Diuretics Flashcards
What diuretic can be used to treat kidney stones?
Thiazide like diuretics as they increase calcium reabsorption and so decrease urinary calcium
What diuretics are GFR dependent?
Thiazide and Loop- larger dose required in patients with reduced GFR
Why may oral furosemide work less effectively in oedematous patients?
Bioavailability may decrease as gut oedema may impair absorption of the drug
What diuretic class is indicated in the treatment of resistant hypertension?
K+ sparing diuretics. Spironolactone is an aldosterone receptor antagonist in the distal convoluted tubule which inhibits Na+ channel expression
What diuretic can be used to treat metabolic alkalosis?
Acetazolamide- a carbonic anhydrase inhibitor that reduces HCO3 absorption
What are the main metabolic effects of Thiazide diuretics?
HyperGLUC (pneumonic)-
- HyperGlycaemia (contraindicated in diabetics)
- HyperLipidaemia
- HyperUricaemia
- HyperCalaemia (increased Ca2+ reabsorption which is good for osteoporosis and in the prevention of kidney stones
Where do thiazide diuretics act?
NaCl cotransporters in the early distal tubule
What diuretics cause acidosis?
K+ sparing and carbonic anydrase inhibitors
What diuretics cause alkalosis?
Loop and Thiazide like diuretics
Where do loop diuretics act?
Inhibit the NaK2Cl transporter in thick ascending loop
Which two diuretics have an effect on serum calcium and what effect do they have?
Loop diuretics decrease serum calcium. Thiazide like diuretics increase serum calcium.
what is the only diuretic class to increase serum K+?
K+ sparing diuretics. All others decrease serum K+
Where do K+ sparing diuretics act?
Distal convoluted tubule (aldosterone receptor antagonist reducing Na+ channel expression- resistant hypertension treatment) and proximal collecting duct on epithelial Na+ channels. Spironolactone in the distal convoluted and amiloride in the collecting duct
Where do osmotic diuretics act? (mannitol)
Act everywhere but mainly proximal tubule and descending loop
Indication for osmotic diuretics?
To reduce intracranial or intraocular pressure
Where do carbonic anhydrase inhibitors act?
Proximal convoluted tubule
How do carbonic anhydrase inhibitors work?
Eliminate Bicarbonate and have a minor diuretic effect leading to metabolic acidosis and alkalinisation of urine. Can treat glaucoma, alkalosis and altitude sickness
Name a carbonic anhydrase inhibitor?
Acetazolamide
Name some Loop diuretics?
Furosemide, bumetanide
Name some thiazide like diuretics?
Hydrochlorothiazide, metolazone
Name some K+ sparing diuretics?
Aldosterone receptor antagonist-Spironolactone
Epithelial Channel Blocker- Amiloride
A patient requires a thiazide like diuretic to prevent the recurrence of kidney stones. How to do you prevent them from become hypokalaemic?
Co prescribe a K+ sparing diuretic
Thiazide side effects?
Hypokalaemia and metabolic alkalosis
HyperGLUC- Glycaemia (caution in diabetes)
Lipidaemia
Uricaemia
CalcaemiaThiazide indications?
Hypertension
Oedema (chronic)
Calcium stone prevantion
Osteoporosis
Thiazide interactions?
Ace Inhibitors
NSAIDS
Glucocorticoids
Loop diuretics calcium effect?
Cause Ca2+ loss (LOOPS LOSE CALCIUM)
Loop side effects?
Hypocalcaemia, hypomagnesaemia, alkalosis, hyperuricaemia (gout), hyperglycaemia
“GO PANDA” Gout, Ototoxicity, low Potassium, allergy, Nephritis, dehydration, Alkalosis
Loop Indictions?
Hypertension, oedema, renal failure, hypercalcaemia, Forced diuresis to clear kidney of toxic substances
K+ Sparing side effects?
Hyperkalaemia, metabolic acidosis, GI upset. Spironolactone can cause amenorrhoea and gynaecomastia/erectile dysfunction
K+ Sparing indications?
Hypertension (especially with hypokalaemia)
ascites/oedema
Osmotic diuretics contraindictions?
progressive heart failure or severe pulmonary oedema
Carbonic Anhydrase Inhibitors Ph effect?
Cause acidosis- (ACetazolamide causes ACidosis)
