Bayer Leans on Vardenafil

Dubbed "the new blockbuster" by Bayer AG management, the PDE5 inhibitor vardenafil is by most accounts more potent, faster acting, and less prone to side effects than its pharmaceutical cousin, Pfizer Inc.'s sildenafil (Viagra). But vardenafil's potential-and its role as a potential savior of Bayer's ailing pharmaceuticals division-may be overshadowed by the chinks that this same promise has helped expose in the Bayer armor.