Re: nebulized furosemide for dyspnea in terminal cancer patients

Prophylaxis and treatment of cancer-related dyspnea with pharmacologic agents: A systematic review and network meta-analysis

INTRODUCTION

Cancer-related dyspnea is a common symptom in patients with cancer. It has also been reported to be a predictor of poorer prognosis, which can then change clinical treatment and advance care planning. Currently, no definitive recommendation for pharmacologic agents for cancer-related dyspnea exists. The aim of this systematic review and network meta-analysis is to compare pharmacologic agents for the prophylaxis and treatment of cancer-related dyspnea.

METHODS

A search was conducted in the databases of PubMed, Embase, and Cochrane CENTRAL through May 2021. Standardized mean differences (SMDs), as reported by studies or calculated from baseline and follow-up dyspnea scores, were amalgamated into a summary SMD and 95% confidence interval (CI) using a restricted maximum likelihood multivariate network meta-analysis.

RESULTS

Twelve studies were included in this review; six reported on prophylaxis of exertional dyspnea, five on treatment of everyday dyspnea, and one on treatment of episodic dyspnea. Morphine sulfate was better at controlling everyday dyspnea than placebo (SMD 1.210; 95% CI: 0.415-2.005). Heterogeneity in study design and comparisons, however, led to some concerns with the underlying consistency assumption in network meta-analysis design.

CONCLUSION

Optimal pharmacologic interventions for cancer-related dyspnea could not be determined based on this analysis. Further trials are needed to report on the efficacy of pharmacologic interventions for the prophylaxis and treatment of cancer-related dyspnea.

Management of Dyspnea in Advanced Cancer: ASCO Guideline

PURPOSE

To provide guidance on the clinical management of dyspnea in adult patients with advanced cancer.

METHODS

ASCO convened an Expert Panel to review the evidence and formulate recommendations. An Agency for Healthcare Research and Quality (AHRQ) systematic review provided the evidence base for nonpharmacologic and pharmacologic interventions to alleviate dyspnea. The review included randomized controlled trials (RCTs) and observational studies with a concurrent comparison group published through early May 2020. The ASCO Expert Panel also wished to address dyspnea assessment, management of underlying conditions, and palliative care referrals, and for these questions, an additional systematic review identified RCTs, systematic reviews, and guidelines published through July 2020.

RESULTS

The AHRQ systematic review included 48 RCTs and two retrospective cohort studies. Lung cancer and mesothelioma were the most commonly addressed types of cancer. Nonpharmacologic interventions such as fans provided some relief from breathlessness. Support for pharmacologic interventions was limited. A meta-analysis of specialty breathlessness services reported improvements in distress because of dyspnea.

RECOMMENDATIONS

A hierarchical approach to dyspnea management is recommended, beginning with dyspnea assessment, ascertainment and management of potentially reversible causes, and referral to an interdisciplinary palliative care team. Nonpharmacologic interventions that may be offered to relieve dyspnea include airflow interventions (eg, a fan directed at the cheek), standard supplemental oxygen for patients with hypoxemia, and other psychoeducational, self-management, or complementary approaches. For patients who derive inadequate relief from nonpharmacologic interventions, systemic opioids should be offered. Other pharmacologic interventions, such as corticosteroids and benzodiazepines, are also discussed. Additional information is available at www.asco.org/supportive-care-guidelines .

Is Inhaled Furosemide a Potential Therapeutic for COVID-19?

The potentially lethal infection caused by the novel Severe Acute Respiratory Disease Coronavirus-2 (SARS-CoV-2) has evolved into a global crisis. Following the initial viral infection is the host inflammatory response that frequently results in excessive secretion of inflammatory cytokines (e.g., IL-6 and TNFα), developing into a self-targeting, toxic "cytokine storm" causing critical pulmonary tissue damage. The need for a therapeutic that is available immediately is growing daily but the de novo development of a vaccine may take years. Therefore, repurposing of approved drugs offers a promising approach to address this urgent need. Inhaled furosemide, a small molecule capable of inhibiting IL-6 and TNFα, may be an agent capable of treating the Coronavirus Disease 2019 cytokine storm in both resource-rich and developing countries. Furosemide is a "repurpose-able" small molecule therapeutics, that is safe, easily synthesized, handled, and stored, and is available in reasonable quantities worldwide.

Controlled Delivery of 80 mg Aerosol Furosemide Does Not Achieve Consistent Dyspnea Relief in Patients

PURPOSE

Aerosol furosemide may be an option to treat refractory dyspnea, though doses, methods of delivery, and outcomes have been variable. We hypothesized that controlled delivery of high dose aerosol furosemide would reduce variability of dyspnea relief in patients with underlying pulmonary disease.

