Dihydrocodeine for breathlessness in "pink puffers"

Recent discoveries from clinical trials: why opioids should not be used for dyspnea management in COPD

INTRODUCTION

Chronic breathlessness among persons with chronic obstructive pulmonary disease (COPD) is a distressing and limiting symptom and a substantial management challenge for healthcare practitioners. Historically, multiple professional respiratory societies have encouraged the prescription of opioid drugs as a therapeutic intervention for chronic breathlessness. However, in 2024, the European Respiratory Society (ERS) published clinical practice guidelines that markedly departed from such traditional recommendations and stated that opioids should not be used for chronic breathlessness.

AREAS COVERED

This manuscript will review recently published, well-designed, randomized controlled trials (literature was searched on PubMed from January 2020 to January 2025) that evaluated the efficacy of oral opioids for chronic breathlessness in persons with COPD and which influenced the new position adopted by ERS in 2024.

EXPERT OPINION

Recent, well-designed, adequately powered clinical trials consistently demonstrate that oral opioids are not effective at reducing chronic breathlessness (nor at improving overall quality of life, functional status or exercise tolerance) amongst individuals with advanced COPD. Other professional respiratory societies need to consider and potentially embrace the new ERS position on opioids for dyspnea in COPD, so as to guide members away from an unhelpful, and in some cases harmful, management paradigm.

Opioids for the palliation of symptoms in people with serious respiratory illness: a systematic review and meta-analysis

BACKGROUND

People living with serious respiratory illness experience a high burden of distressing symptoms. Although opioids are prescribed for symptom management, they generate adverse events, and their benefits are unclear.

METHODS

We examined the efficacy and safety of opioids for symptom management in people with serious respiratory illness. Embase, MEDLINE and the Cochrane Central Register of Controlled Trials were searched up to 11 July 2022. Reports of randomised controlled trials administering opioids to treat symptoms in people with serious respiratory illness were included. Key exclusion criteria included <80% of participants having a nonmalignant lung disease. Data were extracted regarding study characteristics, outcomes of breathlessness, cough, health-related quality of life (HRQoL) and adverse events. Treatment effects were pooled using a generic inverse variance model with random effects. Risk of bias was assessed using the Cochrane Risk of Bias tool version 1.

RESULTS

Out of 17 included trials, six were laboratory-based exercise trials (n=70), 10 were home studies measuring breathlessness in daily life (n=788) and one (n=18) was conducted in both settings. Overall certainty of evidence was "very low" to "low". Opioids reduced breathlessness intensity during laboratory exercise testing (standardised mean difference (SMD) -0.37, 95% CI -0.67- -0.07), but not breathlessness measured in daily life (SMD -0.10, 95% CI -0.64-0.44). No effects on HRQoL (SMD -0.42, 95% CI -0.98-0.13) or cough (SMD -1.42, 95% CI -3.99-1.16) were detected. In at-home studies, opioids led to increased frequency of nausea/vomiting (OR 3.32, 95% CI 1.70-6.51), constipation (OR 3.08, 95% CI 1.69-5.61) and drowsiness (OR 1.37, 95% CI 1.01-1.86), with serious adverse events including hospitalisation and death identified.

CONCLUSIONS

Opioids improved exertional breathlessness in laboratory exercise studies, but did not improve breathlessness, cough or HRQoL measured in daily life at home. There were significant adverse events, which may outweigh any benefits.

European Respiratory Society clinical practice guideline on symptom management for adults with serious respiratory illness

Respiratory symptoms are ubiquitous and impair health-related quality of life in people with respiratory disease. This European Respiratory Society (ERS) task force aimed to provide recommendations for symptomatic treatment in people with serious respiratory illness. The ERS task force comprised 16 members, including representatives of people with serious respiratory illness and informal caregivers. Seven questions were formulated, six in the PICO (Population, Intervention, Comparison, Outcome) format, which were addressed with full systematic reviews and evidence assessed using GRADE (Grading of Recommendations Assessment, Development and Evaluation). One question was addressed narratively. An "evidence-to-decision" framework was used to formulate recommendations. To treat symptoms in people with serious respiratory illness, the task force suggests the use of graded exercise therapy (conditional recommendation, low certainty of evidence); and suggests the use of a multicomponent services, handheld fan and breathing techniques (conditional recommendations, very low certainty of evidence). The task force suggests not to use opioids (conditional recommendation, very low certainty of evidence); and suggests either administering or not administering supplemental oxygen therapy (conditional recommendation, low certainty of evidence). The task force suggests that needs assessment tools may be used as part of a comprehensive needs assessment, but do not replace patient-centred care and shared decision making (conditional recommendation, low certainty of evidence). The low certainty of evidence, modest impact of interventions on patient-centred outcomes, and absence of effective strategies to ameliorate cough highlight the need for new approaches to reduce symptoms and enhance wellbeing for individuals who live with serious respiratory illness.

Management of Refractory Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) is a common condition with an estimated prevalence of 12% in adults over the age of 30 years worldwide. COPD is a leading cause of morbidity and mortality globally, with a substantial economic and social burden. There are an estimated 3 million deaths annually due to COPD. However, most of the patients with COPD respond to routine interventions like bronchodilator therapy, assessing supplemental oxygen needs, smoking cessation, vaccinations, and pulmonary rehabilitation. There is a significant number of patients who unfortunately progress to have persistent symptoms despite these interventions. Refractory COPD is not yet formally defined. Patients with severe persistent symptoms or exacerbations despite appropriate care can be considered to have refractory COPD. Managing refractory COPD needs a multidimensional approach. In this review article, we will discuss essential interventions like ensuring adequate inhaler techniques, exploring the need for non-invasive ventilatory support, use of chronic antibiotics and phosphodiesterase inhibitors to advanced therapies like bronchoscopic lung volume reduction surgery, and the upcoming role of anti-IL5 agents in managing patients with refractory COPD. We will also discuss non-pharmacologic interventions like psycho-social support and nutritional support. We will conclude by discussing the palliative care aspect of managing patients with refractory COPD. Through this review article, we aim to better the approach to managing patients with refractory COPD and discuss new upcoming therapies.

Effectiveness and safety of opioids on breathlessness and exercise endurance in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Opioids are recommended to treat advanced refractory dyspnoea despite optimal therapy by the American Thoracic Society clinical practice guidelines, while newly published randomised controlled trials of opioids in chronic obstructive pulmonary disease yield conflicting results.

AIM

This study aimed to evaluate the effectiveness and safety of opioids for patients with chronic obstructive pulmonary disease.

DESIGN

Systematic review and meta-analysis (PROSPERO CRD42021272556).

DATA SOURCES

Databases of PubMed, EMBASE and CENTRAL were searched from inception to 2022 for eligible randomised controlled trials.

