1. MCQs from High yield areas of Diuretic Pharmacology

2. A 70-year-old man is admitted with a history of heart failure and an acute left ventricular myocardial infarction. He has severe pulmonary edema. Which of the following drugs is most likely to prove useful in the treatment of acute pulmonary edema?
(A) Bumetanide
(B) Ethacrynic acid
(C) Furosemide
(D) Hydrochlorothiazide
(E) Torsemide
Loop diuretics have a rapid onset of action, are very efficacious, and appear to have significant direct smooth muscle-relaxing effects in the pulmonary vessels. They are therefore drugs of choice in acute pulmonary edema. The only drug in the list that is not a loop agent is hydrochlorothiazide. The answer is (C).

3. A 70-year-old woman is admitted to the emergency room because of a "fainting spell" at home. She appears to have suffered no trauma from her fall, but her blood pressure is 110/60 when lying down and 60/40 when she sits up. Neurologic examination and an ECG are within normal limits when she is lying down. Questioning reveals that she has recently started taking "water pills" (diuretics) for a heart condition. Which of the following drugs is the most likely cause of her fainting spell?
(A) Acetazolamide
(B) Amiloride
(C) Furosemide
(D) Hydrochlorothiazide
(E) Spironolactone
The case history suggests that the syncope (fainting) is associated with diuretic use. Complications of diuretics that can result in syncope include both postural hypotension (which this patient exhibits) due to excessive reduction of blood volume and arrhythmias due to excessive potassium loss. Potassium wasting is more common with thiazides (because of their long duration of action), but these drugs rarely cause reduction of blood volume sufficient to result in orthostatic hypotension. The answer is (C).

4. A new diuretic is being studied in human volunteers
A new diuretic is being studied in human volunteers. Compared with placebo, the new drug increases urine volume, increases urinary Ca2+,increases plasma pH, and decreases serum K+.If this new drug has a similar mechanism of action to an established diuretic, it probably
A. blocks the NaCI cotransporter in the DCT
B. blocks aldosterone receptors in the CT
C. inhibits carbonic anhydrase in the PCT
D. inhibits the Na+/K+/2Cl-cotransporter in the TAL
E. acts as an osmotic diuretic
Answer: D. The effects described are typical ofloop diuretics, which inhibit the Na+K+2CI cotransporter in the thick ascending limb. This action prevents the reabsorption of Ca2+ from the paracellular pathway and provides for the use of these drugs in hypercalcemia. The increased load of Na+ in the collecting tubules leads to increased excretion of both K+ and H+, so hypokalemia and alkalosis may occur.

5. A 50-year-old man has a history of frequent episodes of renal colic with high-calcium renal stones. The most useful agent in the treatment of recurrent calcium stones is
(A) Mannitol
(B) Furosemide
(C) Spironolactone
(D) Hydrochlorothiazide
(E) Acetazolamide
The thiazides are useful in the prevention of calcium stones because these drugs inhibit the renal excretion of calcium. In contrast, the loop agents facilitate calcium excretion. The answer is (D).

6. A 55-year-old male with kidney stones has been placed on a diuretic to decrease calcium excretion. However, after a few weeks, he develops an attack of gout. Which diuretic was he taking?
A. Furosemide.
B. Hydrochlorothiazide.
C. Spironolactone.
D. Triamterene.
Answer: B. Hydrochlorothiazide is effective in increasing calcium reabsorption, thus decreasing the amount of calcium excreted, and decreasing the formation kidney stones that contain calcium phosphate or calcium oxalate. However, hydrochlorothiazide can also inhibit the excretion of uric acid and cause its accumulation, leading to an attack of gout in some individuals. Furosemide increases the excretion of calcium, whereas the K+-sparing diuretics, spironolactone and triamterene, do not have an effect.