METHODS

Seventeen patients with chronic exertional dyspnea were recruited. Patients rated recently recalled breathing discomfort on a numerical rating scale (NRS) and the multidimensional dyspnea profile (MDP). They then performed graded exercise using an arm-ergometer. The NRS was completed following each exercise grade, and the MDP was repeated after a pre-defined dyspnea threshold was reached. During separate visits, patients received either aerosol saline or 80 mg of aerosol furosemide in a randomized, double-blind, crossover design. After treatment, graded exercise to the pre-treatment level was repeated, followed by completion of the NRS and MDP. Treatment effect was defined as the difference between pre- and post-treatment NRS at end exercise, expressed in absolute terms as % Full Scale. "Responders" were defined as those showing treatment effect ≥ 20% of full scale.

RESULTS

Final analysis included 15 patients. Neither treatment produced a statistically significant change in NRS and there was no significant difference between treatments (p = 0.45). There were four "responders" and one patient whose dyspnea worsened with furosemide; two patients were responders with saline, of whom one also responded to furosemide. No adverse events were reported.

CONCLUSIONS

High dose controlled delivery aerosol furosemide was not statistically different from saline placebo at reducing exercise-induced dyspnea. However, a clinically meaningful improvement was noted in some patients.

Updates in opioid and nonopioid treatment for chronic breathlessness

PURPOSE OF REVIEW

Chronic breathlessness is a troublesome symptom experienced by people with advanced malignant and nonmalignant disease. Disease-directed therapies are often insufficient in the management of chronic breathlessness. Therefore, pharmacological and nonpharmacological breathlessness-specific interventions should be considered for select patients.

RECENT FINDINGS

There is some evidence to support the use of low-dose opioids (≤30 mg morphine equivalents per day) for the relief of breathlessness in the short term. However, additional studies are needed to understand the efficacy of opioids for chronic breathlessness in the long term.Nonopioid therapies, including inspiratory muscle training, fan-to-face therapy, L-menthol and inhaled nebulized furosemide show some promise for the relief of breathlessness in advanced disease. There is insufficient evidence to support the use of anxiolytics and benzodiazepines and cannabis for chronic breathlessness.

SUMMARY

More research is needed to identify therapies for the management of chronic breathlessness.

Aerosol furosemide for dyspnea: Controlled delivery does not improve effectiveness

Aerosolized furosemide has been shown to relieve dyspnea; nevertheless, all published studies have shown great variability in response. This dyspnea relief is thought to result from the stimulation of slowly adapting pulmonary stretch receptors simulating larger tidal volume. We hypothesized that better control over aerosol administration would produce more consistent dyspnea relief; we used a clinical ventilator to control inspiratory flow and tidal volume. Twelve healthy volunteers inhaled furosemide (40mg) or placebo in a double blind, randomized, crossover study. Breathing Discomfort was induced by hypercapnia during constrained ventilation before and after treatment. Both treatments reduced breathing discomfort by 20% full scale. Effectiveness of aerosol furosemide treatment was weakly correlated with larger tidal volume. Response to inhaled furosemide was inversely correlated to furosemide blood level, suggesting that variation among subjects in the fate of deposited drug may determine effectiveness. We conclude that control of aerosol delivery conditions does not improve consistency of treatment effect; we cannot, however, rule out placebo effect.

Dyspnea

Dyspnea is a subjective experience of breathing discomfort that can only be known through a patient's report. Numeric rating or visual analog scales allow assessment of intensity when the patient can self-report. The Respiratory Distress Observation Scale is a valid, reliable tool for estimating distress when self-report cannot be elicited. Treating dyspnea begins with managing the underlying condition. Other dyspnea-specific evidence-based interventions include morphine and fentanyl, upright positioning, oxygen, invasive and noninvasive ventilation, and balancing rest with activity. Effectiveness has not been established for benzodiazepines, nebulized furosemide, oxygen in the face of normoxemia, other opioids, and nebulized fentanyl.

