Spirapril 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 blood pressure and improving blood flow. It is often prescribed for patients with essential hypertension to prevent complications such as strokes, heart attacks, and kidney problems. Additionally, it may be used in heart failure management to improve cardiac function and reduce symptoms. Its long-acting nature allows for once-daily dosing, enhancing patient compliance.