Diuretics (classification, action, use in sports)

1. Classification of diuretics
2. When are diuretics used?
3. How to take diuretics
4. Can it be taken by children?
5. Treatment with diuretics

Diuretics are medications with a diuretic effect.
When they enter the body, they prevent the reabsorption (reabsorption) of water and salts dissolved in it in the renal tubules. This increases the rate of urine formation and excretion. In simple terms, diuretics are substances that help the body remove water and salts from the body. Experts have proven that with a decrease in reabsorption by just 1%, the volume of urine doubles. Even when taking medications with little effect, patients report frequent and more abundant urination.

Classification of diuretics

Diuretics differ in chemical composition and other parameters. Conventionally, all drugs can be divided into renal and extrarenal. Renal diuretics are powerful drugs that directly affect the kidneys. Extrarenal drugs increase diuresis (the volume of urine produced over a period of time), but affect the body indirectly.

Based on their chemical composition, renal diuretics are divided into several groups:

• Thiazide (moderate, uniform effect);
• Potassium-containing (help remove chlorides and sodium from the body, but not potassium);
• Salt (loop - increase the excretion of salts).

The most popular drug of the thiazide group is dichlorothiazide. Loop diuretics include furosemide, torsemide and bumetanide. Potassium-containing diuretics are triamterene and amiloride.

Extrarenal diuretics include two categories of drugs: osmotic (potassium acetate) and acid-forming (ammonium chloride, calcium chloride).

A quick and pronounced result from the use of diuretics is observed when taking Furosemide and other saline drugs. Due to their powerful effects, such products are called “ceiling”. They begin to act in 15-30 minutes, and the effect lasts up to 18 hours. These drugs accelerate the excretion of water, potassium chloride, sodium and calcium in the urine. Loop diuretics are used in the complex treatment of patients with chronic heart failure, hypertensive crisis, poisoning, and pulmonary edema.

Potassium-sparing drugs and drugs of the thiazide group have a less pronounced diuretic effect compared to loop diuretics. Thiazides are considered moderately potent diuretics. They begin to work 30-60 minutes after administration and maintain the effect for 6-10 hours.

The effect of potassium-containing drugs differs from drugs of other groups. A popular potassium-sparing diuretic is spironolactone. The medications help remove fluid and sodium from the urine, but prevent the loss of potassium. The effect of taking the drug occurs within a few hours. Most often, such drugs are prescribed in combination with drugs of the thiazide group to provide a diuretic effect and avoid potassium deficiency.

In addition to pharmaceuticals, some plants can enhance urine output. A mild diuretic effect is provided by plantain, birch, cranberry fruits, horsetail, bearberry leaf, and prickly pear. Decoctions and infusions are prepared from them and used as part of multi-component pharmaceutical herbal mixtures.

The selection of diuretic drugs and their dosage should be handled by the attending physician. The drugs differ not only in their chemical composition, but also in the duration of their effect on the body and the presence of side effects.

Furosemide

• Has a hypotensive effect
• Promotes increased removal of water from the body
• Promotes the removal of calcium and magnesium ions

More details
THERE ARE CONTRAINDICATIONS. BEFORE USE, READ THE INSTRUCTIONS CAREFULLY OR CONSULT A DOCTOR

Mechanism of action of diuretics[edit | edit code]

The main thing in the mechanism of action of diuretics is their effect on the kidneys, the structural and functional unit - the nephron, on the processes that occur in it (glomerular filtration, tubular reabsorption, secretion).

To understand the mechanism of action of diuretics, let us briefly consider the process of urine formation. Each kidney contains about 1 million non-communicating nephron formations, consisting of a vascular glomerulus (glomerulus), glomerular capsule and tubules. In the renal glomerulus, plasma is filtered from the capillaries into the capsule cavity. The endothelium of the capillaries does not allow blood cells and proteins to pass through. The filtrate is called primary urine, which enters the kidney tubules from the glomerulus through the capsule. Filtration in the kidneys requires that the blood pressure in the glomerular capillaries exceed the oncotic pressure of the blood plasma. With a decrease in blood pressure, filtration in the glomeruli decreases; with an increase, on the contrary, it increases. The glomerular filtration rate depends not only on the blood supply to the kidneys, but also on the number of functioning nephrons.

Glomerular filtration in an adult averages 100 ml/min. During the day, 150-200 liters of fluid are filtered in the kidneys, and only 1.5-2 liters of urine are excreted, i.e. 99% of the primary urine is again absorbed (reabsorbed) in the tubules. The tubules are divided into proximal, which passes into the loop of the nephron (Henle) (V-shaped convoluted tube), and distal, through which urine passes from each nephron into the collecting ducts, and from them into the renal pelvis and through the ureters into the bladder.

