abstract |
Compounds of the formula (I): n n n n n n n n n n wherein R 1 , R 2 , R 4 and R 13 are as defined or a pharmaceutically or veterinarily acceptable salt or polymorph thereof, or a pharmaceutically or veterinarily acceptable solvate or pro-drug thereof: are potent and selective inhibitors of type 5 cyclic guanosine 3′,5′-monophosphate phosphodiesterase (cGMP PDE5) and have utility in the treatment of, inter alia, male erectile dysfunction (MED) and female sexual dysfunction (FSD). |