a diuretic drug used to treat hypertension.

a diuretic drug (trade name Esidrix and HydroDIURIL) used in the treatment of hypertension

Hydrochlorothiazide (Apo-Hydro®, Aquazide H®, Dichlotride®, Hydrodiuril®, Microzide®, Oretic®), sometimes abbreviated HCT, HCTZ, or HZT is a popular diuretic drug that acts by inhibiting the kidney's ability to retain water. This reduces the volume of the blood, decreasing blood return to the heart and thus cardiac output and, by other mechanisms, is believed to lower peripheral vascular resistance.