ticAgentsDiuretics are drugs that work on the kidrThey are useful in clinical conditions to re
Diuretic Agents Diuretics are drugs that work on the kidneys to increase urine volume by reducing salt and water reabsorption from the They are useful in clinical conditions to remove edema, hypertension, renal stones hypercalcemia, etc
Abnormalities in fluid volume and electrolytecomposition are common and important clinicalproblems that can become life threatening ifuntreated.Drugsthatblockthetransportfunctionsof therenal tubules areimportantclinical tools in the treatment of these disordersFor the most part, each diuretic agent actsupon a single anatomic segment of the nephron.Because these segments have distinctive transportfunctions,the actions of each diuretic agent can bebest understood in relation to its site of action inthe nephron and the normal physiology of thatsegment
Abnormalities in fluid volume and electrolyte composition are common and important clinical problems that can become life threatening if untreated. Drugs that block the transport functions of the renal tubules are important clinical tools in the treatment of these disorders. For the most part, each diuretic agent acts upon a single anatomic segment of the nephron. Because these segments have distinctive transport functions, the actions of each diuretic agent can be best understood in relation to its site of action in the nephron and the normal physiology of that segment
1NatNatCl-Ca2+Nat H+PTHLGlomerulusCollectingK+DistaltubuleProximalconvolutedCa2+convolutedtubuleLtubuleNatMg?+5=Na+.K+-2CI+aldosteroneCortexOutermedullaNat-K2CI31.AcetazolamideH,02. Osmotic agents+ADHK3. Loop agents6H0H+4. Thiazides25.AldosteroneantagonistsLoop of6.ADH antagonistsHenleTubule transportsystems and sites of action of diuretics
Na+ - K+ - 2CINa+ - K+ -2CINa+ H+ Na+ Na+ClNa+ H2O 1 2 Mg2+ Ca2+ K+ Ca2+ PTH 3 5 4 +aldosterone H2O +ADH H+ K+ Cortex Outer medulla Glomerulus Loop of Henle Proximal convoluted tubule Collecting tubule Distal convoluted 3 tubule 6 2 1. Acetazolamide 2. Osmotic agents 3. Loop agents 4. Thiazides 5. Aldosterone antagonists 6. ADH antagonists Tubule transport systems and sites of action of diuretics
Normal regulation offluidandelectrolytesbythekidneyDespite making up only 1% of total bodyweight,thThe volume of plasma filtered by the kidneys is teriThis means that the filtered fluid is almost entirely reab
Despite making up only 1% of total body weight, the kidneys receive approximately 25% of the cardiac output. The volume of plasma filtered by the kidneys is termed the This means that the filtered fluid is almost entirely reabsorbed. Normal regulation of fluid and electrolytes by the kidney
A.Glomerularfiltration:Approximately 20% of the plasma enteringthe glomerulus isfiltered.Sinceover 99%ofglomerular filtrate is reabsorbedbytubules,drugs that work on the glomerular filtrationshould get less diuretic effects
Approximately 20% of the plasma entering the glomerulus is filtered. Since over 99% of glomerular filtrate is reabsorbed by tubules, drugs that work on the glomerular filtration should get less diuretic effects. A. Glomerular filtration: