— 藥理與非經腸給藥 · HARD · MCQ —
下列何者描述了納洛酮 (Naloxone) 等鴉片類拮抗劑的作用機轉？
Which of the following describes the mechanism of action of an opioid antagonist like Naloxone?
- ADecreases the metabolism of morphine降低嗎啡的代謝
- BBlocks the production of endorphins阻斷內啡肽的產生
- CIncreases respiratory center sensitivity增加呼吸中樣的敏感性
- DCompetitively binds to opioid receptors✓ 正解與鴉片類受體競爭性結合
— Explanation · 中文詳解 —
納洛酮（Naloxone）是一種純鴉片類拮抗劑，其機轉為與鴉片類藥物競爭性地結合在鴉片類受體（主要是 μ 受體）上。由於其對受體的親和力比嗎啡等鴉片類藥物更高，它能將藥物從受體位點置換出來，進而逆轉鴉片類藥物引起的呼吸抑制與中樞神經抑制。此過程不具備直接促進呼吸中樞的作用，純粹是阻斷鴉片類藥物的結合。
Naloxone is a pure opioid antagonist whose mechanism of action is competitive binding to opioid receptors (primarily the mu receptor). Because its receptor affinity is greater than that of opioids such as morphine, it displaces the agonist from the receptor site, thereby reversing opioid-induced respiratory and central nervous system depression. This process does not directly stimulate the respiratory center—it purely blocks opioid binding.