Cyclooxygenase-2 inhibitor

Cyclooxygenase-2 inhibitors (COX-2 inhibitors), also known as coxibs, are a type of nonsteroidal anti-inflammatory drug (NSAID) that directly target cyclooxygenase-2 (COX-2), an enzyme responsible for inflammation and pain. Targeting selectivity for COX-2 reduces the risk of peptic ulceration and is the main feature of celecoxib, rofecoxib, and other members of this drug class.

After several COX-2–inhibiting drugs were approved for marketing, data from clinical trials revealed that COX-2 inhibitors caused a significant increase in heart attacks and strokes, with some drugs in the class having worse risks than others. Rofecoxib (sold under the brand name Vioxx) was taken off the market in 2004 because of these concerns, while celecoxib (sold under the brand name Celebrex) and traditional NSAIDs received boxed warnings on their labels. Many COX-2–specific inhibitors have been removed from the US market. As of December 2011, only Celebrex (celecoxib) is still available for purchase in the United States. In the European Union, celecoxib, parecoxib, and etoricoxib have been approved for use by the European Medicines Agency.

Paracetamol (acetaminophen) inhibits COX-2 almost exclusively within the brain and only minimally in the rest of the body, although it is not considered an NSAID, since it has only minor anti-inflammatory activity.