A randomised, double-blind controlled trial of intranasal midazolam for the palliation of dyspnoea in patients with life-limiting disease

Pharmacologic Interventions for Breathlessness in Patients With Advanced Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

Improved survival in patients with advanced cancer has increased the need for better understanding of how to manage common symptoms that they may experience, such as breathlessness.

OBJECTIVE

To assess the benefits and harms associated with pharmacologic interventions for breathlessness in adults with advanced cancer.

DATA SOURCES

PubMed, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for studies published from database inception through May 31, 2020, using predefined eligibility criteria within a PICOTS (population, intervention, comparator, outcome, timing, setting) format.

STUDY SELECTION

Randomized clinical trials (RCTs), non-RCTs, and observational studies with a comparison group that evaluated benefits and/or harms and cohort studies that reported harms were selected.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened studies for eligibility, serially abstracted data, independently assessed risk of bias, and graded strength of evidence (SOE).

MAIN OUTCOMES AND MEASURES

Benefits and harms of pharmacologic interventions were compared, focusing on breathlessness, anxiety, exercise capacity, and health-related quality of life. When possible, meta-analyses were conducted and standardized mean differences (SMDs) calculated.

RESULTS

In this systematic review and meta-analysis, a total of 7729 unique citations were identified, of which 19 studies (17 RCTs and 2 retrospective studies) that included a total of 1424 patients assessed the benefits of medications for management of breathlessness in advanced cancer or reported harms. The most commonly reported type of cancer was lung cancer. Opioids were not associated with more effectiveness than placebo for improving breathlessness (SMD, -0.14; 95% CI, -0.47 to 0.18) or exercise capacity ( SMD, 0.06; 95% CI, -0.43 to 0.55) (SOE, moderate); most studies examined exertional breathlessness. Specific dose and/or route of administration of opioids did not differ in effectiveness for breathlessness (SMD, 0.15; 95% CI, -0.22 to 0.52) (SOE, low). Anxiolytics were not associated with more effectiveness than placebo for breathlessness or anxiety (reported mean between-group difference, -0.52; 95% CI, -1.045 to 0.005) (SOE, low). Evidence for other pharmacologic interventions was limited. Pharmacologic interventions demonstrated some harms compared with usual care, but dropout attributable to adverse events was minimal in these short-term studies (range 3.2%-16%).

CONCLUSIONS AND RELEVANCE

Evidence did not support the association of opioids or other pharmacologic interventions with improved breathlessness. Given that studies had many limitations, pharmacologic interventions should be considered in selected patients but need to be considered in the context of potential harms and evidence of an association of nonpharmacologic interventions with improved breathlessness.

Midazolam: an essential palliative care drug

Midazolam is a commonly used benzodiazepine in palliative care and is considered one of the four essential drugs needed for the promotion of quality care in dying patients. Acting on the benzodiazepine receptor, it promotes the action of gamma-aminobutyric acid. Gamma-aminobutyric acid action promotes sedative, anxiolytic, and anticonvulsant properties. Midazolam has a faster onset and shorter duration of action than other benzodiazepines such as diazepam and lorazepam lending itself to greater flexibility in dosing than other benzodiazepines. The kidneys excrete midazolam and its active metabolite. Metabolism occurs in the liver by the P450 system. This article examines the pharmacology, pharmacodynamics, and clinical uses of midazolam in palliative care.

Are the MORECare guidelines on reporting of attrition in palliative care research populations appropriate? A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Palliative care trials have higher rates of attrition. The MORECare guidance recommends applying classifications of attrition to report attrition to help interpret trial results. The guidance separates attrition into three categories: attrition due to death, illness or at random. The aim of our study is to apply the MORECare classifications on reported attrition rates in trials.

METHODS

A systematic review was conducted and attrition classifications retrospectively applied. Four databases, EMBASE; Medline, CINHAL and PsychINFO, were searched for randomised controlled trials of palliative care populations from 01.01.2010 to 08.10.2016. This systematic review is part of a larger review looking at recruitment to randomised controlled trials in palliative care, from January 1990 to early October 2016. We ran random-effect models with and without moderators and descriptive statistics to calculate rates of missing data.

