The combination of epidural opioids with local anesthetics or adjuvants may provide effective pain relief for intractable cancer pain, according to study findings published in the journal Pain Practice.
Pain is commonly experienced with cancer and despite existing pharmacologic treatments, can remain intractable in up to 20% of patients. While epidural analgesia is frequently used in perioperative and obstetric settings, its role in managing patients with cancer pain has not been firmly established.
To more fully understand the safety and efficacy of epidural analgesia in patients with intractable pain from cancer, researchers reviewed relevant randomized controlled trials (RCTs) and observational studies available in PubMed, Embase, and Cochrane Central Register of Controlled Trials.The primary outcome of the review was to assess pain control from epidural analgesia.
Studies in the systematic review included adult participants with chronic cancer pain who had previously received treatment with systemic opioids that resulted in intolerable side effects or undeterred pain, with pain severity measured before and after treatment.A total of 24 studies met eligibility criteria and were included in the review.
Nine of the included studies were RCTs and 15 were observational. While 2 RCTs found that epidural opioids were not superior to systemic opioids, the combination of epidural opioids with local anesthetics or adjuvants showed enhanced analgesic effect in patients with intractable cancer pain.
Additionally, the combination of epidural opioids with local anesthetics or adjuvants increased the duration of analgesic effect and decreased the opioid dose needed to provide relief from pain.The specific epidural adjuvants assessed in the review included calcitonin, clonidine, ketamine, neostigmine, methadone, and dexamethasone. The use of clonidine as an adjuvant was associated with a higher incidence of hypotension.
The researchers noted, “An epidural analgesia may be considered an alternative option for terminal patients with cancer who have pain refractory to conventional therapies or experience intolerable side effects of opioids.”
Study limitations included the heterogeneous methodologies of the eligible studies, making it impossible to conduct a meta-analysis.Further, without pooled data or precision estimates, assessments of certainty of the evidence was also not possible.Lastly, the use of single-center, observational studies with no control group have a high risk of bias. Future RCTs are needed that compare systemic medications with the combination of epidural opioids plus local anesthetics and/or adjuvants.
Hsieh YL, Chen HY, Lin CR, Wang CF. Efficacy of epidural analgesia for intractable cancer pain: a systematic review. Pain Pract. Published online July 16, 2023. doi:10.1111/papr.13273