Chapter 24: Antianginal Drugs – Managing Chest Pain

Anginal pain manifests when the heart shifts to anaerobic metabolism, leading to a build-up of lactic acid. Treatment focuses on correcting the oxygen supply-and-demand imbalance through three primary drug classes: nitrates, beta blockers, and calcium channel blockers (CCBs). Nitrates, such as nitroglycerin and isosorbide, function as potent vasodilators, predominantly decreasing venous return (preload) and promoting redistribution of oxygen-rich blood to the ischemic tissue. Rapid-acting nitrates are essential for acute anginal attacks, while long-acting forms are used prophylactically; crucial nursing considerations include preventing drug tolerance via nitrate-free periods and avoiding co-administration with erectile dysfunction drugs due to severe hypotension risk. Beta blockers (e.g., atenolol, metoprolol) reduce myocardial oxygen demand by slowing the heart rate (negative chronotropy) and decreasing contractility (negative inotropy), which is particularly beneficial for exertional angina and improving outcomes post-myocardial infarction. CCBs (e.g., amlodipine, diltiazem) promote vasodilation by inhibiting calcium influx into smooth muscle cells, effectively reducing systemic vascular resistance (afterload) and treating vasospastic angina. The nursing process for antianginal therapy requires meticulous assessment of vital signs, patient education on preventing orthostatic hypotension, avoiding exacerbating factors (like alcohol or hot environments), and careful monitoring for adverse effects and drug interactions, such as the dangerous combination of CCBs and grapefruit juice.