Celiprolol hydrochloride is primarily used as a beta-blocker in the treatment of hypertension and angina pectoris. It helps to lower blood pressure by blocking the effects of adrenaline on the heart and blood vessels, thereby reducing the heart's workload and improving blood flow. Additionally, it is known for its vasodilatory properties, which further aid in managing cardiovascular conditions. Unlike some other beta-blockers, it has a selective action on beta-1 receptors and partial agonist activity on beta-2 receptors, making it suitable for patients with certain respiratory conditions. It is also used in the management of Marfan syndrome to slow the progression of aortic dilation.