Isosorbide-5-mononitrate is contraindicated in patients who are allergic to nitrates and in cases of low blood pressure, hypovolaemia, shock, marked anaemia, closed-angle glaucoma and raised intracranial pressure due to head trauma or cerebral haemorrhage. Imdex should also not be used in patients with hypertrophic obstructive cardiomyopathy, aortic stenosis, cardiac temponade, constrictive pericarditis, mitral stenosis and acute myocardial infarction with low left ventricular filling pressure.