o-Desethyl sildenafil139755-91-2100 % similar Sildenafil139755-83-277 % similar Sildenafil citrate171599-83-063 % similar Aildenafil496835-35-958 % similar 5-(5-Chlorosulfonyl-2-ethoxyphenyl)-1-methyl-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-D]pyrimidin-7-one139756-22-253 % similar Udenafil268203-93-649 % similar Acetildenafil831217-01-744 % similar Vardenafil dihydrochloride224789-15-541 % similar Vardenafil224785-90-435 % similar Pseudovardenafil224788-34-535 % similar Vardenafil hydrochloride224785-91-534 % similar Mirodenafil862189-95-534 % similar Vardenafil hydrochloride trihydrate330808-88-333 % similar 5-Ethyl-3,5-dihydro-2-[5-[[4-(2-hydroxyethyl)-1-piperazinyl]sulfonyl]-2-propoxyphenyl]-7-propyl-4H-pyrrolo[3,2-D]pyrimidin-4-one hydrochloride (1:2)862189-96-633 % similar