RESULTS

Twenty-four studies including 975 patients, were included. In cross-over studies, opioids improved breathlessness (standardised mean difference, -0.43; 95% CI, -0.55 to -0.30; I2 = 18%) and exercise endurance (standardised mean difference, 0.22; 95% CI, 0.02-0.41; I2 = 70%). However, opioids failed to improve dyspnoea (standardised mean difference, -0.02; 95% CI, -0.22 to 0.19; I2 = 39%) and exercise endurance (standardised mean difference, 0.00; 95% CI, -0.27 to 0.27; I2 = 0%) in parallel control studies that administered sustained-release opioids for more than 1 week. The opioids used in most crossover studies were short-acting and rarely associated with serious adverse effects. Only minor side effects such as dizziness, nausea, constipation and vomiting were identified for short-acting opioids.

CONCLUSIONS

Sustained-release opioids did not improve dyspnoea and exercise endurance. Short-acting opioids appeared to be safe, have potential to lessen dyspnoea and improve exercise endurance, supporting benefit in managing episodes of breathlessness and providing prophylactic treatment for exertional dyspnoea.

COVID-19, Suffering and Palliative Care: A Review

According to the WHO guideline, palliative care is an integral component of COVID-19 management. The relief of physical symptoms and the provision of psychosocial support should be practiced by all healthcare workers caring for COVID-19 patients. In this review, we aim to provide a simple outline on COVID-19, suffering in COVID-19, and the role of palliative care in COVID-19. We also introduce 3 principles of palliative care that can serve as a guide for all healthcare workers caring for COVID-19 patients, which are (1) good symptom control, (2) open and sensitive communication, and (3) caring for the whole team. The pandemic has brought immense suffering, fear and death to people everywhere. The knowledge, skills and experiences from palliative care could be used to relieve the suffering of COVID-19 patients.

Opioid Prescription Method for Breathlessness Due to Non-Cancer Chronic Respiratory Diseases: A Systematic Review

A previous pooled analysis demonstrated significant relief of breathlessness following opioid administration in patients with chronic obstructive pulmonary disease. However, in clinical practice, it is important to know the characteristics of patients responding to opioids, the best prescription methods, and the evaluation measures that can sufficiently reflect these effects. Thus, we performed a systematic review of systemic opioids for non-cancer chronic respiratory diseases. Fifteen randomized controlled studies (RCTs), four non-randomized studies, two observational studies, and five retrospective studies were included. Recent RCTs suggested that regular oral opioid use would decrease the worst breathlessness in patients with a modified Medical Research Council score ≥ 3 by a degree of 1.0 or less on a scale of 1–10. Ergometer or treadmill tests indicated mostly consistent significant acute effects of morphine or codeine. In two non-randomized studies, about 60% of patients responded to opioids and showed definite improvement in symptoms and quality of life. Furthermore, titration of opioids in these studies suggested that a major proportion of these responders had benefits after administration of approximately 10 mg/day of morphine. However, more studies are needed to clarify the prescription method to reduce withdrawal due to adverse effects, which would lead to significant improvements in overall well-being.

Spanish COPD Guideline (GesEPOC) Update: Comorbidities, Self-Management and Palliative Care

The current health care models described in GesEPOC indicate the best way to make a correct diagnosis, the categorization of patients, the appropriate selection of the therapeutic strategy and the management and prevention of exacerbations. In addition, COPD involves several aspects that are crucial in an integrated approach to the health care of these patients. The evaluation of comorbidities in COPD patients represents a healthcare challenge. As part of a comprehensive assessment, the presence of comorbidities related to the clinical presentation, to some diagnostic technique or to some COPD-related treatments should be studied. Likewise, interventions on healthy lifestyle habits, adherence to complex treatments, developing skills to recognize the signs and symptoms of exacerbation, knowing what to do to prevent them and treat them within the framework of a self-management plan are also necessary. Finally, palliative care is one of the pillars in the comprehensive treatment of the COPD patient, seeking to prevent or treat the symptoms of a disease, the side effects of treatment, and the physical, psychological and social problems of patients and their caregivers. Therefore, the main objective of this palliative care is not to prolong life expectancy, but to improve its quality. This chapter of GesEPOC 2021 presents an update on the most important comorbidities, self-management strategies, and palliative care in COPD, and includes a recommendation on the use of opioids for the treatment of refractory dyspnea in COPD.

A critical review of the respiratory benefits and harms of orally administered opioids for dyspnea management in COPD

INTRODUCTION

Dyspnea occurring in chronic obstructive pulmonary disease (COPD) that is refractory to traditional management strategies is a common and challenging problem. Considerable attention has been paid to the off-label use of orally administered opioids as a pharmacotherapy option for refractory dyspnea in COPD. Multiple professional respiratory society guidelines express support for the application of oral opioids for this purpose.

AREAS COVERED

This manuscript will critically review randomized controlled trials undertaken to date that evaluate the efficacy of oral opioids for dyspnea in COPD, as well as phase IV observational studies that examine for potential opioid-related respiratory harms in the COPD population (literature was searched on PubMed up to June 2021). COPD guideline recommendations relating to opioids for dyspnea will subsequently be critiqued.

EXPERT OPINION

Opioid efficacy trials demonstrate at best a small improvement in dyspnea in limited numbers of individuals with COPD, whereas safety trials consistently show an increased risk of respiratory-related exacerbation, hospitalization and death in association with opioid use. In contrast to what is expressed in guidelines, the current body of evidence does not the support the wide application of opioids to manage refractory dyspnea among individuals with COPD, but instead, a highly selective and careful approach.

Opioids in patients with COPD and refractory dyspnea: literature review and design of a multicenter double blind study of low dosed morphine and fentanyl (MoreFoRCOPD)

Background

Refractory dyspnea or breathlessness is a common symptom in patients with advanced chronic obstructive pulmonary disease (COPD), with a high negative impact on quality of life (QoL). Low dosed opioids have been investigated for refractory dyspnea in COPD and other life-limiting conditions, and some positive effects were demonstrated. However, upon first assessment of the literature, the quality of evidence in COPD seemed low or inconclusive, and focused mainly on morphine which may have more side effects than other opioids such as fentanyl. For the current publication we performed a systematic literature search. We searched for placebo-controlled randomized clinical trials investigating opioids for refractory dyspnea caused by COPD. We included trials reporting on dyspnea, health status and/or QoL. Three of fifteen trials demonstrated a significant positive effect of opioids on dyspnea. Only one of four trials reporting on QoL or health status, demonstrated a significant positive effect. Two-thirds of included trials investigated morphine. We found no placebo-controlled RCT on transdermal fentanyl. Subsequently, we hypothesized that both fentanyl and morphine provide a greater reduction of dyspnea than placebo, and that fentanyl has less side effects than morphine.

