Nebulized furosemide as a novel treatment for dyspnea in terminal cancer patients

Dyspnea

The clinical term dyspnea (a.k.a. breathlessness or shortness of breath) encompasses at least three qualitatively distinct sensations that warn of threats to breathing: air hunger, effort to breathe, and chest tightness. Air hunger is a primal homeostatic warning signal of insufficient alveolar ventilation that can produce fear and anxiety and severely impacts the lives of patients with cardiopulmonary, neuromuscular, psychological, and end-stage disease. The sense of effort to breathe informs of increased respiratory muscle activity and warns of potential impediments to breathing. Most frequently associated with bronchoconstriction, chest tightness may warn of airway inflammation and constriction through activation of airway sensory nerves. This chapter reviews human and functional brain imaging studies with comparison to pertinent neurorespiratory studies in animals to propose the interoceptive networks underlying each sensation. The neural origins of their distinct sensory and affective dimensions are discussed, and areas for future research are proposed. Despite dyspnea's clinical prevalence and impact, management of dyspnea languishes decades behind the treatment of pain. The neurophysiological bases of current therapeutic approaches are reviewed; however, a better understanding of the neural mechanisms of dyspnea may lead to development of novel therapies and improved patient care.

Treatment of Dyspnea in Advanced Disease and at the End of Life

Dyspnea is a subjective experience of breathing discomfort that consists of qualitatively distinct sensations, varies in intensity, and can only be known through the patient's report. Dyspnea is akin to suffocation and is one of the most distressing symptoms experienced by patients with advanced illness and at the end of life. Common approaches to dyspnea management, such as pulmonary rehabilitation, breathing strategies, or supplemental oxygen, have become accepted through pragmatic use or because studies do not include dyspnea as a measured outcome. Patients and clinicians urgently need evidence-based treatments to alleviate this frightening symptom. To fill this gap, a group of dyspnea researchers with expertise to conduct a literature review of evidence-based interventions for dyspnea in patients with serious illness produced these guidelines. We present the evidence from the strongest recommendations for practice to the weakest recommendations and include practical considerations for clinical nurses.

Combination adjunctive nebulized furosemide and salbutamol versus single agent therapy in COPD patients: A randomized controlled trial

Background

COPD patients often require multiple therapies to enhance their lung function and reduce their symptoms in exacerbations. This study aimed to investigate the relative effects of combination adjunctive nebulized furosemide and salbutamol therapy versus single agent treatment in COPD patients.

Methods

Sixty-nine COPD patients were randomly divided into two groups. The first group (G1, 34 cases) received salbutamol in their first episode. The second group (G2, 35 cases) received furosemide in their first episode. Spirometry indices (FEV1, FVC, and FEV1/FVC), mMRC and BORG (COPD assessment) were assessed and recorded for all patients.To study the efficacy of combination adjunctive therapy, in 2nd episodes, the nebulized furosemide was added to nebulized salbutamol in the G1, and nebulized salbutamol was added to nebulized furosemide in G2. The aforementioned indices were then re-assessed.

Results

The mean age was (64.92 ± 11.71 years, 55% males. The use of nebulized furosemide and salbutamol as single agents slightly improved the spirometeric parameters, but it was not noteworthy compared to the significant improvement of the FEV1, FVC, FEV1/FVC, mMRC, and Borg parameters with combination therapy (p-value< 0.001). In the first episode, there was no difference in spirometeric indices, between groups (p-value > 0.1), so furosemide is considered as effective as nebulized salbutamol. Also, the results of sequential drugs administration, in the two groups was similar.

Conclusion

Conjunction of nebulized furosemide and salbutamol is more effective than single therapy and can be considered as preferred drug regimen without any reported side effect in the treatment of COPD.

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.

Management of Breathlessness in Palliative Care: Inhalers and Dyspnea-A Literature Review

INTRODUCTION

Dyspnea is prominently observed in palliative care (PC). Dyspnea can be multifactorial, primarily caused by obstructive or restrictive lung diseases or secondarily induced by various comorbidities. Numerous interventions exist, with route of administration and efficacy requiring further discussion. Despite opioids being the first line of treatment, their adverse effects lead to reluctance on the side of patients to take them, creating limitations in patient management planning.

