(r)-Oxybutynin
(R)-oxybutynin is a 4-(diethylamino)but-2-yn-1-ol that has R configuration. It is responsible for virtually all of the antimuscarinic activity of (racemic) oxybutynin. It has a role as a cholinergic antagonist, a calcium channel blocker and a local anaesthetic. It is an enantiomer of an esoxybutynin.