Loop diuretics act on the nephron mainly in the thick ascending links of the loop of. Diuretics, potassiumsparing drug information from drugs. Potassium sparing diuretics university health network. Amiloride midamor is an hyperkalemic diuretic often used in combination with an hypokalemic thiazide diuretic to. Potassiumsparing diuretics are divided into two categories based on their molecular pharmacology. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The action of thiazides depends in part on renal prostaglandin production. Mechanism of action, pharmacokinetics, adverse effects, and therapeutic uses of amiloride hydrochloride, a new potassiumsparing diuretic. This type of diuretics causes a loss of sodium while promoting the retention of potassium. Despite the bewildering number of diuretics available to the physician, these drugs can be divided into 4 main groups, characterised by their site of action on sodium reabsorption in the kidney. Mechanism of action, pharmacokinetics, adverse effects. Amiloride is a potassiumsparing diuretic that does not have much of a diuretic effect when compared to its. Nonpotassium sparing diuretics pronouced di uret ics. It is also used in nephrotic syndrome, the longterm management of.
Low potassium levels from diuretics harvard health. The action of spironolactone is to interfere with sodium reabsorption in distal renal tubules by competitively inhibiting the action of aldosterone. This effect is not of major importance in normal subjects, where postaglandin production is relatively low, but can be significant in patients. Legend ksparing diuretic mechanisms in the cortical collecting duct. The aldosterone blockers spironolactone aldactone and eplerenone inspra are also potassiumsparing diuretics, but they have other effects and uses in. Diuretics treatment summary bnfc content published by nice.
Spironolactone is combined with other diuretics to reduce urinary potassium loss. Loop diuretics and thiazide diuretics are stronger than potassiumsparing diuretics with regard to making the kidneys pass out more fluid. If you need this medicine for another problem, your health care provider will give you more information. They are used as adjunctive therapy, together with other drugs, in the treatment of hypertension and management of congestive heart failure. Thiazide diuretics and loop diuretics are used alone or in combination in the treatment of hypertension or edema due to hf or other causes. A diuretic used to treat hypertension or edema caused by heart failure, renal failure, hepatic cirrhosis, estrogen therapy, and other. However, they also increase the amount of potassium passed out of the body through the kidneys.
By acting on the thick ascending limb, which handles a significant fraction of sodium reabsorption, loop diuretics are very powerful diuretics. Diuretics, potassiumsparing, and hydrochlorothiazide drug. Mechanism of action amiloride is a relatively weak diuretic. This altered handling of sodium and water leads to both diuresis increased water loss and natriuresis increased sodium loss. Amiloride was approved for use in the united states in 1986, but is not widely used. In a previous article, we focused on the mechanism of action, pharmacody. Potassium sparing diuretics information for patients read this medicine fact sheet to learn about. Potassiumsparing diuretics are diuretic drugs that do not promote the secretion of potassium into the urine they are used as adjunctive therapy, together with other drugs, in the treatment of hypertension and management of congestive heart failure. Thiazide diuretics initially lower blood pressure by increasing sodium and water loss as well as other electrolytes and nutrients in the kidneys and decreasing the volume of blood required for the heart to circulate in the body, thereby reducing blood pressure. Used by themselves, potassiumsparing diuretics exert only a mild diuretic effect because the collecting duct reabsorbs only 25% of filtered sodium.
Potassiumsparing diuretics an overview sciencedirect. Potassiumsparing diuretics definition of potassium. The blood sodium from being reabsorbed into the bloodstream in the distal renal tubule, which means more will be sodium will be excreted in your urine. Potassiumsparing diuretics are diuretics that result in increased urine production and also lower blood pressure while increasing serum levels of potassium. Dosing, uses, side effects, interactions, patient handouts, pricing and more from medscape reference. Diuretics, such as amiloride, inhibit sodium selective channels in the late distal convoluted tubule and the cortical collecting duct. Based on the mechanism of action of loop diuretics, the beneficial effects observed in dialysis patients could be explained by the removal of sodium and water. Diuretics can be classified, according to their chemical structure, the major site of action within the nephron and the type of diuresis that they elicit, in three groups. Amiloride midamor spironolactone aldactone triamterene dyrenium interfere with sodiumpotassium exchange in collecting ducts and convoluted tubules competitively bind to aldosterone receptors block the. Potassiumsparing diuretics pharmacology the essential. They act by diminishing sodium reabsorption at different sites in the.
Although loop diuretics have diuretic efficacy greater than that of thiazide or thiazidelike agents, effects on blood pressure are relatively brief and reflex stimulation. Bertram katzung, basic and clinical pharmacology, mc graw hill medical, 2007. Spironolactone is the most commonly used potassium sparing diuretic in children. Mechanism of action most diuretics produce diuresis by inhibiting the reabsorption of sodium at different segments of the renal tubular system this is accomplished by altering how the kidney handles sodium. Sensitivity to thiazide diuretics or other sulfonamidederived medications or potassiumsparing diuretics sympathectomy antihypertensive effects may be enhanced 20. Domenic sica discusses the mechanisms of action of thiazidetype diuretics, comparability to loopdiuretics, and the basis for combining them with nondiuretic antihypertensive medication classes.
