Avanafil is a new, second-generation ED medication. Compared to first-generation ED treatments, such as Sildenafil (Viagra), Avanafil has a higher selectivity (specificity) and affinity for the PDE-5 enzyme. This results in higher peak levels in patients in less time, promoting an erection in a shorter amount of time, typically within 15-30 minutes after oral ingestion. Avanafil also has a reduced side effect profile compared to first-generation ED medications.