RESULTS

One hundred nineteen trials showed a total attrition of 29% (95% CI 28 to 30%). We applied the MORECare classifications of attrition to the 91 papers that contained sufficient information. The main reason for attrition was attrition due to death with a weighted mean of 31.6% (SD 27.4) of attrition cases. Attrition due to illness was cited as the reason for 17.6% (SD 24.5) of participants. In 50.8% (SD 26.5) of cases, the attrition was at random. We did not observe significant differences in missing data between total attrition in non-cancer patients (26%; 95% CI 18-34%) and cancer patients (24%; 95% CI 20-29%). There was significantly more missing data in outpatients (29%; 95% CI 22-36%) than inpatients (16%; 95% CI 10-23%). We noted increased attrition in trials with longer durations.

CONCLUSION

Reporting the cause of attrition is useful in helping to understand trial results. Prospective reporting using the MORECare classifications should improve our understanding of future trials.

Fentanyl treatment for end-of-life dyspnoea relief in advanced cancer patients

PURPOSE

We assessed the effects of subcutaneous-endovenous fentanyl on dyspnoea in a cohort of advanced cancer patients.

METHODS

We performed a retrospective study in a cohort of advanced cancer patients with dyspnoea at rest who received subcutaneous or intravenous fentanyl. Patients with no shortness of breath at rest or at minimal exertion, no rescue doses per 24 h, were deemed to be responders to fentanyl. The period of assessment was 6 days from the beginning of fentanyl treatment.

RESULTS

Seventy-two patients were evaluated: 65% males, 50% ≥ 75 years, Palliative Performance Scale (PPS) median of 30%. Seventy-six percent of the patients were responders to fentanyl. Fentanyl efficacy was not statistically related to age, gender, cancer type, previous opioid treatment, steroid and midazolam doses and PPS. The median fentanyl dose in responders was 25 mcg/h (interquartile range 12-70). It was significantly related to age (37 vs 12 mcg/h, for ≤ 75 vs > 75 years, respectively; p = 0.02). There was not a significant difference between fentanyl doses of responders and non-responder patients. Thirty-six, 23 and 15 patients had sustained improvements in dyspnoea over 48, 72 and 96 h. Fentanyl had no significant toxicity. The length of inclusion in the study and exclusion were related to low performance status (hazard ratio 0.961; _95%CI 0.927-0.996; Cox-regression) but not to fentanyl doses (hazard ratio 0.875; _95%CI 0.620-1.234; Cox-regression).

CONCLUSION

Our preliminary data suggest that subcutaneous-endovenous fentanyl may be associated with dyspnoea relief in dying patients. Further research is needed to confirm these findings.

Pharmacological Management of People Living with End-Stage Chronic Obstructive Pulmonary Disease

Supportive care and pharmacological treatment can improve the quality of life of people with end-stage chronic obstructive pulmonary disease (COPD) who cope on a daily basis with substantial physical, psychological, social and spiritual morbidity. Smoking cessation is the only intervention that reduces the rate of progression of COPD, but evidence-based drug treatments and non-pharmacological strategies can relieve symptoms and reduce the impact of exacerbations. People with severe COPD live with increasingly troublesome breathlessness and other symptoms such as fatigue, pain, sputum production and weight loss. As breathlessness increases, treatment is stepped up from short-acting to long-acting bronchodilators supplemented by non-pharmacological interventions such as pulmonary rehabilitation. Opiates relieve breathlessness, and referral to a multidisciplinary breathlessness service is an option for those with intractable symptoms. Other smoking-related conditions, such as coronary heart disease and lung cancer as well as depression and anxiety are common and should be treated with conventional pharmacotherapy. Acute exacerbations become more frequent and more severe as the disease reaches end-stage. Inhaled corticosteroids in combination with long-acting bronchodilators can reduce the frequency of exacerbations, and supported self-management aims to facilitate timely treatment of deterioration. Palliative care services have traditionally been predicated on identifying people with end-stage disease-a model that does not resonate with the unpredictable, relapsing trajectory of COPD. Approaches to care that promote a flexible approach to palliation alongside curative care could do much to improve the burden of living with severe COPD.

