Diuretics: classification, mechanism of action, groups
Diuretics is diuretic drugs, acting on different parts of the kidneys, increasing urine separation. Classification of diuretics in pharmacology is very wide, all medicines are divided into groups and differ in composition, mechanism of exposure, time of onset and duration of diuretic effect. It is important to know which drugs belong to dioretikam, consider this.
Every day the kidneys excrete about 1.5 liters of urine, which passes through a variety of glomerular filtration, near and distant tubules and loop of Henle. Further urine directly to the ureter and then into urinary bladder, from where is discharged to the outside. In the structures of the tubules is otherwise lost almost 90% of the molecules of the fluid and salts that are needed by the human body. Taking into account these principles of activity of the urinary system, it can be concluded that diuretics have a direct effect on the function of urine production by the kidneys and change their regulation, increasing glomerular filtration. Almost all types of diuretics act by blocking the reverse absorption of salts and water in separate tubules.
Classification by mechanism of action
- drugs that act at the level of the renal tubules cells, for example, mercury diuretics («Eplerenone», «Diacarb», «Indapamide», «Bumetanide»);
- tools that increase the process of the renal circulation («Aminophylline, «Tefillin»);
- drugs from medicinal plants — birch buds, leaves of munity, fruits strawberries.
Table classification of diuretics according to the composition:
|The name of the group||Key representatives||Chemical structure|
|Loop||«Ethacrynic acid», «Furosemide», «Torasemid».||Sulfa derivatives (except for «Ethacrynic acid»)|
|Tiazidove||«Gidrohlortiazid», «Clopamide», «Tsiklometiazid».||Sulfonamides and thiazide derivatives|
|Potassium-sparing||«Triamterene, Aldactone», «Amiloride»||Nesulfonamide connection|
|Osmotic||hypertonic solutions of glucose, sodium chloride, «Mannitol»||Sulfa derivatives|
Loop diuretics act on the reverse-the absorption of potassium, reducing it, leading to increased allocation of potassium from urine. Most often the drugs recommended oral on an empty stomach. There is a variant of the intramuscular and intravenous administration, due to which the effect comes a bit sooner. Use loop diuretics in a day should be no more than 2 times.
Loop diuretics have a potent effect and compatibility with other drugs-diuretics and cardiovascular drugs. Together with nonsteroidal anti-inflammatory tablets is prohibited, because diuretics will potentiate the effects of other drugs on the body.
Thiazide-type diuretics — diuretics neuter impact, and with a loop they differ from those that minimize the excretion of potassium and maximise the concentration of sodium in the kidney, which gives the opportunity to increase the excretion of potassium. Medications have a beneficial effect on the body and does not require the patient to strictly adhere to the restrictions in salt intake.
Clinical pharmacology of diuretics, low potassium, is that diuretic has an effect on the distal renal tubules, which either reduces the secretion of potassium, or is an antagonist of aldosterone. Potassium-sparing drugs used to treat hypertension, to lower blood pressure. However, these have a light diuretic effect, therefore use them only for the treatment of high blood pressure may not be very effective. Therefore, the pill that retains potassium, drink not as a sole and in combination with loop and thiazide diuretic medications, to avoid side effects such as low potassium levels.
The working principle of osmotic diuretics is that they increase the osmotic pressure in blood plasma, thank to which of the tissues that are swollen, is the removal of fluid and increasing the volume of blood that circulates. This reduces the reverse absorption of sodium and chlorine. With the appointment of diuretics should pay attention to the side of the human disease, since they may not act in diseases of the liver and kidneys.
Group of diuretics in terms of impact
Produce a classification and the power of influence, highlighting such types of diuretics:
Light drugs are used in medicine to remove the swelling of the feet and hands the patient during pregnancy. Doctors often prescribe osmotic drugs, because their main effect — elimination of water from the edema. Use mild diuretics and blood pressure in children and the elderly. Often prescribe diuretics that retain potassium in the body. Mild diuretic and are a variety of decoctions of medicinal plants. Medicines in this group have a mild diuretic effect and have no side effects.
