Vardenafil is a potent and highly selective phosphodiesterase type 5 (PDE5) inhibitor with a potency about 10-fold higher than sildenafil. Vardenafil can significantly improve erectile function and works rapidly. Vardenafil is a PDE5 inhibitor with the fastest onset of action among its kind so far found and works as early as 10 minutes after oral administration, providing patients with penile erection sufficient to complete an intercourse. The absolute oral bioavailability is about 15%. Vardenafil is rapidly absorbed with a median tmax of 0.7 h and a terminal half-life (t1/2) of more than 4 h. The observed pharmacodynamic properties, pharmacokinetic characteristics and good safety and tolerability profile showed that vardenafil treatment provides an effective and generally well tolerated treatment for ED.