Question 1

How does lily of the valley work on the heart?

Accepted Answer

Convallaria majalis contains cardiac glycosides, primarily convallatoxin, which inhibit the sodium-potassium ATPase pump in cardiac cells. This inhibition increases intracellular calcium, strengthening heart muscle contractions—a positive inotropic effect—while simultaneously slowing the heart rate. The herb also promotes fluid excretion through mild diuretic action. These combined effects historically made it useful for heart failure and edema. Evidence level: C, based primarily on pharmacological studies and traditional use rather than large-scale clinical trials.

Question 2

Does lily of the valley interact with heart medications?

Accepted Answer

Yes, Convallaria majalis has significant drug interactions, particularly with cardiac medications. Combining it with digoxin or other cardiac glycosides can cause additive toxicity, leading to dangerous arrhythmias. Concurrent use with diuretics may increase the risk of electrolyte imbalances, potentiating cardiac glycoside toxicity. Potassium-depleting medications amplify this toxicity risk. Due to these serious interactions and the herb's narrow therapeutic window, self-medication is strongly contraindicated. Always consult a qualified healthcare provider before use.

Question 3

What is the proper dosage for Convallaria majalis?

Accepted Answer

There is no safe self-medication dosage for Convallaria majalis. Due to its narrow therapeutic index and potential for fatal toxicity, this herb should only be used under medical supervision in standardized pharmaceutical preparations. The concentration of active cardiac glycosides varies significantly in raw plant material, making home preparation extremely dangerous. Historical folk medicine dosages are not reliable guides. Evidence level: C. Professional guidance is essential for any therapeutic use.

Question 4

Is lily of the valley safe during pregnancy?

Accepted Answer

No, Convallaria majalis is unsafe during pregnancy and breastfeeding. The cardiac glycosides can cross the placenta and may affect fetal heart function. The herb's potent effects on cardiac rhythm and its potential to cause uterine contractions pose significant risks to both mother and fetus. Additionally, the narrow therapeutic window and risk of toxicity make any use during pregnancy inadvisable. Breastfeeding mothers should also avoid this herb as cardiac glycosides may pass into breast milk.

Question 5

What are the side effects of lily of the valley?

Accepted Answer

Convallaria majalis can cause serious side effects including cardiac arrhythmias, nausea, vomiting, dizziness, and headache. Due to its potent cardiac glycosides, toxicity can occur even with small amounts, potentially leading to life-threatening heart rhythm disturbances. Death has been reported from contact with the plant. The herb has an extremely narrow therapeutic window, meaning the difference between a therapeutic and toxic dose is very small. Immediate medical attention is necessary if any adverse symptoms occur after exposure.

Herbe de muguet

Sources et citations

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Résumé

Contexte

Usages traditionnels

Composés actifs

Mécanisme d'action

Preuves cliniques

Sécurité et effets indésirables

Interactions médicamenteuses

Synthèse des preuves

Sources PubMed

Sources gouvernementales