The reabsorption process occurs throughout the nephron. In order to increase diuresis by 2 times, it is necessary to increase glomerular filtration by 2 times, which is practically impossible to do, or to reduce reabsorption by only 1%. Thus, urine formation can be significantly increased by reducing tubular reabsorption (Fig. 3.11). In addition to water, sodium, chlorine and potassium ions are reabsorbed in the tubules. It should be taken into account that in the tubules it is necessary to reduce the reabsorption of sodium ions, and water passively follows this osmotically active ion.

The effect of increasing filtration and decreasing reabsorption by 10% on the amount of diuresis

Sodium reabsorption in the kidney tubules occurs as follows. From the lumen of the tubule, Na+ enters the cell through the apical membrane. It is believed that sodium transport within the cell is carried out using a special carrier protein, the synthesis of which is regulated by aldosterone. Aldosterone binds to receptors in cells, is transferred to the nucleus and, influencing DNA, stimulates the synthesis of messenger RNA, which promotes the activation of the synthesis of the carrier protein in the ribosomes. Sodium, which entered the tubule cell, creates a fund (pool) of sodium, which is subsequently actively reabsorbed. Reabsorption is carried out using special pumps that are located on the basement membrane of the tubule wall cells. Several types of such pumps are known, one of them transports Na+ in exchange for K+. Others reabsorb Na+ together with SG or HCO~. This active transport of sodium is carried out due to the energy produced by mitochondria located near the basement membranes.

Reabsorption of sodium by epithelial cells of the renal tubular wall

About 70-80% of the total filtered Na+ is reabsorbed in the proximal tubules, followed by passive reabsorbment of water and SG. Carbonic anhydrase reabsorbs hydrogen carbonate (HCO3). The point of application of diuretics may be the proximal nephron, but their effect is insignificant, since a decrease in reabsorption in the proximal tubule entails a compensatory increase in it in the nephron loop and the distal tubule.

Active transport of Na+ and SG occurs in the nephron loop; its wall is impermeable to water. The action of diuretics primarily occurs in this part of the nephron; they are called loop diuretics. Blockade of sodium reabsorption in this department causes the greatest natriuresis.

Diagram of the nephron and localization of the action of diuretics (Farmakolopya, 2001): 1 - xanthines; 2 - diacarb; 3— mannitol; 4— furosemide, ethacrynic acid; 5 - dichlothiazide; 6— spirolactone, triamtren

Urine formation is completed in the distal nephron and collecting ducts. Transport processes here are controlled by hormonal influences. The sodium-retaining effect of the mineralocorticoid aldosterone and the water-retaining effect of the antidiuretic hormone (vasopressin) are manifested. Passive secretion of K+ from nephron cells occurs through the apical membrane along an electrochemical gradient. The distal tubule and collecting ducts can also be the point of application of diuretics (aldosterone antagonists, triamterene and others), but they are ineffective. Blocking Na+ reabsorption in this compartment, when about 90% of the filtered Na+ has already been reabsorbed, can increase its excretion by only 2-3% - the filtration charge. Sodium transport in the kidneys is also regulated by other factors. This is an atrial natriuretic hormone that is released from the atria when they are stretched, which causes an increase in glomerular filtration rate and inhibition of sodium reabsorption in the collecting ducts. In addition, there is natriuretic hormone - a low-molecular compound that enters the blood when volumoreceptors are stimulated and, like ouabain, blocks Na*, K+-ATPase in the kidneys, which reduces Na+ reabsorption. Substances that act as potential regulators of sodium excretion include estrogens, somatotropin, insulin (increase Na+ reabsorption), progesterone, parathyroidin, glucagon (reduce Na+ reabsorption). Factors that are formed in the kidneys (kinins, prostaglandins, dopamine, etc.) also act locally.

Considering the principles of functioning of the urinary system, it becomes clear that drugs that stimulate urination can directly affect the urinary function of the kidneys or change their hormonal regulation.

The use of diuretics, primarily as a means of symptomatic therapy aimed at reducing edema, also has an important pathogenetic effect on the complex chain of reactions in diseases that are accompanied by the retention of salts and water in the body.

There are more than 20 drugs in the arsenal of diuretics. Which of them should be preferred in a given situation should be helped by knowledge of pharmacokinetics, mechanism of action, possible side effects, and more.

When are diuretics used?

Due to the diuretic effect of diuretics, they are used in the complex treatment of diseases and disorders in the body that are accompanied by edema. First of all, we are talking about diseases of the heart and blood vessels. Diuretics eliminate fluid retention and excess salts, which helps:

• normalize the balance of mineral compounds;
• lower blood pressure;
• ease the work of the heart;
• reduce swelling of the limbs;
• get rid of congestion in the lungs.

