[3] In 2005, the US Food and Drug Administration (FDA) issued a letter of non-approval for parecoxib in the United States.

No reasons were ever documented publicly for the non-approval, although one study noted increased occurrences of heart attacks following cardiac bypass surgery compared to placebo when high doses of parecoxib were used to control pain after surgery.

Efforts to find out the scientific rationale, or more likely the lack thereof, that the FDA used to justify the non-approval of parecoxib in the USA have proven futile due to secrecy issues.

[7] Parecoxib, along with other COX-2 selective inhibitors, celecoxib, valdecoxib, and mavacoxib, were discovered by a team at the Searle division of Monsanto led by John Talley.

Its first perceptible analgesic effect occurs within seven to thirteen minutes, with clinically meaningful analgesia demonstrated within twenty-three to thirty-nine minutes and a peak effect within two hours following administration of single doses of 40 mg by IV or IM injection.