A 12-year-old boy presents with hypertension and hypokalemia. Genetic testing reveals a gain-of-function mutation in the epithelial sodium channel (ENaC) in the distal nephron. Which diuretic is most appropriate for treating his condition?
- A Hydrochlorothiazide
- B Amiloride ✓
- C Spironolactone
- D Furosemide
Correct answer: B. Amiloride
Explanation
This patient has Liddle syndrome, caused by constitutively active ENaC channels causing excessive sodium reabsorption and potassium wasting. Amiloride directly blocks ENaC in the collecting duct, correcting both hypertension and hypokalemia. Spironolactone blocks the mineralocorticoid receptor but does not directly inhibit the overactive ENaC channel. Thiazides and loop diuretics act at different nephron segments and are less effective here.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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