More Questions About Cox-2 Safety Arises From New Research

Two new clinical studies provide further evidence that the use of anti-inflammatory Cox-2 inhibitor drugs could increase the risk of serious cardiovascular events in humans.

The first of two studies published in the medical journal Circulation showed that the Cox-2 inhibitor Bextra (valdecoxib) elevated the combined incidence of heart attack and stroke three-fold in patients undergoing coronary artery bypass graft surgery. Researchers drew this conclusion after using a conventional statistical tool called a meta-analysis to combine the findings of two earlier placebo-controlled trials involving Bextra and Dynastat (parecoxib), both of which are manufactured by Pfizer.

In the second study, mice genetically prone to atherosclerosis, or hardening of the arteries, demonstrated a worsening of the condition when they were given a Cox-2 inhibitor.

The lead researcher of the studies, Garret FitzGerald of the University of Pennsylvania, concluded that the use of Cox-2 inhibitors in clinical trials could endanger high-risk patients. "The clear emergence of a cardiovascular hazard from Cox-2 inhibitors in patients, the weak rationale for a study of their protective properties in the first instance, and now this evidence from mice would indicate to me that a trial in high-risk patients, such as that proposed for Celebrex is, at best, ill-advised," FitzGerald said in a statement.