Known hypersensitivity to isosorbide mononitrate, to any of the excipients of Nitrofix-SR or to other nitrates.
Acute myocardial infarction with low filling pressure, acute circulatory failure (shock, vascular collapse), very low blood pressure, hypertrophic obstructive cardiomyopathy (HOCM), constrictive pericarditis, cardiac tamponade, low cardiac filling pressures, aortic/mitral valve stenosis and diseases associated with a raised intracranial pressure eg, following a head trauma and including cerebral hemorrhage.