A 55-year-old man with hypertension started on hydrochlorothiazide 25 mg daily presents with muscle weakness and fatigue. Vital signs: BP 138/82 mmHg, HR 92 bpm, RR 16/min, Temp 37°C, SpO2 98% on room air. Laboratory studies show serum potassium 3.0 mEq/L (normal 3.5–5.0), fasting glucose 248 mg/dL, arterial pH 7.48, and normal urinary protein. Which mechanism best explains the thiazide-induced hypokalemia?
- A)Decreased reabsorption of potassium in the proximal convoluted tubule
- B)Aldosterone antagonism leading to potassium retention failure
- C)Direct potassium wasting through inhibition of H+ secretion in the distal tubule
- D)Direct inhibition of Na+/K+-ATPase pump in the collecting duct
- E)Increased urinary potassium loss due to enhanced distal tubular secretion via increased sodium deliveryGABARITO
Explicação
Thiazide diuretics inhibit the Na-Cl cotransporter in the distal convoluted tubule, increasing sodium delivery to the collecting duct. This enhanced sodium reabsorption via the Na+/K+-ATPase pump drives increased potassium secretion into the urine, causing hyp... Ver explicação completa e trilha adaptativa →