The popular arthritis drug Vioxx is being recalled after a medical research found that its long-term use may lead to heart attacks and strokes. MSD Korea Ltd., the Korean subsidiary of the U.S. drug giant Merck & Co., said it has voluntarily withdrawn the government's approval on its painkiller Vioxx, following its headquarters' decision to recall the drug. The company plans to collect the medicine from the market over the next two months and has asked doctors to stop prescribing the drug. The move follows the company's own study which found that long-term use of the drug for over 18 months doubled the risk of heart attacks and strokes. Vioxx is the world's most popular painkiller for arthritis, along with Celebrex by Pfizer Inc. It has been sold in some 80 countries since it was first introduced on the market in 1999.