A Montreal study raises questions about even short-term use of the pain drug Vioxx and may harm Merck & Co.'s defense against 11,500 lawsuits, a report said.
The study, published Tuesday in the Canadian Medical Association Journal, said people 65 and older are at the greatest risk of suffering a heart attack within 6-13 days of their first ingestion of Vioxx.
The McGill University study also found elderly patients' heart attack risk did not increase the longer they took the drug, which Merck pulled off the world market in 2004.
A key element of Merck's defense has been that it took 18 months or longer for the heart attack risk to increase, The Wall Street Journal reported.
Reacting to the study, Merck said its strategy was unchanged "and we continue to believe those (short-term) cases have no merit," said lawyer Ted Mayer.
However, plaintiffs' lawyer Andy Birchfield said the study "strengthens our hand tremendously."
"From the very beginning, we have said it doesn't take 18 months," Birchfield said.
Copyright 2006 by United Press International