Existing contraindications to drug usage might largely determine the limitations of pharmacotherapy. The above problem can impact negatively on the effectiveness of pharmacotherapy, especially in case of great beneficial effects from specific drug treatment with existing contraindications. A manuscript presents the case of patient with hypertension arterialis, ischemic heart disease, past myocardial infarction and atrio-ventricular block IIo Mobitz II. The above case shows the possibility of conversion of existing absolute contraindication to non-contraindication, concerning β1-adrenolytic therapy.