Palliative Care Unit and Research Institute, University Hospital La Candelaria, Canary Health Service, Tenerife, Spain.
J Pain Symptom Manage. 2011 Jun;41(6):1098-105. doi: 10.1016/j.jpainsymman.2010.08.017. Epub 2011 Mar 12.
No consensus exists about the most appropriate dose ratio for conversion from parenteral to oral ketamine.
To confirm that a 1:1 dose ratio is suitable for converting subcutaneous (s.c.) to oral ketamine in cancer patients.
Patients with opioid poorly responsive cancer pain, who responded to 0.4, 0.6, or 0.8 mg s.c. ketamine bolus, were treated with 0.1, 0.15, or 0.2mg/kg/h ketamine infusion, respectively. Switching to the oral route, by applying a 1:1 dose ratio, was carried out in patients who experienced adequate pain relief and continued to need ketamine as a coanalgesic. Pain, somnolence, feelings of insobriety, confusion, and cardiovascular parameters were assessed throughout the process.
Twenty-nine patients were enrolled in the study. Ketamine infusion decreased pain intensity from severe to no pain or slight pain in 23 of 29 and six of 29 patients, respectively. The median of s.c. ketamine doses was 0.2mg/kg/h (range 0.1-0.5). After oral switching, 27 of 29 patients remained as successfully controlled as when receiving s.c. ketamine. The other two patients needed a slight dose ratio readjustment, to 1:1.3 and 1:1.5, to maintain pain control. The median of oral ketamine doses was 300 mg/day (interquartile range 240-382.5). Seven of 29 patients receiving s.c. ketamine developed moderate and transitory side effects, such as feelings of insobriety and somnolence. No side effects were present while receiving oral ketamine. No significant changes were observed in cardiovascular parameters.
A 1:1 dose ratio for conversion from s.c. to oral ketamine is safe and effective in cancer pain patients.
对于从静脉注射转换为口服氯胺酮，哪种剂量比例最合适，目前尚未达成共识。
证实静脉注射（SC）至口服氯胺酮的 1:1 剂量比适用于癌症患者。
对阿片类药物治疗反应不佳的癌症疼痛患者，给予 0.4、0.6 或 0.8mg SC 氯胺酮推注后，分别给予 0.1、0.15 或 0.2mg/kg/h 氯胺酮输注。对疼痛缓解充分且仍需要氯胺酮作为辅助镇痛的患者，通过应用 1:1 的剂量比，转换为口服途径。整个过程中评估疼痛、嗜睡、醉酒感、意识模糊和心血管参数。
29 例患者入组研究。23 例患者中，29 例患者的氯胺酮输注使疼痛强度从重度减轻至无疼痛或轻度疼痛，6 例患者的疼痛强度从重度减轻至中度疼痛。SC 氯胺酮剂量的中位数为 0.2mg/kg/h（范围 0.1-0.5）。口服转换后，29 例患者中有 27 例仍能像接受 SC 氯胺酮时一样得到有效控制。另外 2 例患者需要稍作剂量比调整，分别调整为 1:1.3 和 1:1.5，以维持疼痛控制。口服氯胺酮的中位数剂量为 300mg/天（四分位距 240-382.5）。7 例接受 SC 氯胺酮的患者出现中度且短暂的副作用，如醉酒感和嗜睡。接受口服氯胺酮时没有出现副作用。心血管参数无明显变化。
对于癌症疼痛患者，从 SC 到口服氯胺酮的 1:1 剂量比转换是安全有效的。
