In case you were worried that Pfizer was losing some lead from its pencil–and there have been some rumors about new scripts for Levitra and Cialis doing pretty well– MedAdNews reports that apparently Viagra is staring down its rivals. Of course, there is some controversy, as has been replayed (to excess) over at the Pharma Marketing News list serv, that the number of men with ED in the US seems to be expanding to meet the number of men over 16 (100m was one number quoted!) but it does seem as though this "lifestyle" drug will remain a cash cow for Pfizer until it comes off patent.