Triamterene MCQs With Answer

Triamterene MCQs With Answer

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Triamterene MCQs With Answer

Triamterene is a potassium-sparing diuretic that blocks epithelial sodium channels (ENaC) in the late distal tubule and collecting duct. This concise, topic-focused set of Triamterene MCQs with answer is designed for B. Pharm students to deepen understanding of mechanism of action, therapeutic uses, pharmacology, adverse effects, monitoring and clinically important drug interactions. Questions emphasize combination therapy (commonly with hydrochlorothiazide), prevention and detection of hyperkalemia, renal considerations, and counselling points. These practice items reinforce pharmacodynamics, safe prescribing and laboratory monitoring essential for patient care. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the primary molecular target of triamterene in the nephron?

  • Epithelial sodium channels (ENaC) on the luminal membrane of principal cells
  • Aldosterone receptor in the collecting duct
  • Na+/K+ ATPase on the basolateral membrane
  • Thiazide-sensitive NaCl cotransporter in the distal convoluted tubule

Correct Answer: Epithelial sodium channels (ENaC) on the luminal membrane of principal cells

Q2. At which part of the nephron does triamterene exert its main action?

  • Proximal tubule
  • Loop of Henle
  • Late distal tubule and collecting duct
  • Glomerulus

Correct Answer: Late distal tubule and collecting duct

Q3. Which class of diuretics does triamterene belong to?

  • Loop diuretic
  • Thiazide diuretic
  • Osmotic diuretic
  • Potassium-sparing diuretic

Correct Answer: Potassium-sparing diuretic

Q4. Why is triamterene commonly combined with hydrochlorothiazide?

  • To increase calcium excretion
  • To prevent thiazide-induced hypokalemia
  • To antagonize aldosterone directly
  • To block ENaC and NaCl cotransporter simultaneously for stronger natriuresis

Correct Answer: To prevent thiazide-induced hypokalemia

Q5. Co-administration of triamterene with which drug class markedly increases the risk of hyperkalemia?

  • Beta blockers
  • ACE inhibitors and angiotensin receptor blockers (ARBs)
  • Loop diuretics
  • Thiazide diuretics

Correct Answer: ACE inhibitors and angiotensin receptor blockers (ARBs)

Q6. Which laboratory parameters must be monitored regularly in patients on triamterene?

  • Liver enzymes and bilirubin
  • Serum potassium and renal function (creatinine/BUN)
  • Fasting glucose and HbA1c
  • Thyroid function tests

Correct Answer: Serum potassium and renal function (creatinine/BUN)

Q7. Triamterene is contraindicated in which of the following conditions?

  • Hypertension controlled on monotherapy
  • Severe renal impairment or anuria
  • Mild edema responsive to dietary sodium restriction
  • Hypercholesterolemia

Correct Answer: Severe renal impairment or anuria

Q8. What is the effect of triamterene on urinary potassium excretion?

  • Significantly increases potassium excretion
  • Decreases potassium excretion (potassium-sparing)
  • Has no effect on potassium excretion
  • Causes unpredictable swings in potassium excretion

Correct Answer: Decreases potassium excretion (potassium-sparing)

Q9. Is triamterene an aldosterone receptor antagonist?

  • Yes, it competitively blocks aldosterone receptors
  • No, it directly blocks ENaC channels independent of aldosterone
  • Yes, it inhibits aldosterone synthesis
  • No, it acts as an ACE inhibitor

Correct Answer: No, it directly blocks ENaC channels independent of aldosterone

Q10. Which of the following is a common combination brand name for triamterene with hydrochlorothiazide?

  • Lasix
  • Dyazide/Maxzide
  • Spironolactone
  • Mannitol

Correct Answer: Dyazide/Maxzide

Q11. Triamterene can increase serum levels of which narrow therapeutic index drug by reducing renal clearance?

  • Digoxin
  • Lithium
  • Warfarin
  • Phenytoin

Correct Answer: Lithium

Q12. Triamterene is most useful clinically to prevent which electrolyte disturbance caused by other diuretics?

  • Hyponatremia
  • Hypokalemia
  • Hypercalcemia
  • Hypernatremia

Correct Answer: Hypokalemia

Q13. Blocking ENaC with triamterene reduces sodium reabsorption and consequently reduces which of the following in principal cells?

  • Basolateral Na+/K+ ATPase activity directly
  • Electrochemical gradient for potassium secretion into the lumen
  • Aldosterone synthesis in the adrenal cortex
  • Glomerular filtration rate directly

Correct Answer: Electrochemical gradient for potassium secretion into the lumen

Q14. Which of the following adverse effects is most characteristic of triamterene therapy?

  • Profound hypokalemia
  • Hyperkalemia
  • Ototoxicity
  • Severe hyponatremia

Correct Answer: Hyperkalemia

Q15. A patient on triamterene presents with muscle weakness and ECG changes; which laboratory value is most likely to be abnormal?

  • Low serum sodium
  • High serum potassium
  • Low serum calcium
  • Elevated liver enzymes

Correct Answer: High serum potassium

Q16. Which monitoring schedule is appropriate after initiating triamterene in a patient with normal renal function?

  • No monitoring is needed
  • Check serum potassium and creatinine within 3–7 days and periodically thereafter
  • Only monitor blood pressure weekly
  • Weekly liver function tests for the first month

Correct Answer: Check serum potassium and creatinine within 3–7 days and periodically thereafter

Q17. Which statement about triamterene’s mechanism is TRUE?

