Diuretics Flashcards
Effects of Diuretics in Urinary Electrolyte Composition
Furosemide
SOA: Thick ALOH
MOA: Decrease medulla osmotic gradient, stimulate renin release
Useage: for acute pulm edema, HF, ascites
Loop diuretics: Block NKCC (at thick AL & macula densa); can use at low GFR; loss of cations → ↑ gradient → ↓ macula densa ↑ renin
SE: Gout; hypocalcemia; hypokalemic metabolic alkalosis; tinnitus; sulfa allergy
Acetazolamide
SOA: PCT
Usage: For glaucoma & Altitude sickness
MOA: CA inhibitor (bicarb excretion) → inhibit NaHCO3 reabsorption → bicarb excretion
Effect: ↓ aqueous humor & CSF
SE: Nephrolithiasis; hyperchloremic metabolic acidosis;
C/I : COPD, hepatic issue (alkaline urine); sulfa allergy
Mannitol
Osmotic Diuretic - sugar alcohol
Thin Descending LOH (but also PCT)
–> also oppose the action of ADH in the collecting tubule
MOA: inhibits NaCl reabsorption to cause osmosis/increase osmolarity to TF
For cerebral edema & glaucoma
Contra: HF (initial increase in ECF) or renal failure
Potassium Sparing Diuretics
MOA: inhibit epithelial Na channels; ALDOSTERONE receptor antagonists
SOA: LDT & CCT
useage: hypokalemia, alkaline urine, acidosis, kidney stones
types: Spironolcatone; trimaterine, amiloride
Trimaterine
K+ sparing diuretic
MOA: blocks Na entry through Na-selective ion channels ENaC in the apical membrane of the cortical collecting tubule
Usages: ↓ hypokalemia due to thiazides and states of mineralocorticoid excess or hyperaldosteronism
SE: hyperkalemia
C/I: Inhibited by NSAIDs
Spironolactone
type: K+ sparing diurectis
SOA: LDT & CCD
MOA: increased amounts of sodium and water to be excreted, while potassium is retained
Useages: chronic HF; hyperaldosteronism
Blocks aldosterone/ Aldosterone/mineralcorticoid receptor antagonist → (less ENaC expression)
SE: Gynecomastia; sexual dysfunction
Ethacrynic acid
Use if sulfa allergy (to furosemide)
SOA: Thick ALOH
MOA: Decrease medulla osmotic gradient, stimulate renin release
Useage: for acute pulm edema, HF, ascites
Loop diuretics: Block NKCC (at thick AL & macula densa); can use at low GFR; loss of cations
SE: Gout; hypocalcemia; hypokalemic metabolic alkalosis; tinnitus; sulfa allergy
Dorzolamide
SOA: PCT
Usage: For glaucoma; topical - eye drops only - LOCAL
MOA: CA inhibitor (bicarb excretion) → inhibit NaHCO3 reabsorption → bicarb excretion
Effect: ↓ aqueous humor & CSF
SE: Nephrolithiasis; hyperchloremic metabolic acidosis;
C/I : COPD, hepatic issue (alkaline urine); sulfa allergy
Vasopressin Antagonist
Conivaptan: IV
Tolvaptan: via tablet/at home
MOA: Vasopressin/ADH antagonist → inhibition of V2 aquaporins; Inh cyp34A
Site: principal cells at medullary collecting duct
Use: SIADH & euvolemic hyponatremia
Effect: decreased urine osmolarity, hyponatremia, kalemia, calcemia
C/I: hypovolemic hyponatremia
Amiloride
Potassium Sparing Diuretic
MOA: same as the epithelial Na channel blocker Triamterene → blocks uptake of Li+ & Na+ in CCT
Use: lithium-induced NEPHROGENIC DI
Thiazides & Congeners
Hypochlorothiazide & Indapamine
Hydrochlorothiazide & Indapamine
MOA: Block Na/Cl symporter (at early DCT)
Effect: vasodilaton & ↓ insulin
Uses: For HTN, edema, hypercalciuria, nephrogenic diabetes insipidus
SE: Gout; diabetes; hypercalcemia;hypokalemic metabolic alkalosis; sulfa allergy
