Vardenafil is a PDE5 inhibitor with less phosphodiesterase cross-reactivity, suggesting fewer side effects, but is expensive.

“so ideally you want one that only affects five and nothing else and is there one to date that does that uh yes in my opinion the newest one of vanophil has the least correct cross reactivity with the other phosphodasterises so I think it has less side effects the only difference is that it is not generic yet so it's expensively expensive”