Different groups of drugs

Three different groups (substance classes) of diuretics are given to promote water excretion: In the following, the different types of diuretics are presented in more detail and their specific mode of action and side effects are described

Loop diuretics
Thiazides
Potassium saving diuretics

In the treatment of high blood pressure, this group of drugs can also be used in patients whose kidney function is already limited. By means of a marker in the blood, the creatinine value, the kidney function can be assessed and a decision can be made as to whether or not the patient has such a functional impairment. The effect of loop diuretics can be increased by the administration of another drug to promote water excretion, whereby loop diuretics are already highly effective drainage drugs.

If fluid needs to be drained quickly, such as in sudden worsening heart failure, this group of drugs is usually used. Loop diuretics: Active ingredient and trade names Treatment with loop diuretics can lead to a reduction in the potassium and calcium levels in the blood. Both are important blood salts.

If the diuretics are given together with an ACE inhibitor, care must be taken to ensure that the blood pressure does not drop too much. Both drugs lead to a reduction of fluid in the body, which is associated with a reduction in blood pressure. This can lead to dizziness and weakness.

Loop diuretics may be used in patients with diabetes.

Bumetanide, e.g. Burinex®
Furosemide, e.g.
Lasix®®, Furorese®
Torasemide, e.g. Torem®, Unat®, Toacard®
Piretanide, e.g. Arelix®, Piretanide 1 A®
Etacrynic acid, z.B. Hydromedin

Thiazides are the so-called first-choice agents in hypertension therapy, i.e. they are prescribed primarily for combination treatment.

Studies prove their beneficial effect on blood pressure and a significant improvement in the prognosis of hypertension patients. This group of drugs is well suited for long-term therapy of patients with heart failure and high blood pressure. In addition to increased sodium excretion, effects on the blood vessels in the sense of vasodilating effects can be observed, which support the lowering of blood pressure.

Thiazides: Active ingredient and trade names Thiazides lead to a reduction of the sodium, potassium and magnesium levels in the blood in 20% of cases. Thiazides are therefore often combined with potassium-saving diuretics to compensate for potassium loss. This can lead to serious cardiac arrhythmia.

Metabolic disorders in the form of elevated blood sugar and blood lipid levels are possible side effects of therapy with thiazides. Nausea and vomiting may also occur. Thiazides should not be given if the kidney function is impaired, because in this situation they can cause reduced blood flow to the kidneys, which could additionally damage the kidneys

Chlorthalidone, e.g.
Hygroton®
Hydrochlorothiazide, e.g. Disalunil®, Esidrix®, etc.
Xipamide, e. g. Aquaphor®, Aquex®

The potassium-saving drugs, unlike other diuretics, cause a retention of potassium in the body and not the increased excretion of this blood salt. Thus, potassium is saved for the body, hence the name of the group of medicines. The potassium savers are used in combination with thiazides because they alone cause only moderate excretion of water.

Potassium-sparing diuretics must not be given to patients with severe kidney function impairment, renal insufficiency. When combining treatment with ACE inhibitors and administration of potassium, it should be noted that the body loses less potassium due to the effect of the potassium-saving drugs. An elevated potassium level can have serious consequences such as cardiac arrhythmia, so a blood test should be performed at regular intervals to determine the potassium level.

There are two types of medication in this group: aldosterone antagonists and the two drugs triamterene and amiloride. The drugs in this group prevent aldosterone from working in the body: aldosterone increases the amount of fluid in the blood vessels and thus raises blood pressure. The aldosterone antagonists lead to a decrease in the volume in the vessels and thus to lower blood pressure.

This group of diuretics is of great importance in the treatment of heart failure: if an aldosterone antagonist is given together with an ACE inhibitor and a cardiac glycoside, it helps to reduce the mortality of patients with severe heart failure. Aldosterone antagonists: Active substance and trade names Side effects of aldosterone antagonists include an increase in potassium in the blood, possible allergic reactions, nausea, vomiting and diarrhoea. These two active ingredients should also always be given together with preparations of other drug groups, as their effect would be too weak without combination partners.

Amiloride and triamterene are therefore usually given in combination with thiazides or a preparation is prescribed which contains both active ingredients (thiazide and potassium-saving drug). This group of drugs is used to flush fluid out of the body and in the treatment of high blood pressure. Triamterene and Amiloride: Side effects include an increase in blood potassium and possible allergic skin reactions or digestive tract conditions such as diarrhea, nausea, and vomiting.

Thiazide, the combination partner of triamterene or amiloride, counteracts the increased potassium level: While thiazides lead to increased potassium excretion, amiloride and triamterene reduce potassium loss – thus the two effects in the combination treatment balance each other out and can be called a “positive side effect”.

Aldosterone antagonists
Eplerenone, e.g. Inspra®
Potassium canrenoate, e.g.
Aldactone®.
Spironolactone, e.g. Duraspiron®, Verospiron®, and
Amiloride and triamterene
Triamteres, e.g. Arumil®
Amiloride, e.g. Jatropur®