Methods

We describe the design of a robust, multi-center, double blind, double-dummy, cross-over, randomized, placebo-controlled clinical trial with three study arms investigating transdermal fentanyl 12 mcg/h and morphine sustained-release 10 mg b.i.d. The primary endpoint is change in daily mean dyspnea sensation measured on a numeric rating scale. Secondary endpoints are change in daily worst dyspnea, QoL, anxiety, sleep quality, hypercapnia, side effects, patient preference, and continued opioid use. Sixty patients with severe stable COPD and refractory dyspnea (FEV₁ < 50%, mMRC ≥ 3, on optimal standard therapy) will be included.

Discussion

Evidence for opioids for refractory dyspnea in COPD is not as robust as usually appreciated. We designed a study comparing both the more commonly used opioid morphine, and transdermal fentanyl to placebo. The cross-over design will help to get a better impression of patient preferences. We believe our study design to investigate both sustained-release morphine and transdermal fentanyl for refractory dyspnea will provide valuable information for better treatment of refractory dyspnea in COPD.

Trial registration NCT03834363 (ClinicalTrials.gov), registred at 7 Feb 2019, https://clinicaltrials.gov/ct2/show/NCT03834363.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01647-8.

Use of short-acting opioids in the management of breathlessness: an evidence-based review

PURPOSE OF REVIEW

To provide an evidence-based review on the use of short-acting opioids for management of breathlessness in patients with advanced diseases.

RECENT FINDINGS

We identified 28 randomized controlled trials that examined the effect of short-acting opioids on breathlessness under three study settings: as a prophylactic dose given prior to exertion; as a rescue dose for treatment of breathlessness at rest or episodic breathlessness; or as a scheduled medication for overall reduction of breathlessness. These trials varied widely in regard to patient population (opioid naive or tolerant), opioid (formulation, dose, timing of administration, and scheduling) and control intervention. Taken together, there is good evidence to support that short-acting opioids can reduce breathlessness and improve activity level when given before exertion. There is some evidence that parenteral opioids are efficacious for the as needed treatment of episodic breathlessness or breathlessness at rest. However, there is only limited evidence to support scheduled short-acting opioids for overall relief of breathlessness.

SUMMARY

There is evidence to support that short-acting opioids have a pharmacologic effect on breathlessness. More research is needed to clarify how opioids can be prescribed to optimize breathlessness relief, function, and quality of life.

Pharmacologic Management of Chronic Obstructive Pulmonary Disease. An Official American Thoracic Society Clinical Practice Guideline

Background: This document provides clinical recommendations for the pharmacologic treatment of chronic obstructive pulmonary disease (COPD). It represents a collaborative effort on the part of a panel of expert COPD clinicians and researchers along with a team of methodologists under the guidance of the American Thoracic Society.

Methods: Comprehensive evidence syntheses were performed on all relevant studies that addressed the clinical questions and critical patient-centered outcomes agreed upon by the panel of experts. The evidence was appraised, rated, and graded, and recommendations were formulated using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

Results: After weighing the quality of evidence and balancing the desirable and undesirable effects, the guideline panel made the following recommendations: 1) a strong recommendation for the use of long-acting β₂-agonist (LABA)/long-acting muscarinic antagonist (LAMA) combination therapy over LABA or LAMA monotherapy in patients with COPD and dyspnea or exercise intolerance; 2) a conditional recommendation for the use of triple therapy with inhaled corticosteroids (ICS)/LABA/LAMA over dual therapy with LABA/LAMA in patients with COPD and dyspnea or exercise intolerance who have experienced one or more exacerbations in the past year; 3) a conditional recommendation for ICS withdrawal for patients with COPD receiving triple therapy (ICS/LABA/LAMA) if the patient has had no exacerbations in the past year; 4) no recommendation for or against ICS as an additive therapy to long-acting bronchodilators in patients with COPD and blood eosinophilia, except for those patients with a history of one or more exacerbations in the past year requiring antibiotics or oral steroids or hospitalization, for whom ICS is conditionally recommended as an additive therapy; 5) a conditional recommendation against the use of maintenance oral corticosteroids in patients with COPD and a history of severe and frequent exacerbations; and 6) a conditional recommendation for opioid-based therapy in patients with COPD who experience advanced refractory dyspnea despite otherwise optimal therapy.

Conclusions: The task force made recommendations regarding the pharmacologic treatment of COPD based on currently available evidence. Additional research in populations that are underrepresented in clinical trials is needed, including studies in patients with COPD 80 years of age and older, those with multiple chronic health conditions, and those with a codiagnosis of COPD and asthma.

Morphine for dyspnoea in chronic obstructive pulmonary disease: a before-after efficacy study

OBJECTIVES

Dyspnoea in patients with chronic obstructive pulmonary disease (COPD) is frequent and often persists despite conventional treatment. This study aimed to evaluate the efficacy and safety of oral morphine for dyspnoea in Japanese COPD patients.

METHODS

We conducted a multi-institutional, prospective, before-after study of morphine in COPD patients with dyspnoea at rest in seven hospitals. Patients received 12 mg of oral morphine per day (or 8 mg per day if low body weight or renal impairment). Primary outcome was change in the numerical rating scale (NRS) of current dyspnoea in the evening from Day 0 to Day 2. Secondary outcomes included changes in dyspnoea intensity in the evening from Day 0 to Day 1, dyspnoea intensity between the morning from Day 0 to Day 1 and Day 2, vital signs, nausea, somnolence, anorexia and other adverse events (AEs).

RESULTS

A total of 35 patients were enrolled in this study between October 2014 and January 2018. One patient did not receive study treatment. Data from 34 patients was analysed. The NRS of dyspnoea intensity in the evening significantly decreased from 3.9 on Day 0 (95% CI: 3.1 to 4.8) to 2.4 on Day 2 (95% CI: 1.7 to 3.1; p=0.0002). Secondary outcomes significantly improved in a similar manner. There were no apparent changes in the mean scores of the opioid-related AEs and vital signs. One patient experienced grade 3 lung infection not associated with morphine. Other AEs were mild.

CONCLUSION

Oral morphine is effective in alleviating dyspnoea in Japanese COPD patients.Trial registrationUMIN000015288 (http://www.umin.ac.jp/ctr/index.htm).

Incident opioid drug use and adverse respiratory outcomes among older adults with COPD

We evaluated risk of adverse respiratory outcomes associated with incident opioid use among older adults with chronic obstructive pulmonary diseases (COPD).

This was a retrospective population-based cohort study using a validated algorithm applied to health administrative data to identify adults aged 66 years and older with COPD. Inverse probability of treatment weighting using the propensity score was used to estimate hazard ratios comparing adverse respiratory outcomes within 30 days of incident opioid use compared to controls.

