Arthritis drugs known as COX-2 inhibitors raise blood pressure more than older pain relievers, which may explain why the newer medicines have been linked to heart attacks, Australian researchers reported on Monday.The increases were small and varied among the different COX-2 drugs. The risk seemed highest with Merck & Co. Inc.'s Vioxx, the researchers said after reviewing data from more than 45,000 people in 19 studies. Merck pulled Vioxx from the market last September.The study was published online on Monday by the Archives of Internal Medicine.