OBJECTIVES

This paper reviews and highlights the role of inhalers for dyspnea management in PC.

METHODS

The CINAHL, CENTRAL, and OVID databases were searched for scholarly articles on the role of inhalers in dyspnea management from 1998 to the present. A grey literature Internet search was also performed via Google, the World Health Organization, and CareSearch. Twenty-five articles relevant to the subject at hand were located and summarized. The Cochrane Systematic Reviews of Health Promotion and Public Health Interventions Handbook was consulted for structuring.

RESULT

Isolated bronchodilators can be effective in dyspnea management. However, combination with opioids leads to a 52% reduction of dyspnea, demonstrating efficacy of their combined use. There is a role for conventional inhalers not only in patients afflicted with chronic obstructive pulmonary disease, but also in those where obstruction is reversible, and in cases of dyspnea not yet diagnosed.

CONCLUSION

Inhalers can be utilized as adjuvant therapy to opioids, to limit opioid use, augment responses to dyspnea, and/or minimize opioid side effects, especially in opioid-naïve patients. Correct administration can increase the efficacy of short-acting beta-agonists, long-acting beta-agonists, short- and long-acting anticholinergic agents, and inhaled corticosteroids, achieving reduction and alleviation of dyspnea.

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.

The Effect of Aerosol Saline on Laboratory-Induced Dyspnea

PURPOSE

In the 'placebo arm' of a recent study, we found that aerosol saline (sham treatment) produced substantial relief of laboratory-induced dyspnea (Breathing discomfort-BD) in nearly half the subjects. The sham intervention included a physiological change, and instructions to subjects could have produced expectation of dyspnea relief. In the present study, we attempted to discover whether the response to sham aerosol was driven by behavioral or physiological aspects of the intervention.

METHODS

Dyspnea (air hunger) was evoked by constraining tidal volume during graded hypercapnia. We measured [Formula: see text] versus BD relationship before and after aerosol saline. To minimize subjects' expectations of dyspnea relief, participants were clearly instructed that we would only deliver saline aerosol. In Protocol 1, we delivered aerosol saline with a ventilator (mimicking our prior study); in Protocol 2, we delivered aerosol without a ventilator.

RESULTS

Administration of aerosol saline had little effect on BD in this group of subjects with one exception: one subject experienced appreciable reduction in BD in Protocol 1. This treatment effect was less in Protocol 2. The two most likely explanations are (a) that procedures surrounding ventilator administration of aerosol produced a psychological placebo treatment effect even though the subject knew a drug was not given; (b) there were behavioral changes in breathing undetected by our measurements of respiratory flow and volume that altered the subjects comfort.

CONCLUSION

When the expectation of treatment effect is minimized, a significant reduction in dyspnea in response to saline placebo is uncommon but not impossible.

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).

Palliative Pharmacotherapy: State-of-the-Art Management of Symptoms in Patients With Cancer

BACKGROUND

Advanced cancer produces multiple symptoms as patients progress through their disease trajectory. Identifying, measuring, and providing therapy for uncontrolled symptoms becomes important because disease-altering therapies may be no longer possible. Symptoms other than pain that cause distress in patients with cancer include delirium, dyspnea, anorexia, nausea, and fatigue. Precise management of these symptoms can lead to the best possible quality of life and lessen distress. This article reviews current management strategies of these symptoms.

METHODS

The epidemiology, mechanisms, assessment, and therapies of common symptoms in the advanced cancer population are reviewed.

RESULTS

Identifiable approaches facilitate symptom management in advanced illness.

CONCLUSIONS

Using a systematic approach to symptoms in advanced illness can improve the quality of life and lessen distress among patients with cancer and their families, friends, and caregivers.

