Anti-HPN: Diuretics Flashcards
Diuretics MOA
Increase urinary excretion of Na+ (natriuresis) and water (aquaresis) = Diuretics
Site of action: Kidney Tubule
Proximal Convoluted Tubule (PCT)
Main site of HCO3- reabsorption
Reabsorption of Na ions
Water permeable
Thick Ascending Limb (TAL)
Reabsorption of Na+, K+ and Cl-
Secondary reabsorption of Mg, Ca (divalent cations)
Water impermeable
Distal Convoluted Tubule (DCT)
Reabsorption of Na+, Cl-
Reabsorption of Ca (mediated by PTH)
Water impermeable
Collecting Duct (DT)
Reabsorption of Na+
Secretion of K+
Diuretics Drugs
a. PC
* Carbonic Anhydrase Inhibitors (CAIs)
* Osmotic Diuretic (Mannitol)
* Methylxanthine (Caffeine)
* Acidifying salts (NH4Cl)
b. TDL: Osmotic diuretic (Mannitol)
c. TAL: Loop Diuretics
d. DCT: Thiazide diuretics
e. CD: Potassium Sparing Diuretics
Thiazide Diuretics MOA
Inhibits Na+ / Cl- Transporter in early distal convoluted tubule
↑ Na, K excretion ↓ Calcium excretion
First line for hypertension and management of Nephrogenic Diabetic Insipidus
Thiazide Diuretics
Others:
Management of nephrolithiasis
Adjuncts in the management of CHF
Thiazide Diuretics
a. Benzothiazides
* HCTZ, chlorothiazide
b. Thiazide-like
* Metolazone, Indapamide, Chlorthalidone
Side Effects of Thiazide Diuretics
HyperGLUC
Gycemia
Lipidemia
Uricemia
Calcemia
Hypokalemia
MOA of Loop Diuretics
Inhibit Na+/K+/2Cl– transporter in thick ascending limb of loop of Henle.
Loop Diuretics is also called
High Ceiling Diuretics - produces dose-dependent diuresis
Loop Diuretics
i. Sulfonamide-like Compounds
* Furosemide
* Bumetanide
ii. Sulfonylurea
* Torsemide
iii. Phenoxyacetate
* Ethacrynic acid
Clinical Uses of Loop Diuretics
Adjuncts in the management of pulmonary congestion in CHF
Management of oliguric and anuric Acute renal failure
Management of anion poisoning
Side Effects of Loop Diuretics
- Electrolyte-imbalance (hypo-)
- Sulfonamide associated AE: Ototoxicity: increased risk (+) aminoglycosides, cisplatin
- Metabolic Associated AE: HyperGLU: glycemia, lipidemia, uricemia