The Sound of Evolution
Naltrexone
納曲酮
Mechanism of action:
Naltrexone 是一種阿片受體拮抗劑（opioid receptor antagonist）。Naltrexone 的作用特徵是強 μ-阿片受體（μ-opioid receptor）拮抗，加上 κ-、δ-阿片受體拮抗，且作用時間長。Naltrexone 拮抗 μ-阿片受體後，會使腺苷酸環化酶（adenylyl cyclase）不被抑制，cAMP 上升，鈣離子通道恢復正常開啟，突觸小泡重新釋放神經傳遞物質，興奮性傳遞恢復；鉀離子外流減少，神經元去極化（depolarization）能力恢復。Naltrexone 拮抗 κ-、δ-阿片受體的機制與上述類似，其中拮抗 κ 受體可解除其對多巴胺系統的抑制；δ 受體的拮抗則主要使其相關的 Gi/o 訊號途徑被終止。
Reference(s):
1. Schmitz JM et al. (2001). Naltrexone and relapse prevention treatment for cocaine-dependent patients. Addict Behav.
2. Krystal JH et al. (2008). Naltrexone is associated with reduced drinking by alcohol dependent patients receiving antidepressants for mood and anxiety symptoms: results from VA Cooperative Study No. 425, "Naltrexone in the treatment of alcoholism". Alcohol Clin Exp Res.
3. Ray LA et al. (2010). Naltrexone for the treatment of alcoholism: clinical findings, mechanisms of action, and pharmacogenetics. CNS Neurol Disord Drug Targets.