MW -- Drug maker Merck & Co. paid $20.4 million last year to more than 2,000 U.S. doctors and health-care professionals to discuss the company’s products and certain health-care topics with other professionals. The Whitehouse Station, N.J., company posted the new data on payments to individual physicians on its website this week. The company previously disclosed data for the second half of 2009, when it paid $9.4 million to nearly 1,700 professionals.