Non-opioid medications for the relief of chronic breathlessness: current evidence

INTRODUCTION

To evaluate systematically randomised clinical trials investigating non-opioid medications for the management and treatment of chronic breathlessness. Areas covered: The evidence for the role of benzodiazepines, anxiolytics, selective serotonin re-uptake inhibitors (SSRIs), tricyclic antidepressants, antihistamines, cannabinoids, nebulized furosemide and herbal-based treatments were critically reviewed. Search of the Clinical Trials Registry (Clinicaltrial.gov) identified ongoing studies expected to generate new data in the near future in several classes of non-opioid medications for their net effect on chronic breathlessness. Expert commentary: Morphine still has the best level of evidence for the symptomatic treatment of chronic breathlessness. Non-opioid treatments for chronic breathlessness are less studied than morphine and morphine-related medications although evidence is emerging in relation to some options. Currently, there is insufficient evidence to recommend non-opioids in the routine treatment of chronic breathlessness. There is a need to find agents, new as well as re-purposed, that can be used as alternative therapies to opioids for chronic breathlessness for people who are unable to tolerate morphine.

Furosemide

Therapeutic Reviews aim to provide essential independent information for health professionals about drugs used in palliative and hospice care. Additional content is available on www.palliativedrugs.com. Country-specific books (Hospice and Palliative Care Formulary USA, and Palliative Care Formulary, British and Canadian editions) are also available and can be ordered from www.palliativedrugs.com. The series editors welcome feedback on the articles (hq@palliativedrugs.com).

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.

An online survey of Australian physicians reported practice with the off-label use of nebulised frusemide

Background

Off-label prescribing is common in palliative care. Despite inconsistent reports of the benefit of nebulised frusemide for breathlessness, its use continues to be reported.

Methods

An online survey was emailed to 249 members of the Australian and New Zealand Society of Palliative Medicine to estimate the use of nebulised frusemide for breathlessness by Australian physicians involved in palliative care in the previous 12 months.

Results

There were 52/249 (21%) respondents to the survey. The majority (44/52; 85%) had not prescribed nebulised frusemide in the previous 12 months. The most common (18/44; 43%) reason for not prescribing nebulised frusemide was a belief that there was not enough evidence to support its use. Whilst only a few respondents (8/52; 15%) reported having used nebulised frusemide, all that had used it thought there was at least some benefit in relieving breathlessness.

Conclusion

This report adds to the series of case studies reporting some benefit from nebulised frusemide in relieving breathlessnes.

The acute haemodynamic effect of nebulised frusemide in stable, advanced heart failure

PURPOSE

To assess the acute haemodynamic effects of nebulised frusemide in a stable advanced heart failure population.

PROCEDURE

In this randomised, double blind, placebo controlled trial, people with stable, advanced heart failure undergoing right heart catheterisation were randomised to receive either 40 mg (4 ml) of nebulised frusemide or 4 ml of normal saline. Following inhalation of the study medication, subjects' pulmonary pressures were recorded every 15 min for 1 h.

FINDINGS

There were no significant changes in the weighted average time course data of the subjects (n=32) in either group over the study period, in particular no differences were observed in haemodynamic parameters between the two groups. Weighted average pulmonary capillary wedge pressure after 60 min in the frusemide group was 22.5 (SD 6.5) mmHg (n=14) compared to the placebo group's 24.0 (SD 7.3) mmHg (n=18), p=0.55. The frusemide group had a significantly greater change in the median volume of urine in the bladder over the study period (186 ml IQR 137.8-260.8) compared to the placebo group (76 ml IQR 39.0-148.0) p=0.02.

CONCLUSION

This study showed that nebulised frusemide had no significant clinical effect on the haemodynamic characteristics of the subjects.

Dyspnea review for the palliative care professional: treatment goals and therapeutic options

Although dyspnea is frequently encountered in the palliative care setting, its optimal management remains uncertain. Clinical approaches begin with accurate assessment, as delineated in part one of this two-part series. Comprehensive dyspnea assessment, which encompasses the physical, emotional, social, and spiritual aspects of this complex symptom, guide the clinician in choosing therapeutic approaches herein presented as part two. Global management of dyspnea is appropriate both as complementary to disease-targeted treatments that target the underlying etiology, and as the sole focus when the symptom has become intractable, disease is maximally treated, and goals of care shift to comfort and quality of life. In this setting, current evidence supports the use of oral or parenteral opioids as the mainstay of dyspnea management, and of inhaled furosemide and anxiolytics as adjuncts. Nonpharmacologic interventions such as acupuncture and pulmonary rehabilitation have potential effectiveness, although further research is needed, and use of a simple fan warrants consideration given its potential benefit and minimal burden and cost.

Interventions for alleviating cancer-related dyspnea: a systematic review

PURPOSE

Dyspnea is one of the most distressing symptoms experienced by terminally ill cancer patients. This study aimed to evaluate the role of interventions for the palliation of dyspnea.

