Diuretics Flashcards
Thiazide diuretics
Hydrochlorothiazide chlorthalidone indapamide
Secreted from OASS in PCT
Thiazide
*uric acid too (why they fight in the first place)
*some antibodies
*loop diuretics
Inhibits thiazide
Probenecid
Loop
*high efficacy rapid onset and short duration
Frisemide and Torsemide (Sulfonamides)
Ethacrynic acid(Non Sulfonamides)
Also antagonised by probenecid and also decrease uric acid excretion
Loop diuretics
Thick Ascending Limb
For Na K Cl cotransport
Loop
Ototoxic - to hair cells of the inner ear
Loop - deafness and hearing defect especially with otoyoxic drugs like gentamicin
Fetotoxic
Thiazide and loop contraindications
Together with kidney and liver failure, digitalis toxicity(hypok), corticos, pregnancy and gout
Mild and moderate hypertensive
Thiazide
Other antihypertensive vaso dilators
Hydralazine and minoxidil (inhibit salt and water retention)
Useless when GTR is less than 30
Thiazide
Use loop
Na channel blocker
K channel opener
Thiazide for HF
When body doesn’t respond to loop
Jmpairs release of insulin causing hyperglycemia
Thiazide adverse effect
Powerful diuretic effect
Loop diuretics
Decreases net positive potential for Ca and Mg reabsorption
Frusemide
Can be used eleven when GFR less than 10
Loop
Loop is ideal for hypertension
But it’s short duration of action makes it disadvantageous
*used in oedemas too
*and hypercalcemia not hypo (because it inhibits common carrier preventing Ca influx through net positive created by K
Loop treatment of hylercalcemia
Furosemide plus electrolyte replacement plus IV
Ototoxicity (damafes hair cells of the inner ear) of Aminoglycosides e.g.
Gentamicin.
- Probenecid Renal tubular excretion of Frusemide.
Fruit juice
Counteract hypokalemia thiazide adverse effects (that worsens digitalis toxicity)
*k retaining diuretic like spironolactone
Thiazide helps idiopathic hypercalcuria, stones or osteoporosis
As it prevents Ca from being excreted - hyoercalcuria
Thiazide in heart failure (loop is still better)
Diuresis - for the systemic oedema
Arterial VD - decreased TPR decreasing preload
Frusemide plus wrfarin
Displaces it from plasma protein binding site
Why thiazide useful in subdiuretic doses as an antihypertensive
It’s diuresis doesn’t really contribute much
Majorly its VD properties
*release prostacyclin
*depletes Na from arterial wall
*hyperpolarisation; k channel opener
VD properties of thiazide
NSAIDS with thiazide contraindicated
Antagonizes antihypertensive prostacyclin
VD used with thiazide
Hydralazine ao minoxidil
Thiazide in oedema
Cardiac
Hepatic
Pre menstrual tension syndrome
Frusemide plus lithium carbonate
Decreases renal clearance
Frusemide plus Aminoglycosides like gentamicin
Increases Ototoxicity
Frusemide plus Aminoglycosides and cephalosporins
Nephrotixicopty
Decreases diuretic effect of frusemide
NSAIDs decreasing Prostaglandin
Potassium Retaining Diuretics
*weak (low efficacy diuretics)
Competitive antagonists of aldosterone - spironolactone eplerelenone finerenone
Direct inhibitors of Na influx in CCT - triamterene amiloride
Refractory oedema from CHF plus essential hypertension plus polycystic ovary sundrome
Spironolactone
HF
*decreases remodelling and improves Perfusion
Eplerenone and finerenone
Effective in cases of hyperaldosteronism
Competitive antagonists like spironolactone as they fight for its receptors causer hypoNa hyper K and hypoH
Chronic Kidney disease
Finerenenorone
Spironoven with thiazide and loop yod aynergh
To synthesise effect and correct hypokalemia
Less hyperkalemia
Spironolactone
Weak diuretic K Retaining
And slow onset 2 - 3 days
Eplerenone and finrenone
More selective than spironolactone so not as much side effects (angmdrogen thing, progesterone, Glucocorticoids)
Osmotic diuretics
*Taken IV in emergencies
Mannitol
Not metabolised.
Not active.
Non toxic.
Inhibits water reabsorption so increases urine
Mannitol
Therapeutic uses of mannitol
Oedema in tissues (lowers intracranial and IO P
In acute reanl failure
No mannitol in pulmonary oedema
Blood from lungs taken to bvs return to lungs again
Oral mannitol
Diarrhea - increases osmotic pressure in GIT which draws water in the food and all
Carbonic Anhydrase inhibitors
*In PCT as that’s where 85 to 90 % obicarbonate is reabsorbed
Acetazolamide
Dorzolamide
Carbonic AI weak because
Decreases bicarbonate in blood increases NaCl reabsorption in rest of nephron
*severe metabolic acidosis still
Increased bicarbonate
Increases Stone formation
Dorzolamide orally or as eye drops
Open angle glaucoma to decrease aqueous humour production
Dorzolamide IV
Closed angle glaucoma
Another weak diuretic
More for diabetes (3rd line)
SGLT2 Inhibitors
*Dapagliflozin
*Cangliflozin in 206 textbook
Adverse effect of dapagliflozin
UTI because glucose fermentation and all
