This combination product contains two active ingredients: ramipril and hydrochlorothiazide. ramipril belongs to the class of medications called ace inhibitors. it works by relaxing blood vessels and by making the heart pump more efficiently. hydrochlorothiazide belongs to the class of medications known as diuretics or "water pills" and helps control blood pressure by getting rid of excess salt and water.ramipril - hydrochlorothiazide is used to treat high blood pressure. this combination medication is prescribed when your doctor feels it is appropriate for you to be taking both medications and you have taken ramipril and hydrochlorothiazide as separate medications without any problems. it may take 2 to 4 weeks to see the full effects of this medication.