A- kaliuretic diuretics:
1- Loop diuretics:
* Molecules: furosemide; bumetanide
* Action Site: large segment of the ascending limb of the loop of Henle.
* Action: It inhibits the reabsorption of NaCl (25 to 30% of the filtered sodium)
NB -> this action persists in renal failure
2- Thiazides Related:
* Molecules: hydrochlorothiazide; indapamide (Fludex®)
* Target: the initial portion of the distal tube (dilution segment)
* Action: inhibits the reabsorption of sodium and chlorine; saldiurétique the action is gradual and moderate (5 to 10% of Na + filtered).
* Other: weak inhibitory activity of carbonic anhydrase => increased excretion of bicarbonate. decrease urinary calcium.
Carbonic anhydrase inhibitors -> acetazolamide (Diamox®): used to have no effect on acid-base balance and its extrarenal share (glaucoma)
B- sparing diuretics:
Molecules:
* Aldosterone antagonists -> spironolactone; potassium canrenoate (Soludactone®)
* Direct Diuretics -> amiloride (Modamide®); triamterene (in combination)
* The combination of any of these with a thiazide diuretic used to limit the urinary loss of K + (Modurétic®)
– These drugs work in the distal convoluted tubule to inhibit reabsorption of sodium in exchange for potassium excretion
– The non-aldosterone antagonist diuretics directly inhibit ion transport at the distal tubular cells
– Effects: mild increase the excretion of Na + with decreased excretion of K + and H + -> the urine becomes alkaline, the ammoniénémie and titratable acidity decreased while shedding bicarbonate.
– The spironolactone added back calcium excretion.
– The spironolactone has extrarenal effects: heart (LVH reduction and prevention of fibrosis); antiandrogenic effect.
* Comments
– Diuretics decrease initially and blood volume in a second time peripheral resistance
– Edema and ascites of cirrhosis -> spironolactone often associated with furosemide
– Indication of thiazide if stones -> decreased urinary calcium excretion
– The loop diuretics majorem the ear, and nephrotoxicity of aminoglycosides
– The combination of several kaliuretic diuretics majorem the depleting effect.
– The combination of a diuretic NSAIDs may induce acute renal failure with acute tubular necrosis and dehydration.
C- Side effects:
– The thiazédiques diuretics and loop diuretics can reduce glucose tolerance and promote the onset of diabetes; the thiazédiques may aggravate pre-existing diabetes; the hyperglycaemic effect could be due to a glycogenolytic Action
– Hyperuricemia is seen in most of the subjects treated with hypokalemic diuretics.
– Thiazide decrease renal calcium excretion => hypercalcemia. Conversely, furosemide increases urinary calcium and promotes calcium nephrolithiasis and nephrocalcinosis.
– The long-term use of diuretics thiazédiques increases in triglycerides and cholesterol.
– Acute Pancreatitis -> hydrochlorothiazide
– Dysmenorrhea and gynecomastia -> spironolactone
– Metabolic alkalosis hypokalemic
– Metabolic acidosis hyperkalaemic
D- notes:
– HTA
– Heart failure (loop diuretics, spironolactone)
– PAO (furosemide IV)
– Edema and ascites in cirrhotic spironolactone (often associated with furosemide)
– Calcium Nephrolithiasis -> thiazides (they decrease urinary calcium)
– Acute hypercalcemia -> furosemide is useful
– Acute glaucoma -> inhibitor of carbonic anhydrase (Diamox)
