Study to Assess the Safety and Efficacy of Etoricoxib Versus Ibuprofen in the Treatment of Dysmenorrhea (MK-0663-145 AM1)

A Phase III, Randomized, Active-Comparator-Controlled, 2-period, Crossover, Double-Blind Study in China to Assess the Safety and Efficacy of Etoricoxib 120 mg Versus Ibuprofen up to 2400 mg (600 mg Q6h) in the Treatment of Patients With Primary Dysmenorrhea

This is a study to determine the overall analgesic effect of a single oral dose of etoricoxib compared to ibuprofen in participants with moderate-to-severe primary dysmenorrhea.

Participants who meet all the study entry criteria will be randomly allocated to 2 possible sequences of the 2 treatment regimens over the course of 2 menstrual cycles.

In treatment sequence 1, participants will receive etoricoxib 120 mg daily in menstrual cycle 1, and ibuprofen up to 2400 mg/daily in menstrual cycle 2. In treatment sequence 2, participants will receive ibuprofen up to 2400 mg/daily in menstrual cycle 1 and etoricoxib 120 mg daily in menstrual cycle 2.

Inclusion Criteria:

• Agree to remain abstinent or use double-barrier contraception throughout the study. Participants who are status post tubal ligation are exempt from this requirement.
• Moderate or severe primary dysmenorrhea during a minimum of 4 of the previous 6 menstrual cycles. Moderate: Over-the-counter analgesics provide significant relief in most menstrual cycles; discomfort interferes with usual activity. Severe: Over-the-counter analgesics not consistently effective, or prescription analgesics required in at least some menstrual cycles; discomfort is incapacitating causing an inability to work or do usual activity.
• Willing to limit alcohol intake to 2 drinks or equivalent per day for the duration of the study and follow-up period as well as to avoid exercise during the first 24 hours postdose in each menstrual cycle.
• Able to read, understand, and complete diary.

Exclusion Criteria:

• Use of an intrauterine device. Pregnant, breast feeding, or <6 weeks postpartum.
• Active gastric ulcer or history of inflammatory bowel disease.
• Uncontrolled hypertension.
• Uncontrolled diabetes mellitus or renal disease.
• Class II-IV congestive heart failure.
• Coronary artery bypass graft surgery, angioplasty, myocardial infarction, cerebrovascular accident or transient ischemic attack within the past 6 months.
• Unstable angina.
• Mild, moderate, or severe hepatic insufficiency.
• Any personal or family history of an inherited or acquired bleeding disorder.
• History of neoplastic disease; Exceptions: 1)adequately treated basal cell carcinoma or carcinoma in situ of the cervix; 2) other malignancies which have been successfully treated > or equal to 5 years prior to screening. Participants with a history of leukemia, lymphoma, malignant melanoma, and myeloproliferative disease are ineligible for the study regardless of the time since treatment.
• Allergic to etoricoxib, ibuprofen, acetaminophen, indomethacin, or other nonsteroidal anti-inflammatory drugs (NSAIDs), or cyclooxygenase (COX)-2 inhibitors, or to components in Saridon (propyphenazone/paracetamol/caffeine).
• Recent history of chronic analgesic or tranquilizer use or dependence.
• Morbidly obese and demonstrates significant health problems stemming from the obesity.
• Current user of recreational or illicit drugs or had a recent history of drug or alcohol abuse or dependence.
• Participated in another clinical study within the last 4 weeks.
• Not able to swallow oral medications: surgical or anatomical conditions that will preclude from swallowing and absorbing oral medications on an ongoing basis.