Induced cardiac hypersensitivity reactions (myo- & pericarditis). Discontinue treatment at 1st appearance of signs & symptoms of severe skin reactions eg, skin rash, mucosal lesions or any other sign of hypersensitivity; if renal function deteriorates. Terminate treatment if blood dyscrasia is suspected. Promptly w/draw & not to be reintroduced treatment if symptoms of acute intolerance syndrome (including cramping, acute abdominal pain & bloody diarrhoea, sometimes fever, headache & rash) occurs. Minimal change nephropathy, acute/chronic interstitial nephritis & renal failure; severe cutaneous adverse reactions including DRESS (eg, SJS & TEN); increased liver enzyme levels; serious blood dyscrasias. Cases of nephrolithiasis. Potential risk of cross-sensitivity reactions w/ sulphasalazine. May delay onset of action due to organic or functional obstruction in upper GIT. Patients w/ conditions predisposing to myo- or pericarditis development. Closely monitor patients w/ chronic lung function impairment, especially asthma. Perform haematological investigation if patient develops unexplained bleeding, bruising, purpura, anaemia, fever or sore throat. Evaluate renal function prior to initiation of therapy & at least twice a yr. Ensure adequate fluid intake during treatment. May lead to falsely elevated test results when measuring urinary normetanephrine by liqd chromatography w/ electrochemical detection. Mild to moderate renal impairment. Hepatic impairment. Leukopenia, thrombocytopenia & anaemia in infants born to mothers exposed to treatment during pregnancy. Lactation. Not to be used by paed patients ≤50 kg & <10 yr.