Side effects of ACE inhibitors

At the beginning of the therapy a strong reduction in blood pressure with dizziness may occur, which is why a low initial dose is recommended. If there is a strong drop in blood pressure, the patient receives fluid through the vein (infusions) and his upper body is laid flat while the legs are positioned high up so that more blood can flow back into the upper half of the body. The typical side effects of ACE inhibitors are dry irritable cough in 10-15% of patients.

When taking ACE inhibitors, there is an increase in potassium, a blood salt, because less aldosterone is produced, which is responsible for the excretion of potassium. It can also lead to so-called angioneurotic edema: swelling of the lips and mucous membranes of the mouth. Less frequent side effects are allergic skin reactions, a reduction in red blood cells (anemia) or white blood cells (leukopenia).

Since the drug is excreted from the body with the urine via the kidneys, it is possible that the function of the kidneys may deteriorate. This side effect occurs mainly in patients who have kidney vessels damaged by arteriosclerosis. One of the main side effects of ACE inhibitors is irritable cough.

This can be explained by the functions of the angiotensin converting enzyme. Besides the function of converting angiotensin 1 to angiotensin 2, it also has a so-called kinase function. This means that the enzyme also breaks down tissue hormones, the so-called kinines, such as bradykinin and substance P. These tissue hormones play an important role in inflammation.

Together with other endogenous factors, they cause vasodilation. This is important in inflammatory situations so that the immune cells can gain access to the diseased tissue. In addition, they also ensure pain sensitisation.

These functions are normally adequately regulated by the angiotensin-converting enzymes, as they break down tissue hormones. The ACE inhibitors inhibit the breakdown of bradykinin and substance P. This means that the tissue hormones are increasingly present. The advantage is that, in addition to the blood pressure-lowering effects of the ACE inhibitors, vasodilation occurs.

This in turn causes a reduction in blood pressure. The disadvantage is that these tissue hormones can trigger inflammatory symptoms. They can irritate nerve endings by sensitizing them to pain.

In the course of treatment with ACE inhibitors, they do this preferably in the throat. In addition, increased potassium levels caused by the ACE inhibitors can intensify these processes. The vascular hormones can also cause oedema.

This happens mainly in parts of the body where there is a lot of spongy tissue. This is the case in the neck area. This is where the ACE inhibitors can cause oedema.

There is thus a risk of life-threatening angioedema developing. Therefore, the side effect of irritable cough is to be taken very seriously. In some patients, the irritable cough occurs right at the beginning of the therapy, while in other patients it is not noticed until several weeks after the start of treatment.

If irritable cough is noticed, the doctor should be informed immediately. Life-threatening situations are rare, but can occur. These can be avoided by acting early.

In most cases, this is followed by a switch to another medication to lower blood pressure, so-called angiotensin 2 receptor blockers. Colloquially, hyperlipidemia corresponds to an increase in blood lipids. These play a role in elevated blood pressure and thus also in the treatment with antihypertensive drugs such as ACE inhibitors.

Both high blood pressure and high blood lipids increase the risk of developing arteriosclerosis. Atherosclerosis in turn increases the risk of cardiovascular disease. These are among the most common causes of death.

Various measures and drugs are used to reduce these risk factors. However, some measures and drugs reduce one risk factor while increasing another. For example, there are various antihypertensive drugs that increase blood lipids – in other words, they can lead to hyperlipidemia. According to current knowledge, ACE inhibitors are not among them. This means that the risk of developing or increasing hyperlipidemia through ACE inhibitors is lower than with many other antihypertensive drugs.