Nitrates are used to treat and prevent angina (chest pain) due to heart disease. Some have other uses, such as treating pain from anal fissures. Nitrates work by relaxing and widening your blood vessels. They help improve blood flow and reduce the workload on your heart to treat angina. These medications come in different forms, including oral pills, patches, sprays, and ointments. Examples include nitroglycerin (Nitrostat, Nitro-Dur, Nitrolingual), isosorbide mononitrate (Monoket), and isosorbide dinitrate (Isordil) for angina. An example of a nitrate for anal fissure pain includes nitroglycerin (Rectiv). You can choose the form that best fits your needs.