Diuretics Flashcards
Thiazides: give example, site of action and mechanism.
Example – hydrochlorothiazide
Site of action – distal convoluted tubule
Mechanism – inhibition of NCC–> block Na+ and Cl- reabs (also increases ca++ reabs)
Loop diuretic: give example, site of action and mechanism.
Example – furosemide
Site of action – Loop of Henle (TAL)
Mechanism – inhibition of NKCC–> block Na+, Cl- and K+ reabs
Potassium sparing
- Sodium channel inhibitors: give example, site of action and mechanism.
Example – Triamterene, Amiloride
Site of action – cortical collecting tubule
Mechanism – inhibition of ENaC–> inhibit K+ secretion (inhibits Na+ reabs) and facilitates H+ secretion
Potassium sparing- Aldosterone antagonists: give example, site of action and mechanism.
Example – Spironolactone
Site of action –cortical collecting tubule
Mechanism – inhibition of aldosterone receptor–> Repress the expression of EnaC and Na+/K+ ATPase
Osmotic diuretic: give example, site of action and mechanism.
Example – Manitol
Site of action – proximal tubule and loop of Henle (DTL)
Mechanism – osmotic action
Thiazides
Hydrochlorothiazide, Chlorthalidone, Bendroflumethiazide, Indapamide, Metolazone
Loop diuretics
Sulfonamide derivatives: Furosemide, Bumetanide, Torsemide
Non-sulfonamide loop diuretic: Ethacrynic acid
K+ Sparing-Na+ channel Inhibitors
Amiloride and Triamterene
K+ Sparing-Aldosterone Antagonist
Spironolactone and Eplerenone.
Carbonic Anhydrase Inhibitors. MOA?
Acetazolamide and Methazolamide
MOA: Inhibits carbonic anhydrase in apical membrane and cytoplasm of epithelial cells in the proximal convoluted tubules.• Block absorption of Na thru (Na/HCO3 exchanger)
Osmotic diuretic
Mannitol
What is a major SE of thiazide diuretics?
Hypokalemic metabolic alkalosis and hyperuricemia
What are 2 major SE of Loop diuretics?
Hyperuricemia (gout) – d/t decreased excretion of uric acid
Hypomagnesaemia → osteoporosis
What is a major SE of Triamterene (K+ sparing- Na+ channel inhibitor)?
Reduce glucose tolerance (careful w/ diabetics)
What is a major SE of Spironolactone (Potassium sparing: Aldosterone Antagonist)?
Spironolactone may cause gynecomastia, impotence, hirsutism, irregular menses, and postmenopausal bleeding (less with Eplerenone).
B/C Spironolactone can bind to other sexual (steroid) receptors, blocking them.
What is a major SE of mannitol (osmotic diuretics)?
Dehydration and hypernatremia d/t Excessive loss of more water relative to sodium.
Sulfonamide derivative Loop diuretics are important and widely used in CV disturbances. What makes them unique?
They decrease total body fluid and increase amount in veins–> double effect in decreasing HTN
