On what three segments of the kidney nephron do osmotic agents such as mannitol exert their diuretic effects?
Proximal convoluted tubule, thin descending loop of Henle, and collecting duct
On what segment of the kidney nephron do loop agents such as furosemide exert their diuretic effects?
The ascending limb of the Loop of Henle
On what segment of the kidney nephron do thiazides exert their diuretic effects?
Distal convoluted tubule
On what segment of the kidney nephron do potassium-sparing agents exert their diuretic effects?
On what segment of the kidney nephron do antidiuretic hormone antagonists exert their effects?
In the proximal convoluted tubule, the filtrate is _____ (hypotonic/isotonic/hypertonic) to blood plasma.
In the thin descending limb of the loop of Henle, the filtrate is _____ (hypotonic/isotonic/hypertonic) to blood plasma.
In the thick ascending limb of the loop of Henle and the distal convoluted tubule, the filtrate is _____ (hypotonic/isotonic/hypertonic) to blood plasma.
On what segment of the kidney nephron does the diuretic acetazolamide exert its effects?
Proximal convoluted tubule
What are the clinical uses of mannitol?
To treat shock, drug overdose, and elevated intracranial/intraocular pressure
What is the mechanism of action of mannitol?
Mannitol acts as an osmotic diuretic, increasing osmolarity within the renal tubules producing increased urine volume
What two toxicities are associated with mannitol?
Pulmonary edema and dehydration
In what two conditions is mannitol contraindicated?
Anuric renal failure, congestive heart failure
What four toxicities are associated with acetazolamide?
Hyperchloremic metabolic acidosis (ACIDazolamide causes ACIDosis), neuropathy, ammonia toxicity, and sulfa allergic reactions
What is the mechanism of action of acetazolamide?
It acts as a carbonic anhydrase inhibitor, causing self-limited sodium bicarbonate diuresis and a reduction in total-body bicarbonate stores
What are the four clinical uses of acetazolamide?
To treat glaucoma, metabolic alkalosis, and altitude sickness, and to cause urinary alkalinization
What are three (general) the clinical uses of furosemide?
To treat edematous states (congestive heart failure, cirrhosis, nephrotic syndrome, pulmonary edema), hypertension, and hypercalcemia
Name one loop diuretic.
Furosemide, also known as Lasix
What is the mechanism of action of furosemide?
It inhibits the sodium-potassium-chloride cotransport system in the thick ascending limb of the loop of Henle, thereby abolishing the hypertonicity of the medulla and preventing the concentration of urine
What is the effect of the diuretic furosemide on calcium handling in the kidney nephron?
Furosemide increases calcium excretion (remember: "loops lose calcium")
Name six toxicities associated with use of loop diuretics; use the mnemonic "OH DANG!"
Ototoxicity, Hypokalemia, Dehydration, Allergy (sulfa), Nephritis (interstitial), and Gout
Ethacrynic acid has a mechanism of action similar to which other drug?
Which loop diuretic is used to diurese patients who are allergic to sulfa drugs?
Name five toxicities of ethacrynic acid.
Ototoxicity, hypokalemia, dehydration, and interstitial nephritis
Serum levels of which substances are increased as a result of the effects of hydrochlorothiazide?
Glucose (hyperGlycemia), lipids (hyperLipidemia), uric acid (hyperUricemia), and calcium (hyperCalcemia) (remember: HyperGLUC)
What is the mechanism of action of hydrochlorothiazide?
It reduces the diluting capacity of the kidney nephron by inhibiting sodium chloride reabsorption in the early distal tubule
_____ (Furosemide/Hydrochlorothiazide) increases calcium excretion, whereas _____ (furosemide/hydrochlorothiazide) decreases calcium excretion.
Name four clinical uses of hydrochlorothiazide.
To treat hypertension, congestive heart failure, idiopathic hypercalciuria, and nephrogenic diabetes insipidus
Name seven toxicities associated with hydrochlorothiazide.
Hypokalemic metabolic alkalosis, hyponatremia, hyperglycemia, hyperlipidemia, hyperuricemia, hypercalcemia, and sulfa allergy
What are the three clinical uses of potassium-sparing diuretics?
To treat hyperaldosteronism, potassium depletion, and congestive heart failure