Okamoto Yoshiaki, Tsuneto Satoru, Tanimukai Hitoshi, Matsuda Yoichi, Ohno Yumiko, Tsugane Mamiko, Uejima Etsuko
Department of Pharmacy, Ashiya Municipal Hospital, Hyogo, Japan.
Am J Hosp Palliat Care. 2013 Aug;30(5):450-4. doi: 10.1177/1049909112454325. Epub 2012 Jul 24.
Ketamine is often used to manage neuropathic pain in patients with cancer. However, it occasionally causes psychotomimetic effects such as vivid dreams, nightmares, illusions, hallucinations, and altered body image.
To examine whether gradual dose titration of ketamine for management of neuropathic pain prevents psychotomimetic effects in patients with advanced cancer.
This was a retrospective chart review. We administered ketamine when neuropathic pain in patients with advanced cancer became refractory to opioids and oral adjuvant analgesics. The starting dose of ketamine was 10 mg/d by continuous intravenous infusion. The dose was gradually increased by 10 mg/d every 4 to 6 hours to 50 mg/d or until the pain was relieved. It was subsequently increased by 25 mg/d every 12 to 24 hours until the pain was relieved.
For this study, we enrolled 46 patients with advanced cancer. The mean age was 52.2 ± 16.9 years. The mean dose at onset of action and maximum dose of ketamine were 56 ± 58 and 272 ± 214 mg/d, respectively. The mean pain intensity (numerical rating scale) decreased significantly from 7.3 ± 2.0 to 3.5 ± 2.2 after the administration of ketamine (P < .01). The effectiveness was 69.5%. No psychotomimetic effect of less than 300 mg/d was observed during the introduction phase even though psychotropic drugs were not prescribed. Mild sedation was observed in 3 patients (7%) as the only adverse effect during the introduction phase.
Gradual dose titration of ketamine for management of neuropathic pain can prevent psychotomimetic effects in patients with advanced cancer.
氯胺酮常用于治疗癌症患者的神经性疼痛。然而，它偶尔会引起拟精神病效应，如生动的梦境、噩梦、幻觉、错觉以及身体形象改变。
研究氯胺酮用于治疗神经性疼痛时逐渐滴定剂量是否能预防晚期癌症患者出现拟精神病效应。
这是一项回顾性病历审查。当晚期癌症患者的神经性疼痛对阿片类药物和口服辅助镇痛药无效时，我们给予氯胺酮治疗。氯胺酮的起始剂量为通过持续静脉输注10毫克/天。每4至6小时将剂量逐渐增加10毫克/天，直至达到50毫克/天或疼痛缓解。随后每12至24小时增加25毫克/天，直至疼痛缓解。
本研究纳入了46例晚期癌症患者。平均年龄为52.2±16.9岁。氯胺酮起效时的平均剂量和最大剂量分别为56±58毫克/天和272±214毫克/天。给予氯胺酮后，平均疼痛强度（数字评分量表）从7.3±2.0显著降至3.5±2.2（P<.01）。有效率为69.5%。在引入阶段，即使未开具精神药物，也未观察到剂量低于300毫克/天的拟精神病效应。在引入阶段，仅3例患者（7%）出现轻度镇静这一不良反应。
氯胺酮用于治疗神经性疼痛时逐渐滴定剂量可预防晚期癌症患者出现拟精神病效应。
