PDE5A and premature ejaculation: EAU guidelines on ED, premature ejaculation, penile curvature and priapism (2019 version) [33], Andrology Branch of Chinese Medical Association guidelines for the diagnosis and treatment of ED (2016 version) [34] and the Chinese expert consensus on the use of tadalafil 5 mg once a day for the treatment of ED [35] showed that PDE5 inhibitor is currently the first-line drug for the treatment of ED.