Summary

This document describes kidney functions, diuretics, and associated conditions. It includes details of different diuretic classes, their mechanisms of action, and clinical indications. The document offers a comprehensive overview of the topic for students.

Full Transcript

Renal Physiology 1 Urine formation: Enables reabsorption of nutrients, water, and electrolytes. Helps eliminate metabolic waste products. Takes place in the nephrons within the kidneys. Includes processes of filtration, reabsorption, and secretion. © McGraw Hill...

Renal Physiology 1 Urine formation: Enables reabsorption of nutrients, water, and electrolytes. Helps eliminate metabolic waste products. Takes place in the nephrons within the kidneys. Includes processes of filtration, reabsorption, and secretion. © McGraw Hill 1 Figure 25.1 - The Nephron Access the text alternative for slide images. © McGraw Hill 2 Figure 25.2 - Urine Formation Access the text alternative for slide images. © McGraw Hill 3 Renal Physiology 2 Tubular reabsorption. Renal tubules reabsorb ions and nutrients filtered at the glomerulus. Cation exchange and chloride ion transport are mechanisms that reabsorb sodium ions. Osmotic gradient is established along the nephron. © McGraw Hill 4 Renal Physiology 3 Water is reabsorbed within the proximal convoluted tubules and the collecting ducts. Water rushes toward sodium ions in the blood through aquaporins. Helps maintain plasma volume and water balance. © McGraw Hill 5 Renal Physiology 4 Tubular secretion. Acid–base balance is maintained through acidification of urine. Specialized transport systems remove weak acids and bases from the blood. Interactions between drug and metabolic waste products may cause altered drug excretion. © McGraw Hill 6 Conditions Associated with Renal Dysfunction Effects of reduced renal function. Decreased urine flow, oliguria, or anuria. Lead to accumulation of toxic products and ions. Can cause uremia, edema, and hypertension. © McGraw Hill 7 Clinical Indications For Diuretic Use 1 Management of anuria, hypertension, and edema. Classes of diuretics. Osmotic agents. Carbonic anhydrase inhibitors. Thiazide and thiazide-like compounds. Organic acids. © McGraw Hill 8 Clinical Indications For Diuretic Use 2 Potassium-sparing diuretics. ADH antagonists. Each class of diuretics produce diuresis. Inhibit water and/or sodium ion reabsorption in the kidneys. Intensity varies as per the class. © McGraw Hill 9 Osmotic Diuretics 1 Clinical indications. Treatment of anuria and oliguria. Indications of mannitol. May be indicated for acute renal failure or for treatment of drug toxicity or overdose. Cerebral edema and glaucoma. Localized swelling and pressure (intraocular, cerebral). © McGraw Hill 10 Osmotic Diuretics 2 Mechanism of action. Administered intravenously. Act osmotically, attracting fluid from edematous tissues. Create an osmotic gradient within the renal tubular lumen to prevent water reabsorption. Adverse effects. Nausea, dizziness, headache, and chills. Strain on cardiac function. © McGraw Hill 11 Carbonic Anhydrase Inhibitors 1 Clinical indications: Adjunct treatment in CHF or drug-induced edema. Aqueous humor and glaucoma. Epilepsy. Acute mountain sickness. © McGraw Hill 12 Carbonic Anhydrase Inhibitors 2 Mechanism of action. Inhibition of carbonic anhydrase. Results in excretion of sodium ions into urine. Distal convoluted tubules increase the secretion of potassium ions. Leads to increased loss of potassium in the urine. Acid–base balance is affected. Production of bicarbonate ions is inhibited. © McGraw Hill 13 Carbonic Anhydrase Inhibitors 3 Route of administration. Acetazolamide and methazolamide are well absorbed following oral administration. Drug can be administered intravenously for rapid relief. Adverse effects. Drowsiness, anorexia, gastrointestinal distress, headache, depression, allergic rash, acidosis, hypokalemia and