Hydrochlorothiazide vs. Chlorthalidone for the Treatment of Hypertension.

Chlorthalidone reduces systolic blood pressure by 10 mm Hg more than hydrochlorothiazide at equal dosages in patients using monotherapy. Low-dose chlorthalidone and controlled-release hydrochlorothiazide reduce 24-hour ambulatory systolic blood pressure and diastolic blood pressure, whereas immediate-release hydrochlorothiazide may only reduce daytime systolic blood pressure.