Nitroglycerin for angina

Nitroglycerin is a type of nitrate prescribed for chest pain associated with angina. Tablet and spray formulations are referred to as short-acting preparations. This is because the effect of the medicine lasts for around 20-30 minutes. They are used to provide rapid relief from the pain as and when it happens. They can also be used before the pain is expected to happen, such as before exercise that is likely to cause chest pain (for example, before climbing stairs).

Other formulations which contain nitroglycerin are skin patches and ointment. These are longer-acting nitrates, as the medicine in these preparations works for a longer period of time. They are often referred to as transdermal nitrates. They are prescribed to prevent the pain from developing.

Pain associated with angina develops if part of your heart muscle does not get as much blood and oxygen as it needs. It is usually caused by narrowing of your coronary arteries due to a build-up of a fatty substance called atheroma. The narrowing makes it more difficult for blood to flow to your heart muscle.

Nitroglycerin works in two ways. It relaxes blood vessels in your body (causing them to widen) and this reduces the strain on your heart, making it easier for your heart to pump blood around your body. It also relaxes and widens blood vessels in your heart (coronary arteries), which increases the flow of blood to your heart muscle.

There is also a rectal ointment of nitroglycerin available (Rectiv®) but this is used for a completely different condition. If this has been prescribed for you, please see a separate medicine leaflet called Glyceryl trinitrate rectal ointment for more information.