The efficacy of nebulized furosemide and salbutamol compared with salbutamol alone in reactive airway disease: a double blind randomized, clinical trial

We undertook this randomized clinical trial to investigate whether adding furosemide to salbutamol could improve the peak expiratory flow rate (PEFR) and clinical signs of reactive airway disease (RAD) patients. Eligible 18- to 55-year-old patients were randomly divided into intervention and control groups. Patients received 5 mg of nebulized salbutamol and 40 mg of nebulized furosemide in the intervention group and 5 mg of nebulized salbutamol alone in the control group. Patients in both groups received 100 mg of methylprednisolone intravenously stat. Severity of the RAD was estimated before and 45 minutes after treatment in both groups. PEFR was estimated before treatment and at 15, 30, and 45 minutes later. Ninety patients were enrolled, 45 in each group. There were no significant differences between two groups regarding gender, mean age, and normalized PEFR. The baseline mean PEFR was not significantly different between groups (P = 0.58). A repeated measure analysis of variance revealed that the differences between the two treatments was significant (P = 0.0001) and the behavior of two treatments was not similar across the time (P = 0.001). Comparison of clinical severity of acute RAD revealed no significant differences between groups at the end of the trial (0.06). This study showed that adding nebulized furosemide to salbutamol in RAD patients improved PEFR.

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.

Symptom control and palliative care: management of breathlessness

Breathlessness remains a common and significant problem in palliative care. This article reviews the most commonly used interventions and discusses strategies to improve this symptom.

Mechanisms of dyspnea in chronic lung disease

PURPOSE OF REVIEW

To discuss three emerging areas of research triggering new hypotheses for mechanisms of dyspnea.

RECENT FINDINGS

There has been an emphasis on the importance of lung volumes in evaluating symptoms and lung function in patients with chronic obstructive pulmonary disease. Dyspnea intensity seems to more closely correlate with measures of hyperinflation than airflow limitation, highlighting the importance of neuromechanical dissociation in the development of dyspnea. Inhaled furosemide has demonstrated a beneficial effect in laboratory-induced dyspnea, and the sensation of air hunger has been ameliorated by this therapy, possibly via activation of pulmonary stretch receptors. There appear to be distinct affective and sensory components of dyspnea, and the affective dimension may be modifiable, although this has not been fully studied.

SUMMARY

Dyspnea in chronic obstructive pulmonary disease is clearly related to hyperinflation, and lung volumes are valuable for characterizing disease. It remains unclear whether a limitation in tidal volume due to dynamic hyperinflation is the key factor in exertional dyspnea in this disease. Research of inhaled furosemide demonstrates the importance of afferent sensory input in modifying dyspnea, and deserves further study. The contributions of the affective and sensory components of dyspnea remain unclear, but should be studied further.

Nebulized furosemide for the management of dyspnea: does the evidence support its use?

Dyspnea is a common and distressing symptom associated with multiple chronic illnesses and high levels of burden for individuals, their families and health care systems. The subjective nature dyspnea and a poor understanding of pathophysiological mechanisms challenge the clinician in developing management plans. Nebulized furosemide has been identified as a novel approach to dyspnea management. This review summarizes published studies, both clinical and experimental, reporting the use of nebulized furosemide. The search criteria yielded 42 articles published in the period 1988 to 2004. Although nebulized furosemide appeared to have a positive influence on dyspnea and physiological measurements, caution must be taken with the results primarily coming from small-scale clinical trials or observation trials. Despite the limitations of the studies reported, given the range of conditions reporting effectiveness of nebulized furosemide, further investigation of this potential novel treatment of dyspnea is warranted.

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.

The etiology and management of intractable breathlessness in patients with advanced cancer: a systematic review of pharmacological therapy

Intractable breathlessness is a common, devastating symptom of advanced cancer causing distress and isolation for patients and families. In advanced cancer, breathlessness is complex and usually multifactorial and its severity unrelated to measurable pulmonary function or disease status. Therapeutic advances in the clinical management of dyspnea are limited and it remains difficult to treat successfully. There is growing interest in the palliation of breathlessness, and recent work has shown that a systematic, evidence-based approach by a committed multidisciplinary team can improve lives considerably. Where such care is lacking it may be owing to therapeutic nihilism in clinicians untrained in the management of chronic breathlessness and unaware that there are options other than endurance. Optimum management involves pharmacological treatment (principally opioids, occasionally oxygen and anxiolytics) and nonpharmacological interventions (including use of a fan, a tailor-made exercise program, and psychoeducational support for patient and family) with the use of parenteral opioids and sedation at the end of life when appropriate. Effective care centers on the patient's needs and goals. Priorities in breathlessness research include studies on: neuroimaging, the effectiveness of new interventions, the efficacy, safety, and dosing regimens of opioids, the contribution of deconditioning, and the effect of preventing or reversing breathlessness.

