Diuretics for hypertension.

A67-year-old African-American woman was referred to a hypertension specialty clinic for refractory hypertension and intermittent hypokalemia. Evaluations for primary aldosteronism and renal artery stenosis were negative; plasma renin was low. She had been hypertensive for 15 years. Most recently, she had taken chlorthalidone 25 mg, amlodipine 5 mg, and metoprolol 50 mg twice daily. She was not diabetic and had never smoked. Her blood pressures were in the range of 160 to 170/95 to 100 mm Hg. Except for her being mildly overweight (body mass index, 28), the physical examination was unremarkable, with no sign of target organ damage. Voltage criteria for left ventricular enlargement were present on the ECG. She was considered to be adherent to medication. Spironolactone 50 mg/d was prescribed, and her dose of chlorthalidone was reduced to 12.5 mg/d. Over the next year, her blood pressure fell to the range of 135 to 145/85 mm Hg, and serum potassium was consistently normal.