As a rheumatologist, it is to no surprise that my office telephone has been ringing off the hook with patients concerned about the recent safety issue Vioxx, a COX-2 inhibitor. I’m sure you’ve heard that Vioxx has been pulled from market recently because of its increased incidence of hypertension, heart attack or stroke. But before we explore this issue, let’s go back several years.

Prior to the emergence of COX-2s, non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin were the drugs of choice to suppress the production of prostaglandins, a key chemical associated with inflammation. By decreasing prostaglandin production, the inflammatory substances that cause pain, swelling, and redness, commonly seen in arthritis was reduced and controlled.

On the other hand, because not all prostaglandins are harmful, and some actually help protect the lining of our stomach and balance fluid exchange and vascular tone, the reduction in prostaglandins for inflammation created a risk for gastrointestinal complications such as irritation, ulcers, and bleeding.

Restoring hope to those predisposed to GI complications, Cox-2 inhibitor NSAIDs such as Vioxx, Celebrex and Bextra emerged, proving to be less irritating on the stomach because they selectively blocked only bad prostaglandin, maintaining the good protective ones. 

Unfortunately, even though the actual reason remains unclear, recent studies have shown that Vioxx can increase the incidence of cardiovascular accidents and heart attacks because it may possibly block some good prostaglandins.

While Celebrex, Bextra and Vioxx belong to same category of COX-2 inhibitors, they are similar, but may not actually be the same. At present, most studies investigating their potential for cardiovascular side effects have not shown an increase in cardiovascular events, as did Vioxx. However, further studies are needed to affirm all Cox-2 inhibitors’ safety.