New Vioxx Study Finds Cardiovascular Risk Highest in First Two Weeks

MONTREAL - A new Canadian study suggests that the risk of heart attack from taking Merck & Co. Inc.'s now-withdrawn painkiller Vioxx may be most significant within the first two weeks of use, contradicting previous studies that found increased heart risks only after 18 months.

The observational study, published online on May 2 by the Canadian Medical Association Journal, found that a quarter of the people who suffered a heart attack while taking Vioxx did so within 13 days of beginning the therapy. The research also showed that cardiovascular risk did not increase with the length of treatment, and returned …