How Successful Is Parenteral Oxycodone for Relieving Terminal Cancer Dyspnea Compared With Morphine? A Multicenter Prospective Observational Study

Context: Parenteral morphine is widely used for dyspnea of imminently dying cancer patients (terminal dyspnea). However, the efficacy of other opioids such as oxycodone remains largely unknown. Objectives: To explore the efficacy of parenteral oxycodone vs. morphine by continuous infusion over 24 hours in cancer patients with terminal dyspnea. Methods: This was a pre-planned subgroup analysis of a multicenter prospective observational study. Inclusion criteria were advanced cancer patients admitted to palliative care units, Eastern Cooperative Oncology Group performance status = 3-4, and a dyspnea intensity ≥2 on the Integrated Palliative care Outcome Scale (IPOS) for which oxycodone or morphine was initiated by continuous infusion. We measured dyspnea IPOS scores over 24 hours. Results: We analyzed 164 patients who received oxycodone (n = 26) and morphine (n = 138) for dyspnea (median survival = 5 days). The mean age was 70 years, 58 patients (35%) had lung cancer, and 97 (59%) had lung metastases. Complete case analysis revealed that mean dyspnea IPOS scores decreased from 3.0 (standard deviation = 0.7) to 1.5 (0.7) in the oxycodone group (difference in means = 1.5; P < 0.001), and from 2.9 (0.7) to 1.6 (1.0) in the morphine group (difference in means = 1.3; P < 0.001). No significant between-group differences existed in the IPOS scores at 24 hours (P = 0.753). Adverse events were seen in no and 5 patients in the oxycodone and morphine groups, respectively. Conclusion: Parenteral oxycodone may be equally effective and safe as morphine in the treatment of terminal dyspnea in cancer patients. Future randomized controlled trials should confirm the efficacy and safety of opioids other than morphine for terminal dyspnea.