Antianginal drugs
Although angina’s cardinal symptom is chest pain, the drugs used to treat angina aren’t typically analgesics.
Instead, antianginal drugs treat angina by reducing myocardial oxygen demand (reducing the amount of oxygen the heart needs to do its work), by increasing the supply of oxygen to the heart, or both.
The three classes of antianginal drugs discussed in this section include:
Warning!
Adverse reactions to adenosine
Common adverse reactions to adenosine include:
- facial flushing
- shortness of breath
- dyspnea
- chest discomfort.
Now I get it!
How antianginal drugs work
Angina occurs when the coronary arteries (the heart’s primary source of oxygen) supply insufficient oxygen to the myocardium. This increases the heart’s workload, increasing heart rate, preload (blood volume in the ventricle at the end of diastole), afterload (pressure in the arteries leading from the ventricle), and force of myocardial contractility.
Antianginal drugs (nitrates, beta-adreneric blockers, and calcium channel blockers) relieve angina by decreasing one or more of these four factors. This diagram summarizes how antianginal drugs affect the cardiovascular system.
- nitrates (for treating acute angina)
- beta-adrenergic blockers (for long-term prevention of angina)
- calcium channel blockers (used when other drugs fail to prevent angina).
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