When combined with other medications, diuretics relieve shortness of breath and other symptoms of chronic heart failure.

In addition to cardiac diseases, diuretics are used in the treatment of a number of other diseases. Diuretics are used for chronic renal failure and nephrotic syndrome (edema), liver cirrhosis, glaucoma, diabetes insipidus, gout, neonatal edema syndrome, neurological diseases that lead to increased intracranial pressure.

Contraindications and indications for use

Indications:

1. Urinary tract diseases.
2. Arterial hypertension.
3. Renal dysfunction.
4. Edema.
5. Moist rales in the lungs.
6. Rapid weight gain.
7. Ascites.
8. Hydrothorax.
9. Endocrine diseases.
10. Increased liver size.

Contraindications:

1. Elevated uric acid levels.
2. Diabetes.
3. Tuberculosis.
4. Diseases of the liver, kidneys.
5. Pregnancy.
6. Lactation period.
7. Individual intolerance to components.
8. Hepatitis.
9. Thrombosis.
10. Cancer.

Side effects:

1. Dizziness.
2. Weakness.
3. Fainting.
4. Dehydration.
5. Nausea.
6. Disorders of the gastrointestinal tract.
7. Diarrhea.
8. Decreased libido.
9. Skin rashes.
10. Increased blood cholesterol levels.

How to take diuretics

Preparations for diuretic therapy are available in the form of tablets, powders and solutions for intravenous administration. Depending on the clinical case, the doctor selects one drug or a combination of several drugs with different mechanisms of action.

The basic rule for taking diuretics is to use the medicine on an empty stomach and take it with plenty of water.

Liver cirrhosis2

2Div. Also, ascites is a worsening of liver cirrhosis.

– Medicine for the world.
– 1998. – T. V. – Part 1. – P. 4-11 and Ascites: a new look at the classic problem.
– Medicine for the world. – 2004. – T. XVI. – Part 2. – P. 77–83. (Note switch)

To treat ascites with swellings associated with cirrhosis, you can apply more principles to the importance of sechoginal and the exchange of sodium in the skin. Ascites is often associated with liver cirrosis, which worsens the prognosis. The importance of treating ascites is divided into three stages: in the first stage, ascites is diagnosed only by ultrasound; in the other case, there is apparently a slightly symmetrical enlargement of the abdomen; with the third - a sign of enlargement of the abdomen. To identify the etiology, a sample of ascitic tissue can be taken. In fact, the universal recommendation in this situation is to remove sodium and water.

In case of ascites of the 2nd or 3rd stage, to combat hyperaldosteronism, it is absolutely necessary to take spironolactone at a dose of 100–200 mg per day, every hour. In addition to this, you can monitor the results of treatment. Vaginal expenditure should not exceed 0.5 kg per day in patients without peripheral swellings and 1.0 kg with obvious swellings. If there is no reaction to the addition of 100 mg spironolactone, a low dose loop diuretic can be added. In case of overly aggressive treatment with diuretics, acute hepatorenal syndrome may occur. Side effects of spironolactone administration include hyperkalemia, metabolic acidosis, and gynecomastia, which usually resolve after dose reduction or drug administration.

The treatment of choice in patients with stage III ascites is paracentesis due to the use of transection and injection of sodium. However, since the volume of the liquid exceeds 5 liters, it is recommended to remove it in one procedure. To prevent neurological complications after paracentesis, it is necessary to carry out infusion therapy with a synthetic plasma exchanger or albumin, especially after evacuation of more than 5 liters of liquid. In patients with refractory ascites, there are indications for transjugular intrahepatic portosystemic shunt (TIPS). At the end of the randomized follow-up M. Rossle et al. (2000) found that TIPS is superior to large-volume paracentesis in eliminating ascites and prolonging survival (58 vs. 32% in patients who lost 2 days of life). Many patients with ascites and cirrhosis are candidates for liver transplantation.

Treatment with diuretics

When prescribing diuretics, doctors adhere to the principles of rational therapy:

• At the first stage, a medicine with a moderate effect is prescribed.
• At the beginning of therapy, a minimum dosage of the drug is recommended with a gradual increase until the desired effect of diuretics is achieved. With intensive treatment, it is normal to increase the daily volume of urine by 800-1000 ml, and with maintenance therapy - by no more than 200 ml per day.
• For the majority, the optimal combination of diuretics with different mechanisms of action is optimal.
• To achieve a therapeutic effect, medications must be taken daily for the period recommended by your doctor.

