Diuretics • Effects & side effects of water tablets

Diuretics are diuretics. The drugs, also known as water tablets, are used for various heart problems and kidney problems. When should diuretics not be taken and what side effects are possible?

Article content at a glance:

22 tips for a healthy heart

What are diuretics?

In addition to ACE inhibitors, calcium channel blockers and beta blockers, diuretics are also drugs against high blood pressure (antihypertensive drugs). They promote the elimination of water and electrolytes through the kidneys. This means that the active ingredients change the amount and composition of urine, which is used in various diseases of the heart and kidneys. The withdrawal of water also reduces the blood volume, which in turn leads to a drop in blood pressure.

Within the diuretics there are different groups of active substances that influence the kidney metabolism differently:

  • Osmodiuretics: They are not absorbed into the kidney cells and draw water from the blood through an osmotic gradient.

  • Carboanhydrasehemmer: They inhibit the enzyme carbonic anhydrase in the kidneys, which means that less water flows into the back of the eye. Therefore, these diuretics are mainly used for glaucoma. At the same time, they increase phosphate excretion.

  • Thiaziddiuretika: They promote the excretion of sodium and increase the amount of primary urine.

  • Loop diuretics: They prevent the reabsorption of sodium and potassium in the loop-shaped section of the kidney (“Henle loop”). As a result, the minerals are excreted together with the water.

  • Aldosteronantagonisten: These diuretics block the aldosterone receptor so that fewer sodium channels are formed in the kidney through which the mineral enters the cells.

  • Vasopressinantagonisten: They prevent the installation of certain transport proteins in the walls of the collecting ducts in the kidney. As a result, water cannot get into the cells and more is excreted.

  • Potassium-sparing diuretics: These drugs inhibit the excretion of potassium, while they increase that of sodium and water. As a side effect, there can be an excess of potassium.

In what diseases diuretics are used

Water tablets are prescribed for various diseases of the heart and kidneys. The risk of such diseases increases with age, which is why diuretics are often prescribed to the elderly.

Indications for diuretics:

Since, depending on the active ingredient group and the health of the person affected and the underlying disease, severe side effects can occur, the risk-benefit ratio must be weighed up on an individual basis.

Contraindications for the administration of water tablets

In certain cases, treatment with diuretics is not possible or is not recommended. These include very low blood pressure, reduced blood volume (hypovolemia), severe liver and kidney dysfunction and the electrolyte balance. Other contraindications for taking diuretics are pregnancy, breastfeeding and a known drug allergy.

Diuretics can have side effects

As diuretics increase the body’s excretion of water, the blood becomes thicker as a result. Blood clots (thrombi) can form more easily, so that taking water tablets increases the risk of thrombosis. Loop diuretics in particular cause a short-term increased urine excretion, which can result in a strong feeling of thirst, calf cramps and a painful urge to urinate.

Long-term use of diuretics can worsen the metabolism of people with diabetes mellitus. A previously unnoticed diabetes can also manifest itself through water tablets.

The use of diuretics can lead to electrolyte disorders, especially potassium, sodium, magnesium and calcium. The consequences can be cardiac arrhythmias, muscle cramps, dizziness or gastrointestinal problems. The risk of low magnesium levels (hypomagnesaemia) and high or low potassium levels (hyper- or hypokalaemia) can be reduced by taking various potassium-neutral diuretics in combination.

What to look out for when taking water tablets?

Treatment with diuretics changes the body’s water and electrolyte balance. Therefore, depending on the preparation, the mineral concentration in the blood is regularly checked by a doctor. Weight and blood pressure should also be measured daily at the start of taking and weekly later. In order not to disturb sleep by an increased urge to urinate, water tablets should be taken if possible in the morning or in the first half of the day.

During treatment, one should watch out for possible side effects such as heart stumbling, muscle cramps or other unexpected physical reactions – if unsure, sufferers should consult their family doctor. Anyone who sweats heavily, has a fever or suffers from diarrhea should make sure to drink enough while taking water tablets. Otherwise too much water will be withdrawn from the body. The simultaneous intake of potassium-containing preparations should be clarified by a doctor. People with edema and heart failure, on the other hand, should adhere to and not exceed the amount prescribed by the doctor.

People with diabetes should carefully monitor their blood sugar as diuretics can increase blood sugar levels. Dietary supplements with potassium and vitamin D should only be taken after consultation with a doctor, so as not to additionally burden or disturb the electrolyte balance.

Diuretic resistance: if the water tablets don’t work

Diuretic resistance is when people do not respond adequately to treatment with diuretics. The causes can be very diverse: from an unsuitable dosage of the water tablets to incorrect intake by those affected to various health disorders. These include, for example, low blood pressure (hypotension), chronic kidney disease or a reduced level of proteins in the blood plasma (hypoproteinemia).


Source: Lifeline | Das Gesundheitsportal by www.lifeline.de.

*The article has been translated based on the content of Lifeline | Das Gesundheitsportal by www.lifeline.de. If there is any problem regarding the content, copyright, please leave a report below the article. We will try to process as quickly as possible to protect the rights of the author. Thank you very much!

*We just want readers to access information more quickly and easily with other multilingual content, instead of information only available in a certain language.

*We always respect the copyright of the content of the author and always include the original link of the source article.If the author disagrees, just leave the report below the article, the article will be edited or deleted at the request of the author. Thanks very much! Best regards!