− Hypersensitivity to the active substance or to any of the excipients. − Conditions where the effects of Ventavis on platelets might increase the risk of haemorrhage (e. g. active peptic ulcers, trauma, intracranial haemorrhage). − Severe coronary heart disease or unstable angina; − Myocardial infarction within the last six months; − Decompensated cardiac failure if not under close medical supervision;