Effects of high-dose opioid analgesia on survival, pain relief, quality of life and adverse drug reactions in cancer and neuropathic pain patients: a retrospective cohort study in real-world clinical practice.

Background: Pain is a common symptom among cancer patients and directly affects their prognosis. As the leading drug for pain management, opioids are widely prescribed. So it is necessary to get people a correct understanding and application of opioids. In order to examine whether the use of high-dose opioids might affect survival and quality of life, this retrospective cohort study was performed to explore the outcomes of patients receiving high-dose opioids for pain management in a first-class tertiary hospital in China. Methods: We retrospectively searched medical records of inpatients and outpatients with pain who were treated with opioids in The First Affiliated Hospital, Zhejiang University School of Medicine from July to December 2021. Forty-three cases who were treated with high-dose opioids meeting inclusion criteria. Among these patients, 37 had cancer pain and 6 had neuropathic pain. All patients had regular follow-up when readmission until to April 7, 2022. Medical records of patients on high-dose opioids (equivalent to morphine ≥300 mg/d) was collected, including numerical rating scale (NRS), Karnofsky performance score (KPS), survival and adverse drug reactions (ADRs). Pain relief, quality of life, survival, and ADRs of patients after pain treatment were analyzed and evaluated. Results: The NRS score was significantly reduced and pain was relieved after high-dose opioid treatment. The before and after average NRS score of cancer pain was 5.2±1.6 Conclusions: Multimodal high-dose opioid pain treatments are important approaches to effectively relieve moderate to severe pain and improve the quality of life of patients. This study provides a clinical basis for future pain treatment with high-dose opioids.