Which diuretic is most frequently combined with an antihypertensive drug?

• A. chlorthalidone
• B. bendroflumethiazide
• C. potassium-sparing diuretic
• D. hydrochlorothiazide

Answer: (D)

In hypertension management, using a diuretic alongside another antihypertensive is common because it adds to blood pressure reduction by decreasing fluid volume and, over time, vascular resistance. Among diuretics, a thiazide like hydrochlorothiazide is the most frequently used in these combination regimens. It acts by inhibiting the Na-Cl transporter in the distal convoluted tubule, producing modest diuresis that lowers blood volume, and, with continued use, helps reduce peripheral resistance. Its long track record, broad availability, good tolerability, and presence in many fixed-dose combinations with ACE inhibitors or ARBs make it the go-to partner for other antihypertensive drugs. While other diuretics such as chlorthalidone or bendroflumethiazide are also used, hydrochlorothiazide is the most commonly paired with another antihypertensive. Potassium-sparing diuretics are useful to offset potassium loss but are not the most frequent primary partner in standard HTN regimens.