7. (A) Amiloride plus saline infusion (B) Furosemide plus saline infusion
Which of the following therapies would be most useful in the management of severe hypercalcemia?
(A) Amiloride plus saline infusion
(B) Furosemide plus saline infusion
(C) Hydrochlorothiazide plus saline infusion
(D) Mannitol plus saline infusion
(E) Spironolactone plus saline infusion
Diuretic therapy of hypercalcemia requires a reduction in calcium reabsorption in the thick ascending limb. However, a loop diuretic alone would reduce blood volume around the remaining calcium so that serum calcium would not decrease appropriately. Therefore, saline infusion should accompany the loop diuretic. The answer is (B).

8. (A) Reduce blood volume or vascular resistance, or both
When used chronically to treat hypertension, thiazide diuretics have all of the following properties or effects EXCEPT
(A) Reduce blood volume or vascular resistance, or both
(B) Have maximal effects on blood pressure at doses below the maximal diuretic dose
(C) May cause an elevation of plasma uric acid and triglyceride levels
(D) Decrease the urinary excretion of calcium
(E) Cause ototoxicity
Thiazides do not cause ototoxicity; loop diuretics do. The answer is (E).

9. (E) Metabolic alkalosis
Which of the following is not a complication of therapy with thiazide diuretics?
(A) Hypercalciuria
(B) Hyponatremia
(C) Hypokalemia
(D) Hypemricemia
(E) Metabolic alkalosis
Thiazides produce all of the effects listed except hypercalciuria. They reduce urine calcium and for this reason are useful in chronic stone-formers. The answer is (A).

10. (B) Hydrochlorothiazide (C) Losartan (D) Spironolactone
A patient with long-standing diabetic renal disease and hyperkalemia and recent-onset congestive heart failure requires a diuretic. Which of the following agents would be LEAST harmful in a patient with severe hyperkalemia?
(A) Amiloride
(B) Hydrochlorothiazide
(C) Losartan
(D) Spironolactone
(E) Triamterene
Hyperkalemia should not be treated with drugs that interfere with aldosterone production (eg, losartan, an angiotensin II receptor blocker) or collecting tubule potassium excretion (eg, amiloride, spironolactone, triamterene). These agents are all capable of increasing serum potassium. Hydrochlorothiazide would not reduce serum potassium rapidly, but it would not increase it. The answer is (B).

11. A 75-year-old woman with hypertension is being treated with a thiazide
A 75-year-old woman with hypertension is being treated with a thiazide. Her blood pressure responds and reads at 120/76 mm Hg. After several months on the medication, she complains of being tired and weak. An analysis of the blood indicates low values for which of the following?
A. Calcium.
B. Uric acid.
C. Potassium.
D. Sodium.
E. Glucose
Answer: C. Hypokalemia is a common adverse effect of the thiazides and causes fatigue and lethargy in the patient. Supplementation with potassium chloride or with foods high in K+ corrects the problem. Alternatively, one may add a potassium-sparing diuretic like spironolactone. Calcium, uric acid, and glucose are usually elevated by thiazide diuretics. The sodium loss does not weaken the patient.

12. Which of the following diuretics would be most useful in a patient with cerebral edema'?
(A) Acetazolamide
(B) Amiloride
(C) Ethacrynic acid
(D) Furosemide
(E) Mannitol
An osmotic agent is needed to remove water from the cells of the edematous brain and reduce intracranial pressure. The answer is (E).

13. (A) Acetazolamide for glaucoma
A 60-year-old patient complains of paresthesias and occasional nausea associated with one of her drugs. She is found to have hyperchloremic metabolic acidosis. She is probably taking
(A) Acetazolamide for glaucoma
(B) Amiloride for edema associated with aldosteronism
(C) Furosemide for severe hypertension and congestive failure
(D) Hydrochlorothiazide for hypertension
(E) Mannitol for cerebral edema
Paresthesias and gastrointestinal distress are common adverse effects of acetazolamide, especially when it is taken chronically, as in glaucoma. The observation that the patient has metabolic acidosis also suggests the use of acetazolamide. The answer is (A).

