Hydralazine Products | Cleanchem - Hydralazine is a vasodilator used to treat high blood pressure (hypertension) and heart failure. It works by relaxing the smooth muscles in the blood vessels, leading to vasodilation and a decrease in blood pressure. Hydralazine is often used in combination with other antihypertensive medications to help manage blood pressure and improve symptoms of heart failure, particularly when other treatments are ineffective.