Tadalafil:the preference of erectile dysfunction patients and their partners

Erectile Dysfunction(ED)is a common male diseases which directly affects the life quality of the patients and their partners.Phosphodiesterase 5(PDE5)inhibitors are the first choice among the drugs for the treatment of ED.Nowadays,3 types of PDE5 inhibitors(Sildenafil,vardenafil and tadalafil)are commonly used in clinic at practice.But which is preferred by ED patients and their partners and what are the potential reasons for their preference?