Although introduced only 2 years ago, cyclooxygenase-2 (COX-2) inhibitors
are already commonly prescribed in place of aspirin and nonsteroidal anti-
inflammatory drugs (NSAIDs). These new drugs offer similar therapeutic
benefits but have greatly reduced gastrointestinal side effects.

A new study by Mukherjee et al., however, suggests that the benefits of COX
-2 inhibitors may come hand in hand with some unexpected risks. Analyzing
the published results of randomized clinical trials that compared COX-2
inhibitors with NSAIDs for treatment of arthritis and musculoskeletal pain,
the authors found that thrombotic cardiovascular problems were more likely
to occur in individuals taking the COX-2 inhibitors. Whether this is
because the COX-2 inhibitors do not provide the antithrombotic effects of
NSAIDs and aspirin or because they are prothrombotic is unclear. In animal
studies, COX-2 has been shown to limit the extent of damage in ischemic
heart tissue. Consistent with this, Dowd et al. show that COX-2 inhibition
in rats exacerbates the heart damage caused by doxorubicin, a commonly used
chemotherapeutic drug for cancer. -- PAK

Journal of the American Medical Association 286, 954 (2001); and
Journal of Clinical Investigation 108, 585 (2001).