The current clinical use of adjuvant analgesics for refractory cancer pain in Japan: a nationwide cross-sectional survey

Background: Although adjuvant analgesics are used to treat opioid-refractory cancer pain, there is insufficient evidence to support this practice and limited data to guide the choice depending on cancer pain pathophysiology, dose titration and starting dose. This survey aimed to clarify the current use of adjuvant analgesics for treating opioid-refractory cancer pain.Methods: In this cross-sectional study, we sent an online survey questionnaire to 208 certified palliative care specialists. Primary outcomes were (i) effective pathophysiological mechanism of cancer pain and (ii) initiating doses and time period to the first response to each adjuvant analgesic therapy.Results: In total, 87 (42%) palliative care specialists responded. Of all patients with cancer pain, 40% of patients (median) with refractory cancer pain were prescribed adjuvant analgesics. Additionally, 94.3, 93.1 and 86.2% of palliative care specialists found dexamethasone/betamethasone effective for neuropathic pain caused by tumor-related spinal cord compression, pregabalin effective for malignant painful radiculopathy and dexamethasone/betamethasone effective for brain tumor or leptomeningeal metastases-related headache, respectively. The median starting dose of pregabalin, dexamethasone/betamethasone, lidocaine and ketamine were 75, 4, 200, and 50 mg/day, respectively, and the median time to the first response of those medications were 5, 3, 2 and 3 days, respectively.Conclusions: Many palliative care specialists select adjuvant analgesics depending on the pathophysiological mechanism of cancer pain in each case. They used such adjuvant analgesics in low doses for cancer pain with short first-response periods.

背景：尽管辅助镇痛药被用于治疗阿片类药物难治性癌痛，但支持这种做法的证据不足，且依据癌痛病理生理学、剂量滴定和起始剂量来指导选择的数据有限。本调查旨在阐明目前辅助镇痛药在治疗阿片类药物难治性癌痛中的应用情况。 方法：在这项横断面研究中，我们向208名获得认证的姑息治疗专家发送了一份在线调查问卷。主要结果是（i）癌痛的有效病理生理机制以及（ii）每种辅助镇痛治疗首次起效的起始剂量和时间。 结果：共有87名（42%）姑息治疗专家回复。在所有癌痛患者中，有40%（中位数）的难治性癌痛患者被开具了辅助镇痛药。此外，94.3%、93.1%和86.2%的姑息治疗专家分别发现地塞米松/倍他米松对肿瘤相关脊髓压迫引起的神经性疼痛有效，普瑞巴林对恶性疼痛性神经根病有效，地塞米松/倍他米松对脑肿瘤或软脑膜转移相关头痛有效。普瑞巴林、地塞米松/倍他米松、利多卡因和氯胺酮的中位起始剂量分别为75毫克/天、4毫克/天、200毫克/天和50毫克/天，这些药物首次起效的中位时间分别为5天、3天、2天和3天。 结论：许多姑息治疗专家根据每种情况下癌痛的病理生理机制选择辅助镇痛药。他们使用低剂量的此类辅助镇痛药治疗癌痛，且首次起效时间较短。