Diuretics Flashcards
Describe sodium reabsorption at the PCT
Na+/K+ ATPase brought sodium into the interstitium.
Na+/H+ exchanger brought sodium into the intracellular compartment from the tubular lumen.
Role of Carbonic Anhydrase
CA associates H+ with CO2 to form Carbonic Acid. Carbonic acid diffuses into the intracellular compartment where CA again converts Carbonic acid to CO2 and H2O. H2O is then reabsorbed into the interstitium along with the other solutes.
CA finally converts H2O and CO2 into H+ and HCO3-.
Name the CA-inhibitor
Acetazolamide
Acetazolamide MOA
Inhibits carbonic anhydrase. HCO3-1 and Na+ remain in the tubular lumen. Water is also unable to be reabsorbed.
Does Acetazolamide cause metabolic acidosis or alkalosis?
Acidosis b/c HCO3- is unable to be reabsorbed.
Acetazolamide treatment?
Decreases intraoccular pressure
Decreases production of CSF.
Prevent mountain sickness.
Acetazolamide adverse effects
Hypokalemia
Type II renal tubular acidosis
Calcium phosphate stones.
Sulfa allergy.
Mannitol MOA
Osmotic diuresis
Mannitol treatment?
Decreases intracranial and intraocular pressure
Mannitol adverse effects.
Expanded extracellular volume causing pulmonary edema.
Hyponatremia.
Exacerbate heart failure
Explain reabsorption at the Loop of Henle
Na+/K+ ATPase reabsorbs sodium into the interstitium.
The Na/K/2Cl transporter brings these ions into the intracellular compartment.
Is the the ascending limb of the loop of Henle permeable to water?
No, this segment is called the diluting segment.
Name the loop diuretics
Furosemide
Ethacrynic Acid
Furosemide MOA
Inhibits the N/K/Cl co-transporter
Loop diuretics promote the excretion of what ions and why?
Mg and Ca
These are excreted because diuretics lower the positive charge w/in the tubular lumen
Connection b/w loop diuretics and prostaglandins?
Induce the expression of COX-2 thereby increasing production of prostaglandins.
Prostaglandins dilate the afferent arteriole and cause an increased excretion of salt.
Loop diuretics treatment?
1st line for acute symptomatic HF
Pulmonary edema
Liver failure
Hypertension
Loop diuretics adverse effects?
Ototoxicity Sulfa allergy Interstitial nephritis Hyperuricemia Alkalosis
Reabsorption at the DCT
Na/K ATPase drive sodium into the interstitium.
Na/Cl co-transporter drives these ions into the intracellular compartment.
PTH regulates the active reabsorption of calcium at the DCT
Name Thiazide diuretics
Hydrochlorothiazide
Chlorthalidone
Thiazide diuretics MOA
Inhibit the NCC and promote the excretion of sodium and chloride.
Enhanced reabsorption of Ca++
Thiazide treatment?
Hypertension
Symptomatic treatment of HF
Nephrogenic diabetes insipidus
Prevent calcium stones
Thiazide adverse effects
Hypercalcemia Hyperlipidemia Hyperglycemia Hyperuricemia Increased lithium Hyperkalemia Hypernatremia Sulfa allergy Alkalosis
Name the K+ sparing diuretics
Triamterene
Spirinolactone
Amiloride
Eplerenone
Reabsorption at the collecting duct
Aldosterone exerts its effects here.
Contains principal cells.
Na/K ATPase brings sodium into the interstitium.
ENaC reabsorbs Na+ from the tubular lumen.
K+ is excreted
Alpha-intercalated cells excrete H+ via the H+ ATPase
Amiloride MOA
Inhibit ENaC, thus inhibiting reabsorption of Na+
Triamterene MOA
Inhibits ENaC
Eplerenone MOA
Mineralocorticoid receptor antagonist, thus inhibiting the effects of Aldosterone
Spirinolactone MOA
Mineralocorticoid receptor antagonist
Eplerenone and Spirinolactone treatment
1* or 2* Hyperaldosteronism
K+ Sparing diuretics treatment
Heart failure
Prevent myocardial remodeling
Nephrogenic DI
Liddle’s Syndrome
K+ Sparing diuretics adverse effects
Hyperkalemia Acidosis Type 4 renal tubular acidosis Inhibition of testosterone synthesis Polycystic ovarian syndrome causing symptoms of androgen excess Gynecomastia Impotence
