigue, and visual disturbances. Unlike digitalis, Scilla glycosides cause more pronounced gastrointestinal symptoms before cardiac effects appear. The therapeutic dose is close to the toxic dose, making overdose a significant risk with unstandardized preparations (Evidence Level B).

Scilla Squill

Sources & Citations

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Evidence summary

PubMed sources

Government sources