Diuretics Flashcards
What are the classes of drugs that act on the renal tubule?
Carbonic anhydrase inhibitors Osmotic diuretics Loop diuretics Thiazides Potassium sparing diuretics Aldosterone antagonists ADH antagonists
Where do carbonic anhydrase inhibitors act?
PCT
Where do osmotic diuretics act?
PCT
Descending limb of LOH
CD
Where do Loop diuretics act?
Thick ascending limb of LOH
Where do thiazides act?
DCT
Where do potassium sparing diuretics act?
CD
Where do aldosterone antagonists act?
CD
Where do ADH antagonists act?
CD
What are examples of osmotic diuretics?
Mannitol
What is the mechanism of mannitol?
Increases osmolarity of filtrate so water follows
What are the routes of administration for mannitol?
IV
What are the indications for mannitol?
Cerebral oedema
Raised ICP
What are the side effects of mannitol?
Cough
Headache
Vomiting
What are examples of carbonic anhydrase inhibitors?
Acetazolamide
Brinzolamide
Dorzolamide
What are the indications for carbonic anhydrase inhibitors?
Glaucoma
Altitude sickness
What are the routes of administration for carbonic anhydrase inhibitors?
PO
IV
What is the mechanism of carbonic anhydrase inhibitors?
Inhibits carbonic anhydrase
Reduces formation of hydrogen and bicarbonate ions from CO2
Promotes renal excretion of Na, K, HCO3, H2O
What are the side effects of carbonic anhydrase inhibitors?
Acidosis
Renal stones
What are examples of loop diuretics?
Furosemide
Bumetanide
What are indications for loop diuretics?
Oedema
Heart failure
Hypertension
What is the mechanism of loop diuretics?
Inhibit Na/K/2Cl cotransporter in the loop of Henle
Na remains in tubule and water follows
What are the side effects of loop diuretics?
Myalgia Thirst Weight loss Headaches Alkalosis
What is an example of a thiazide diuretic?
Bendroflumethiazide
What is an example of a thiazide like diuretic?
Indapamide
What is the indication for Bendroflumethiazide?
Hypertension
What is the route of administration for Bendroflumethiazide?
Oral
What is the mechanism of action of Bendroflumethiazide?
Inhibits Na reabsorption in DCT
What are side effects of Bendroflumethiazide?
Hypokalaemia Increased urea Impaired glucose tolerance Nausea Dizziness
What is the indication for indapamide?
Hypertension
What are the routes of administration of indapamide?
PO
What is the mechanism of action of indapamide?
Inhibits Na reabsorption in DCT
What are the side effects of indapamide?
Hypokalaemia Increased urea Impaired glucose tolerance Nausea Dizziness Mild rash
What is an example of a potassium sparing diuretic?
Amiloride
What is the indication for amiloride?
Oedema
Hypertension
Heart failure
With low potassium
What are the routes of administration for amiloride?
Oral
What is the mechanism of amiloride?
Blocks ENaC at luminal surface of renal tubule
What are side effects of amiloride?
Hyperkalaemia Constipation Dizziness Dry mouth D+V
What is an example of an aldosterone antagonist?
Spironolactone
What are the indications for spironolactone?
Oedema Ascites Hypertension Heart failure Nephrotic syndrome
What is the mechanism of spironolactone?
Competes with aldosterone at mineralocorticoid receptor
Prevents upregulation of ENaC
What are the side effects of spironolactone?
Hyperkalaemia
Impotence
Painful gynaecomastia
Refractory hyperaldosteronism
What is an example of an ADH antagonist?
Tolvaptan
What is the route of administration of tolvaptan?
Oral
What are the indications for tolvaptan?
Hyponatraemia
PCKD
What is the mechanism of tolvaptan?
Blocks AHD at receptor so inhbits aquaporin expression
Reduces free water reabsorption so increases plasma sodium concentration
What are the side effects of tolvaptan?
Hypernatraemia Deranged liver function Dry mouth Constipation Dehydration
