Used primarily in the prevention and long-term management of angina pectoris (chest pain due to heart disease). It works by relaxing blood vessels, reducing the heart's workload and oxygen demand. This effect helps improve blood flow and decreases the frequency of angina attacks. It is preferred over other nitrates due to its longer duration of action and more predictable absorption. Often prescribed in sustained-release formulations for once-daily dosing. Not suitable for immediate relief of acute angina episodes.