Parecoxib is a prodrug and is converted to valdecoxib. Valdecoxib is metabolised by CYP3A4 and CYP2C9, but is not an inhibitor or inducer of them. Valdecoxib is an inhibitor of CYP2C19, but no data indicates mechanism-based inhibition.

Parecoxib is a prodrug and is converted to valdecoxib in vivo.

Parecoxib is indicated for the short-term treatment of postoperative pain in adults.

Parecoxib is rapidly and almost completely converted to valdecoxib and propionic acid in vivo. Valdecoxib is metabolised by CYP3A4 and CYP2C9 (SPC). OH-valdecoxib is an active metabolite, but it is not further metabolised by CYP enzymes (Ibrahim 2002). The half-life elimination of parecoxib is 22 minutes and 8 hours for valdecoxib after i.v or i.m administration of parecoxib. Co-administration of omeprazole, a CYP2C19 substrate, with valdecoxib increased the plasma concentration of omeprazole by 46%. This indicates that valdecoxib may be an inhibitor of CYP2C19 (SPC). Co-administration of a single-bolus propofol (CYP2C9 substrate) or midazolam (CYP3A4 substrate) with parecoxib did not affect the pharmacokinetics of bolus propofol (Ibrahim 2002 and SPC) or midazolam (Ibrahim 2002 and SPC). This indicates that parecoxib and valdecoxib is not inhibitors or inducers of CYP2C9 and CYP3A4.

C. Andersson: 2 observations of safe use. S. Thunell: 2 obersvations of safe use.