ACE-inhibitors (ACE-I) belong among my favorite medications. They are relatively frequently prescribed as potent antihypertensives and have a great importance in modern medicine.


ACE-inhibitors can block the so-called called ACE enzyme (angiotensin-converting enzyme) and thus prevent our body to produce a substance known as angiotensin II, which increases blood pressure. The effect of the drugs is mainly done by decrease of serum concentration of angiotensin II.

Medical use

ACE-inhibitors reduce high blood pressure and belong among antihypertensive agents. They have a very positive effect on the heart muscle and protect it. That is why they are frequently used to treat hypertension in patients with chronic heart failure. Similar protective effect has been also reported in kidney tissue and therefore, ACE-Inhibitors are commonly prescribed to diabetics with hypertension who are threatened by diabetic nephropathy.

Used substances

The commonly used ACE-Inhibitors contain for example these substances - ramipril, captopril, enalapril, perindopril, lisinopril and others.


ACE-inhibitors may cause increase in plasma potassium concentration (hyperkalemia). Therefore, it is advisable to check the patient's serum level of potassium some time after beginning the therapy with ACE-I. Another typical side effect is unpleasant dry cough, which is a common cause of discontinuation of ACE-Inhibitor therapy. Finally, large doses of ACE-Inhibitors can cause low blood pressure with all its consequences (fatigue, dizziness, fainting), which is, however, possible in all antihypertensives.


ACE-Inhibitors should not be used in patients with renal artery stenosis, because they can further decrease the blood flow into the affected kidney and threaten its function. In addition, ACE-Inhibitors may endanger human fetus and they should not be prescribed to pregnant women.


ACE-inhibitors are great medications in single or combined therapy of hypertension. Their positive effect on the heart muscle and kidneys makes them widely prescribed. Nevertheless, we are somehow restricted in their usage by possible side-effects.


Jiri Stefanek, MD  Author of texts: Jiri Stefanek, MD
 Sources: basic text sources