Moderate Sodium Restriction and Various Diuretics in the Treatment of Hypertension: Effects of Potassium Wastage and Blood Pressure Control

Changes in total body potassium level and blood pressure (BP) were determined in multiple studies on 12 hypertensive subjects ingesting a diet either moderately restricted or higher in sodium. On both diets, the following diuretics were randomly given for four-week intervals: chlorthalidone, hydrochlorothiazide, or furosemide. Total body exchangeable potassium level fell 225 mEq with lower sodium intake and 455 mEq with higher intake, combining all diuretics. Chlorthalidone caused more potassium wastage than the other diuretics. The average falls in mean BP were 13.9 mm Hg with the lower sodium diet and 9.1 with the higher sodium diet, combining all diuretics. Combining both diets, chlorthalidone produced the greatest fall and furosemide produced the slightest. These data suggest that if a diuretic is used to treat hypertension, a diet moderately restricted in sodium and a single morning dose of a diuretic of intermediate duration of action offer the best balance of efficacy and safety for most patients.