— 藥理與非經腸給藥 · EASY · MCQ —
下列何者描述了乙型阻斷劑的治療效果？
Which of the following describes the therapeutic effect of a beta-blocker?
- ACauses immediate bronchodilation引起立即支氣管擴張
- BDecreases heart rate and myocardial oxygen demand✓ 正解降低心率與心肌氧氣需求量
- CIncreases heart rate for better perfusion增加心率以改善灌流
- DIncreases blood pressure升高血壓
— Explanation · 中文詳解 —
乙型阻斷劑（Beta-blockers）透過阻斷心臟的交感神經受體（Beta-1 receptors），產生負性變時（降低心跳）與負性變力（降低收縮力）效應。此機制能顯著減少心肌氧氣需求（Myocardial oxygen demand），是治療心絞痛、高血壓及心臟衰竭的核心藥物。臨床上，護理師需監測心跳與血壓，確保病人不會出現過度心跳過緩或低血壓。
Beta-blockers reduce heart rate and myocardial contractility by blocking sympathetic receptors, thereby decreasing myocardial oxygen demand. This mechanism is therapeutic for managing angina, hypertension, and heart failure, rather than causing bronchodilation or increasing heart rate.