does a single dose of adenosine in epidural space reduce cancer-related neuropathic pain? a randomized clinical trial

Background: systemic and intrathecal adenosine reduce chronic neuropathic and nociceptive pain; however, the effect of adenosine epidural injection in the treatment of neuropathic cancer-related pains remains unclear. objectives: the objective of this study was to evaluate the efficacy of a single epidural administration of adenosine in alleviating chronic neuropathic pain in patients with primitive neuroectodermal tumors. methods: in this single-blind randomized clinical trial with the unique id of irct2017031428878n1, 88 patients with chronic neuropathic pain were divided into two equivalent groups. two groups were treated with a single dose epidural administration of ropivacaine, 0.75 ml/kg from 0.2% solution (both groups), plus adenosine, 50 mcgr/kg (adenosine group), or normal saline (control group). patients were evaluated on the days 1, 2, 3, 5, 7, 10, and 14 after injection. results: both groups showed a reduction in pain severity according to verbal rating scale (vrs) (3 ± 0.09-1 ± 0.05 in adenosine, 4 ± 0.08-1 ± 0.00 in the control group) and visual analogue scale (vas) (7 ± 0.25-1 ± 0.12 in adenosine, 8 ± 0.22-1 ± 0.06 in the control group); however, this reduction was significantly higher in the control group (p < 0.0005). the intensity of neuropathic pain decreased in both groups according to douleur neuropathique 4 questions (dn4) scores (from 5 ± 0.23-1 ± 0.04 in adenosine group, and from 5.5 ± 0.24-1 ± 0.00 in the control group) without a significant difference between the groups (p = 0.19). adenosine group had less nausea and vomiting (p < 0.0005).there was no significant difference in patient satisfaction levels between adenosine and control groups (p = 0.09). conclusions: administration of bolus epidural adenosine is not effective in reducing neuropathic pain in patients with primitive neuroectodermal tumors.