A NEW study examining the effects of low-dose morphine on sleep and breathlessness in people with chronic obstructive pulmonary disease (COPD) has revealed mixed findings. While morphine had no significant impact on sleep efficiency or next-day alertness, it increased the risk of nocturnal hypoventilation, raising concerns about its safety during sleep.
The randomized, double-blind crossover trial involved 19 participants with COPD experiencing chronic breathlessness. Over three days, participants received either 20mg/day of sustained-release morphine or a placebo, with outcomes assessed via overnight polysomnography.
The primary outcome, sleep efficiency, showed no difference between morphine and placebo groups (66% vs. 67%). Morphine did not alter the frequency of sleep-disordered breathing events or impair driving simulator performance the next day. However, the study found that morphine reduced overnight oxygen saturation levels and increased transcutaneous carbon dioxide (TcCO2) levels, with 42% of participants meeting criteria for nocturnal hypoventilation compared to 21% on placebo.
While low-dose morphine has been suggested to reduce breathlessness in COPD through sleep-related mechanisms, this trial did not find systematic reductions in breathlessness. Adverse effects, including nausea, were more frequent with morphine.
The researchers concluded that although low-dose morphine does not affect overall sleep efficiency or daytime alertness, its potential to cause hypoventilation during sleep warrants caution. Clinicians prescribing morphine for COPD should weigh its benefits for breathlessness against the risks of respiratory complications during sleep.
Reference
Altree TJ et al. The effects of low-dose morphine on sleep and breathlessness in COPD: A randomized trial. CHEST. 2024;DOI: 10.1016/j.chest.2024.11.040.
Aleksandra Zurowska | AMJ
