Arthritis Drugs Linked to Heart Attacks
 (Washington, MSNBC News, 4/18/03)

Studies on mice performed by University of Pennsylvania researchers indicate that Cox-2 inhibitors, a class of drugs used to treat arthritis, may increase the risk of heart attack. Both of the popular pain relievers, Vioxx and Celebrex, block the Cox-2 enzyme, a source of prostacyclin which dilates blood vessels and keeps platelets from clumping. The scientists believe that, in the absence of Cox-2, the Cox-1 enzyme, which normally constricts blood vessels and facilitates clotting, may get out of control and precipitate a heart attack.