To the average diureticum include thiazide drugs. The effect is observed after 20-60 minutes after application and lasts for 7-15 hours. Used in complex therapy of high blood pressure (excluding beta-blockers), chronic swelling, which are caused by acute heart failure, diabetes, kidney stones and glaucoma.
To diureticum are potent diuretic
- «Lasix», which can be used both orally and by injection. Its main benefit is the fast results.
- «Spironolactone» which is used in a variety of edema.
- «Mannitol», produced in powder form for use when oedema of brain and lungs, and chemical poisoning.
The speed of onset of effect and duration
Group of diuretics for the speed of onset desired result:
- emergency actions;
Emergency, medium, slow and prolonged action
The effect of diuretics quick impact starts in a few minutes and lasts up to 2-8 hours. List of diuretics: «Furosemide», «Uregyt», «Mannitol». Diuretics secondary effect result after 1-4 hours, and their effect is observed for 9-24 hours. Drug names: «Hydrochlorthiazide», «Diacarb», «Triamteren». Slow diuretic effect occurs after 2-4 days after application, and lasts approximately 5-7 days. The most famous tool in this group is «Spironolactone».
Diuretics for the swelling
During therapy of chronic oedema is often used as strong diuretic: «Furosemide», «Piratenet», «Torasemid». They should take a short period of time, taking breaks in order to prevent habituation, and subsequently lowering effect, a diuretic. Most often the treatment is according to the following scheme: diuretics are taken in the 5-20 mg / day until the swelling subsides. Then make a break for a few weeks and then resume treatment.
In addition to potent diuretics, for the treatment of edema used diuretics and medium effect. Examples: «Politized», «Clopamide», «Motosalon», «Gidrokhlorisiazit». To use the drugs recommended 25 mg per day. Treatment should be for a long time, without assigning breaks.
In situations where swelling is not severe, experts recommend lungs (potassium-sparing) diuretics: «Amiloride», «Spironolactone», «Triamteren». Prescribe drugs in the dose of 200 mg per day, divided into 2-3 doses. The duration of treatment is several weeks, then the rate resumed when necessary after 2 weeks.
Combination diuretics at the same time have a diuretic effect and lowers blood pressure. The main advantage of these drugs is that the effect occurs after 1-3 hours after administration and lasts from 6 to 9 hours. The most well-known combined diureticum include: «Alertid mit», «Triamtezid», «DIACID», «Isobars». Used in the morning sickness during pregnancy, high blood pressure and chronic heart failure.
Diuretics prescribed to patients with high blood pressure paired with clinical lesions of the skeleton, in order to avoid new fractures. However, the drugs that retain calcium in the body, it is recommended to adopt and people who present a high risk of damage to the musculoskeletal system, for example, patients of advanced age. To drugs ability to kept potassium include thiazide diuretics, which, unlike loop and potassium-sparing, do not provoke excretion of potassium with urine. Studies have shown that patients who are prescribed calcium saving medicines for the treatment of high blood pressure, are less liable to fractures than patients who take other types of diuretics.
Antihypertensive diuretics is diuretic medication used for the treatment of high blood pressure. The mechanism is that the volume circulating in the body blood and cardiac output gradually decreases, and blood vessels restrict peripheral resistance. The main advantage of diuretics with hypotensive effects, is that their job is to reduce blood pressure and is not inferior to dedicated tools (beta-blockers), designed to treat hypertension.
However, the price of diuretics almost 10 times lower than the cost of beta-blockers. This is a very important factor when choosing a drug, because often hypertension affects elderly people, whose wealth is not always possible to Finance the long and expensive treatment. The medications that have antihypertensive action include: powerful diuretics (loop, osmotic and saline diuretics), moderate (thiazide) and soft (potassium-sparing).
A diuretic of the new generation
Modern diuretics are synthetic drugs with powerful effects on the body of the patient. The main task of diuretics new-generation is that they increased the mechanism of impact forces. Diuretic medicines are harmless for older people and pregnant women. Not so long ago in Switzerland, was produced by the potent drug called «Tripas» in which the creators have increased the period of its half-life from the body. This drug is used orally 1 tablet daily. In addition, the test is now undergoing a completely new group of diuretics are antagonists of vasopressin receptors. At the moment we know only the name of one diuretic in this group «Rolofylline».