An article published in Science this month sheds light on concerns that a new class of drugs called COX-2 inhibitors might trigger a chain of events that can harm the cardiovascular system. Prescription painkillers such as Vioxx and Celebrex belong to a class of drugs known as non-steroidal anti-inflammatory drugs, or NSAIDs. Other NSAIDS include ibuprofen, ketoprofen, and aspirin. COX-2 inhibitors are a newer class of NSAIDs that work by selectively blocking only the COX-2 enzyme, while traditional NSAIDs block both the COX-1 and COX-2 enzyme.

The COX-1 enzyme promotes blood vessel constriction. The enzyme COX-2 helps thin the blood. Cox-2 inhibitors like Vioxx upset the balance between these two enzymes. This imbalance then promotes blood clotting and constriction of blood vessels, which could lead to heart attack, stroke, and sudden cardiac death.

Source: Science, April 19, 2002.