Morphine for dyspnoea in chronic obstructive pulmonary disease: A before-after efficacy study

Objectives Dyspnoea in patients with chronic obstructive pulmonary disease (COPD) is frequent and often persists despite conventional treatment. This study aimed to evaluate the efficacy and safety of oral morphine for dyspnoea in Japanese COPD patients. Methods We conducted a multi-institutional, prospective, before-after study of morphine in COPD patients with dyspnoea at rest in seven hospitals. Patients received 12 mg of oral morphine per day (or 8 mg per day if low body weight or renal impairment). Primary outcome was change in the numerical rating scale (NRS) of current dyspnoea in the evening from Day 0 to Day 2. Secondary outcomes included changes in dyspnoea intensity in the evening from Day 0 to Day 1, dyspnoea intensity between the morning from Day 0 to Day 1 and Day 2, vital signs, nausea, somnolence, anorexia and other adverse events (AEs). Results A total of 35 patients were enrolled in this study between October 2014 and January 2018. One patient did not receive study treatment. Data from 34 patients was analysed. The NRS of dyspnoea intensity in the evening significantly decreased from 3.9 on Day 0 (95% CI: 3.1 to 4.8) to 2.4 on Day 2 (95% CI: 1.7 to 3.1; p=0.0002). Secondary outcomes significantly improved in a similar manner. There were no apparent changes in the mean scores of the opioid-related AEs and vital signs. One patient experienced grade 3 lung infection not associated with morphine. Other AEs were mild. Conclusion Oral morphine is effective in alleviating dyspnoea in Japanese COPD patients. Trial registration UMIN000015288 (http://www.umin.ac.jp/ctr/index.htm).