The COX-2 inhibitor valdecoxib, has demonstrated effective post-operative pain relief and significantly reduced patient consumption of the opiate analgesic morphine, when administered post-operatively to patients undergoing knee replacement surgery. This is according to an investigational study presented at the annual meeting of the American Academy of Orthopedic Surgeons.
“Avoiding post-operative pain is a major priority, and a significant source of anxiety, for patients undergoing surgery,” said principal investigator Lowell Reynolds, M.D., Medical Director, Loma Linda University. “We are encouraged by the results of this study as they suggest valdecoxib may be a viable alternative for treating post-surgical pain.”
In this multicenter, double-blind study, 209 patients were randomized to receive valdecoxib (20 mg or 40 mg) or placebo as soon as they could tolerate oral medication following surgery, and subsequent doses at 12, 24, and 36 hours after the first dose or until discontinuation of morphine.
Morphine administration by a patient controlled analgesia (PCA) pump began following administration of study medication. Efficacy was assessed by measuring the total amount of morphine consumed over the first 24 and 48 hours following the first dose of valdecoxib.
Average consumption of morphine in the morphine plus placebo group was 69.5 mg on day one and 27.1 mg on day two. Patients who received valdecoxib 40 mg every 12 hours consumed 56.5 mg and 16.7 mg morphine on day one and day two, respectively. These figures represent significant reductions of 19 percent and 38 percent versus placebo on day one and two, respectively. Patients receiving valdecoxib 20 mg every 12 hours also consumed a lower total average amount of morphine versus placebo.
Although morphine consumption in the valdecoxib group was comparable to placebo on day one, patients in the valdecoxib group consumed significantly less morphine on day two than those in the placebo group.
Overall, during the 48 hours post surgery, morphine consumption by patients receiving valdecoxib every 12 hours was reduced by 16.3 percent and 24.2 percent, respectively, compared with those patients receiving morphine plus placebo.
Additionally, a higher percentage of patients treated with valdecoxib plus morphine described their study medication as “good” or “excellent,” compared with 70 percent of patients receiving morphine plus placebo.
In addition, patients receiving valdecoxib plus morphine reported greater reductions in pain intensity than those receiving placebo, even though those patients consumed more morphine.
There were no significant differences in the incidence of most adverse events between treatment groups, but the incidence of fever was significantly higher among patients receiving morphine alone versus either group of patients receiving morphine plus valdecoxib.