<unk> 's indications and contraindications are the same as with other PDE5 inhibitors; it is closely related in function to sildenafil citrate (Viagra) and tadalafil (Cialis). The difference between the<unk>  molecule and sildenafil citrate is a nitrogen atom's position and the change of sildenafil's piperazine ring methyl group to an ethyl group. Tadalafil is structurally different from both sildenafil and<unk> .<unk> 's relatively short effective time is comparable to but somewhat longer than sildenafil's.<unk>  also does not have an effect on PDE6, which means that it does not have vision adverse effects. Beyond its indications for erectile dysfunction,<unk>  may be effective in the treatment of premature ejaculation, where it may significantly increase the time from penetration to ejaculation.
Vardenafil
Avanafil
Udenafil
Tadalafil
Mesterolone
Telmisartan
Sildenafil
Norpipanone