Etoricoxib in the treatment of primary dysmenorrhea in Chinese patients: a randomized controlled trial.

Objective: Assess the efficacy and safety of etoricoxib 120 mg compared with ibuprofen 600 mg qid in the treatment of moderate to severe primary dysmenorrhea in Chinese women. Methods: This multicenter, double-blind, two-period, cross-over study randomized healthy, Chinese women >= 18 years of age to etoricoxib 120 mg qd or ibuprofen up to 2400 mg (600 mg qid) upon onset of moderate or severe primary dysmenorrhea symptoms during two menstrual cycles. The primary efficacy endpoint was Total Pain Relief score over the first 6 hours (TOPAR6). Secondary endpoints included Sum of Pain Intensity Difference scores over the first 6 hours (SPID6) and Patient's Global Evaluation (GLOBAL) of pain at 6 and 24 hours post initial dose. The primary hypothesis was that etoricoxib would be non-inferior to ibuprofen. Adverse experiences (AE) were monitored and evaluated. Results: A total of 139 patients were included in this study. Difference in least squares (LS) mean (95% CI) TOPAR6 score for etoricoxib vs. ibuprofen was 0.89 (0.03, 1.76) (p = 0.043). LS mean (95% CI) difference for etoricoxib vs. ibuprofen SPID6, GLOBAL6, and GLOBAL24 were 0.20 (-1.16, 1.57) (p = 0.768), 0.26 (0.07, 0.45) (p = 0.007), and 0.36 (0.17, 0.54) (p<0.001), respectively. AEs were rare, with the following AEs determined to be drug-related: hypomenorrhea (two patients on etoricoxib) and allergic dermatitis (one patient on ibuprofen). Limitations of the study design include a sample size that is not adequate for evaluation of rare adverse effects, an evaluation period that was limited to 24 hours, and inconsistent frequency of active treatment doses between etoricoxib (once daily) and ibuprofen (up to four times daily). Conclusions: The primary objective of the study was met, demonstrating that etoricoxib 120 mg qd was non-inferior to ibuprofen 600 mg qid; further, etoricoxib was statistically superior to ibuprofen 600 mg qid according to the primary endpoint (TOPAR6) and patient global assessments of study medication. Etoricoxib and ibuprofen were generally well tolerated.