Different classes of drugs

Many different drugs are used in the treatment of high blood pressure. However, one cannot say that one group of drugs is the best in general. Depending upon cause and particularly depending upon further existing Begleiterkrankungen the best medicine must be selected for the individual case from the group of the so-called Antihypertonika. Basically one differentiates: which are based in each case on different effective principles and are described in the following.

Diuretics
Beta blocker
ACE Inhibitors
AT1 Blocker
Calcium channel blocker
Spare medication

Diuretics

Diuretics are drugs that increase water and salt excretion of the body in the kidneys. They are also called diuretic drugs.Due to the increased fluid loss, the blood volume in the body decreases and, similar to the model of the garden hose, by turning off the tap a little, the pressure in the hose or in the body’s vascular system now decreases and the blood pressure drops. The additional loss of salt supports this effect.

Salts have the property to bind water to themselves. If salts (especially sodium) are now lost through the urine, additional water excretion occurs. Dehydrating drugs, however, are usually not used alone for the treatment of high blood pressure, but as a combination with other active ingredients, e.g. the so-called thiazides from the group of dehydrating drugs are particularly suitable.

They are effective for a very long time and of medium strength, which makes them very suitable for long-term, moderate drainage. Unfortunately, their efficacy only reliably occurs with good kidney function. Patients with kidney damage often lose their effectiveness and other diuretics must be used.

Well-known representatives of thiazides are hydrochlorothiazide (HCT) or xipamide, a substance chemically related to thiazides. In addition to their draining effect, they also have a direct effect on the vascular system after a longer period of therapy. This becomes less sensitive to the narrowing nerve impulses and thus remains rather relaxed.

Since this effect only occurs with a delay of about 1-2 weeks, the effect can only be reliably assessed after 3-4 weeks of therapy. Side effects occur rather rarely during the treatment with thiazides. If they do occur, they cause nausea, vomiting or discomfort in the digestive tract.

Most of the diuretics also carry the risk of derailment of the body’s salt balance. The kidney is a central organ of salt regulation in our body. Sodium, potassium, calcium and chloride are the most important substances.

Many diuretics cause a loss, especially of potassium, by interfering with this sensitive system. For this reason, potassium levels should be checked regularly. Particularly in older people, this control should be carried out by taking blood samples every 7-14 days at the beginning.

With stable potassium concentrations, this control is then sufficient on a monthly basis. A potassium-rich diet (e.g. nuts, cocoa, broccoli, kohlrabi, dried fruit, bananas, currants) or the intake of potassium tablets can often prevent the potassium level from falling too low. If a stronger dehydration than that desired with thiazides has occurred, loop diuretics such as torasemide are also used.

Their effectiveness is still given in cases of impaired kidney function, when thiazides already have no effect on the kidneys. Loop diuretics act at one site of the kidney, the Henle’s loop, hence the name loop diuretic. Due to their strong and rapid drainage, they are particularly well suited for a derailment of blood pressure to enormously high values.

In contrast to the thiazides, they are much more likely to have side effects. The most important ones are circulation problems, headaches and thirst. In addition, the salt balance (= electrolyte balance) of the body can be disrupted more than by other diuretics due to the strong dehydration and especially a lack of potassium (=hypokalemia) can be dangerous, not least for the heart.