Vioxx (Molecule of the Month for May 2005)
Rofecoxib, Ceoxx and Ceeoxx
Vioxx is a nonsteroidal anti-inflammatory drug (NSAID) that was used in the treatment of osteoarthritis, acute pain conditions, and dysmenorrhoea. Formerly marketed by Merck & Co. under the trade names Vioxx, Ceoxx and Ceeoxx, it was voluntarily withdrawn from the market in 2004 because of concerns about increased risk of heart attack and stroke. Rofecoxib was one of the most widely used drugs ever to be withdrawn from the market. Worldwide, over two million people were prescribed Vioxx at the time. In the year before withdrawal, Merck had a sales revenue of US$2.5 billion from Vioxx.
Vioxx belongs to the group of NSAIDs known as COX-2 selective inhibitors or coxibs (CycloOXygenase-2 InhiBitors). Being COX-2 selective means that these drugs act specifically on one form of the cyclooxygenase (COX) enzyme, namely the COX-2, whereas previous NSAIDs inhibited both COX-1 and COX-2. This specificity allows rofecoxib and other COX-2 inhibitors to reduce inflammation and pain while minimizing undesired gastrointestinal adverse effects - peptic ulcers - that are common with non-selective NSAIDs such as aspirin, naproxen, and ibuprofen.
It is currently unknown whether the increased risk of adverse cardiovascular events is common to all COX-2 inhibitors. Recent studies have demonstrated the increased risk of cardiovascular events associated with the use of celecoxib, valdecoxib and parecoxib.
Update by Karl Harrison
(Molecule of the Month for May 2005 )