Renal Pharmacology Flashcards
What type of diuretic is mannitol?
Osmotic diuretic (it’s a sugar that pulls water into tubules)
Where is mannitol’s site of action?
Proximal convoluted tubule and descending LOH
Describe mannitol’s mechanism
Increase tubular fluid osmolarity and increase urine flow. Decrease intracranial/intraocular pressure
What clinical circumstances use Mannitol?
Drug overdose, elevated intracranial/intraocular pressure (head trauma)
What are some adverse effects of mannitol?
Pulmonary edema, dehyrdration
What are contraindications for mannitol?
Anuria, CHF, active cerebral hemorrhage
Where does Acetazolamide function?
PCT
Describe the mechanism of Acetazolamide
Carbonic anhydrase inhibitor in the PCT. Decreases NaHCO3 synthesis and thus decreases total body HCO3- stores
What clinical uses does Acetazolamide have?
Glaucoma (decrease aqueous humor production), urinary alkalinzation, metabolic alkalosis, altitude sickness, pseudotumor cerebri
What are adverse effects of Acetazolamide
Proximal Renal Tubular Acidosis (Type 2), Paresthesias, NH3 toxicity (more NH3 is retained), sulfa allergy
List three common Loop diuretics (FuTor Bum)
Furosemide, Bumetanide, Torsemide
Describe the mechanism of loop diuretics (where they act, what they do)
Act on Thick Ascending LoH. Inhibit Na/K/2Cl cotransporter. Abolish hypertonicity, preventing concentration of urine. Stimulate PGE release (vasodilate AA). Increase Ca+2 excretion
When are loop diuretics used?
Edematous states (HF, cirrhosis, nephrotic syndrome, pulm edema), hypertension, hypercalcemia
Adverse Effects of Loop diuretics (OH DANG A)
Ototoxicity Hypokalemia Dehydration Allergy (sulfa) Nephritis (interstitial) Gout Alkalemia
When do you use Ethacrynic acid?
When a patient needs loop diuretic but has sulfa allergy
What are the adverse effects of Ethacrynic acid?
Similar to furosemide but more ototoxic
Where do thiazide diuretics act?
Distal convoluted tubule
Mechanism of thiazide diuretics (HCTZ, chlorthalidone, metolazone)
Inhibit NaCl reabsorption in DCT. Inhibit Ca+2 excretion.
Clinical use of Thiazide diuretics
Hypertension, HF, idiopathic hypercalciuria, nephrogenic diabetes insipidus, osteoporosis
Adverse effects of thiazide diuretics (HyperGLUC)
Hypokalemic metabolic acidosis, hyponatremia, hyperglycemia, hyperlipidemia, hyperuricemia, hypercalcemia. Sulfa allergy
List three potassium-sparing diuretics (The K+ STAys)
Spironolactone and eplerenone; Triamterene, Amiloride
Mechanism of spironolactone and epleronone?
competitive aldosterone receptor antagonists in cortical collecting tubule
Mechanism of Triamterene and Amiloride
Block Na+ channels in cortical collecting tubule
Clinical use of K+-sparing diuretics
Hyperaldosteronism, K+ depletion, HF, hepatic ascites (spironolactone), nephrogenic DI (amiloride)
Adverse effects of K+sparing diuretics
Hyperkalemia (arrythmias), endocrine effects with spironolactone (gynecomastia, antiandrogen effects)
How does ATII act on the PCT?
Increases Na/H+ exchange, leading to increased HCO3- reabsorption (contraction alkalosis)
Describe paradoxical aciduria with loop and thiazide diuretics
K+ loss leads to K+ depleted state. In cortical collecting tubule, H+ (rather than low K+) is exchanged for Na+ leading to alkalosis and paradoxical aciduria
Describe the mechanism of ACEIs
Inhibition of ACE and conversion of AI to AII. Acts on efferent arterioles. Decreases AII, leads to increase of renin due to loss of negative feedback. Prevents inactivation of bradykinin so increased vasodilation
What is the effect of ACE inhibitors on GFR?
Decreased GFR
Clinical use of ACE inhibitors (-prils)
Hypertension, heart failure (decreases mortality), proteinuria in diabetic neuropathy. Prevents unfavorable heart remodeling as a result of chronic hypertension
Which electrolyte abnormalities do you get with loop diuretics?
Hypokalemia, metabolic alkalosis and hypocalcemia
Which electrolyte abnormalities do you get with thiazide diuretics?
Hyponatremia, Hypokalemia, metabolic alkalosis, Hypercalcemia
Which electrolyte abnormalities do you get with Acetazolamide?
Metabolic acidosis, hypokalemia
Which electrolyte abnormalities do you get with K+ sparing diuretics?
Hyperkalemia, metabolic acidosis
What are common side effects of chlorthalidone?
Muscle weakness, cramps and possible rhabdomyolysis
Which medications help with reducing progression to renal failure in patients with diabetes?
ACE inhibitors
Why do ACEIs lead to coughing?
Inhibit degradation of bradykinin
Which antiviral can cause renal calcium and magnesium wasting (leading to hypocalcemia and hypomagnesemia)?
Foscarnet
Chlorthalidone is what type of diuretic
Thiazide
Hypercholesterolemia and hyperglycemia occur with use of thiazide diuretics due to
decreased insulin secretion and increased insulin resistance
Hyperuricemia with use of thiazide diuretics occurs because
of increased reabsorption in PT due to decreased renal blood flow
Best diuretics for patients in heart failure (increased RAAS, audible S3)
Aldosterone-inhibitors (Spironolactone or eplerenone)
