A study by investigators at the McGill University Health Centre ( MUHC ) found that a quarter of patients who suffered a myocardial infarction while taking Vioxx ( Rofecoxib ) did so within the first two weeks of taking the drug.
The research, published in the Canadian Medical Association Journal ( CMAJ ),demonstrated that cardiovascular risks from taking Vioxx may occur much earlier than previously believed.
" Our previous study on COX-2 inhibitors, which included Vioxx and Celebrex ( Celecoxib ), evaluated whether there was an increased risk of myocardial infarction while taking these medications; the answer was yes for Vioxx," says Linda Levesque, at McGill University in Montreal and lead author of the new study. " Our current study assessed the pattern of cardiovascular risk in Québec seniors over a three year period, in order to establish the timing of this risk."
Levesque, in collaboration with James Brophy and Bin Zhang discovered that the risk of myocardial infarction from Vioxx is much more acute than previously recognized.
" A quarter of individuals in our study who suffered an acute myocardial infarction did so within two weeks of their first Vioxx prescription," says Levesque.
" The additional cardiovascular risk from Vioxx actually decreased with longer duration of use, suggesting that the period of highest susceptibility for most people taking Vioxx may occur earlier than previously believed," noted Levesque. The study also documents that cardiovascular risk returns to normal within one month of stopping the drug.
Vioxx was voluntarily withdrawn from the market on September 30, 2004 after a study showed it doubled patients' risk of myocardial infarction and strokes after 18 months of use.
The MUHC study is the first to specifically address the question of the timing of cardiovascular risk associated with COX-2 inhibitors.
Source: McGill University, 2006