The correct answer is C) Lisinopril.
Why This is the Correct Answer
Lisinopril is an ACE (Angiotensin-Converting Enzyme) inhibitor. A chronic, dry, hacking cough is a classic, well-documented adverse effect unique to this class of antihypertensives, occurring in roughly 5% to 20% of patients.
• The Mechanism: ACE is responsible for breaking down bradykinin and substance P (both are pro-inflammatory tachykinins) in the respiratory tract. When you block ACE with a drug like Lisinopril, bradykinin and substance P accumulate in the upper and lower respiratory tracts. This accumulation sensitizes sensory airway neurons, triggering an involuntary, dry cough reflex.
• Clinical Presentation: The cough typically develops within weeks to months of starting the medication, is completely unresponsive to standard antitussive cough syrups, and can only be resolved by discontinuing the drug (the cough usually resolves within 1 to 4 weeks after stopping).
Why the Other Options are Incorrect
• A) Amlodipine: This is a dihydropyridine calcium channel blocker. Its classic adverse effects include peripheral ankle edema, flushing, headache, and reflex tachycardia—not a dry cough.
• B) Bendroflumethiazide: This is a thiazide diuretic. Its primary side effects are metabolic abnormalities: hyperuricemia (gout), hyperglycemia, hypercalcemia, and hypokalemia.
• D) Atenolol: This is a cardioselective (\beta_1) beta-blocker. While non-selective beta-blockers (like Propranolol) can cause bronchospasm and wheezing in asthmatic patients due to \beta_2 blockade, they do not cause a bradykinin-mediated chronic dry cough.