Trial of Etoricoxib (Arcoxia) Taken Prophylactically to Prevent Ramadan Headache

Inclusion Criteria: * Age 18 -65. * Patients will be enrolled if they declared that they intended to complete the dawn to dusk Ramadan fast, and had demonstrated their commitment by doing so for the previous three years (unless medically prevented.) * Patient states that he/she typically suffered from headache during fasting in the past. Exclusion Criteria: * Patients with a history of severe cardiovascular disease, diabetes, asthma, COPD, hypertension, or a history of bleeding, particularly in the gastrointestinal tract * Patients who have experienced bronchospasm, acute rhinitis, nasal polyps, angioneurotic oedema, urticaria, or allergic-type reactions after taking acetylsalicylic acid or NSAIDs including COX-2 (cyclooxygenase-2) inhibitors * Pregnant or lactating patients. Sexually active women of childbearing age will be included only if using birth control * Severe hepatic dysfunction * Estimated renal creatinine clearance \<30 ml/min * History of peptic ulcer, erosive gastritis, esophagitis or inflammatory bowel disease * Congestive heart failure * Patients with hypertension whose blood pressure is persistently elevated above 140/90mmHg and has not been adequately controlled Established ischaemic heart disease, peripheral arterial disease, and/or cerebrovascular disease * Cancer or any other malignant disease * History of medication overuse. Overuse of analgesics or antimigraine drugs according to the IHS criteria (chapter 8)