Drugs credited for lower American cholesterol levels

The growing use of cholesterol-lowering pills is believed to be a major cause of the improvement in average cholesterol rates among Americans.

Among the best-known prescription drugs for lowering cholesterol are Lipitor, made by Pfizer Inc.; Zocor, by Merck & Co.; and Pravachol, from Bristol-Meyers Squibb. Another is Mevacor, a product Merck hopes to begin selling over the counter.