One common cause of chest pain is angina pectoris. This is a sudden, severe, pressing chest pain radiating to the neck, jaw, back and arms. It is caused by insufficient coronary blood flow to meet the oxygen demands of the myocardium. Or in simple terms – there is not enough blood flow to the heart muscles.
Traditionally, angina is divided into stable angina (also known as effort induced or classic), unstable angina and Prinzmetal angina (also known as variant, vasospastic or rest angina)
Stable angina is the most common type of angina. The presentation is typically a short lasting, burning, heavy, squeezing feeling in the chest. It is caused by reduction of coronary perfusion (decrease in blood supply to the heart muscles) due to a fixed obstruction produced by atherosclerosis. A fixed obstruction means that when there is an increase in demand in oxygen supply (during exertion or exercise) the body is not able to increase the supply of oxygen. This pain is usually relieved by rest or nitroglycerin.
In unstable angina, symptoms occur with increased frequency, duration and intensity. The chest pain is triggered by progressively less effort, or even at rest. Unstable angina may also present as new onset of chest pain. The pain is not relieved by rest or nitroglycerin. Unstable angina requires hospital admission.
Three classes of drugs, used either alone or in combination, are effective in treating patients with angina. These drugs lower the oxygen demand of the heart by affecting the blood pressure, venous return (how much blood is return to the heart), heart rate and contractility.
| Nitrates | Calcium Channel Blockers | Beta-blockers |
| Nitroglycerine (taken under the tongue)
Isosorbide dinitrate Isosorbide mononitrate |
Nifedipine
Verapamil Diltiazem
|
Propranolol
Atenolol Metoprolol |
Table 1: Examples of drugs used to treat angina pectoris
Each drug has its own mechanism of action, clinical indication and adverse effects. The doctor will choose the appropriate drug or combination of drugs based on the patient’s symptoms and diagnosis. It is extremely important to follow the guidelines given by the doctor when taking these drugs.
Written by:
Dr Hidayatul Radziah Ismawi
Pharmacologist, Kulliyyah of Medicine
International Islamic University Malaysia
References:
- Katzung B.G.(Ed.), (2017). Basic & Clinical Pharmacology, 14e. McGraw Hill.
- Cubeddu. Lippincott’s Illustrated Reviews: Pharmacology. 4th ed. Philadelphia: Lippincott Williams & Wilkins, 2009.