14. (D) Hydrochlorothiazide (E) Spironolactone
A 55-year-old patient with severe post-hepatitis cirrhosis is started on a diuretic for another condition. Two days later he is found in a coma. The drug most likely to cause coma in a patient with cirrhosis is
(A) Acetazolamide
(B) Amiloride
(C) Furosemide
(D) Hydrochlorothiazide
(E) Spironolactone
The carbonic anhydrase inhibitors cause metabolic acidosis and urinary alkalosis. Patients with severe impairment of liver function are unable to synthesize urea efficiently and become dependent on renal excretion of ammonium ion to rid the body of nitrogenous wastes. However, in alkaline urine the ammonium ion is rapidly converted to ammonia gas. which is very rapidly reabsorbed. Hyperammonemia results, with severe neurologic consequences. The answer is (A).

15. A drug that increases the formation of dilute urine in water-loaded subjects and is used to treat SIADH is
(A) Acetazolamide
(B) Amiloride
(C) Demeclocycline
(D) Desmopressin
(E) Ethacrynic acid
Inability to form dilute urine in the fully hydrated condition is characteristic of SIADH. Antagonists of ADH are needed to treat this condition. The answer is (C).

16. A drug that is useful in glaucoma and high-altitude sickness is
(A) Acetazolamide
(B) Amiloride
(C) Demeclocycline
(D) Desmopressin
(E) Ethacrynic acid
Carbonic anhydrase inhibitors are useful in glaucoma and altitude sickness. The answer is (A).

17. DIRECTIONS (Items 15-16): Different diuretic drugs act at different sites in the
nephron. The diagram below denotes such potential sites of action with the letters A-E.For questions 15 and 16, select the lettered site of action that applies to the description given.
Answer for 15. Spironolactone is an aldosterone receptor antagonist, acts intracellularly in the cortical collecting tubule, and causes potassium retention. The answer is (E).
15. Site of action of a drug that blocks a steroid receptor and causes potassium retention.

18. DIRECTIONS (Items 15-16): Different diuretic drugs act at different sites in the
nephron. The diagram below denotes such potential sites of action with the letters A-E.For questions 15 and 16, select the lettered site of action that applies to the description given.
Answer for 16. Loop diuretics block the Na+/K+/2C1 - cotransporter. The answer is (C).
16. Site of action of a drug that blocks a sodium, potassium, and chloride cotransporter and increases calcium excretion.

19. 17. Identify the substance denoted 17. (A) Bicarbonate
DIRECTIONS (Items 17-20): The diagram below shows some of the steps involved in the reabsorption of bicarbonate. For each of the numbered items in the diagram, identify the substance denoted
The substance denoted 17 results from the combination of bicarbonate ion with a proton: this is carbonic acid. The answer is (C).
17. Identify the substance denoted 17.
(A) Bicarbonate
(B) Carbon dioxide
(C) Carbonic acid
(D) Carbonic anhydrase
(E) Hydrogen ion

20. 18. Identify the substance denoted 18. (A) Bicarbonate
DIRECTIONS (Items 17-20): The diagram below shows some of the steps involved in the reabsorption of bicarbonate. For each of the numbered items in the diagram, identify the substance denoted
The substance denoted 18 is countertransported against sodium in the PCT cell and combines with bicarbonate ion to yield carbonic acid; it is a proton. The answer is (E).
18. Identify the substance denoted 18.
(A) Bicarbonate
(B) Carbon dioxide
(C) Carbonic acid
(D) Carbonic anhydrase
(E) Hydrogen ion

21. 19. Identify the substance denoted 19. (A) Bicarbonate
DIRECTIONS (Items 17-20): The diagram below shows some of the steps involved in the reabsorption of bicarbonate. For each of the numbered items in the diagram, identify the substance denoted
Substance 19 and water are the products of the dissociation of carbonic acid; this is carbon dioxide. The answer is (B).
19. Identify the substance denoted 19.
(A) Bicarbonate
(B) Carbon dioxide
(C) Carbonic acid
(D) Carbonic anhydrase
(E) Hydrogen ion

