阿摩線上測驗
34.進行腸道切除手術後，若選用嗎啡（morphine）作為術後止痛，可能造成病人出現腸阻塞情形，下 列何者最不適合用於改善此術後不良反應？
(A)naloxegol
(B)alvimopan
(C)naldemedine
(D)naltrexone
統計： A(163), B(1026), C(351), D(1487), E(0) #3381355
詳解 (共 9 筆)
*術後止痛* 會用鴉片致效劑
Lowdose naloxone (0.04 mg) has an increasing role in the treatment of adverse effects that are commonly associated with intravenous or epidural opioids. Careful titration of the naloxone dosage can often eliminate the itching, nausea, and vomiting while sparing the analgesia. For this purpose, oral naloxone, and modified analogs of naloxone and naltrexone, have been approved by the FDA. Analogs include methylnaltrexone bromide and naldemedine for the treatment of constipation in patients with opioidinduced constipation (OIC) with chronic noncancer pain and latestage advanced illness—and naloxegol, naldemedine, and alvimopan for the treatment of postoperative ileus following bowel resection surgery. Methylnaltrexone has a quaternary amine preventing it from crossing the bloodbrain barrier. Naloxegol is pegylated naloxone, which limits penetration into the CNS and through peripheral μantagonism mitigates constipation. Naldemedine and alvimopan are considered peripheral μreceptor antagonists. The principal mechanism for the selective therapeutic effect of these agents is peripheral enteric μreceptor antagonism with minimal CNS penetration.
低劑量納洛酮（0.04毫克）對於治療靜脈注射或硬脊膜外給予鴉片類藥物所引起的常見副作用，扮演了越來越重要的角色。謹慎地調整納洛酮的劑量，通常可以在保留止痛效果的同時，消除搔癢、噁心和嘔吐等症狀。為此，美國食品藥物管理局（FDA）已核准口服納洛酮，以及納洛酮和納曲酮（naltrexone）的修飾類似物上市。
這些類似物包括：
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甲基納曲酮（methylnaltrexone bromide）與naldemedine：用於治療患有慢性非癌症疼痛和晚期疾病患者的鴉片類藥物引起的便秘（Opioid-Induced Constipation, OIC）。
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Naloxegol、naldemedine與alvimopan：用於治療腸道切除手術後的術後腸阻塞（postoperative ileus）。
這些藥物的作用機制各有特點：
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甲基納曲酮帶有四級胺（quaternary amine），此結構使其無法穿過血腦屏障（blood-brain barrier）。
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Naloxegol是聚乙二醇化（pegylated）的納洛酮，這種修飾限制了它滲透進入中樞神經系統（Central Nervous System, CNS），並透過周邊μ型鴉片受體（μ-antagonism）的拮抗作用來緩解便秘。
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Naldemedine和alvimopan被歸類為周邊μ型鴉片受體拮抗劑。
(以原文書內容為主，AI內容僅供參考)
