Two randomized, double-blind, parallel-group single-dose 2 x 2 factorial analgesic studies compared a single-dose or a 2-tablet dose of a combination of 7.5 mg hydrocodone bitartrate with 200 mg ibuprofen with each constituent alone and with a placebo in women with moderate or severe postoperative pain from abdominal or gynecologic surgery. A nurse-observer recorded patient reports of pain intensity and pain relief periodically for 8 hours. In both studies, the combination was significantly superior to placebo for sum of the pain intensity differences (SPID), total pain relief (TOTPAR), peak pain intensity difference (PID) and pain relief, global evaluation, and time to remedication. The combination was likewise significantly superior to both hydrocodone and ibuprofen for most of these summary measures of analgesia. In a factorial analysis, both the hydrocodone and ibuprofen effects were significant for most summary measures of analgesia, whereas results of the interaction contrast were consistent with the concept that the analgesic effect of the combination represents the additive analgesia of its 2 constituents.