Diuretics Flashcards
Why do does mannitol only act on the dL, PCT and collecting tubules?
These are the parts of the nephron permeable to water.
Why do loop diuretics cause a metabolic alkalosis?
Increased excretion of Cl in proportion to HCO3- - body starts to make more HCO3- (anion) to correct.
Increased Na+ delivery to distal tubule - more for aldosterone sensitive pump which exchanges Na for H+, more H+ loss = alkalosis.
Also more Na+ means more K+ loss - H+ will move into cells - alkalosis
Why do thiazide diuretics cause increased Ca2+ reabsorption?
Decreased Na Cl- activity means better gradient for basolateral Ca2+/Na exchanger means more Na+ into cell and more Ca2+ out.
What effect does caffiene have on the kidney?
Alcohol?
Increased GFR and decreased Na+ reabsorption
Inhibits ADH release.
Give two diuretics that cause hypochloraemic alkalosis.
Thiazide
Loop diuretics
Give some ADRs of furosemide.
Bumetanide?
Ototoxicity (impaired ion transport across stria vascularis of inner ear)
Alkalosis
Increased LDLs and TAGs
Gout
Myalgia
Give 3 ADRs of spironolactone.
Painful gynaecomastia
Hyperkalemia
Impotence
Why should ACEi + amiloride/ spironolactone not be used?
Increased hyperkalemia
Aminoglycosides + loop diuretics?
Digoxin + thiazide/loop?
Why?
Ototoxicity
Nephrotoxicity
Hypokalemia
Increased digoxin binding to Na+ K+ ATPase when when hypokalemic.
B-blockers + thiazides?
Steroids + thiazide and loop?
Hyperglycaemia, hyperlipidaemia, hyperuricaemia
Increased hypokalemia risk
Lithium + thiazide and loop?
Thiazide - increase lithium levels
Loop - decrease lithium levels
Carbamezepine + thiazides
Hyponatremia
Give two diuretics that should be used in
Heart failure
Another thing these both are indicated for?
Nephrotic syndrome first line?
CKD?
Loop diuretics
Spironolactone
Decompensated liver disease
Loop diuretics
Loop diuretics
Give three reasons why in CKD loop diuretic resistance may be acquired.
Nephrotic syndrome - less protein binding.
Fewer nephrons
More competition of OAT due to more waste products being secreted.
Gut oedema - impact on blood flow.
Define refractory oedema.
Oedema that does not respond to dietary sodium changes and combined diuretic treatment including a loop diuretic.
