Agents that promote the formation of urine, primarily by decreasing tubular reabsorption of Na+ and the osmotic equivalent of water from the kidney tubule
Diuretics generally act at the level of the functional unit of the kidney, the ___________.
Different classes of diuretics is a result of affecting the physiological effects at the _________________________.
Proximal tubules, Ascending loop of Henle, and Distal tubules
Diuretics are commonly indicated for the treatment of what things?
Edema, Ascites (associated with cirrhosis), HF, hypertension, and Acute Renal Failure.
Thiazide diuretics are prescribed most as initial therapy for what?
Why are diuretics prescribed as the first treatment for Hypertension?
High efficacy, low side effects, and low cost
What type of diuretic is used in the management of acute to severe heart failure?
Intravenous loop diuretics
(True/False) The majority of chronic heart failure patients require chronic diuretic therapy
What is the main site of action of the loop diuretics believed to be?
On the thick ascending limb (TAL) of the loop of Henle
What is the MOA of loop diuretics?
Inhibit reabsorption of Na, K, Ca, Mg and Cl ions by inhibiting the luminal Na+/K+/2Cl-cotransporter on thick-segmented ascending loop of Henle ( may also inhibit Na and Cl reabsorption on proximal and distal tubules)
What change in ion excretion/retention would be expected with Loop diuretics?
↑ excretion of Na, Cl, K, Ca, and Mg and ↑ retention in uric acid
What type of diuretic produces a peak diuresis much greater than that observed with other classes, sometimes referred to as "torrential" diuretics or high ceiling diuretics?
Loop diuretics have no ceiling (True/False).
False, just a high ceiling
What is the main site of action for Thiazide diuretics?
What is the MOA of Thiazide diuretics?
Inhibit tubular reabsorption of Na and Cl in the distal tubule.
What changes in ion excretion/retention are expected with Thiazide diuretic use?
↑ Excretion of Na, Cl, K, ↓ excretion of Ca,↑ retention of uric acid
What are the two subclasses of K sparing diuretics?
Pteridine analogs and Aldosterone antagonists
What does Aldosterone regulate?
Na+/H2O re-absorption from distal tubule
Aldosterone results in what ion concentration changes?
Its action results in Na and water retention and K excretion.
K sparing, Aldosterone antagonist diuretics cause what change in ion concentrations?
↓ Na and water and ↑ in K
What is the MOA of spironolactone?
Spirolactone used in what situations?
1.) Hypertension as an adjunct therapy with Thiazides to minimize hypokalemia 2.) When therapeutic effect of other diuretics ceases 3.) Adjunct in severe HF 4.) Hyperaldosteronism
Is Spirolactone commonly used?
What hormonal effects does Aldosterone have?
Androgenic and Progestogenic
Eplerenone has what MOA?
Aldosterone antagonist (newly marketed)
What benefit does Eplerenone have over Spirolactone?
More favorable side effects, and can be used alone or in combinationa db treatment of HF
Pteridine analogs have what MOA?
Act on the distal tubules, block the reabsorption of Na and secretion of K ions by
Do Pteridine analogs have aldosterone antagonistic effects?
What is the physiological effect of Pteridine analogs?
Weak diuretic action with a potassium sparing effect
What are the three pharmacophores of Loop diuretics?