A 4-week randomized study of acetaminophen extended-release vs rofecoxib in knee osteoarthritis

403 patients suffering from moderate pain associated with osteoarthritis (OA) of the knee were randomized into three groups. The groups consisted of an acetaminophen extended-release (APAP ER) group, a 12.5 mg rofecoxib group, and a 25 mg rofecoxib group. Following four weeks of treatment each group produced a significant reduction in WOMAC pain scores from baseline measures. APAP ER was found to be non-inferior, in terms of reduction in pain scores, when compared to the 12.5mg dose of rofecoxib. However, this non-inferiority was not established in comparison to the larger rofecoxib dose.