With the stakes and potential profits so high, it is not surprising that the City has become over-excited by the latest outbreak of the so-called ' cholesterol wars'. News that AstraZeneca, the Anglo-Swedish drugs giant, has developed a pill, Crestor, which is alleged to be 8% better than the present best-selling cholesterol-lowering drug, has been greeted with more jubilation than the discovery of a major oilfield.