From Reuters:

Pfizer Inc. is bracing for cheap competition to its biggest-selling product, the cholesterol drug Lipitor, a further worry for investors already reeling from the failure of its most important experimental medication. Last week, a raft of generic drugmakers announced that they had received U.S. approval to sell cheap versions of Merck & Co.’s rival cholesterol treatment Zocor, setting the stage for a precipitous drop in price that analysts say will cut into sales of Lipitor.

Pfizer’s ability to defend Lipitor, which generates annual sales of more than $12 billion (U.S.), is particularly important as the world’s biggest drug maker faces increasing competition to its other important products such as the impotence drug Viagra. Lipitor itself faces patent expiration in 2011. The company had hoped torcetrapib, an experimental cholesterol drug that the company recently said failed in clinical trials, would replace Lipitor.

The availability of generic cholesterol medications will be welcome news for the many uninsured and underinsured Americans who have been paying inflated prices for Lipitor and other brand name drugs.