Clinical Dilemma: Dyspnea

OBJECTIVES

To review the current state of evidence for the nursing treatment of cancer-related dyspnea.

DATA SOURCES

Nursing and medical literature, published guidelines, and Cochrane Systematic reviews.

CONCLUSION

Limited evidence exists for the current strategies used to treat dyspnea among persons with cancer.

IMPLICATIONS FOR NURSING PRACTICE

Nurses must be cognizant of the level of evidence or the lack of scientific evidence supporting treatment strategies used. Keeping abreast of the developments in the area of dyspnea management is imperative as research adds to the current body of evidence. Nurses are uniquely positioned to add to the body of evidence through collaboration with nurse researchers.

Unlabeled uses of nebulized medications

PURPOSE

The uses, dosing recommendations, benefits, and disadvantages of unlabeled drugs administered by nebulization are reviewed.

SUMMARY

Nebulization is gaining popularity as a treatment alternative, and many drugs are used unlabeled in a nebulized form, including the opioids, lidocaine, magnesium sulfate, amphotericin B, and colistin. The opioids are frequently used to treat dyspnea in end-stage diseases. Common dosages include 1-2 mg every two hours as needed for hydromorphone and 25-50 microg every two hours for fentanyl citrate. Lidocaine can be used to relieve bronchoconstriction and cough symptoms as well as acting as a local anesthetic. It is typically given in a dose between 20 and 160 mg. Nebulized magnesium sulfate can be used in managing acute asthma and is given in dosages between 125 and 250 mg every 20 minutes, with no more than four consecutive doses. Nebulized amphotericin B can be used to prevent infections in immunocompromised patients. A typical amphotericin B regimen is 25 mg every 24 hours. Nebulized colistin is being studied in the prevention and treatment of gram-negative infections and in patients awaiting lung transplants. Colistin is often given as 75 mg every 12 hours to combat infections.

CONCLUSION

Unlabeled nebulization of opioids, lidocaine, magnesium, amphotericin B, and colistin is an alternative method of treatment for patients with pulmonary problems or infections or for those undergoing bronchoscopy. More research is needed to develop guidelines for their use since nebulization may provide benefits to many patients who otherwise cannot be treated or would be at risk of systemic adverse effects of the drugs.

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.

Management of Symptoms Other than Pain

Symptom management requires an understanding of the likely cause of the symptom in the individual patient, comprehensive assessment, and evidence-based interventions. This article explores the management strategies for common symptoms encountered in palliative care practice. Stomatitis, xerostomia, dysphagia, nausea and vomiting, anorexia, constipation, dyspnea, and fatigue are among the symptoms reviewed.

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 .

Management of dyspnea

Patients with cancer frequently report dyspnea, the uncomfortable awareness of breathing. Lung involvement with cancer does not predict its occurrence. Patients describe it as one of the most frightening and distressing symptoms, and patient self-report is the only reliable measure. Measurements of respiratory rate, oxygen saturation, and arterial blood gases do not measure dyspnea. Opioids in modest doses have been demonstrated to give effective relief of dyspnea, whether or not identifiable reversible causes exist. Medical management of dyspnea can be directed at the underlying cause when the potential benefits outweigh the burdens of such treatment. In rare cases where symptomatic treatment is unable to control dyspnea to the patient's satisfaction, sedation is an effective, ethical option.

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.

Effect of nebulized furosemide in terminally ill cancer patients with dyspnea

We evaluated the effect of ultrasonically nebulized furosemide (20 mg) on dyspnea uncontrollable by standard therapy in patients with terminal cancer. Dyspnea was evaluated using the Cancer Dyspnea Scale (CDS) before and 60 min after inhalation. Changes in arterial blood gases, hemoglobin oxygen saturation (SpO2), heart rate (HR), and respiratory rate (RR) also were evaluated. In 12 of 15 patients (80%), total dyspnea scores by CDS improved significantly after inhalation of furosemide (P = 0.007), especially concerning a reduced sense of effort (P = 0.013) and reduced anxiety (P = 0.04). No significant changes were observed in the partial pressure of oxygen in arterial blood (PaO2), the partial pressure of carbon dioxide in arterial blood (PaCO2), SpO2, HR, or RR. Inhalation of nebulized furosemide appears to be effective against dyspnea in terminally ill cancer patients.