Convallatoxin is a glycoside extracted from Convallaria majalis. The whole plant is toxic and contains irritating substances: saponins, responsible for digestive disorders, and cardiac glycosides (nearly 20 glycosides). The principal component of glycosides is convallatoxin, which is responsible for cardiovascular disorders because of its digitalis-like effect. Manifestations of this poisoning are similar to those seen in digitalis intoxication in the elderly: digestive disorders, bradycardia, high blood pressure, and arrhythmias.1 The mechanisms underlying the toxicity are identical to those of digitalis, acting primarily on the inhibition of Na-K ATPase membrane and the elevation of intracellular calcium. For these reasons, lily of the valley was once used to treat heart failure. However, the therapeutic window was small and toxicity was frequently encountered, so this use was abandoned.
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