Silodosin (KAD 3213; KMD 3213) is a potent, selective and orally active α1A-adrenergic receptor (α1A-AR) blocker. Silodosin exhibits high affinity for α1A-AR (Ki=0.036 nM), over 162-fold and 50-fold than for α1B-AR and α1D-AR with Ki values of 21 nM and 2.0 nM, respectively. Silodosin is an effective and well-tolerated agent, it can be used for the investigation of LUTS/BPH[1][3].