hyperuricemia. Aggravate metabolic acidosis. © McGraw Hill 14 Thiazide and Thiazide-like Diuretics 1 Clinical indications. Edema. Mild to moderate hypertension. Administered with loop diuretic in refractory heart failure caused by systolic function. Includes chlorothiazide, chlorthalidone, and metolazone. © McGraw Hill 15 Thiazide and Thiazide-like Diuretics 2 Mechanism of action. Produce diuresis by inhibiting sodium transport. Increase chloride and potassium excretion. Cause hypochloremic alkalosis and hypokalemia. Hyponatremia can occur in elderly patients. Renal excretion of calcium ions is reduced. © McGraw Hill 16 Thiazide and Thiazide-like Diuretics 3 Adverse effects: Orthostatic hypotension. Hypokalemia, hyperuricemia, and hyperglycemia. Change in cholesterol levels. Hypersensitivity reactions. © McGraw Hill 17 Organic Acid (Loop) Diuretics 1 Clinical indications. Relieves edema. Administered to thiazide-resistant patients. Useful in severe peripheral edema and pulmonary edema. Reduces edema associated with CHF, liver cirrhosis, and renal disease. Ethacrynic acid helps in the short-term management of ascites. © McGraw Hill 18 Organic Acid (Loop) Diuretics 2 Include bumetanide, ethacrynic acid, furosemide, and torsemide. Mechanism of action. Inhibit sodium and chloride ion transport in the loop of Henle. Significant loss of sodium, chloride, and water occurs. © McGraw Hill 19 Organic Acid (Loop) Diuretics 3 Adverse effects: Nausea, hypotension, hypokalemia, hyperuricemia, hyperglycemia, and ototoxicity. Drugs should not be administered along with aminoglycoside antibiotics. Contraindicated in patients with anuria or who have severe electrolyte depletion. © McGraw Hill 20 Potassium-Sparing Diuretics 1 Clinical indications. Helps control potassium depletion. Used in the treatment of edema, hypertension, and primary hyperaldosteronism. Prevents the development of hypokalemia. Include amiloride, spironolactone, and triamterene. © McGraw Hill 21 Potassium-Sparing Diuretics 2 Mechanism of action. Inhibit potassium secretion in the distal convoluted tubules. Produce mild diuresis without electrolyte or acid–base disturbances. Adverse effects. Nausea, diarrhea, and hyperkalemia. Spironolactone and triamterene can cause gynecomastia. © McGraw Hill 22 Antidiuretic Hormone (ADH) 1 Regulates water balance by controlling water loss in the urine. Antagonists. The vaptans. Interact with vasopression (ADH) receptors to remove water. Includes conivaptan and tolvaptan. © McGraw Hill 23 Antidiuretic Hormone (ADH) 2 Xanthine diuretics. Naturally occurring drugs. Produce a mild diuretic response. Increase blood flow through the kidneys to stimulate urine flow. © McGraw Hill 24 Preferred Treatment 1 ADH antagonists. Euvolemic and hypervolemic hyponatremia. Carbonic anhydrase inhibitors. Glaucoma, edema with alkalosis, and mountain sickness. Loop diuretics. Pulmonary and peripheral edema, hypertension, acute hypercalcemia or hyperkalemia, and acute renal failure. © McGraw Hill 25 Preferred Treatment 2 Thiazides. Hypertension, mild heart failure, nephrolithiasis, and nephrogenic diabetes insipidus. Osmotic diuretics. Improve renal failure and reduce intracranial pressure and glaucoma. Potassium-sparing diuretics. Hypokalemia due to other diuretics and postmyocardial infraction. © McGraw Hill 26 Adverse Effects Chronic use can produce changes in electrolyte and acid–base balance. Hypokalemia. Orthostatic hypotension and dehydration. Overdose can lead to exaggerated clinical effects. © McGraw Hill 27 Drug Interactions and Incompatibilities Diuretics: Potentiate digoxin toxicity. Should not be used concomitantly with lithium. Mannitol, chlorothiazide, ethacrynic acid, and furosemide are incompatible with specific solutions or infusions. © McGraw Hill 28 End of Main Content Copyright 2022 © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.

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