  • It inhibits the Na+/K+/2Cl− cotransporter in the loop of Henle
  • It competitively antagonizes aldosterone at nuclear receptors
  • It blocks apical sodium channels decreasing the lumen-negative potential that drives K+ secretion
  • It increases prostaglandin synthesis to promote diuresis

Correct Answer: It blocks apical sodium channels decreasing the lumen-negative potential that drives K+ secretion

Q18. Which patient factor increases the risk of triamterene-induced hyperkalemia?

  • High dietary sodium intake
  • Baseline chronic kidney disease or reduced GFR
  • Concomitant use of loop diuretics
  • Young age with normal renal function

Correct Answer: Baseline chronic kidney disease or reduced GFR

Q19. In an overdose producing severe hyperkalemia from triamterene, which immediate treatment is appropriate to stabilize the myocardium?

  • Oral potassium supplements
  • Intravenous calcium (e.g., calcium gluconate)
  • Intravenous magnesium sulfate
  • High-dose loop diuretic orally

Correct Answer: Intravenous calcium (e.g., calcium gluconate)

Q20. Which of the following best describes the natriuretic potency of triamterene when used alone?

  • Very potent natriuretic, similar to loop diuretics
  • Moderate natriuretic effect, greater than thiazides
  • Mild natriuretic effect; often used adjunctively
  • No natriuretic effect at all

Correct Answer: Mild natriuretic effect; often used adjunctively

Q21. Which adverse effect requires counseling patients to stop triamterene and seek urgent care?

  • Mild transient headache
  • Symptoms of hyperkalemia such as palpitations, muscle weakness or paresthesia
  • Minor skin dryness
  • Occasional mild thirst

Correct Answer: Symptoms of hyperkalemia such as palpitations, muscle weakness or paresthesia

Q22. Combining triamterene with which potassium-containing supplement or salt substitute is contraindicated or should be avoided?

  • Calcium carbonate supplement
  • Potassium chloride or potassium salt substitutes
  • Magnesium oxide supplement
  • Vitamin D supplement

Correct Answer: Potassium chloride or potassium salt substitutes

Q23. Which patient population requires extra caution or dose adjustment when prescribing triamterene?

  • Patients with well-controlled asthma
  • Patients with chronic kidney disease and reduced GFR
  • Patients with hyperthyroidism
  • Young healthy adults

Correct Answer: Patients with chronic kidney disease and reduced GFR

Q24. Which of the following best explains why triamterene can lead to hyperkalemia?

  • It increases aldosterone secretion, causing potassium retention
  • It blocks sodium entry through ENaC, reducing the electrochemical drive for potassium secretion
  • It inhibits the Na+/K+ ATPase directly
  • It increases gastrointestinal potassium absorption

Correct Answer: It blocks sodium entry through ENaC, reducing the electrochemical drive for potassium secretion

Q25. Which clinical use is appropriate for triamterene or its combinations?

  • Management of acute pulmonary edema as first-line monotherapy
  • Treatment of chronic hypertension and edema, often combined with thiazide diuretics
  • Rapid reduction of serum calcium in hypercalcemia
  • Emergency treatment of diabetic ketoacidosis

Correct Answer: Treatment of chronic hypertension and edema, often combined with thiazide diuretics

Q26. Which concurrent medication would raise concern if prescribed with triamterene due to additive hyperkalemic risk?

  • Metformin
  • Spironolactone or eplerenone (other potassium-sparing agents)
  • High-dose vitamin C
  • Beta-2 agonists

Correct Answer: Spironolactone or eplerenone (other potassium-sparing agents)

Q27. Which counseling point is important when a patient starts triamterene?

  • Start high-dose potassium supplements immediately
  • Avoid salt substitutes containing potassium and report muscle weakness or palpitations
  • Stop monitoring electrolytes after the first week
  • Expect immediate dramatic weight loss within 24 hours

Correct Answer: Avoid salt substitutes containing potassium and report muscle weakness or palpitations

Q28. If a laboratory result shows hyperkalemia while on triamterene, which immediate step is most appropriate?

  • Increase the dose of triamterene
  • Review and discontinue contributing medications such as ACE inhibitors or potassium supplements
  • Prescribe oral potassium supplements
  • Ignore it unless symptomatic

Correct Answer: Review and discontinue contributing medications such as ACE inhibitors or potassium supplements

Q29. Triamterene’s diuretic effect is primarily achieved by:

  • Inhibiting carbonic anhydrase in the proximal tubule
  • Blocking apical sodium channels to reduce sodium reabsorption and downstream water retention
  • Increasing renal prostaglandin production
  • Activating the sympathetic nervous system

Correct Answer: Blocking apical sodium channels to reduce sodium reabsorption and downstream water retention

Q30. For B. Pharm students, which concept is most important to emphasize about triamterene prescribing?

  • It requires no monitoring and is always safe with other medications
  • Understanding its potassium-sparing mechanism, monitoring electrolytes and avoiding interacting drugs is essential
  • It is the first-line agent for heart failure in all patients
  • It exclusively treats metabolic acidosis

Correct Answer: Understanding its potassium-sparing mechanism, monitoring electrolytes and avoiding interacting drugs is essential

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