Groups of diuretics
Full classification of diuretics would have to consider all aspects of their action. But today it does not exist, because diuretic drugs have totally different chemical structure. They differentiate too much from each other in the duration and mechanism of action on the organism of the patient.
Different groups of drugs have different effects on the kidneys. They help to excrete salt and water from the body. Diuretics are mainly divided into the following groups:
– Loop diuretics (act on the cortical segment of the Henle loop). Loop diuretics are the most powerful of existing diuretics.
– Potassium-sparing diuretics. Potassium-sparing diuretics also increase the excretion of sodium ions, but at the same time reduce the excretion of potassium ions.
– Osmotic diuretics. Osmotic diuretics do not block urine formation.
– Thiazides are very effective diuretics that belong to benzotiadiazina derivatives (Hydrochlorothiazide(Esidrix), Cyclopenthiazide).
Contraindications to diuretics
Diuretics are prohibited in loss of kidney function. These preparations should not be prescribed during dehydration and to patients without signs of swelling.
Swelling caused by kidney disease (nephritis, etc.) can appear all over the body, but it is most clearly visible on the face, especially around the eyes. Renal swelling is usually soft to the touch, with pale skin around it. It is formed because unhealthy kidneys badly output salt and water. Protein concentration reduces in blood, while the permeability of vessel walls increases. Different allergies and endocrine disorders are rare causes of swelling. If the patient observes swelling of the legs and it appears mostly in the evenings after work, it is likely to be caused by heart failure. Such symptom as swelling requires immediate examination to determine the cause. Only qualified doctor should appoint the treatment.
Action of diuretics
Diuretics have different effect on urine formation, depending on their mechanism of action and its localization (different parts of the nephron), physical and chemical properties.
Loop diuretics act throughout the ascending portion of the nephron loop (loop of Henle) and dramatically prevent the reabsorption of sodium and chlorine ions, increasing allocation of potassium ions. According to the chemical structure, they are derivatives of sulfamoyl anthranilic and dichlorophenoxyacetic acid (Furosemide(Lasix), Ethacrynic acid, Bumetanide etc. ). Loop diuretics and benzothiadiazines are useful in the treatment of hpertension and congestive heart failure. They increase the urine output, what results into the blood volume reduction.
Osmotic diuretics increase the osmotic pressure of "primary urine" during filtration. This prevents water reabsorption in the proximal tubules. They can be prescribed during cerebral edema as dehydrating agents. The most active osmotic diuretics (Mannitol, etc. ) are used to cause diuresis in acute poisoning (by barbiturates, salicylates, etc.), acute renal failure, as well as acute heart failure in patients with reduced kidney filtration.
Diuretics, notably, diuretics of the thiazide group are used in combination with other antihypertensives or during monotherapy. Their effect develops mainly in the cortical segment of the nephron loop, where the reabsorption of cations (potassium and sodium) is blocked. Besides, thiazides relax vascular wall directly. This leads to the change in the metabolic processes in the cell membranes of the arterioles, in particular, the sodium ion concentration is reduced, which reduces swelling and decrease the peripheral vascular resistance. Thiazides change vascular reactivity and reduce the pressor reactions on vasoconstrictors (epinephrine). According to studies, thiazide diuretics are more effective than beta-blockers.
Potassium-sparing diuretics are less effect than loop diuretics, but they do not provoke hypokalemia. They operate in the distal tubules where sodium and potassium ions are exchanged. The main representatives of this group of drugs are: spironolactone and triamterene. Those preparations are differ in their mechanism of action. Spironolactone is an aldosterone antagonist and its therapeutic activity is higher, the greater the level of production of aldosterone in the body. Triamterene is not an aldosterone antagonist. Under the influence of this preparation, sodium ions remain in the lumen of the tubule and hold water, which leads to increased diuresis.
Our online pharmacy offers you such diuretics as: Demadex, Lasix, Esidrix.
Demadex is used to reduce extra fluid in the body caused by liver or kidney disease, heart failure. It can also be used to lower high blood pressure. This prevents strokes, heart attacks, kidney problems.
Lasix is used to treat edema in chronic heart failure hepatic cirrhosis, kidney disease (including nephrotic syndrome), acute heart failure (pulmonary edema), brain edema, hypertensive crisis (independently or in combination with other antihypertensive drugs), hypertension (severe), hypercalcemia, eclampsia.
Esidrix is used to treat edema associated with hepatic cirrhosis, congestive heart failure and estrogen or corticosteroid therapy. It also is used during different forms of hypertension.