Incident opioid use was associated with significantly increased emergency room visits for COPD or pneumonia (HR 1.14, 95% CI 1.00–1.29; p=0.04), COPD or pneumonia-related mortality (HR 2.16, 95% CI 1.61–2.88; p<0.0001) and all-cause mortality (HR 1.76, 95% CI 1.57–1.98; p<0.0001), but significantly decreased outpatient exacerbations (HR 0.88, 95% CI 0.83–0.94; p=0.0002). Use of more potent opioid-only agents was associated with significantly increased outpatient exacerbations, emergency room visits and hospitalisations for COPD or pneumonia, and COPD or pneumonia-related and all-cause mortality.

Incident opioid use, and in particular use of the generally more potent opioid-only agents, was associated with increased risk for adverse respiratory outcomes, including respiratory-related mortality, among older adults with COPD. Potential adverse respiratory outcomes should be considered when prescribing new opioids in this population.

Treatment Recommendations for Respiratory Symptoms in Cancer Patients: Clinical Guidelines from the Japanese Society for Palliative Medicine

BACKGROUND

Respiratory symptoms, dyspnea, cough, and death rattle, are common and distressing in advanced cancer patients. Palliation of respiratory symptoms is important to improve quality of life in cancer patients and their families/caregivers. Currently published clinical guidelines for the management of these respiratory symptoms in cancer patients did not cover the topics comprehensively or were not based on formal process for the development of clinical guidelines.

METHODS

The Japanese Society for Palliative Medicine (JSPM) decided to develop comprehensive clinical guidelines for the management of respiratory symptoms in cancer patients following the formal guideline developing process.

RESULTS

This article provides a summary of the recommendations with the rationales, as well as a short summary of the developing process, of the JSPM respiratory symptom management guidelines. We established 26 recommendations and all recommendations are based on the best available evidences and expert consensus.

DISCUSSION

More future clinical researches and continuous guideline updates are required to improve the quality of respiratory symptom management in cancer patients.

Pharmacological management of breathlessness in COPD: recent advances and hopes for the future

INTRODUCTION

Activity-related breathlessness is often the dominant symptom in patients with chronic obstructive pulmonary disease (COPD) and usually persists despite optimal medical therapy. Currently, our inability to meaningfully alter the pathophysiology of the underlying disease means that we must focus our attention on relieving this distressing symptom so as to improve exercise tolerance and quality of life.

AREAS COVERED

The current review examines the neurobiology of breathlessness and constructs a solid physiological rationale for amelioration of this distressing symptom. We will examine the efficacy of interventions which: 1) reduce the increased central drive to breathe (opioids); 2) improve the respiratory system's ability to appropriately respond to this increased demand (bronchodilators); and 3) address the important affective dimension of breathlessness (anxiolytics). Expert commentary: Advances in our understanding of the mechanisms of activity-related breathlessness in COPD, and its measurement in the clinical domain, now set the stage for the development of effective management strategies on an individual patient basis.

Opioids for the palliation of refractory breathlessness in adults with advanced disease and terminal illness

BACKGROUND

Breathlessness is a common and disabling symptom which affects many people with advanced cardiorespiratory disease and cancer. The most effective treatments are aimed at treating the underlying disease. However, this may not always be possible, and symptomatic treatment is often required in addition to maximal disease-directed therapy. Opioids are increasingly being used to treat breathlessness, although their mechanism of action is still not completely known. A few good sized, high quality trials have been conducted in this area.

OBJECTIVES

To determine the effectiveness of opioid drugs in relieving the symptom of breathlessness in people with advanced disease due to malignancy, respiratory or cardiovascular disease, or receiving palliative care for any other disease.

SEARCH METHODS

We performed searches on CENTRAL, MEDLINE, EMBASE, CINAHL, and Web of Science up to 19 October 2015. We handsearched review articles, clinical trial registries, and reference lists of retrieved articles.

SELECTION CRITERIA

We included randomised double-blind controlled trials that compared the use of any opioid drug against placebo or any other intervention for the relief of breathlessness. The intervention was any opioid, given by any route, in any dose.

DATA COLLECTION AND ANALYSIS

We imported studies identified by the search into a reference manager database. We retrieved the full-text version of relevant studies, and two review authors independently extracted data. The primary outcome measure was breathlessness and secondary outcome measures included exercise tolerance, oxygen saturations, adverse events, and mortality. We analysed all studies together and also performed subgroup analyses, by route of administration, type of opioid administered, and cause of breathlessness. Where appropriate, we performed meta-analysis. We assessed the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and created three 'Summary of findings' tables.

MAIN RESULTS

We included 26 studies with 526 participants. We assessed the studies as being at high or unclear risk of bias overall. We only included randomised controlled trials (RCTs), although the description of randomisation was incomplete in some included studies. We aimed to include double blind RCTs, but two studies were only single blinded. There was inconsistency in the reporting of outcome measures. We analysed the data using a fixed-effect model, and for some outcomes heterogeneity was high. There was a risk of imprecise results due to the low numbers of participants in the included studies. For these reasons we downgraded the quality of the evidence from high to either low or very low.For the primary outcome of breathlessness, the mean change from baseline dyspnoea score was 0.09 points better in the opioids group compared to the placebo group (ranging from a 0.36 point reduction to a 0.19 point increase) (seven RCTs, 117 participants, very low quality evidence). A lower score indicates an improvement in breathlessness. The mean post-treatment dyspnoea score was 0.28 points better in the opioid group compared to the placebo group (ranging from a 0.5 point reduction to a 0.05 point increase) (11 RCTs, 159 participants, low quality evidence).The evidence for the six-minute walk test (6MWT) was conflicting. The total distance in 6MWT was 28 metres (m) better in the opioids group compared to placebo (ranging from 113 m to 58 m) (one RCT, 11 participants, very low quality evidence). However, the change in baseline was 48 m worse in the opioids group (ranging from 36 m to 60 m) (two RCTs, 26 participants, very low quality evidence).The adverse effects reported included drowsiness, nausea and vomiting, and constipation. In those studies, participants were 4.73 times more likely to experience nausea and vomiting compared to placebo, three times more likely to experience constipation, and 2.86 times more likely to experience drowsiness (nine studies, 162 participants, very low quality evidence).Only four studies assessed quality of life, and none demonstrated any significant change.

AUTHORS' CONCLUSIONS

There is some low quality evidence that shows benefit for the use of oral or parenteral opioids to palliate breathlessness, although the number of included participants was small. We found no evidence to support the use of nebulised opioids. Further research with larger numbers of participants, using standardised protocols and with quality of life measures included, is needed.

Opioids: an unexplored option for treatment of dyspnea in IPF

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is the most common among the idiopathic interstitial pneumonias and has the worst prognosis, with a median survival of 3-5 years. The most common symptom in IPF is dyspnea, impacting on the patient's quality of life and life expectancy. Morphine in the treatment of dyspnea has been investigated but with conflicting results. This review aims to clarify the role of opioids in the treatment of dyspnea in patients with IPF.

