New nerve-sparing techniques aimed at lowering the incidence of impotence to 40% to 60% are now being developed and used in these surgeries. Temporary impotence is also associated with these procedures, even those in which nerve-sparing techniques were used. It can take as long as 6 to 18 months for full erections to return. Maximum usage up to twice daily buy Viagra 120mg here 50mg viagra online without prescription But depending on the type of treatment selected, a prostate cancer patient can suffer some rather uncomfortable side effects, among them impotence and incontinence.