METHODS

We conducted a systematic review of randomized controlled trials assessing all pharmacologic and nonpharmacologic interventions for dyspnea palliation in cancer patients, and searched the Cochrane Library, MEDLINE, conference proceedings, and references. Two reviewers independently appraised the quality of trials and extracted data.

RESULTS

Our search yielded 18 trials. Fourteen evaluated pharmacologic interventions: seven assessing opioids (a total of 256 patients), five assessing oxygen (137 patients), one assessing helium-enriched air, and one assessing furosemide. Four trials evaluated nonpharmacologic interventions (403 patients). The administration of subcutaneous morphine resulted in a significant reduction in dyspnea Visual Analog Scale (VAS) compared with placebo. No difference was observed in dyspnea VAS score when nebulized morphine was compared with subcutaneous morphine, although patients preferred the nebulized route. The addition of benzodiazepines to morphine was significantly more effective than morphine alone, without additional adverse effects. Oxygen was not superior to air for alleviating dyspnea, except for patients with hypoxemia. Nursing-led interventions improved breathlessness. Acupuncture was not beneficial.

CONCLUSION

Our review supports the use of opioids for dyspnea relief in cancer patients. The use of supplemental oxygen to alleviate dyspnea can be recommended only in patients with hypoxemia. Nursing-led nonpharmacologic interventions seem valuable. Only a few studies addressing this question were performed. Thus, further studies evaluating interventions for alleviating dyspnea are warranted.

Effect of inhaled furosemide on air hunger induced in healthy humans

Recent evidence suggests that inhaled furosemide relieves dyspnoea in patients and in normal subjects made dyspnoeic by external resistive loads combined with added dead-space. Furosemide sensitizes lung inflation receptors in rats, and lung inflation reduces air hunger in humans. We therefore hypothesised that inhaled furosemide acts on the air hunger component of dyspnoea. Ten subjects inhaled aerosolized furosemide (40 mg) or placebo in randomised, double blind, crossover experiments. Air hunger was induced by hypercapnia (50+/-2 mmHg) during constrained ventilation (8+/-0.9 L/min) before and after treatment, and rated by subjects using a 100 mm visual analogue scale. Subjects described a sensation of air hunger with little or no work/effort of breathing. Hypercapnia generated less air hunger in the first trial at 23+/-3 min after start of furosemide treatment (58+/-11% to 39+/-14% full scale); the effect varied substantially among subjects. The mean treatment effect, accounting for placebo, was 13% of full scale (P=0.052). We conclude that 40 mg of inhaled furosemide partially relieves air hunger within 1h and is accompanied by substantial diuresis.

Furosemide (Nebulized): Dyspnea in Cancer Patients

Off-Label Drug Uses

This Hospital Pharmacy feature is extracted from Off-Label DrugFacts, a quarterly publication available from Facts and Comparisons. Off-Label DrugFacts is a practitioner-oriented resource for information about specific FDA-unapproved drug uses. This new guide to the literature will enable the health care professional/clinician to quickly identify published studies on off-label uses and to determine if a specific use is rational in a patient care scenario. The most relevant data are provided in tabular form so that the reader can easily identify the scope of information available. A summary of the data—including background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations—precedes each table of published studies. References direct the reader to the full literature for more comprehensive information prior to patient care decisions. Direct questions or comments on “Off-Label Drug Uses” to hospitalpharmacy@drugfacts.com .

Effects of inhaled furosemide on exertional dyspnea in chronic obstructive pulmonary disease

The aim of this study is to investigate the effects of inhaled furosemide on the sensation of dyspnea produced during exercise in patients with stable chronic obstructive pulmonary disease (COPD). In a double-blind, randomized, crossover study we compared the effect of inhaled furosemide on dyspneic sensation during exercise testing with that of placebo. Spirometry and incremental and constant-load exercise testing were performed after inhalation of placebo or furosemide on 2 separate days in 19 patients with moderate or severe COPD. Subjects were asked to rate their sensation of respiratory discomfort using a 100-mm visual analog scale. There was significant improvement in mean FEV1 and FVC after inhalation of furosemide (p = 0.038 and 0.005, respectively) but not after placebo. At standardized exercise time during constant-load exercise testing but not during incremental exercise, the mean dyspneic visual analog scale score was lower after inhalation of furosemide compared with placebo (33.7 +/- 25.2 vs. 42.4 +/- 24.0 mm, respectively, p = 0.014). We conclude that inhalation of furosemide alleviates the sensation of dyspnea induced by constant-load exercise testing in patients with COPD and that there is significant bronchodilation after inhalation of furosemide compared with placebo in these patients.