Benzodiazepines for the relief of breathlessness in advanced malignant and non-malignant diseases in adults

BACKGROUND

This is an updated version of the original Cochrane review published in Issue 1, 2010, on 'Benzodiazepines for the relief of breathlessness in advanced malignant and non-malignant diseases in adults'. Breathlessness is one of the most common symptoms experienced in the advanced stages of malignant and non-malignant disease. Benzodiazepines are widely used for the relief of breathlessness in advanced diseases and are regularly recommended in the literature. At the time of the previously published Cochrane review, there was no evidence for a beneficial effect of benzodiazepines for the relief of breathlessness in people with advanced cancer and chronic obstructive pulmonary disease (COPD).

OBJECTIVES

The primary objective of this review was to determine the efficacy of benzodiazepines for the relief of breathlessness in people with advanced disease. Secondary objectives were to determine the efficacy of different benzodiazepines, different doses of benzodiazepines, different routes of application, adverse effects of benzodiazepines, and the efficacy in different disease groups.

SEARCH METHODS

This is an update of a review published in 2010. We searched 14 electronic databases up to September 2009 for the original review. We checked the reference lists of all relevant studies, key textbooks, reviews, and websites. For the update, we searched CENTRAL, MEDLINE, and EMBASE and registers of clinical trials for further ongoing or unpublished studies, up to August 2016. We contacted study investigators and experts in the field of palliative care asking for further studies, unpublished data, or study details when necessary.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) assessing the effect of benzodiazepines compared with placebo or active control in relieving breathlessness in people with advanced stages of cancer, chronic obstructive pulmonary disease (COPD), chronic heart failure (CHF), motor neurone disease (MND), and idiopathic pulmonary fibrosis (IPF).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified titles and abstracts. Three review authors independently performed assessment of all potentially relevant studies (full text), data extraction, and assessment of methodological quality. We carried out meta-analysis where appropriate.

MAIN RESULTS

Overall, we identified eight studies for inclusion: seven in the previous review and an additional study for this update. We also identified two studies awaiting classification in this update. The studies were small (a maximum number of 101 participants) and comprised data from a total of 214 participants with advanced cancer or COPD, which we analysed. There was only one study of low risk of bias. Most of the studies had an unclear risk of bias due to lack of information on random sequence generation, concealment, and attrition. Analysis of all studies did not show a beneficial effect of benzodiazepines for the relief of breathlessness (the primary outcome) in people with advanced cancer and COPD (8 studies, 214 participants) compared to placebo, midazolam, morphine, or promethazine. Furthermore, we observed no statistically significant effect in the prevention of episodic breathlessness (breakthrough dyspnoea) in people with cancer (after 48 hours: risk ratio of 0.76 (95% CI 0.53 to 1.09; 2 studies, 108 participants)) compared to morphine. Sensitivity analyses demonstrated no statistically significant differences regarding type of benzodiazepine, dose, route and frequency of delivery, duration of treatment, or type of control. Benzodiazepines caused statistically significantly more adverse events, particularly drowsiness and somnolence, when compared to placebo (risk difference 0.74 (95% CI 0.37, 1.11); 3 studies, 38 participants). In contrast, two studies reported that morphine caused more adverse events than midazolam (RD -0.18 (95% CI -0.31, -0.04); 194 participants).

AUTHORS' CONCLUSIONS

Since the last version of this review, we have identified one new study for inclusion, but the conclusions remain unchanged. There is no evidence for or against benzodiazepines for the relief of breathlessness in people with advanced cancer and COPD. Benzodiazepines caused more drowsiness as an adverse effect compared to placebo, but less compared to morphine. Benzodiazepines may be considered as a second- or third-line treatment, when opioids and non-pharmacological measures have failed to control breathlessness. There is a need for well-conducted and adequately powered studies.

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.