Summary: The frequency of occurrence of heart failure in Europe is about 1‒2%. The European Society of Cardiology 2021 guidelines present four main medications in the heart failure treatment: 1) beta-blockers, 2) angiotensin converting enzyme inhibitors (ACEi)/angiotensin receptor blockers (ARB) and neprilysin inhibitors (ARNI), 3) aldosterone antagonists, 4) sodium-glucose transport protein 2. ACEi and ARB can be used in multiple diseases, but ARNI are used only in heart failure. In HFrEF ACEi should be used in every patient, ARB only during intolerance or contraindications. ARNI are the next level during treatment (instead of ACEi). The most common side effects during ACEi, ARB and ARNI treatment are: hypotension, hyperkalemia, deterioration of renal function. That is why the control of creatinine and electrolytes is very important. Unfortunately, most of patients in Poland cannot afford ARNI. In February 2021 US Food and Drug Administration (FDA) registered ARNI in patient with heart failure with preserved ejection fraction.