Margaret Noyes Essex, Hee-Youn Choi, Pritha Bhadra Brown, Raymond Cheung

Parecoxib is an injectable cyclooxygenase-2 inhibitor with proven postoperative analgesic efficacy in a variety of settings, including total knee arthroplasty (TKA). The effect of ethnicity on the efficacy of parecoxib for post-TKA pain has not been studied. This was a parallel-group, double-blind, randomized, placebo- controlled study of ethnically Korean patients aged ≥18 years who had unilateral TKA. Patients who reported moderate or severe pain 6 hours after the end of postoperative opioid analgesia were randomized to receive a single intravenous dose of parecoxib sodium 40 mg or placebo. Patients were evaluated for 24 hours postdose. The primary efficacy endpoints included time-specific pain intensity difference (PID), time-specific pain relief (PR), and time to rescue medication. The incidence and nature of adverse events (AEs) assessed safety. Of the 116 patients randomized, 58 received parecoxib and 58 placebo. Mean (SD) PID was significantly greater for parecoxib vs placebo 1 hour postdose (0.69 [0.67] vs 0.40 [0.59], respectively; p<0.05), and for each time point up to 24 hours. Similarly, mean (SD) PR was significantly greater for parecoxib vs placebo 1.5 hours postdose (1.63 [0.85] vs 1.07 [0.90], respectively; p=0.001), and for each time point up to 24 hours. The median time (hours:minutes) to rescue medication was significantly longer for parecoxib vs placebo (21:30 vs 4:08, respectively; p<0.001). Generally, fewer AEs were reported with parecoxib than placebo, and the AE profile was consistent with previous studies. These results are comparable to the findings from a similarly designed study in a Caucasian patient population. Parecoxib 40 mg significantly improved postoperative pain vs placebo in Korean patients after TKA. The efficacy and safety of parecoxib in Korean patients is similar to that seen in Caucasian patients.