Do Types of Opioids Matter for Terminal Cancer Dyspnea? A Preliminary Multicenter Cohort Study

Context: Dyspnea is among the most distressing symptoms in the last weeks to days of life (terminal dyspnea). While physicians frequently use parenteral opioids other than morphine for terminal dyspnea, little is known about their effects in cancer patients. Objectives: To explore the effectiveness and safety of parenteral morphine, oxycodone, and hydromorphone for cancer patients with terminal dyspnea. Methods: This was a secondary analysis of a multicenter cohort study that consecutively enrolled advanced cancer patients with moderate/severe terminal dyspnea. Participating palliative care physicians initiated parenteral opioids (morphine/oxycodone/hydromorphone), utilizing a standardized treatment algorithm. We examined the dyspnea intensity (Integrated Palliative care Outcome Scale [IPOS]) at 24 and 48 hours. Results: Of 108 patients (mean age = 72), 66 (61%), 34 (32%), and 8 (7.4%) received morphine, oxycodone, and hydromorphone, respectively. At 24 hours, mean dyspnea IPOS scores significantly decreased from 3.0 (standard error (SE) = 0.1) at the baseline to 1.6 (0.1), 2.9 (0.1) to 2.0 (0.2), and 3.5 (0.2) to 1.2 (0.4) in the morphine (P < 0.001), oxycodone (P < 0.001), and hydromorphone (P = 0.011) groups, respectively. At 48 hours, the IPOS scores significantly reduced from 2.9 (0.1) at the baseline to 1.4 (0.1), 2.9 (0.1) to 1.6 (0.2), and 3.5 (0.2) to 1.2 (0.2) in the morphine (P < 0.001), oxycodone (P < 0.001), and hydromorphone (P = 0.004) groups, respectively. No significant differences in mean scores were found among the three groups at 24 (P = 0.080) and 48 hours (P = 0.322). Adverse events were rare. Conclusion: Parenteral morphine, oxycodone, and hydromorphone may be similarly effective and safe for cancer patients with terminal dyspnea.