It is important to be aware of the side effects of diuretics. Accidental or intentional abuse of such drugs leads to disruption of water and electrolyte balance. With prolonged use or an incorrectly selected dosage of diuretics, the risk of side effects increases:

• dehydration;
• heart rhythm disturbances;
• excessive decrease in blood pressure.

Headaches and muscle pains, nausea, vomiting, disturbances in the functioning of the gastrointestinal tract, weakness and convulsions, and drowsiness may also be observed. If you are hypersensitive to the drug, an allergic reaction may occur.

With prolonged diuretic therapy, mandatory monitoring of potassium and creatinine is indicated. If these indicators deviate significantly from the norm, a diuretic dosage adjustment or its complete discontinuation is required.

Admission rules

Before taking diuretics, you should consult a specialist. The daily dosage of the drug for the treatment of diseases is prescribed by the doctor. When using diuretics for weight loss, you must follow a drinking regime. To avoid dehydration, you need to drink at least 2 liters of water daily. Maintain a proper and balanced diet. Avoid junk and fried foods, sugar, salt, and alcoholic beverages. Every 2-3 days, weigh yourself in the morning and control your weight. If you feel unwell and side effects occur, you should stop taking it.

Nephrotic syndrome3

3Div. also article Scratches of the lower ends: diagnostic orientation

. – Medicine for the world. – 1999. – T. VI. – Part 1. – pp. 27-31. (Note switch)

Nephrotic syndrome often causes swelling and is characterized by severe proteinuria, hypoalbuminemia, hyperlipidaemia and swelling. Discussion will continue as to whether the swelling is a consequence of the decrease in oncotic pressure, or the evidence of an excessive amount of sodium, which is necessary to stop the water; Most of the researchers tend to converge on another hypothesis. Treatment includes the exchange of intravenous sodium and a combination of loop diuretics, aldosterone antagonists and drugs for the treatment of primary illness.

Scrubs, due to the action of the lips

Foot swelling is caused by many medications, especially vasodilators, estrogens, NSAIDs and calcium channel blockers. Among calcium channel blockers, the most common compounds are dihydropyridine5. The intensity of the effect lasts for a long time and grows over time. Remnants of drug effects result from capillary hypertension; for their treatment, ACE inhibitors and angiotensin receptor blockers are effective, rather than sedative ones.

5 This group includes amlodipine, felodipine, isradipine, nifedipine, nemodipine, nitrendipine, lacidipine, rhiodipine. (Note switch)

Chronic venous insufficiency4

4The same article Varicose veins: not only a cosmetic problem

. – Medicine for the world. – 2000. – T. VIII. – Part 3. – P. 130-136; Part 4. – pp. 201-203. (Note switch)

Venous insufficiency is a common etiology of swellings of the lower ends. If swelling appears, especially one-sided, it is necessary to exclude thrombosis of the deep veins of the lower end. Until the swelling of the legs heals, persistent dermatitis, swelling and cellulite will occur. The effectiveness of diuretics is limited. Keeping the nose in an elevated position above the level of the heart and tightening the thick punches can change venous insufficiency and swelling.

Lymphedema6

6Div. also the article by Lymphedema

. – Medicine for the world. – 2004. – T. XVII. – Part 2. – pp. 77–86. (Note switch)

The term “lymphedema” refers to a set of conditions that are characterized by excessive regional accumulation of protein-rich substances in the interstitium. Distinguish between primary and secondary lymphedema (in the world, the lymphoma is more frequent and develops with filariasis). In the USA, lymphedema is most often treated after removal of the axillary lymph nodes (up to 80% of patients after this operation).

Differentiating lymphedema from other forms of swelling is important, especially in the early stages. The presence of lymphedema is indicated by Stemmer's sign, a bump on the dorsal surface of the foot with a “square” appearance of the toes. To confirm the diagnosis, CT or NMR can be performed (sensitivity to human NMR, lower CT). Lymphedema can be distinguished from other types of swelling due to the presence of the characteristic “honeycomb” structure of the subcutaneous fat cells.

Indications for treatment include an increase in arm circumference by 2 cm, equal to the preoperative period. It’s a very difficult time to stop wearing a tight garment, to carefully look behind the skin, to stop the weakening of arterial pressure and the squeezing of an injured end. Effective measures may include physical exercises, looking after the skin, wearing compression panties or mittens, comprehensive anti-abdominal physiotherapy, a two-phase process of special manual massage and drainage of lymph nodes. At the early stages of the disease, diuretics may be effective; Prote then the stench rarely helps. Surgical treatment is less effective, but can ensure a change in the volume of endocrine tract in patients with an important form of elephantiasis.

Prepared by Bogdan Boris