Dihydroergotamine differs from ergotamine in the following respect :: (A) It is a more potent oxytocic, (B) It has antiemetic property, (C) It has high oral bioavailability, (D) It is more potent α-adrenergic blocker and less potent vasoconstrictor
Answer is D. Hydrogenation of ergot alkaloids decrease their vasoconstrictor action and increase the α-blocking activity.