With Merck's cholesterol-lowering drug Zocor about to lose its patent protection, Pfizer is preparing an intense campaign to maintain brand loyalty to its best-selling Lipitor. Pfizer will be up against a host of insurers who are anxious to see members use the least-expensive drugs that work for their condition. But Pfizer will be using all its marketing might to illustrate the unique characteristics of their drug. Payers' focus: Lipitor costs $2 per day while generic Lipitor is likely to ring up at 35 cents per day. Article