Isosorbide mononitrate is used to prevent chest pain (also called angina). Angina happens when the blood supply to the muscles of your heart are restricted, due to narrowing of the blood vessels supplying the heart.
Isosorbide mononitrate works by widening blood vessels, letting more blood and oxygen reach the heart which reduces strain on your heart, making it easier for the heart to pump blood.
NOTE: isosorbide mononitrate will not treat chest pain (an angina attack) that has already started. Your doctor will give you a spray (GTN spray) to use if you have an attack of angina. Read more about angina and GTN spray.
Isosorbide mononitrate is also sometimes used together with other medicines for people with heart failure. This is a condition where there is a problem with the pumping action of the heart. Read more about heart failure.
In New Zealand isosorbide mononitrate is available as immediate-release tablets (20 mg) and slow release tablets (40 mg and 60 mg).