Efficacy and Safety Study of Meloxicam Versus Mefenamic Acid in Patients With Dysmenorrhea

Inclusion Criteria: * Female patients between 18 to 40 years * Patients experiencing primary (functional) dysmenorrhea during the last 3 consecutive menstrual periods. Diagnosis will be based on symptoms and clinical signs: abdominopelvic pain, may radiate to the back and along the thighs; systemic symptoms including nausea, vomit, diarrhoea, headache, fatigue, nervousness, dizziness; the symptomatology should be usually some hours to one day before commencement of visible vaginal bleeding * Evaluation of lumbar and/or abdominopelvic pain due to dysmenorrhea \> 35 mm through a 100 mm visual analogue scale (VAS) * Outpatients * Patients granting their written informed consent * Therapy with a NSAID (nonsteroidal antiinflammatory drug) is required or recommended Exclusion Criteria: * Known or suspected hypersensitivity to trial drugs or their excipients, analgesics, antipyretics or NASIDs * Analgesic concomitant treatment (between each cycle paracetamol administration will be allowed) * To initiate hormonal contraception or intrauterine devices after inclusion to this trial or during the last 3 months * Abdominal surgery or pelvic procedure scheduled during the study * Patients with organic dysmenorrhea (endometriosis, salpingitis, adnexitis, uterine retroversion, tubal cysts, ovarian cysts, pathological vaginal secretion, painful pelvic exploration, etc.) * Patients with neoplastic disorders * History of recent abdominal or pelvic trauma requiring surgery * Peptic ulcer within the past 6 months * Pregnancy or breast feeding * Asthma, nasal polyps, angioneurotic edema or rash following aspirin or NSAIDs administration * Concomitant treatment with anti-coagulants, including heparin and aspirin, lithium or methotrexate * Concomitant administration of other NSAIDs (including aspirin \> 150 mg daily) or analgesics * Confinement to bed rest * Administration of any NSAID during two days (three for oxicams) before the first administration of the trial drug * Present treatment or treatment within the last two months with corticosteroids * Impaired renal function (serum urea \> 125 % of the upper limit of normal range; serum creatinine \> 150 % of the upper limit of normal range) * Sever liver injury (alanine amino transferase ALAT \> 2 x the upper normal range limit or aspartate amino transferase ASAT \> 2 x the upper normal range limit) * Hematological disorder (platelet count \< 100,000/mm\*\*3, leucocyte count \< 3,000/mm\*\*3) * Participation in another clinical trial during this study or the previous month * Previous participation in this trial * Patient unable to comply with protocol * Bleeding disorders