Diuretic.docx

Learning Objectives: DIURETICS -Osmotic Diuretics (entire tubule) -Mannitol \- M of A: Mannitol is freely filtered and not reabsorbed. Its presence increases osmolarity, drawing water into the urine. \- Uses: 1) decrease cerebrospinal fluid volume, 2) excretion of toxic substance \- Adverse eff...

Learning Objectives: DIURETICS -Osmotic Diuretics (entire tubule) -Mannitol \- M of A: Mannitol is freely filtered and not reabsorbed. Its presence increases osmolarity, drawing water into the urine. \- Uses: 1) decrease cerebrospinal fluid volume, 2) excretion of toxic substance \- Adverse effects: cause pulmonary edema in patients with congestive heart failure \- given I.V. \- Carbonic Anhydrase Inhibitors (proximal tubular) \- Acetazolamide \- M of A: inhibits carbonic anhydrase, causing increased urinary bicarbonate excretion, urine is more alkaline, high pH. Use this drug when you want to get rid of bicarbonate \- Uses: 1) treat metabolic alkalosis, 2) create an alkaline urine to facilitate urinary excretion of acidic drugs \- Adverse effects: may produce metabolic acidosis \- Loop Diuretics (loop of Henle) \- Furosemide \- M of A: inhibits the Na-K-2Cl transporter in the tubular lumen, causing a decrease in Sodium absorption. \- Uses: 1) removal of edema, 2) hypertension \- Adverse effects: Hypokalemia (low Potassium level), Ototoxicity (ear poisoning), activation of Renin angiotensin aldosterone system \- Drug interaction: Aminoglycosides (can cause ototoxicity) \- Thiazide Diuretics (distal tubule) \- Hydrochlorothiazide \- Chlorothiazide \- Chlorthalidone \- M of A : sodium and chloride are reabsorbed by the NaCl cotransporter in the early distal tubule, Thiazide block sodium chloride cotransporter, which leave sodium and chloride in the urine, thereby attracting water into the urine. \- Uses: 1) hypertension, 2) removal of edema and ascites \- Adverse effects: hypokalemia, activation of Renin angiotensin aldosterone system \- Potassium-sparing Diuretics (late distal tubule and collecting duct) \- Epithelial Na Channel (ENaC) Antagonists - M of A: ENaC blockers inhibit sodium reabsorption, and therefore decrease potassium secretion \- Amiloride \- Uses: used with loop or thiazide diuretics to prevent diuretic-induced hypokalemia \- Aldosterone Receptor Antagonists - M of A: Spironolactone blocks aldosterone receptor (receptor that absorbs sodium) \- Spironolactone \- Uses: block actions of increased blood levels \- Adverse effects for Amiloride & Spironolactone: hyperkalemia