To access the efficacy and safety of Meloxicam 7.5 mg and 15 mg once daily compared with Mefenamic acid 500 mg t.i.d. over a treatment period of 3-5 days, during an observation period of 3 menstrual cycles, for the symptomatic relief of primary 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