Isosorbide mononitrate is in a group of drugs called nitrates. Isosorbide mononitrate dilates
(widens) blood vessels, making it easier for blood to flow through them and easier for the heart to
pump.
Isosorbide mononitrate is used to prevent angina attacks (chest pain).
Isosorbide mononitrate
will not treat an angina attack that has already begun.
Isosorbide mononitrate may also be used for other purposes not listed in this medication guide.