Delapril hydrochloride is primarily used as an antihypertensive agent, effectively managing high blood pressure by inhibiting the angiotensin-converting enzyme (ACE). This action helps relax blood vessels, reducing the workload on the heart and improving blood flow. It is often prescribed in combination with other medications to enhance its efficacy in treating hypertension. Additionally, it may be used in managing heart failure and protecting kidney function in patients with diabetes, as it helps reduce proteinuria and slows the progression of renal damage. Its therapeutic benefits make it a valuable component in cardiovascular and renal health management.