METHODS

A literature search was performed using the MeSH and PubMed databases. As only very few studies included patients with IPF, studies conducted primarily with patients with chronic obstructive pulmonary disease were also included. In total, 14 articles were found.

RESULTS

Seven studies reported use of systemic morphine and seven studies of inhaled morphine. Five of the seven studies investigating systemic administration detected an improvement in either dyspnea or exercise capacity, whereas no beneficial effect on dyspnea was detected in any study using inhaled morphine. No severe adverse effects such as respiratory depression were reported in any study, although constipation was reported as a notable adverse effect.

CONCLUSIONS

Results were inconsistent, but in some studies systemic morphine administration showed a significant improvement in the dyspnea score on a visual analog scale without observation of severe side effects. Nebulized morphine had no effect on dyspnea.

Incident opioid drug use among older adults with chronic obstructive pulmonary disease: a population-based cohort study

AIMS

The purpose of the present study was to describe the scope, pattern and patient characteristics associated with incident opioid use among older adults with chronic obstructive pulmonary disease (COPD).

METHODS

This was a retrospective population-based cohort study using Ontario, Canada, healthcare administrative data. Study participants were individuals aged 66 years and older with physician-diagnosed COPD, identified using a validated algorithm, who were not receiving palliative care. We examined the incidence of oral opioid receipt between 1 April 2003 and 31 March 2012, as well as several patterns of incident opioid drug use.

RESULTS

Among 107,109 community-dwelling and 16,207 long-term care resident older adults with COPD, 72,962 (68.1%) and 8811 (54.4%), respectively, received an incident opioid drug during the observation period. Among long-term care residents, multiple opioid dispensings (8.8%), dispensings for >30 days' duration (up to 19.8%), second dispensings (35-43%) and early refills (24.2%) were observed. Incident opioid dispensing was also observed to occur during COPD exacerbations (6.9% among all long-term care residents; 18.1% among long-term care residents with frequent exacerbations). These same patterns of incident opioid use occurred among community-dwelling individuals, but with relatively lower frequencies.

CONCLUSIONS

New opioid use was high among older adults with COPD. Potential safety concerns are raised by the degree and pattern of new opioid use, but further studies are needed to evaluate if adverse events are associated with opioid drug use in this older and respiratory-vulnerable population.

Opioids, Exertion, and Dyspnea

The aim of this paper is to review the evidence for a role for opioids as an intervention for exertion induced breathlessness with regard to exercise tolerance and breathlessness intensity. Current knowledge about exogenous opioids in exertion-induced breathlessness due to disease comes from a variety of phase 2 feasibility or pilot designs with differing duration, doses, drugs, exercise regimes, underlying aetiologies, and outcome measures. They provide interesting data but firm conclusions for either breathlessness severity or exercise endurance cannot be drawn. There are no adequately powered phase 3 trials of opioids which show improved exercise tolerance and/or exertion induced breathlessness. Low dose oral morphine seems well tolerated by most, and is beneficial for breathlessness intensity. Current work to investigate the effect on exercise tolerance is ongoing.

Managing dyspnea in patients with advanced chronic obstructive pulmonary disease: a Canadian Thoracic Society clinical practice guideline

Dyspnea is a cardinal symptom of chronic obstructive pulmonary disease (COPD), and its severity and magnitude increases as the disease progresses, leading to significant disability and a negative effect on quality of life. Refractory dyspnea is a common and difficult symptom to treat in patients with advanced COPD. There are many questions concerning optimal management and, specifically, whether various therapies are effective in this setting. The present document was compiled to address these important clinical issues using an evidence-based systematic review process led by a representative interprofessional panel of experts. The evidence supports the benefits of oral opioids, neuromuscular electrical stimulation, chest wall vibration, walking aids and pursed-lip breathing in the management of dyspnea in the individual patient with advanced COPD. Oxygen is recommended for COPD patients with resting hypoxemia, but its use for the targeted management of dyspnea in this setting should be reserved for patients who receive symptomatic benefit. There is insufficient evidence to support the routine use of anxiolytic medications, nebulized opioids, acupuncture, acupressure, distractive auditory stimuli (music), relaxation, handheld fans, counselling programs or psychotherapy. There is also no evidence to support the use of supplemental oxygen to reduce dyspnea in nonhypoxemic patients with advanced COPD. Recognizing the current unfamiliarity with prescribing and dosing of opioid therapy in this setting, a potential approach for their use is illustrated. The role of opioid and other effective therapies in the comprehensive management of refractory dyspnea in patients with advanced COPD is discussed.

WITHDRAWN: Opioids for the palliation of breathlessness in advanced disease and terminal illness

BACKGROUND

Breathlessness is a common symptom in people with advanced disease. The most effective treatments are aimed at treating the underlying cause of the breathlessness but this may not be possible and symptomatic treatment is often necessary. Strategies for the symptomatic treatment of breathlessness have never been systematically evaluated. Opioids are commonly used to treat breathlessness: the mechanisms underlying their effectiveness are not completely clear and there have been few good-sized trials in this area.

OBJECTIVES

To determine the effectiveness of opioid drugs given by any route in relieving the symptom of breathlessness in patients who are being treated palliatively.

SEARCH METHODS

An electronic search was carried out of Medline, Embase, CINAHL, T he Cochrane L ibrary, Dissertation Abstracts, Cancercd and SIGLE. Review articles and reference lists of retrieved articles were hand searched. Date of most recent search: May 1999.

SELECTION CRITERIA

Randomised double-blind, controlled trials comparing the use of any opioid drug against placebo for the relief of breathlessness were included. Patients with any illness suffering from breathlessness were included and the intervention was any opioid, given by any route, in any dose.

DATA COLLECTION AND ANALYSIS

Studies identified by the search were imported into a reference manager database. The full texts of the relevant studies were retrieved and data were independently extracted by two review authors. Studies were quality scored according to the Oxford Quality scale. The primary outcome measure used was breathlessness and the secondary outcome measure was exercise tolerance. Studies were divided into non-nebulised and nebulised and were analysed both separately and together. A qualitative analysis was carried out of adverse effects of opioids. Where appropriate, meta-analysis was carried out.

MAIN RESULTS

Eighteen studies were identified of which nine involved the non-nebulised route of administration and nine the nebulised route. A small but statistically significant positive effect of opioids was seen on breathlessness in the analysis of studies using non-nebulised opioids. There was no statistically significant positive effect seen for exercise tolerance in either group of studies or for breathlessness in the studies using nebulised opioids.

