ACE inhibitors, mechanism of action, indications and classification - Traditional medicine and medicinal plants

ACE inhibitors, mechanism of action, indications and classification

ACE inhibitors are the most common group of drugs for the treatment of hypertension. While studying the instructions for these drugs, many questions usually arise. What is ACE and ACE? How does the drug suppress (inhibit) ACE? And what does this process have to do with lowering blood pressure? Let’s try to deal with these issues together. And at the same time, we will find out what drugs belong to ACE inhibitors and how they differ.

Mechanism of action of ACE inhibitors 

ACE inhibitors act on one of the mechanisms of blood pressure regulation – the renin-angiotensin-aldosterone system (RAAS). This system is a complex of hormones, enzymes, and biologically active substances released by the kidneys, liver, and blood vessel wall cells. Interacting with each other, they lead to narrowing of blood vessels and to an increase in blood pressure.

A powerful vasoconstrictor is angiotensin II, which is converted from its precursor angiotensin I by a special enzyme. This enzyme is called angiotensin converting enzyme or ACE. If you block the work of this enzyme, then angiotensin I will not turn into angiotensin II, and therefore the pressure will not increase. This, in fact, is the effect of ACE inhibitors.

mechanism of action of ACE inhibitors

It is worth noting that the effect of angiotensin II is not limited only to an increase in blood pressure. This biologically active substance activates the sympathetic nervous system, causing heart palpitations, triggers the adrenal glands, which leads to the release of the antidiuretic hormone aldosterone. This hormone slows down the renal filtration, retains sodium and water in the body. As a result, the volume of circulating fluid increases, which is the cause of edema and another factor in increasing blood pressure.

In addition, angiotensin II leads to myocardial hypertrophy (an increase in the volume of the heart muscle) and the vascular wall. These changes further aggravate the course of hypertension. An enlarged heart cannot fully perform its functions of pumping blood, and blood vessels lose the ability to narrow and expand in response to changes in blood pressure.

It turns out that angiotensin II not only causes hypertension, but also disrupts the work of important internal organs – the heart, kidneys and blood vessels. And ACE inhibitors reduce blood pressure and prevent the development of concomitant diseases. Therefore, ACE inhibitors are prescribed for hypertension and to protect the internal organs from the negative effects of high blood pressure.

It turns out that angiotensin II not only causes hypertension, but also disrupts the work of important internal organs – the heart, kidneys and blood vessels. And ACE inhibitors reduce blood pressure and prevent the development of concomitant diseases. Therefore, ACE inhibitors are prescribed for hypertension and to protect the internal organs from the negative effects of high blood pressure.

Effects of ACE inhibitors 

Two groups of effects of ACE inhibitors can be conditionally distinguished:

  1. Lowering blood pressure
  2. Protection of internal organs (organoprotective effect)

By and large, the very reduction of high blood pressure is already a reliable prevention of so – called vascular disasters-heart attack, stroke, heart failure, arrhythmia and other diseases associated with hypertension. But ACE inhibitors have other beneficial effects. Let’s look at them.

ACE inhibitors and heart

  • The prevent and reverse the development of hypertrophy of the left ventricle. Studies have shown that with regular use of ACE inhibitors, the process of increasing the mass of the myocardium stops, and in some cases, the heart muscle can return to normal size.

Left ventricular hypertrophy is the most common complication of hypertension. Thickening of the heart muscle occurs in response to a prolonged increase in load, because at high pressure, the heart exerts more effort to push blood into the vessels. The result of left ventricular hypertrophy can be heart failure and heart attack.

  • Weakening of the processes of myocardial fibrosis.

Myocardial fibrosis – the replacement of muscle tissue with connective tissue. This process can lead to arrhythmias and heart failure.

ACE inhibitors and blood vessels

  • Preventing thickening of the blood vessel wall. This returns the vessels to their lost functions-to respond to changes in blood pressure by expanding or contracting.
  • Aniaterosclerotic effect-an obstacle to the destruction of the inner wall of blood vessels.
  • Antithrombotic action-suppression of the formation of blood clots in the blood vessels.

ACE inhibitors and metabolism

  • Inhibition of the release of aldosterone from the adrenalglands, which leads to the normalization of diuresis( urination), the removal of excess sodium and water from the body and the normalization of water balance.
  • Positive effect on lipid and carbohydrate metabolism – increase the sensitivity of tissues to insulin, improve glucose uptake, accelerate the breakdown of VLDL and increase the amount of HDL (decrease in “bad “and increase in” good” cholesterol).

