<unk>  (1-methyl-D-lysergic acid butanolamide or UML-491) is a prescription drug formerly used for prophylaxis of cluster headaches/migraine headaches, but is no longer recommended due to retroperitoneal/retropulmonary fibrosis.
Methysergide
Cabergoline
Metergoline
Brexanolone
Allylestrenol
Methylergonovine 
Oxypertine
Iopromide