AUTHORS' CONCLUSIONS

There is evidence to support the use of oral or parenteral opioids to palliate breathlessness although numbers of patients involved in the studies were small. No evidence was found to support the use of nebulised opioids. Further research with larger numbers of patients, using standardised protocols and with quality of life measures is needed.

Effect of nebulized morphine on dyspnea of mustard gas-exposed patients: a double-blind randomized clinical trial study

Background. Dyspnea is one of the main complaints in a group of COPD patients due to exposure to sulfur mustard (SM) and is refractory to conventional therapies. We designed this study to evaluate effectiveness of nebulized morphine in such patients. Materials and Methods. In a double-blind clinical trial study, 40 patients with documented history of exposure to SM were allocated to two groups: group 1 who received 1 mg morphine sulfate diluted by 4 cc normal saline 0.5% using nebulizer once daily for 5 days and group 2 serving as control who received normal saline as placebo. They were visited by pulmonologist 7 times per day to check symptoms and signs and adverse events. Different parameters including patient-scored peak expiratory flow using pick flow meter, visual analogue scale (VAS) for dyspnea, global quality of life and cough, and number of respiratory rate, night time awaking for dyspnea and cough have been assessed. Results. The scores of VAS for dyspnea, cough and quality of life and also respiratory rate, heart rate, and night time awaking due to dyspnea and night time awaking due to cough improved significantly after morphine nebulization without any major adverse events. Also pick expiratory flow has been improved significantly after nebulization in each day. Conclusion. Our results showed the clinical benefit of nebulized morphine on respiratory complaints of patients due to exposure to SM without significant side effects.

An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea

BACKGROUND

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.

PURPOSE

The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.

METHODS

An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.

RESULTS

Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.

CONCLUSIONS

Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.

An official American Thoracic Society statement: update on the mechanisms, assessment, and management of dyspnea

BACKGROUND

Dyspnea is a common, distressing symptom of cardiopulmonary and neuromuscular diseases. Since the ATS published a consensus statement on dyspnea in 1999, there has been enormous growth in knowledge about the neurophysiology of dyspnea and increasing interest in dyspnea as a patient-reported outcome.

PURPOSE

The purpose of this document is to update the 1999 ATS Consensus Statement on dyspnea.

METHODS

An interdisciplinary committee of experts representing ATS assemblies on Nursing, Clinical Problems, Sleep and Respiratory Neurobiology, Pulmonary Rehabilitation, and Behavioral Science determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant expertise. The final content of this statement was agreed upon by all members.

RESULTS

Progress has been made in clarifying mechanisms underlying several qualitatively and mechanistically distinct breathing sensations. Brain imaging studies have consistently shown dyspnea stimuli to be correlated with activation of cortico-limbic areas involved with interoception and nociception. Endogenous and exogenous opioids may modulate perception of dyspnea. Instruments for measuring dyspnea are often poorly characterized; a framework is proposed for more consistent identification of measurement domains.

CONCLUSIONS

Progress in treatment of dyspnea has not matched progress in elucidating underlying mechanisms. There is a critical need for interdisciplinary translational research to connect dyspnea mechanisms with clinical treatment and to validate dyspnea measures as patient-reported outcomes for clinical trials.

Using laboratory models to test treatment: morphine reduces dyspnea and hypercapnic ventilatory response

RATIONALE

Opioids are commonly used to relieve dyspnea, but clinical data are mixed and practice varies widely.

OBJECTIVES

Evaluate the effect of morphine on dyspnea and ventilatory drive under well-controlled laboratory conditions.

METHODS

Six healthy volunteers received morphine (0.07 mg/kg) and placebo intravenously on separate days (randomized, blinded). We measured two responses to a CO(2) stimulus: (1) perceptual response (breathing discomfort; described by subjects as "air hunger") induced by increasing partial pressure of end-tidal carbon dioxide (Pet(CO2)) during restricted ventilation, measured with a visual analog scale (range, "neutral" to "intolerable"); and (2) ventilatory response, measured in separate trials during unrestricted breathing.

MEASUREMENTS AND MAIN RESULTS

We determined the Pet(CO2) that produced a 60% breathing discomfort rating in each subject before morphine (median, 8.5 mm Hg above resting Pet(CO2)). At the same Pet(CO2) after morphine administration, median breathing discomfort was reduced by 65% of its pretreatment value; P < 0.001. Ventilation fell 28% at the same Pet(CO2); P < 0.01. The effect of morphine on breathing discomfort was not significantly correlated with the effect on ventilatory response. Placebo had no effect.

CONCLUSIONS

(1) A moderate morphine dose produced substantial relief of laboratory dyspnea, with a smaller reduction of ventilation. (2) In contrast to an earlier laboratory model of breathing effort, this laboratory model of air hunger established a highly significant treatment effect consistent in magnitude with clinical studies of opioids. Laboratory studies require fewer subjects and enable physiological measurements that are difficult to make in a clinical setting. Within-subject comparison of the response to carefully controlled laboratory stimuli can be an efficient means to optimize treatments before clinical trials.

Palliative management of refractory dyspnea in COPD

COPD is a progressive illness with worldwide impact. Patients invariably reach a point at which they require palliative interventions. Dyspnea is the most distressing symptom experienced by these patients; when not relieved by traditional COPD management strategies it is termed "refractory dyspnea" and palliative approaches are required. The focus of care shifts from prolonging survival to reducing symptoms, increasing function, and improving quality of life. Numerous pharmacological and non-pharmacological interventions can achieve these goals, though evidence supporting their use is variable. This review provides a summary of the options for the management of refractory dyspnea in COPD, outlining currently available evidence and highlighting areas for further investigation. Topics include oxygen, opioids, psychotropic drugs, inhaled furosemide, Heliox, rehabilitation, nutrition, psychosocial support, breathing techniques, and breathlessness clinics.

[Limiting factors of exercise capacity in patients with COPD]

Chronic Obstructive Pulmonary Disease (COPD) is a major cause of morbidity and mortality worldwide. Moderate to severe COPD patients demonstrate severe impairments in exercise performance in daily activities, significantly affecting their quality of life. There are several causes for this limitation found in literature: air-flow limitation, lung hyperinflation, respiratory and peripheral muscles weakness, among others. In this study we intended to identify the potentially relevant factors that influence exercise performance in a group of moderate to severe COPD patients. We studied 24 male patients, 64,13 + 8,46 years old (46-83 years), FEV1: 46,96 + 12,99% predicted, FRC: 144,71 + 26,86% predicted, DLCO: 69,88 + 16,49 % predicted, PaO2: 78,25 + 7,82 mmHg, PaCO2: 40,78 + 4,28 mmHg. Patients performed an incremental symptom-limited cycle exercise. We correlated rest and exercise lung function parameters with peak oxygen uptake, maximal work rate and time span to exertion. The main contributors to exercise limitation were gas exchange abnormalities, ventilatory limitation and smaller values of body mass index. Rest lung hyperinflation didn't correlate with exercise performance. Dynamic exercise hyperinflation contributed greatly to exercise intolerance, through progressive restriction to tidal volume expansion necessary to deal with increasing exercise metabolic demands. Rest lung function parameters didn't correlate with exercise performance, stressing the importance of cardio-pulmonary exercise testing in the detection of exercise limitation factors in each patient. The identification of exercise limitation factors will certainly contribute to towards defining the best therapeutic approach in COPD patients.

