alkaloids with powerful hypotensive effects isolated from American or European Hellebore (veratrum viride Ait. liliaceae and veratrum album L. liliaceae). They increase cholinergic and decrease adrenergic tone with appropriate side effects and at higher doses depress respiration and produce cardiac arrhythmias; only the ester alkaloids have been used as hypotensive agents in specific instances. They have been generally replaced by drugs with fewer adverse effects.