An anti-arrhythmic drug derived from beta-dichroine, an active component of the Chinese medicinal herb, Dichroa febrifuga Lour (image), which acts by blocking Na+–especially in the inactivated state and Ca2+ channels. It also partially blocks K+ channels (Ito and IK).
Chemical name 2,6-bis[pyrrolidin-1-ylmethyl]-4-[quinazolin-4-ylamino] phenol
Reference Eur J Pharmacol. 2010 Nov 25;647(1-3):139-46