Adverse respiratory effects of opioids for chronic breathlessness: to what extent can we learn lessons from chronic pain?

Abstract

We would like to thank K.T.S. Pattinson and colleagues for their interest in our review and their comprehensive comments [1]. We agree that the quality of the included studies was low, and the studies were small and not designed to examine the safety of opioids, as stated in our discussion [2]. Indeed, respiratory depression was not included as an outcome in over half of the studies. Of note, in the 25 studies that did include the outcome, only 11 stated a definition. Therefore, we recommended in our review to include "a common respiratory outcome set in all trials of opioids for breathlessness, so that a more robust synthesis could be conducted". Although chemoreflex response is useful in laboratory research, measurement of blood gases remains the basis for evaluation in clinical practice, with the assessment of arterial blood gases being more reliable than the assessment of capillary blood gases [3] or transcutaneous measurement [4].

Chronic breathlessness: time for Cinderella to go to the ball!

“…However, a dose titration study of extended release morphine for breathlessness showed that over half of responders did so by 10 mg per 24 h and over 90% by 20 mg per 24 h [24]; doses not associated with excess mortality or hospital admission in 4 years' follow-up of people with severe COPD [25]. These are doses markedly lower than those associated with psychological dependence and misuse; issues in relation to opioids for pain should not be automatically assumed for breathlessness [26]. The misuse potential is lower with extended release preparations compared with immediate release [27] and for morphine compared with other oral opioids [28].…”