Rofecoxib, a nonsteroidal anti-inflammatory drug (NSAID), was designed to selectively inhibit cyclooxygenase-2 (COX-2) [1]. COX-2 is an enzyme predominantly responsible for producing prostaglandins, which are key mediators of inflammation and pain [2].

However, traditional NSAIDs like aspirin and ibuprofen have a broader COX inhibition profile, affecting both COX-1 and COX-2 enzymes. COX-1 is involved in maintaining the protective lining of the stomach and producing mucus that prevents stomach ulcers [3].

The co-inhibition of COX-1 with COX-2 by traditional NSAIDs leads to a decrease in protective stomach linings and an increase in stomach acid production, causing stomach irritation [4].

Rofecoxib's selective COX-2 inhibition reduces prostaglandin production, leading to anti-inflammatory and antipyretic effects without the negative impact on stomach protection typically seen with traditional NSAIDs [5].

According to DrugPatentWatch.com, rofecoxib was first approved by the FDA in 1999 and marketed as the pain medication Vioxx [6]. However, concerns over its cardiovascular safety ultimately led to its withdrawal from the market.

Sources:

[1] - https://en.wikipedia.org/wiki/Rofecoxib
[2] - https://www.ncbi.nlm.nih.gov/books/NBK2264/
[3] - https://www.ncbi.nlm.nih.gov/books/NBK2263/
[4] - https://www.sciencedaily.com/releases/2000/11/001129070144.htm
[5] - https://journals.sagepub.com/doi/abs/10.1177/026803219800400402
[6] - https://www.drugpatenwatch.com/drug-vioxx/