547-549 - Renal Drugs Flashcards
Describe the effects of mannitol on:
- tubular fluid osmolarity
- urine flow
- intracranial/intraocular pressure
- ↑ tubular fluid osmolarity
- ↑ urine flow
- ↓ intracranial/intraocular pressure
What are the clinical uses of mannitol?
- Drug overdose
2. ↑ intracranial/intraocular pressure
What are the toxicities of mannitol?
- pulmonary edema
2. dehydration
Contraindications of mannitol use?
- anuria
2. CHF
What is the mechanism of acetazolamide?
carbonic anhydrase inhibitor – causes self-limited NaHCO3 diuresis and ↓ total body HCO3- stores
What are 5 clinical uses of acetazolamide?
- Glaucoma
- Urinary alkalinization
- Metabolic alkalosis
- Altitude sickness
- Pseudotumor cerebri
What are the toxicities of acetazolamide?
- Hyperchloremic metabolic acidosis
- Paresthesias
- NH3 toxicity
- Sulfa allergy
“ACID”azolamide causes ACIDosis
What is furosemide?
A sulfonamide loop diuretic that inhibits N/K/2 Cl cotransporter of TAL
What effect do loop diuretics on the tonicity of the medulla of the kidney?
abolish the hypertonicity of the medulla → prevents concentration of urine
What effects do loop diuretics have on PGE release?
stimulates PGE release → vasodilation of afferent arteriole (inhibited by NSAIDS)
What effect do loop diuretics have on Ca2+?
↑ Ca2+ excretion (Loops Lose Calcium)
What are the clinical uses of loop diuretics?
- Edematous states: CHF, cirrhosis, nephrotic syndrome, pulmonary edema
- Hypertension
- Hypercalcemia
What are the toxicities of loop diuretics?
- Ototoxicity
- Hypokalemia
- Dehydration
- Allergy (sulfa)
- Nephritis (interstitial)
- Gout
OH DANG
What is ethacrynic acid?
A loop diuretic with the same action as furosemide, but derived from phenoxyacetic acid (so not a sulfonamide). It’s used for diuresis in patients allergic to sulfa drugs.
What are the toxicities of ethacrynic acid?
similar to furosemide (OH DANG) - can cause hyperuricemia – do not use to treat gout
Where do thiazides work?
early distal tubule
What effect do thiazides have on Ca2+?
↓ Ca2+ excretion
What are the toxicities of hydrochlorothiazide?
- Hypokalemic metabolic alkalosis
- hyponatremia
- hyperGlycemia
- hyperLipidemia
- hyperUricemia
- hyperCalcemia
- Sulfa alergy
HyperGLUC
What are the K+ sparing diuretics?
- Spironolactone
- Eplerenone
- Triamterene
- Amiloride
Which drugs are competitive aldosterone receptor antagonists in the cortical collecting tubule?
- Spironolactone
2. Eplerenone
Which drugs block Na+ channels in the CCT?
- Triamterene
2. Amiloride
What is the clinical use of K+ sparing diuretics?
- Hyperaldosteronism
- K+ depletion
- CHF
What are the toxicities of K+ sparing diuretics?
- Hyperkalemia (can → arrhythmias)
2. Endocrine effects (spironolactone → gynecomastia, antiandrogen effects)
Which diuretics increase urine K+?
loop and thiazides
Which diuretics increase urine NaCl?
All except acetazolamide
Which diuretics cause acidemia?
- CA inhibitors (↓ bicarb reabsorption)
2. K+ sparing (aldosterone blockade prevents K+ secretion and H+ secretion; also, ↑ K+ → exchange for H+ exiting cells)
Which diuretics cause alkalemia?
- loop diuretics
2. thiazides
What are the 3 mechanisms by which loop and thiazide diuretics can cause alkalemia?
- contraction alkalosis
- K+ loss from body → loss from cells in exchange for H+ uptake
- K+ loss from body → H+ is exchanged rather than K+ for Na+ in CCT → alkalosis and “paradoxical aciduria”
Which diuretics cause increased urine Ca2+?
loop diuretics (↓ paracellular Ca2+ reabsorption → hypocalcemia)
Which diuretics cause ↓ urine Ca2+?
thiazides (enhanced paracellular Ca2+ reabsorption in distal tubule)
Name 3 ACE inhibitors:
- Captopril
- Enalopril
- Lisinopril
What is the mechanism of action of ACE inhibitors?
Inhibit ACE → ↓ angiotensin II → ↓ GFR by preventing constriction of efferent arterioles
What are the clinical uses of ACE inhibitors?
- HTN
- CHF
- proteinuria
- diabetic nephropathy
- prevent unfavorable heart remodeling as a result of chronic HTN
What are the toxicities of ACE inhibitors?
- Cough
- Angioedema (contraindicated in C1 esterase inhibitor deficiency)
- Teratogen (fetal renal malformations)
- ↑ Creatinine (↓ GFR)
- Hyperkalemia
- Hypotension
- Renal failure if used in bilateral renal artery stenosis (↓ GFR)
Captopril’s CATCHH