Silodosin is a selective antagonsit of alpha-1a adrenergic receptor which was developed by Kissei Pharmaceutical. The drug was approved by FDA under the name Rapaflo for the treatment of signs and symptoms associated with benign prostatic hyperplasia.

KMD-3241 (Dehydro Silodosin) is a silodosin metabolite (also known as an impurity of Silodosin). Silodosin is a selective antagonsit of alpha-1a adrenergic receptor which was developed by Kissei Pharmaceutical and approved by FDA under the name Rapaflo for the treatment of signs and symptoms associated with benign prostatic hyperplasia. The affnities of silodosin metabolites, KMD-3241, KMD-3289 and KMD-3295, for alpha1A-AR subtype receptor were equal to or lower than that of silodosin.