Diuretics

Question 1

Diuretics

Answer 1

Reduce BP -> increase excretion of water and sodium

Duiresis vs naturesis
D -> Excretion of water
N-> excretion of sodium

Can combine diuretics with other cardiac meds - CCBs, ACE, ARB, BB, etc
Can combine diuretics with each other

Question 2

Water follows sodium

Answer 2

Reabsorption water and sodium -> inc BP

Diuretic prevent reabsorption of water and sodium -> dec BP -> dec plasma volume

Question 3

Hyperuricemia and sulfa allergies

Answer 3

Loops and thiazides have aromatic ring that is also present in sulfa antibiotics -> most patients are allergic to them

Based on severity of reaction to sulfa assess risk of prescribing thiazides or loop diuretic

K sparing diuretics do not have loop
Ethancynic acid - loop diuretic that does not have ring structure

Question 4

Loop diuretics

Answer 4

Most potent - “thick ascending loop of Henle”

Watch allergy to sulfa!
Drug examples: -mide and -nide
Furosemide, torsemide, bumetanide

Eracrynic acid - no sulfa worries

MOA: inhibit Na/Cl/K symporter -> increase excretion of each
Induce renin release (increase BP) -> plasma volume depletion

Uses; HTN, CHF, edema, pulmonary edema, *preferred in renal disease

Electrolyte abnormalities:
Hypo - kalemia (K) , calcemia (Ca), magnesmia (Mg)
Hyper-uricemia - competition between Uric acid and diuretics inhibits some excretion of Uris acid on same transporters -> potentiation of gout

Side effects: hypovolemia, hypotension

Question 5

Thiazides diuretics

Answer 5

Distal convoluted tubule

All end in -thaizide
Watch sulfa allergy

MOA: inhibit Na/Cl symporter - promote secretion of Mg
Increase reabsorption of Uria in proximal tubule -> increase plasma Uris acid levels -> gout/arthritis

Uses: first line HTN therapy, edema, CHF

Electrolyte abnormalities:
hypo- aklemia (K) , magnesemia(Mg)
Hyper- calcemia (Ca), uricemia competition between Uric acid and diuretics inhibits some excretion of Uris acid on same transporters -> potentiation of gout

Side effects: hypovolemia, hypotension

Question 6

Potassium sparing diuretics - aldosterone antagonists

Answer 6

Least potent diuretic, no sulfa worries, used in conjunction with other diuretics to prevent excretion of K

Collecting duct

Examples: spironolactone, eperenone (-one)

MOA: block aldosterone from binding -> inhibit Na/K pump -> increase excretion of Na/ retention of K

Uses: HTN, edema, CHF

Electrolyte abnormalities:
Hyper- kalemia (K) uricemia, competition between Uric acid and diuretics inhibits some excretion of Uris acid on same transporters -> potentiation of gout

Side Effect: endocrine - gynecomastia, impotence, arrythmia

Question 7

Potassium sparing diuretic - sodium channel blockers

Answer 7

Least potent - no sulfa worries

Collecting ducts

More favorable renal dosing profiles

Examples: Amiloride, triamterene

MOA: block Na channels -> inhibition of Na reabsorption / retention of K

Uses: HTN, edema, CHF

Electrolyte abnormalities:
Hyper- kalemia (K) uricemia competition between Uric acid and diuretics inhibits some excretion of Uris acid on same transporters -> potentiation of gout

Side Effect: arrythmia