New York--Pfizer and Warner-Lambert Co. agreed to continue their co-marketing of Lipitor, the No. 1 cholesterol drug in the U.S., for an additional 10 years. They will also work together on other projects, including finding new uses for the combination of Lipitor and Norvasc, the world's top-selling anti-hypertension drug developed by Pfizer. They will also co-promote Relpax, Pfizer's migraine drug. The companies started marketing Lipitor together in 1997; it now accounts for about 46% of new prescriptions for cholesterol-lowering drugs. The two companies hope to develop a single product to treat both hypertension and cholesterol problems. From Crain's New York Business.