What is benazepril-hydrochlorothiazide used for? Benazepril-hydrochlorothiazide is used to lower high blood pressure in adults by relaxing the blood vessels and reducing the volume of the blood. Because of its effects, this drug can also lower the risks associated with long-term high blood pressure. Benazepril-hydrochlorothiazide has not been approved for use in children and, at this time, there are no universally accepted off-label uses of this drug.