Does morphine use help with breathlessness?

Treatment with oral morphine falls short of improving breathlessness due to cardiorespiratory conditions, as shown in a study.

The study included 143 adults with moderate to severe chronic breathlessness (modified Medical Research Council breathlessness scale [mMRC] grade ≥3) due to cardiac disease, respiratory disease, post-COVID-19, or cancer. These patients were randomly assigned to receive treatment with either long-acting morphine at 5–10 mg plus docusate sodium 100 mg (n=75) or placebo morphine plus placebo laxative (n=68). Treatment was administered orally twice daily for 56 days.

Worst breathlessness score in the past 24 h at day 28, measured using a numerical rating scale (NRS; 0 indicating not breathless at all, and 10 indicating worst imaginable breathlessness), was the primary outcome. Secondary outcomes included physical activity levels, worst cough NRS, quality of life, and morphine-related toxicities.

Two participants in the morphine group and one in the placebo group did not receive treatment, leaving 140 in the modified intention-to-treat population (mean age 70.5 years, 66 percent male, 94 percent White). By day 28, 88 percent of participants in the morphine group and 99 percent in the placebo group had at least 90 percent treatment adherence.

Worst breathlessness score at day 28 did not significantly differ between the morphine and placebo groups (6.19 vs 6.10; adjusted mean difference, 0.09, 95 percent confidence interval [CI], –0.57 to 0;75; p=0.78).

Likewise, no significant between-group difference was observed in any secondary measures, except for an improvement in cough seen at day 56 with morphine (adjusted mean difference, –1.41, –2.18 to –0.64). Participants in the morphine group had increased moderate to vigorous physical activity at day 28 compared with those in the placebo group (adjusted mean difference, 9.51 min/day), but the difference was not significant after multiple-measures correction.

In terms of safety, morphine was associated with more adverse events (AEs) (251 vs 162), serious adverse events (15 vs 3), and treatment discontinuation (13 vs 2). There were no treatment-related deaths documented during the study.