The Effect of Opioids and Benzodiazepines on Exacerbation Rate and Overall Survival in Patients with Chronic Obstructive Pulmonary Disease on Long-Term Non-Invasive Ventilation

Background: There is a growing concern that opioids and benzodiazepines can depress the respiratory drive and could contribute to worsening respiratory failure and higher exacerbation frequency in COPD. However, the relationship between the exacerbation rate and medication taken is poorly understood in patients with chronic respiratory failure due to COPD. Methods: As part of a service evaluation project, we analysed 339 patients with COPD who were established on long-term non-invasive ventilation (LT-NIV) at our tertiary centre. We investigated the relationship between benzodiazepine and opioid prescription and clinical outcomes as well as their impact on the exacerbation rate and overall survival following setup. Results: Before LT-NIV setup, 40 patients took benzodiazepines and 99 patients took opioids. Neither benzodiazepine nor opioid use was associated with changes in daytime blood gases, overnight hypoxia or annual exacerbations before NIV setup, but patients taking opioids were more breathless as assessed by modified Medical Research Council scores (3.91 +/- 0.38 vs. 3.65 +/- 0.73, p < 0.01). Long-term NIV significantly reduced the number of yearly exacerbations (from 3.0/2.0-5.0/ to 2.8/0.71-4.57/, p < 0.01) in the whole cohort, but the effect was limited in those who took benzodiazepines (from 3.0/2.0-7.0/ to 3.5/1.2-5.5/) or opioids (3.0/2.0-6.0/ to 3.0/0.8-5.5/). Benzodiazepine use was associated with reduced exacerbation-free survival and overall survival (both p < 0.05). However, after adjustment with relevant covariates, the relationship with exacerbation-free survival became insignificant (p = 0.12). Opioids were not associated with adverse outcomes. Conclusions: Benzodiazepines and opiates are commonly taken in this cohort. Whilst they do not seem to contribute to impaired gas exchange pre-setup, they, especially benzodiazepines, may limit the benefits of LT-NIV.