Kronenberg Robert H
Thunderbird Samaritan Medical Center, Glendale, AZ 85306, USA.
J Pain Palliat Care Pharmacother. 2002;16(3):27-35. doi: 10.1080/j354v16n03_03.
Ketamine is a parenteral anesthetic agent that provides analgesic activity at sub-anesthetic doses. It is an N-methyl-D-aspartate (NMDA) receptor antagonist with opioid receptor activity. Controlled studies and case reports on ketamine demonstrate efficacy in neuropathic and nociceptive pain. Because ketamine is a phencyclidine analogue, it has some of the psychological adverse effects found with that hallucinogen, especially in adults. Therefore, ketamine is not routinely used as an anesthetic in adult patients. It is a frequently used veterinary anesthetic, and is used more frequently in children than in adults. The psychotomimetic effects have prompted the DEA to classify ketamine as a Schedule III Controlled Substance. A review of the literature documents the analgesic use of ketamine by anesthesiologists and pain specialists in patients who have been refractory to standard analgesic medication regimens. Most reports demonstrate no or mild psychotomimetic effects when ketamine is dosed at sub-anesthetic doses. Patients who respond to ketamine tend to demonstrate dramatic pain relief that obviates the desire to stop treatment due to psychotomimetic effects (including hallucinations and extracorporeal experiences). Ketamine is approved by the FDA for intravenous and intramuscular administration. Use of this drug by the oral, intranasal, transdermal, rectal, and subcutaneous routes has been reported with analgesic efficacy in treating nociceptive and neuropathic pain. Ketamine also has been reported to produce opioid dose sparing and good patient acceptance. A transdermal formulation is currently under patent review in Brazil and an intranasal formulation is currently undergoing phase I/II clinical trials.
氯胺酮是一种胃肠外麻醉剂，在亚麻醉剂量时具有镇痛活性。它是一种具有阿片受体活性的N-甲基-D-天冬氨酸（NMDA）受体拮抗剂。关于氯胺酮的对照研究和病例报告表明其对神经性疼痛和伤害性疼痛有效。由于氯胺酮是苯环己哌啶类似物，它具有一些与那种致幻剂相关的心理不良反应，尤其是在成年人中。因此，氯胺酮在成年患者中不常规用作麻醉剂。它是一种常用的兽用麻醉剂，在儿童中比在成人中使用更频繁。其拟精神病效应促使美国药品管理局将氯胺酮列为III类管制物质。文献综述记录了麻醉医生和疼痛专家在对标准镇痛药物治疗方案无效的患者中使用氯胺酮进行镇痛的情况。大多数报告表明，当氯胺酮以亚麻醉剂量给药时，不会产生或只会产生轻微的拟精神病效应。对氯胺酮有反应的患者往往会有显著的疼痛缓解，从而消除了因拟精神病效应（包括幻觉和体外体验）而停止治疗的想法。氯胺酮已获美国食品药品监督管理局批准用于静脉内和肌内注射。据报道，通过口服、鼻内、透皮、直肠和皮下途径使用这种药物在治疗伤害性疼痛和神经性疼痛方面具有镇痛效果。据报道，氯胺酮还能减少阿片类药物的用量，且患者接受度良好。一种透皮制剂目前正在巴西接受专利审查，一种鼻内制剂目前正在进行I/II期临床试验。
