Research Area: Endocrinology Biological Activity: Silodosin(Rapaflo) is an α1-adrenoceptor antagonist with high uroselectivity. It causes practically no orthostatic hypotension (in contrast to other α1 blockers). Since Silodosin is a highly selective inhibitor of the α1A adrenergic receptor, it causes practically no orthostatic hypotension (in contrast to other α1 blockers). On the other hand, the high selectivity seems to cause more problems with ejaculation. [1]