1What is the primary action of most diuretics?
Direct inhibition of \text{Na}^{+} transport at one or more major anatomical sites along the nephron.
2What are diuretics defined as?
Drugs promoting the excretion of water and electrolytes by the kidneys, thus increasing the rate of urine flow.
3What is the functional unit of the kidney where urine is formed?
The nephron.
4Name five traditional classes of diuretic drugs.
Thiazide diuretics, Loop diuretics, Potassium-sparing diuretics, Osmotic diuretics, and Carbonic Anhydrase Inhibitors (CAIs).
5What is the mechanism of action for Loop diuretics?
They inhibit \text{Na}^{+} and \text{Cl}^{-} reabsorption in the thick ascending limb of the loop of Henle by blocking the \text{Na}^{+}-\text{K}^{+}-2\text{Cl}^{-} symporter.
6What are Loop diuretics often used to treat?
Severe heart failure (to reduce peripheral and pulmonary edema), and chronic and acute renal failure.
7What is a key difference in biochemical effects between Loop diuretics and Thiazides regarding calcium?
Loop diuretics may precipitate hypocalcemia due to increased \text{Ca}^{2+} excretion, unlike Thiazides, which increase \text{Ca}^{2+} reabsorption.
8What is the mechanism of action for Thiazide diuretics?
Inhibiting \text{Na}^{+} and \text{Cl}^{-} reabsorption at the distal convoluted tubule by blocking the \text{Na}^{+}-\text{Cl}^{-} symporter.
9What is a common use for diuretics like Thiazides and Loop diuretics?
Managing edema, hypertension, and heart failure.
10What effect do diuretics have on blood volume and venous pressure?
They decrease blood volume and venous pressure.
11What is the mechanism of action for Carbonic Anhydrase Inhibitors (e.g., Acetazolamide)?
They inhibit the carbonic anhydrase enzyme, reducing \text{H}^{+} ions for \text{Na}^{+}-\text{H}^{+} exchange and \text{HCO}_{3}^{-} reabsorption, leading to \text{Na}^{+}, \text{K}^{+}, \text{HCO}_{3}^{-}, and water excretion.
12How do osmotic diuretics (e.g., Mannitol) work?
They produce an osmotic diuresis and prevent water reabsorption by exerting an osmotic effect in the renal tubule.
13Name two classes of \text{K}^{+}-sparing diuretics.
Inhibitors of renal epithelial \text{Na}^{+} channels (e.g., Triamterene, Amiloride) and Mineralocorticoid Receptor Antagonists (e.g., Spironolactone).
14Which class of diuretics can cause a hypokalemia, hypomagnesemia, and a hypochloremic alkalosis?
Loop diuretics and Thiazides.
15What is the term for a drug that primarily causes an increase in renal sodium excretion?
A natriuretic.
16What is the primary site of action for Loop Diuretics?
Thick ascending limb of the loop of Henle
17Name a drug classified as a Loop Diuretic.
Furosemide (or Bumetanide, Torsemide, Ethacrynic acid)
18What is the primary mechanism of action for Loop Diuretics?
Inhibiting the \text{Na}^{+}-\text{K}^{+}-2\text{Cl}^{-} symporter
19What is the primary site of action for Thiazide Diuretics?
Distal convoluted tubule
20Name a drug classified as a Thiazide Diuretic.
Hydrochlorothiazide (or Chlorothiazide, Chlorthalidone, Indapamide, Metolazone)
21What is the primary mechanism of action for Thiazide Diuretics?
Inhibiting the \text{Na}^{+}-\text{Cl}^{-} symporter
22What are the two subclasses of Potassium-Sparing Diuretics?
Epithelial \text{Na}^{+} channel blockers and Aldosterone antagonists
23Name a drug classified as an Epithelial \text{Na}^{+} Channel Blocker (a type of Potassium-Sparing Diuretic).
Amiloride (or Triamterene)
24Name a drug classified as an Aldosterone Antagonist (a type of Potassium-Sparing Diuretic).
Spironolactone (or Eplerenone)
25What is the primary mechanism of action for the Aldosterone Antagonists?
Blocking the aldosterone receptor, leading to reduced synthesis of \text{Na}^{+} channels and \text{Na}^{+}-\text{K}^{+} ATPase
26What is the primary site of action for Carbonic Anhydrase Inhibitors (CAIs)?
Proximal convoluted tubule
27Name a drug classified as a Carbonic Anhydrase Inhibitor (CAI).
Acetazolamide (or Dorzolamide, Methazolamide)
28What is the primary mechanism of action for Carbonic Anhydrase Inhibitors (CAIs)?
Inhibiting the carbonic anhydrase enzyme, reducing \text{H}^{+} available for \text{Na}^{+}-\text{H}^{+} exchange
29What is the classification of the drug Mannitol?
Osmotic Diuretic
30How do Osmotic Diuretics primarily cause diuresis?
By increasing the osmolarity of the glomerular filtrate, which prevents water reabsorption
31What is the primary site of action for Loop Diuretics?
Thick ascending limb of the loop of Henle
32What is the primary mechanism of action for Loop Diuretics?
Inhibiting the \text{Na}^{+}-\text{K}^{+}-2\text{Cl}^{-} symporter
33Name a common drug classified as a Loop Diuretic.
Furosemide (or Bumetanide, Torsemide)
34What is the primary site of action for Thiazide Diuretics?
Distal convoluted tubule
35What is the primary mechanism of action for Thiazide Diuretics?
Inhibiting the \text{Na}^{+}-\text{Cl}^{-} symporter
36Name a drug classified as a Thiazide Diuretic.
Hydrochlorothiazide (or Chlorthalidone)
37What are the two main subclasses of Potassium-Sparing Diuretics?
Epithelial \text{Na}^{+} channel blockers and Aldosterone antagonists
38What is the primary mechanism of action for Aldosterone Antagonists?
Blocking the aldosterone receptor
39Name a drug classified as a Carbonic Anhydrase Inhibitor (CAI).
Acetazolamide
40What is the classification of the drug Mannitol?
Osmotic Diuretic
41How do Osmotic Diuretics primarily cause diuresis?
By increasing the osmolarity of the glomerular filtrate, which prevents water reabsorption