Pfizer Vows to Revive Viagra

Katen added that she was most disappointed by the fact that the U.S. impotence drug market hasn't expanded like the company had expected. "That means we have to slog it out in the market," said Katen, referring to the competing drugs Cialis and Levitra.

Analysts have warned that unless the impotence drug market expands significantly over the next few years, companies could get locked into a vicious marketing war in which rising advertising expenses chew up profit margins. But their concerns have focused on the new drugs rather than the market leader.

Cialis was developed by the Bothell, Wash.-based biotechnology company Icos and is being marketed with Eli Lilly.

Levitra was developed by Germany's Bayer and is being marketed with another multinational giant, GlaxoSmithKline.