Parecoxib

drugbox
IUPAC_name = "N"-{ [4-(5-methyl-3-phenylisoxazol-4-yl)phenyl]
sulfonyl}propanamide

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CAS_number = 202409-33-4
ATC_prefix = M01
ATC_suffix = AH04
PubChem = 119828
DrugBank =
C = 19 | H = 18 | N = 2 | O = 4 | S = 1
molecular_weight = 370.422 g/mol
bioavailability = 100%
protein_bound = 98%
metabolism = Hepatic to valdecoxib and propionic acid
CYP extensively involved (mainly CYP3A4 and 2C9)
elimination_half-life = 22 minutes (parecoxib)
8 hours (valdecoxib)
excretion = Renal (70%, metabolites)
licence_EU = Dynastat
pregnancy_category = Not recommended
legal_UK = POM
routes_of_administration = Intravenous and intramuscular

Parecoxib is a water soluble and injectable prodrug of valdecoxib. It is marketed as Dynastat in the European Union. Parecoxib is a COX2 selective inhibitor in the same category as celecoxib (Celebrex) and rofecoxib (Vioxx). As it is injectable, it can be used perioperatively when patients are unable to take oral medications. It is approved through much of Europe for short term perioperative pain control much in the same way ketorolac (Toradol) is used in the United States. However, unlike ketorolac, parecoxib has no affect on platelet function and therefore does not promote bleeding during or after surgery. In addition, ketorolac has a much higher gastrointestinal toxicity profile compared to most other nonsteroidal antiinflammatory drugs (NSAIDs) including ibuprofen and naprosyn. However, in the United States ketorolac is the only injectable NSAID, although it is banned in many European countries due to concerns about surgical bleeding and stomach ulcers after surgery.

In 2005, the 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. The drug is not approved for use after cardiac surgery in Europe. No other surgeries ever demonstrated such complications with parecoxib, and the non-approval is likely the result of the sharp criticism of the FDA approving another COX-2 inhibitor, rofecoxib (Vioxx). Since parecoxib was submitted for approval by the FDA one year after the withdrawal of rofecoxib from the market, it was likely a political decision by the FDA to not approve another COX-2 inhibitor at that time. Ketorolac, still banned in much of Europe, is therefore the only option in the United States, and it is not clear whether parecoxib will be resubmitted to the FDA in the future.