Drugs acting on the ascending limb of the loop of henle have a powerful but short acting diuretic effect. Papich dvm, ms, dacvcp, in saunders handbook of veterinary drugs fourth edition, 2016. Potassiumsparing diuretics information, uses and side. One widely used example of a potassiumsparing diuretic is spironolactone. Taking a potassiumsparing diuretic may be especially important if you have heart failure. Study 29 terms potassium sparing diuretics flashcards. Nonpostassium sparing diuretics may cause potassium a mineral in your body to be lost along with the fluid. Bilal mirza 4th year download in your computer according to site of action and mechanism of action. What this medicine is why you need to take it what side effects to watch for this fact sheet was created by the university health network pharmacy department. A sulfamyl diuretic used to treat edema in congestive heart failure, hepatic and renal disease, and nephrotic syndrome. They are occasionally used to counteract the potassiumwasting effects of thiazides. A subclass of diuretics which does not limit the secretion of potassium into the urine. However, when amiloride is used alongside another diuretic, it enhances total diuresis and counteracts potassium loss to a greater extent than it otherwise would on its own.
Caution is also required in jaundiced infants because of the risk of hyperbilirubinemia with hydrochlorothiazide. Potassiumsparing diuretics these agents increase diuresis, but without causing potassium to be lost from the body. Potassiumsparing diuretics, which block the epithelial sodium channel enac, are widely prescribed for hypertension as a secondline drug in patients taking other diuretics e. Most of the different types of potassiumsparing diuretics work in a specific area of the kidney, where they can block potassium excretion while increasing the elimination of sodium and water. Mechanism of action loop diuretics act on the nephron mainly in the thick ascending links of the loop of henle. Furosemide a loop diuretic used to treat hypertension and edema in congestive heart failure, liver cirrhosis, renal disease, and hypertension.
Amiloride hydrochloride is a new, orally administered, potassiumsparing diuretic with mild natriuretic and diuretic properties. Osmotic diuretics are often used in the management of cerebral edema. The potassiumsparing diuretics used for treating hf are the aldosterone receptor. Name potassiumsparing diuretics accession number dbcat002702 dbcat000816, dbcat002346 description. Less powerful than loop diuretics but they retain potassium instead of wasting it. However, at low doses the use of potassiumsparing diuretics has not been found to produce a clinically significant reduction in blood pressure. Diuretic therapy in heart failure current approaches ncbi. The collecting duct is the major site of action in the kidney of. Diuretics are often used to fight or prevent swelling in people with heart failure, but taking a potassiumsparing diuretic helps people with heart failure feel better, stay out of the hospital, and live longer. Potassium sparing diuretics list amiloride hydrochloride midamar amiloride is a potassium sparing diuretic that does not have much of a diuretic effect when compared to its potassium sparing activity 1.
For triamterene only in addition to those listed for all potassiumsparing diuretics amantadine. Potassiumsparing diuretics have weak diuretic and antihypertensive properties and are used mainly to conserve potassium in patients receiving thiazide or loop diuretics. Non potassium sparing diuretics accession number dbcat003863 description. Potassiumsparing diuretics are diuretic drugs that do not promote the secretion of potassium into the urine. Mechanism of action of potasium sparing diuretics source. The ability to induce negative fluid balance has made diuretics useful in the treatment of a variety of conditions, particularly edematous states and hypertension. Potassium sparing diuretics drugs list, mechanism of. Typically used for patients who have high risk for hypokalemia associated with diuretic use.
The first approved drug of this class, chlorothiazide, was marketed under the trade name diuril beginning in 1958. The thiazide drug class was discovered and developed at merck and co. Potassiumsparing diuretics reduce the amount of water in your system without affecting levels of potassium. Potassiumsparing diuretics and aldosterone antagonists. A subclass of diuretics that limits the secretion of potassium into the urine. Abby sage, tony d mogg, in cardiology of the horse second edition, 2010. Potassium sparing diuretics are a class of drugs that work by changing way the nephrons in your kidneys produce urine. Other potassiumsparing diuretics directly inhibit sodium channels associated with the. Their mechanism depends on renal prostaglandin production. Its mechanism of action is still poorly understood, it initially inhibits sodium reabsorption and secondarily potassium excretion. Includes diuretics, potassiumsparing side effects, interactions and indications.
Several other products combine a potassiumsparing diuretic in a single pill with a thiazide diuretic dyazide, maxzide, and moduretic. Potassiumsparing diuretics are often combined with either a loop diuretic or a thiazide diuretic. Potassiumsparing diuretics are diuretic drugs that do not promote the secretion of potassium. Interactions between antihypertensive drugs and other medications. Diuretics, potassiumsparing drug information, professional.
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