Meta-analysis on the effectiveness and safety of morphine in managing clinical symptoms of chronic obstructive pulmonary disease

Objective The effectiveness of morphine in treating patients with chronic obstructive pulmonary disease (COPD) remains uncertain. This study aims to assess the effectiveness and safety of morphine in COPD patients. Methods Following Cochrane's methodology, this study conducted a systematic review and meta-analysis. The search scope included publications until August 2023 from databases such as PubMed, Web of Science, Embase, and The Cochrane Library. The review encompassed randomized controlled trials using morphine for COPD treatment. The effect was analyzed using fixed and random-effects models, presenting the effect size as the standardized mean difference (SMD) with a 95 % confidence interval (CI). Results A total of ten publications were included (three randomized controlled studies and seven randomized crossover studies) comprising 380 patients diagnosed with COPD. Morphine did not reduce patients' breathlessness (SMD: −0.26; 95 % CI: −0.88 to 0.35), nor did it impact their quality of life (SMD: −0.12; 95 % CI: −0.29 to 0.06), blood oxygen saturation (SMD: 0.05; 95 % CI: −0.17 to 0.28), or respiratory rate (SMD: 0.22; 95 % CI: −0.43 to 0.86). Regarding side effects, statistical significance was observed only for fatigue (p = 0.014); other side effects did not reach statistical significance. Conclusion In chronic obstructive pulmonary disease (COPD), the therapeutic efficacy of morphine remains uncertain, and the relationship between morphine dosage and improvement in COPD symptoms cannot be determined. Additionally, the likelihood of fatigue occurrence is higher with long-term use. More systematic evaluation methods and larger-scale randomized controlled trials are needed to obtain more reliable data.