Upidosin (Rec 15/2739) is an α-1 adrenoceptor ( α-1 AR ) antagonist. Upidosin shows moderate selectivity for the α-1A AR subtype. Upidosin shows uroselectivity in urethra and prostate with a K b value of 2-3 nM higher than in ear artery and aorta with a K b value of 20-100 nM. Upidosin inhibits.