The advantage of avanafil over other PDE-5 inhibitors is its rapid onset of action and high selectivity.
Maximum plasma levels of Avanafil are reached within 30 to 45 minutes, the half-life is six to 17 hours.
Avanafil also acts highly selectively on phosphodiesterase 5, and its effect on PDE-5 is much stronger than on other known phosphodiesterases.
The factor of about 20,000 higher selectivity for PDE-5 compared to PDE-3 is important because PDE-3,
an enzyme found in heart and blood vessels, is involved in controlling cardiac contractility.
The more than 100 times higher selectivity of avanafil for PDE-5 compared to PDE-6 is also clinically significant, as the latter occurs in the retina and is responsible for phototransduction there.
Changes in colour vision, e.g. in sildenafil, are caused by inhibition of PDE-6.