Diuretics Flashcards
Where do carbonic anhydrase inhibitiors act
They act at the proximal tubule
Carbonic anhydrase function
Enzymes in the lumen and the basolateral membrane.
They convert carbon dioxide and water into carbonic acid and vice-versa.
Carbonic anhydrase inhibitor
Proximal tubule diuretic.
Inhibits the carbonic enzyme.
This results in less hydrogen atoms and therefore less sodium can be reabsorbed via a Na-H exchanger.
E.g. methazolamide , acetazolamide, diclofenamide
Proximal tubule
60-70% of Na & water is reabsorbed here.
Loop diuretics
Act on the ascending limb of the loop.
Inhibit the Na+, K+ ,Cl- co-transporter.
Ergo less sodium is reabsorbed into the blood. More sodium in the lumen increases pressure and therefore acts as a diuretic.
Can cause hypokalemia
E.g. furosemide , bumetanide
Loop of henle
- Water is absorbed in the DESCENDING limb.
- Na+ and Cl- are reabsorbed in the ASCENDING limb.
TRUE OR FALSE
Loop diuretics are suitable for patients with Osteoporosis
FALSE - They cause increased excretion of calcium
Where do Thiazide diuretics act?
Distal tubule
Thiazide diuretics
They inhibit the Na+, Cl co-transporter leading to an increase of sodium in the lumen.
E.g. hydrochlorothiazide
What drug acts at the collecting ducts?
Potassium-sparing diuretic
Potassium-sparing diuretic
They act in two ways:
* Amiloride inhibits the Na+ transporter.
* Spironolactone acts as an aldosterone antagonist by inhibiting the hormone from causing the synthesis of more channel proteins.
E.g. Amiloride , Eplerenone , Spironolactone
What is a common side effect from potassium-sparing diuretics
Hyperkalemia
