Dysuria esp in males; tremor, euphoria, fatigue, pulmonary infiltration, nausea, vomiting, diarrhoea, flatulence, constipation, dyspepsia, abdominal pain, melaena, haematemesis, ulcerative stomatitis, exacerbation of Crohn's disease and colitis, gastritis, pancreatitis; oedema, HTN, cardiac failure; nephritis, hepatitis, jaundice, abnormal liver function; visual disturbances, optic neuritis, headache, paraesthesia, depression, confusion, hallucinations, tinnitus, vertigo, tremor, dizziness, malaise, drowsiness; thrombocytopenia, neutropenia, agranulocytosis, anaemia. Potentially Fatal: Exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis; GI bleeding, ulceration or perforation.