How do antihypertensive drugs work on the kidneys? What does it mean if an antihypertensive drug protects the kidneys?

Hello,Some medications, like telmisartan, act on a hormonal system called the renin-angiotensin-aldosterone system (RAAS). This system takes place mainly in the kidneys and helps to maintain stable blood pressure. For example, if the blood pressure decreases, the kidney will identify this decrease in blood pressure and, in order to increase it, will activate the RAAS. Thus, the kidneys will decrease the excretion of salt (NaCl), water and tighten certain vessels. In the end, all these effects will increase the pressure When a person has a high blood pressure, there would be a disturbance of the RAAS. So, we give drugs from the ARB (Angiotensin Receptor Blockers) class like telmisartan or ACEI (Angiotensin Converting Enzyme Inhibitors) that block this system to lower the pressure. This system can be deregulated in both people with and without kidney failure So we say that these drugs protect the kidney, because by promoting better blood flow to the kidneys, we protect them from possible damage. The image I give for the kidney is that of a sieve. If you send too much water through it (blood pressure), the mesh of the strainer may be damaged and become too "loose". The medications given are therefore used to reduce the amount of water (blood pressure) and to make the mesh stronger. This effect is particularly important in certain populations such as those with kidney failure and diabetics

We look forward to hearing from you,Sarah-Yan Chagnon, pharmacist

The person with renal insufficiency or diabetes often already has kidneys that are not functioning well, so by giving these drugs we want to delay the degradation of the kidneys. Since it is a preventive measure, in some cases we give these drugs even to people who do not have high blood pressure, because the protective effect is still present For the person undergoing dialysis, the kidneys function very little, so the filtration of waste and the elimination of water is done with a machine. However, the machine is not as efficient as our kidneys, so the person must still take several medications to reduce pressure and eliminate water. Thus, ARBs or ACE inhibitors can be used