Pharmaceutical stocks led a drop Friday on Wall Street after a study found that Pfizer Inc.'s arthritis drug and painkiller Celebrex increased the risk of heart attacks. The subsequent drop in Pfizer shares accounted for nearly half the decline on the blue-chip Dow Jones Industrial Average, which lost 55.72 points, or 0.52 per cent, to close at 10,649.92. The broader Standard & Poor's 500 Index fell 8.99 points, or 0.75 per cent, to 1,194.22, and the technology-laden Nasdaq Composite Index dropped 10.95 points, or 0.51 per cent, to 2,135.20. For the week, however, all three indices ended in positive territory, in large part to major mergers announced the first four trading days of the week. The Dow rose 1 per cent, the S&P 500 0.5 per cent and the Nasdaq 0.3 per cent. The study of Celebrex, the best-selling arthritis drug, was conducted by the U.S. National Cancer Institute and found that patients who took 400- and 800-milligram doses of Celebrex daily had a 2.5-fold increase in their risk of a heart attack compared with those on placebos. Pfizer, the world's biggest drugmaker, said the study was inconsistent with other research and it had no plans to withdraw Celebrex, which is in the same class of drugs as Vioxx, which Merck took off the market for similar reasons in September. The news was compounded by other drug warnings. Eli Lilly & Co. added a safety warning to Strattera, an attention-deficit disorder medication, after two patients suffered severe liver damage, and a study found that Iressa, a lung-cancer drug made by AstraZeneca, did not prolong the lives of its patients. On currency markets, the euro traded at 1.3312 dollars, up from 1.3245 on Thursday. The dollar fell against the yen, fetching 104.16 yen, compared with 104.77 on Thursday. Gold fell 60 cents to trade at 438.90 dollars per fine ounce .