22. 20. Identify the substance denoted 20. (A) Bicarbonate
DIRECTIONS (Items 17-20): The diagram below shows some of the steps involved in the reabsorption of bicarbonate. For each of the numbered items in the diagram, identify the substance denoted
20. The substance denoted 20 is the enzyme that catalyzes the dissociation of carbonic acid into water and carbon dioxide. The answer is (D).
20. Identify the substance denoted 20.
(A) Bicarbonate
(B) Carbon dioxide
(C) Carbonic acid
(D) Carbonic anhydrase
(E) Hydrogen ion

23. Which side effect is associated with spironolactone? A. Alkalosis
B. Hirsutism
C. Hyperkalemia
D. Hypercalcemia
E. Hyperglycemia
Answer: C. Spironolactone blocks aldosterone receptors thereby inhibiting the production of Na+ channels in the collecting duct and is used as a K+-sparing agent because the reabsorption of Na+ in the CT is coupled (indirectly) to the secretion of K+ ions. Hyperkalemia is characteristic of this drug and may lead to clinical consequences at high doses, or if patients fail to discontinue K+ supplements or ingest foodstuffs high in K+. Because Na+ reabsorption is associated with secretion of protons, spironolactone causes retention of H+ ions, leading to acidosis. It has no significant effect on the renal elimination of Ca2+ or on the plasma level; of glucose.

24. to treat edema would be one that acts at site
23. (Answer :C) Patients with reduced kidney functions should not be given carbonic anhydrase inhibitors or potassium-sparing diuretics, and thiazides are usually ineffective if the glomerular filtration rate (GFR) is low. The loop diuretics are the best choice.
In a 60-year-old patient with marked kidney disease, the choice of an agent
to treat edema would be one that acts at site

25. pressure would be a compound acting at site
(Answer :B) Osmotic diuretics act at sites where the nephron is freely permeable to water. The compound is not absorbed; it remains in the nephron after filtration and creates osmotic pressure, holding water in the nephron. This action results in a reduction of total body water and results in a reduction of intracranial pressure.
In a 24-year-old man suffering from a head injury received in a motorcycle
accident, the most appropriate agent to employ for reduction of intracranial
pressure would be a compound acting at site

26. Hypercalcemia requiring the elimination of calcium ion is effectively
(Answer :C) Loop diuretics act at the site of calcium reabsorption, thus preventing resorption and promoting calcium diuresis. However, it is necessary to administer saline simultaneously since contraction of fluid volume can accentuate the hypercalcemia.
Hypercalcemia requiring the elimination of calcium ion is effectively
managed by administering diuretics that act at site

27. Compounds acting at site were widely used to manage hypertension
(Answer :D) The thiazides still play an important role in patients who require multiple drugs to control blood pressure; they enhance the efficacy of ACE inhibitors and prevent volume retention in patients treated with vasodilators. These agents are also important because of their low cost.
Compounds acting at site were widely used to manage hypertension
and are still effective agents in many (two thirds) patients. They may
cause potassium depletion.

28. A patient with ascites and severe edema as a consequence of advanced
(Answer :F) Aldosterone antagonists (spironolactone) effectively counteract the high levels of aldosterone often found in these patients.
A patient with ascites and severe edema as a consequence of advanced
liver disease would be expected to respond well to an agent acting at site

29. Drugs acting at site prevent the reabsorption of sodium bicarbonate.
(Answer :A) Carbonic anhydrase inhibition leads to depletion in the body bicarbonate stores. However, since bicarbonate can be reabsorbed by noncarbonic anhydrase-dependent sites, it loses its effectiveness. Acetazolamide, the prototype, is rarely used for diuresis but is used to reduce production of aqueous humor or cerebral spinal fluid.
Drugs acting at site prevent the reabsorption of sodium bicarbonate.

30. (A) aldosterone antagonists (B) carbonic anhydrase inhibitors
Many patients routinely consume NSAIDs for the management of fever, headache, or muscle aches due to inflammation. NSAIDs will inhibit the action of all of the following EXCEPT
(A) aldosterone antagonists
(B) carbonic anhydrase inhibitors
(C) mannitol
(D) thiazides
(E) triamterene
(Answer :C) The action of thiazides, loop diuretics, spironolactone, and triamterene are all dependent on renal prostaglandin production.