Development of a directly compressible poly(ethylene oxide) matrix for the sustained-release of dihydrocodeine bitartrate

The purpose of this study was to design and evaluate a directly compressible hydrophilic poly(ethylene oxide) (PEO) matrix for the oral sustained delivery of dihydrocodeine bitartrate (DHCT). A direct compression method was used to prepare PEO matrices, and the amount of PEO in the matrices was varied to optimize in vitro DHCT release profiles. In vitro release studies indicated that the matrices containing 20%-70% w/w of PEO with molecular weight of 5.0 x 10(6) showed a similar release profile, as estimated with DT50%, to that exhibited by a marketed product, DHC Continus. In vivo bioavailability study revealed that the difference in the pharmacokinetic parameters such as AUC0-30 and Tmax of the selected sustained-release formulation containing 60% w/w of PEO 5.0 x 10(6) and DHC Continus was statistically insignificant (p > 0.05). Thus, it could be concluded that the extent of bioavailability of the sustained-release formulation developed here was similar to that of DHC Continus although Cmax values of these two preparations were significantly different (p < 0.05). From the data obtained in this research, hydrophilic PEO matrices were found to be a novel sustained-release carrier for the oral delivery of DHCT.

Opioids, respiratory function, and dyspnea

Dyspnea, the sensation of difficult breathing, is a common debilitating symptom in advanced cancer and chronic progressive cardiopulmonary disease. Primary treatment is correction of the underlying etiology. In incurable illness wherein the cause is irreversible and the goal is palliation, opioids are the drugs of choice for symptomatic relief. This article reviews current knowledge in the pathophysiology of dyspnea, proposed opioid mechanism of action, and evidence of efficacy.

A systematic review of the use of opioids in the management of dyspnoea

BACKGROUND

Opioids are commonly used to treat dyspnoea in palliative medicine but there has been no formal evaluation of the evidence for their effectiveness in the treatment of dyspnoea. A systematic review was therefore carried out to examine this.

METHODS

The criteria for inclusion required that studies were double blind, randomised, placebo controlled trials of opioids for the treatment of dyspnoea secondary to any cause. The methods used to identify suitable studies included electronic searching of the literature, hand searching of the literature, and personal contact with relevant individuals and organisations. Random effects meta-analyses were performed on all included studies and on various subgroups (studies involving nebulised opioids or patients with chronic obstructive pulmonary disease (COPD)). Subgroups were compared using meta-regression. Some studies included in the systematic review could not be included in the meta-analysis because insufficient data were presented.

RESULTS

Eighteen studies fulfilled the criteria for the review. The meta-analysis showed a statistically significant positive effect of opioids on the sensation of breathlessness (p=0.0008). Meta-regression indicated a greater effect for studies using oral or parenteral opioids than for studies using nebulised opioids (p=0.02). The subgroup analysis failed to show a positive effect of nebulised opioids on the sensation of breathlessness. The results of the subgroup analysis of the COPD studies were essentially similar to the results of the main analysis.

CONCLUSION

This review supports the continued use of oral and parenteral opioids to treat dyspnoea in patients with advanced disease. There are insufficient data from the meta-analysis to conclude whether nebulised opioids are effective, but the results from included studies that did not contribute to the meta-analysis suggest that they are no better than nebulised normal saline.

Palliative care of the chronically critically ill patient

Evidence is accumulating that distressing physical and emotional symptoms are prevalent among patients with critical illness, including those requiring prolonged mechanical ventilation, and that suffering is underestimated and undertreated by caregivers. Although patients and their families rank communication as a preeminent concern, it remains deficient in process and content, even when the illness requires weeks of critical care. Strategies are available to improve symptom management and communication about appropriate goals of care. For the CCI, whose risks of death, disability, and suffering are so high, it is essential that excellent palliative care be provided along with restorative treatment in an integrated way.

Managing dyspnea and cough

Dyspnea, like pain, is a subjective experience that incorporates physical elements and affective components. Management of breathlessness in patients with cancer requires expertise that includes an understanding and assessment of the multidimensional components of the symptom, knowledge of the pathophysiologic mechanisms and clinical syndromes that are common in cancer, and familiarity with the indications and limitations of the available therapeutic approaches. Relief of breathlessness should be the goal of treatment at all stages of cancer. Good control of dyspnea will improve the patient's quality of life.

Meta-analyses involving cross-over trials: methodological issues

BACKGROUND

Meta-analysis of randomized controlled trials (RCTs) is usually based on trials where patients are randomized individually into two different, parallel, treatment groups. This paper concentrates on RCTs of a different design-two-period, two-treatment cross-over trials.

METHODS

The characteristics of these trials are outlined, with detailed examples of methods for analysis for both continuous and binary data. These case studies are then extended into the context of a meta-analysis. The Cochrane Library was surveyed to assess current practice for synthesis.

RESULTS

Methods are described for continuous and binary data for use both when the necessary paired data are given and also when they need to be calculated or imputed, and some suggestions are provided to help people wishing to synthesize data from cross-over trials into meta-analyses. The survey suggested that about 8% of the trials in the Cochrane library were cross-over trials and 18% of the reviews referred to such trials, although there was no consistent approach to their inclusion into the reviews.

CONCLUSIONS

Methods do exist for including valuable information from two-period, two-treatment cross-over trials into quantitative reviews. However, poor reporting of cross-over trials will often impede attempts to perform a meta-analysis using the available methods.

Nebulized fentanyl citrate improves patients' perception of breathing, respiratory rate, and oxygen saturation in dyspnea

Dyspnea, a subjective symptom of impaired breathing, occurs in 70% of terminally ill cancer patients. Current treatments are suboptimal and little is known about the patient's perception of effect. We tested nebulized inhaled fentanyl citrate on patient perceptions, respiratory rate, and oxygen saturation. The study was conducted using a convenience sample of 35 cancer patients on a dedicated oncology unit. We assessed patient perception (did breathing stay the same, worsen, or improve), respiratory rate, and oxygen saturation by pulse oximetry at baseline, 5 minutes, and 60 minutes. Twenty-six of 32 (81%) patients reported improvement in breathing, 3 (9%) were unsure, and 3 (9%) reported no improvement. Oxygen saturation improved from 94.6% at baseline to 96.8% at 5 minutes and 96.7% at 60 minutes (P = 0.0069 compared to baseline). Respiratory rates improved from a baseline of 28.4/min to 25.9/min at 5 minutes and 24.1/min at 60 minutes (P = 0.0251 compared to baseline). No side effects were observed. Inhaled nebulized fentanyl citrate significantly improved patient perception of breathing, respiratory rate, and oxygen saturation. This inexpensive and readily available treatment may offer substantial relief of end-of-life dyspnea. Randomized trials, dose, and length of effect trials are underway.

