Mercadante S
Department of Anaesthesia and Intensive Care, Buccheri La Ferla Hospital & Pain Relief and Palliative Care, SAMOT, Palermo, Italy.
Palliat Med. 1996 Jul;10(3):225-30.
Ketamine has been shown to have potent analgesic properties at low dosages. Bioavailability is high when it is given parenterally, but low after oral or rectal administration. Active metabolites should account for part of the analgesic effect of ketamine during long-term oral administration. NMDA receptor inhibition by ketamine may reflect a wind-down phenomenon, and should alleviate NMDA-related neuropathic pain, reversing the rightward shift of the opioid-response curve. A synergistic effect between ketamine and opioids has been observed in cancer pain patients who have lost an analgesic response to high doses of morphine. Further studies need to be carried out to confirm the benefits of ketamine in cancer pain, and to determine the best route of administration, dosages and the incidence of side effects.
已证明氯胺酮在低剂量时有强效镇痛特性。胃肠外给药时生物利用度高，但口服或直肠给药后生物利用度低。长期口服给药时，活性代谢物应是氯胺酮镇痛作用的一部分。氯胺酮对N-甲基-D-天冬氨酸（NMDA）受体的抑制作用可能反映了一种减弱现象，应能减轻与NMDA相关的神经性疼痛，逆转阿片类药物反应曲线的右移。在对高剂量吗啡失去镇痛反应的癌症疼痛患者中，已观察到氯胺酮与阿片类药物之间的协同作用。需要开展进一步研究以证实氯胺酮对癌症疼痛的益处，并确定最佳给药途径、剂量及副作用发生率。
