Angina

Dorothy Tscheng, BScPhm, Drug Information Pharmacist, Drug Information and Research Centre, Toronto

Angina is chest pain (sometimes described as discomfort or pressure) due to a condition called coronary heart disease. In order for the heart to function properly, blood must bring oxygen flow to bring oxygen to the heart muscle. Angina results when the heart needs more oxygen than it is getting, for example during exercise or when under emotional stress. This is often due to a narrowing of the heart’s blood vessels (’atherosclerosis’) or when blood vessels supplying the heart muscle vigorously contract (’coronary artery spasm’). Other causes of angina may include exposure to extreme temperatures, consumption of alcohol and cigarette smoking.

Each person might describe angina pain differently. It may be described as actual pain, persistent indigestion, uncomfortable pressure or squeezing/tightness in the chest. Sometimes the symptoms are felt in parts of the body distant from the heart, such as the jaw, neck, back, shoulders or arms. Angina symptoms usually last a few minutes and go away with rest. People with ’stable’ angina have episodes of chest pain that occur predictably (for example, during exercise), while those with ’unstable’ angina may have symptoms that occur at unexpected times or when at rest.

Immediate rest is the most important thing to remember when symptoms occur. Nitroglycerin is often used to treat an attack. Nitroglycerin relaxes the blood vessels in the heart, thereby increasing the blood and oxygen supply to the heart muscle. Nitroglycerin is available as tablets or a spray to be used under the tongue.

Other medications that lower blood pressure or reduce the heart rate (pulse) can be prescribed to help prevent angina symptoms from occurring. These include agents known as ’beta-blockers’ and ’calcium-channel-blockers’. Aspirin is commonly used by people with angina to prevent the formation of clots inside blood vessels, which can lead to angina symptoms. Surgical procedures that widen or bypass narrowed arteries may be considered if medications fail to control symptoms.

If at anytime you use three doses of nitroglycerin within 15 minutes (or as directed by your doctor), and your angina symptoms are still present, it is very important that you go a hospital emergency department right away. It is also important that you see your doctor if you have stable angina and the pattern or frequency of your symptoms increase. The dose of your medication may need to be adjusted or a new medication may be required to help relieve the symptoms.

For more information on angina, visit the Heart and Stroke Foundation of Canada at www.heartandstroke.ca.

The information in this newsletter was prepared and reviewed by pharmacists for the Canadian Pharmaceutical Journal.