ACE and kidney inhibitors

  • Improvement ofrenal filtration, stopping the progression of pathological processes in the kidneys. Due to this, normal diuresis is restored, and excess fluid leaves the body.

ACE inhibitors are among the most studied drugs. They have shown good results in a number of basic clinical studies. ACE inhibitors have been shown to significantly reduce the risks of heart attack, stroke, heart failure, arrhythmias, atherosclerosis, and kidney disease. In addition, these drugs do not depress the central nervous system, do not cause withdrawal syndrome and erectile dysfunction. That is, ACE inhibitors do not affect potency, which is important for men.

ACE inhibitors can also prevent the development of type II diabetes in patients with risk factors.

Indications for the use of ACE inhibitors

Показания к применению ингибиторов АПФ

ACE inhibitor – the drug of choice for the treatment of hypertension with concomitant diseases such as:

  • Type II diabetes mellitus;
  • Heart failure;
  • Atherosclerosis;
  • Metabolic syndrome;
  • Condition after a heart attack;
  • Coronary heart disease;
  • Violation of the function of the left ventricle of the heart;
  • Kidney diseases, including diabetic nephropathy.

Classification of ACE inhibitors 

ACE inhibitors include several active substances that are available under different trade names and have some differences. Let’s break them down.

Classification of ACE inhibitors

The characteristics of each drug are taken into account when prescribing. For example, for patients with severe liver damage, lisinopril is suitable, since it is already a ready-made drug and does not need to be metabolized in the liver. For a mild effect, perindopril is better. It is often prescribed to elderly patients in order to avoid sudden drops in blood pressure. Captopril is more often recommended together with diuretics as an ambulance for a hypertensive crisis.

Classification of ACE inhibitors:

According to the duration of the effect, short-acting aCEI (captopril), medium-acting aCEI (enalapril), and long-acting aCEI (ramipril, perindopril, and lisinopril) can be distinguished. Long-acting ACE inhibitors keep blood pressure normal for a day.

Depending on the route of elimination, three groups of drugs can be distinguished:

  1. They are mainly excreted by the kidneys – perindopril, lisinopril
  2. They are excreted by the liver and kidneys equally – fosinopril.

Side effects of ACE inhibitors

After studying the effects of ACE inhibitors, it may seem that these are almost ideal drugs that will suit almost everyone. However, this is not the case. Like any medications, ACE inhibitors can cause side effects that need to be kept in mind:

  • Excessive decrease in blood pressure up to hypotension (the so-called ” hypotension of the first dose”)
  • Digestive disorder
  • Violation of taste sensations
  • Changes in blood parameters – thrombocytopenia, anemia, leukopenia, etc.
  • Allergic reactions-from rash to angioedema
  • Dry cough
  • The combined use of alcohol and ACE inhibitors is highly undesirable. In such cases, the influence of alcohol on the central nervous system increases, as well as the pressure drops excessively.
  • The combined use of NSAIDs and ACE inhibitors leads to a decrease in the analgesic effect.

Why do ACE inhibitors cause coughing?

The most common side effect of ACE inhibitors is a dry cough. This is especially true of enalapril. At the same time, the severity of the cough does not depend on the dose of the drug at all. You may be interested to know the cause of this phenomenon.

Our body constantly produces a biologically active substance – bradykinin. One of its main tasks is to expand the blood vessels. This is one of the mechanisms of blood pressure regulation. Control the level of bradykinin is carried out with the help of angiotensin II. As we have already said, this substance is blocked by ACE inhibitors. Accordingly, bradykinin has no choice but to accumulate in the body, dilating blood vessels and irritating nerve endings. He, by the way, is the culprit of possible allergic reactions, including Quincke’s edema.

That’s why you can’t take these drugs yourself without a doctor’s prescription. Even if your neighbor or relative is ideally helped by lisinopril, for example, this does not mean that it is shown to you. And in general, following the recommendations of ordinary people with such a serious disease as hypertension is not the best idea. The use of ACE inhibitors should be monitored by a doctor.

The information provided in this article is just an adapted description of ACE inhibitors, but by no means a call to action!

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