Opioids for the palliation of breathlessness in terminal illness

BACKGROUND

Breathlessness is a common symptom in people with advanced disease. The most effective treatments are aimed at treating the underlying cause of the breathlessness but this may not be possible and symptomatic treatment is often necessary. Strategies for the symptomatic treatment of breathlessness have never been systematically evaluated. Opioids are commonly used to treat breathlessness: the mechanisms underlying their effectiveness are not completely clear and there have been few good-sized trials in this area.

OBJECTIVES

To determine the effectiveness of opioid drugs given by any route in relieving the symptom of breathlessness in patients who are being treated palliatively.

SEARCH STRATEGY

An electronic search was carried out of Medline, Embase, Cinahl, the Cochrane library, Dissertation Abstracts, Cancercd and SIGLE. Review articles and reference lists of retrieved articles were hand searched. Date of most recent search: May 1999

SELECTION CRITERIA

Randomised double-blind, controlled trials comparing the use of any opioid drug against placebo for the relief of breathlessness were included. Patients with any illness suffering from breathlessness were included and the intervention was any opioid, given by any route, in any dose.

DATA COLLECTION AND ANALYSIS

Studies identified by the search were imported into a reference manager database. The full texts of the relevant studies were retrieved and data were independently extracted by two reviewers. Studies were quality scored according to the Jadad scale. The primary outcome measure used was breathlessness and the secondary outcome measure was exercise tolerance. Studies were divided into non-nebulised and nebulised and were analysed both separately and together. A qualitative analysis was carried out of adverse effects of opioids. Where appropriate, meta-analysis was carried out.

MAIN RESULTS

Eighteen studies were identified of which nine involved the non-nebulised route of administration and nine the nebulised route. A small but statistically significant positive effect of opioids was seen on breathlessness in the analysis of studies using non-nebulised opioids. There was no statistically significant positive effect seen for exercise tolerance in either group of studies or for breathlessness in the studies using nebulised opioids.

REVIEWER'S CONCLUSIONS

There is evidence to support the use of oral or parenteral opioids to palliate breathlessness although numbers of patients involved in the studies were small. No evidence was found to support the use of nebulised opioids. Further research with larger numbers of patients, using standardised protocols and with quality of life measures is needed.

Lung opioid receptors: pharmacology and possible target for nebulized morphine in dyspnea

Opioid receptors are located throughout the respiratory tract. Yet, these have received relatively scant attention compared to other opioid receptors. The most abundant sites within the respiratory tract appear localized within the alveolar walls, other sites appear to line the smooth muscle within the trachea and main bronchi near the lumen. There is about 100-times greater [3H]morphine binding density within the bronchioles and lobes than in the main bronchi or trachea. In addition to the usual mu, delta and kappa types of opioid receptors, 'non-conventional' opioid binding sites have been suggested, although the function of these or of the other opioid receptors in the pulmonary tract is not known. However, they might explain the otherwise counterintuitive apparent utility of morphine treatment of dyspnea. Dyspnea is a common and distressing symptom in terminally-ill cancer patients and patients with chronic lung disease. It results from multiple causes, is difficult to treat and is a significant precipitating factor for late-stage hospital or hospice admissions. Nebulized morphine or other opioids have been reported to have beneficial effect, but the mechanism by which opioids might produce this seemingly contradictory effect is not clear. We review here lung opioid receptor distribution, pharmacology and possible clinical relevance in the treatment of dyspnea.

Management of dyspnea in severe chronic obstructive pulmonary disease

Progression of chronic obstructive pulmonary disease (COPD) is frequently associated with increasing dyspnea; indeed, patients with severe COPD constitute the largest group of patients with chronic respiratory insufficiency. The sensation of dyspnea in these patients is mostly related to increased work of breathing, a consequence of an increased resistive load, of hyperinflation, and of the deleterious effect of intrinsic positive end-expiratory pressure (PEEP(i)). Once optimal medical treatment has been provided, pharmacological treatments of dyspnea exist (beta2-agonists, methylxanthines, opiates) but seldom suffice. Nonpharmacological complementary treatments must be envisioned. Patients with severe hyperinflation should be screened as possible candidates for lung reduction surgery. Pulmonary rehabilitation-including chest therapy, patient education, exercise training-has been established as effective on quality of life (QoL) and dyspnea. Noninvasive positive pressure devices may be effective for symptomatic treatment of severe dyspnea: continuous positive airway pressure (CPAP) counteracts the deleterious effect of PEEP(i) in patients with severe hyperinflation; intermittent positive pressure breathing (IPPB) may decrease dyspnea and discomfort during nebulized therapy; finally noninvasive positive pressure ventilation (NIPPV) has been shown to be effective on the sensation of dyspnea and QoL in COPD with severe hypercapnia.

The effects of morphine on dyspnea and ventilatory function in elderly patients with advanced cancer: a randomized double-blind controlled trial

BACKGROUND

Dyspnea represents a very frequent and distressing symptom in patients with advanced cancer. This study was undertaken to assess the efficacy of morphine on dyspnea and its safety for ventilatory function in elderly advanced cancer patients.

PATIENTS AND METHODS

Nine elderly patients with dyspnea due to lung involvement were randomized to receive either morphine subcutaneously (5 mg in seven opioid-naïve patients and 3.75 mg in two patients on top of their regular oral dose of 7.5 mg q4 h) or placebo on day 1. On day 2, they were crossed over to receive the alternate treatment. Dyspnea was assessed every fifteen minutes using a visual analogue scale (VAS: 0-100 mm) and the ordinal scale developed by Borg (0-10 points). Pain, somnolence and anxiety were assessed using VAS. Respiratory effort, respiratory rate and oxygen saturation were also measured repeatedly.

RESULTS

Mean changes in dyspnea 45 minutes after injection were -25 +/- 10 mm and -1.2 +/- 1.2 points for morphine, versus 0.6 +/- 7.7 mm (P < 0.01) and -0.1 +/- 0.3 points (P = 0.03) for placebo on VAS and Borg scale, respectively. No relevant changes were observed in somnolence, pain, anxiety, respiratory effort and rate, and oxygen saturation.

CONCLUSIONS

Morphine appears effective for cancer dyspnea, and it does not compromise respiratory function at the dose level used.