31. (C) hydrochlorothiazide (0) mannitol (E) spironolactone
In a patient with altered hearing, the agent most likely to exacerbate this deficit is
(A) acetazolamide
(B) furosemide
(C) hydrochlorothiazide
(0) mannitol
(E) spironolactone
(Answer :B) The loop diuretics cause a dose-related loss of hearing that is usually reversible. They should be avoided in patients with hearing loss or in patients who are on other ototoxic drugs such as gentamicin or aminoglycoside antibiotics.

32. A. Hydrochlorothiazide B. Spironolactone C. alsartan D. Atenolol
Which would be the initial treatment choice to manage the hypertension in an African-American woman with a past medical history of gout and severe hypokalemia?
A. Hydrochlorothiazide
B. Spironolactone
C. alsartan
D. Atenolol
E. Enalapril
Answer: B. African American patients with hypertension respond poorly to valsartan, atenolol and enalapril. Hydrochlorothiazide is generally consider the first-line drug. However, and because of the patient's medical history of hypokalemia and gout, spironalctone is the drug of choice. Additionally, the feminizing hormonal effects of spironolactone may be bothersome in men, but not in women.

33. In a patient with CHF being treated with digoxin
(A) a high intake of sodium should be avoided
(B) diuretic therapy should be limited to loop diuretics
(C) diuretics will prevent arrhythmias
(D) oral mannitol is the agent of choice if diuretics are employed
(E) potassium ion supplements should be administered routinely
(Answer :A) The adherence to a low-sodium diet may prevent the development of hypokalemia. High sodium leads to increased potassium secretion. Hypokalemia in the presence of digoxin would be expected to cause arrhythmias. Administration of potassium is not routinely necessary.

34. (C) hydrochlorothiazide (D) mannitol (E) spironolactone
Most diuretics have the potential to cause hypokalemia; however, in the presence of beta blockers or ACE inhibitors, hyperkalemia would be expected with the administration of
(A) acetazolamide
(B) furosemide
(C) hydrochlorothiazide
(D) mannitol
(E) spironolactone
(Answer :E) The aldosterone antagonists may cause severe hyperkalemia in the presence of altered renal function, agents that inhibit rennin formation (beta blockers), or agents that reduce angiotensin II activity (ACE inhibitors, angiotensin receptor blockers).

35. (B) carbonic anhydrase inhibitors (C) loop diuretics
In a 65-year-old man with benign prostatic hypertrophy (BPH), which of the following agents should be avoided?
(A) ADH antagonists
(B) carbonic anhydrase inhibitors
(C) loop diuretics
(D) osmotic diuretics
(E) potassium-sparing diuretics
(Answer :E) Compounds that inhibit aldosterone, synthetic steroids, may cause gynecomastia, BPH, impotence, or other endocrine abnormalities.

36. C. A carbonic anhydrase inhibitor. D. A loop diuretic. E. A K-blocker.
A group of college students is planning a mountain climbing trip to the Andes. Which of the following drugs would be appropriate for them to take to prevent mountain sickness?
A. A thiazide diuretic.
B. An anticholinergic.
C. A carbonic anhydrase inhibitor.
D. A loop diuretic.
E. A K-blocker.
Answer: C. Acetazolamide is used prophylactically for several days before an ascent above 10,000 feet. This treatment prevents the cerebral and pulmonary problems associated with the syndrome as well as other difficulties, such as nausea.

37. A. Hydrochlorothiazide. B. Acetazolamide. C. Spironolactone.
An alcoholic male has developed hepatic cirrhosis. To control the ascites and edema, he is prescribed which one of the following?
A. Hydrochlorothiazide.
B. Acetazolamide.
C. Spironolactone.
D. Furosemide.
E. Chlorthalidone.
Answer: C. Spironolactone is very effective in the treatment of hepatic edema. These patients are frequently resistant to the diuretic action of loop diuretics, although a combination with spironolactone may be beneficial. The other agents are not indicated.