Safety of long-acting beta-agonists: urgent need to clear the air remains

Patterns of bronchodilator therapy in asthmatic outpatients

Background: Bronchodilators are used to treat asthma symptoms. The administration of this therapy can be given through monotherapy or in combination to achieve the maximum therapeutic effect. Objective: This study aimed to examine the prescribing pattern of bronchodilators in asthmatic outpatients. Methods: A retrospective study was done by reviewing and analyzing medical records of asthmatic outpatients from January 2019 until December 2020. Data analysis was performed descriptively. Results: In this study, bronchodilators were administered by inhalation 97.4% compared to oral routes 2.6%. Combination bronchodilator therapy showed 54.7% compared to monotherapy by 46.3%. The combination ICS/LABA budesonide/formoterol 160/4.5 mcg was the most widely used 45.7%. Conclusion: The use of a bronchodilator was in accordance with the Global Initiative for Asthma guidelines. The route of drug administration through inhalation is more widely used than oral. Combination bronchodilators were more recommended than bronchodilator monotherapy to control asthma symptoms.

Current long-acting muscarinic antagonists for the treatment of asthma

INTRODUCTION

The role of long-acting muscarinic antagonists (LAMAs) is well established in uncontrolled asthma, but not in milder stages.

AREAS COVERED

This review examines the main randomized controlled trials (RCTs) that have investigated LAMAs administered as monotherapy or in combination to asthmatic patients, according to the different phenotypes. It offers an overview of the role of LAMAs or their fixed dose combinations (FDCs) in the treatment across all the different stages of asthma.

EXPERT OPINION

Tiotropium is now widely recognized as treatment for moderate to severe uncontrolled asthma (step 4-5) in adults and children. The most recent new evidence is: a) in adults, three different LAMA/long-acting β₂-agonist (LABA)/inhaled corticosteroid (ICS) FDCs have been recently approved, extending the treatment options for these patients; b) therapy with LAMAs does not depend on patient's Th2 status and justifies the indication regardless of patient's phenotyping; c) in the milder stages, the high variability of response to LAMAs and the lack of a good phenotyping of patients represents the main obstacle in prescribing LAMAs. A better characterization of parasympathetic tone activity could improve LAMAs prescription.

An electrochemiluminescence energy resonance transfer system for highly sensitive detection of brombuterol

In this work, an electrochemiluminescence resonance energy transfer (ECL-RET) system was established based on the modified graphite phase carbon nitride to detect brombuterol residues in food. The ultrasonic-assisted acidification exfoliation modification improved the conductivity and specific surface area of the graphite phase carbon nitride (g-C₃N₄). In addition, the carboxylated g-C₃N₄ nanosheets as ECL donors and the Au-Ag alloy nanoparticles as ECL acceptors could respectively directly carry antigen and antibody. Therefore, the trouble of introducing additional bridge molecules was avoided. A competitive immunoassay strategy was used for the detection of brombuterol, where brombuterol in the sample would compete with the coating antigen for the limited binding sites on antibody. The proposed ECL immunosensor for brombuterol detection exhibited high sensitivity with a wide linear range from 0.001 ng mL^-1 to 1000 ng mL^-1 and a low detection limit at 0.31 pg mL^-1. This work adopts a very simple way to design the sensor without losing its sensitivity, bringing convenience to its possible future applications.

Efficacy and safety of the combination fluticasone propionate plus salmeterol in asthmatic preschoolers: An observational study

BACKGROUND

Inhaled Corticosteroids (ICS) are the cornerstone of asthma management in pediatric patients. However, in some cases, asthma is not adequately controlled on ICS alone. Long-acting beta₂-agonists (LABA) are one of the available additional therapies but their use has rarely been studied among children younger than 5 years.

OBJECTIVE

The aim of this observational study was to evaluate the efficacy and safety of the combination of fluticasone propionate and salmeterol (FP/SA) in asthmatic children younger than 5 years of age.

METHODS

A retrospective study of 796 children under the age of 5 years (2.87 ± 1.22 years, 64.2% males), who were treated with FP/SA was conducted. Hospitalization rates, frequency of wheezing, exercise induced asthma, nocturnal wheeze and drug-related side-effects were recorded through children's medical records.

RESULTS

The children had previously received short-acting β₂-agonists (73%), ICS (17%), montelukast (1%), and ICS with montelukast (2%). Mean duration of therapy with FP/SA was 12.45 ± 9.14 months. After adjusting for age, gender, and duration of treatment, a 89% reduction was recorded in annual hospitalization rates (from 27.13% before treatment to 3.01% after FP/SA therapy, p < 0.001), a 71% reduction in incidence of exercise-induced asthma (36.8% vs. after 10.6%, p < 0.001), a 81% reduction in nocturnal asthma (33.7% vs. after: 6.4%, p < 0.001), as well as in frequency of wheezing (p < 0.01),. No previous treatment carry-on effect was observed. No major drug-related side-effects occurred in the study group.

CONCLUSIONS

Combination therapy (FP/SA) is well-tolerated and highly effective in asthmatic children under the age of 5 years.

Duration of bronchoprotection of the long-acting muscarinic antagonists tiotropium & glycopyrronium against methacholine-induced bronchoconstriction in mild asthmatics

The duration of bronchoprotection against methacholine-induced bronchoconstriction by long-acting muscarinic antagonists (LAMA's) in asthmatics and whether these drugs differ in their pharmacodynamic properties remain to be determined. The most recent published guidelines for methacholine challenge testing (MCT) suggest that LAMA's should be abstained from for 48 h prior to testing, perhaps one week in the case of tiotropium. The objectives were to determine and compare the duration of protection of a single dose of two different LAMA's, tiotropium and glycopyrronium, against methacholine-induced bronchoconstriction. Thirteen mild-to-moderate asthmatics [with a forced expiratory volume in 1 s (FEV1) > 65% of predicted and a baseline methacholine provocation concentration causing a 20% reduction in FEV1 (PC20) ≤ 8 mg/mL] completed this double-blind, double-dummy, crossover study. Methacholine challenges were performed before treatment (5 μg tiotropium or 50 μg glycopyrronium) and at 1, 24, 48, 72, 96 and 168 h post-treatment. The minimum duration between treatment administration was 11 days. Both drugs provided significant bronchoprotection, each producing greater than a 16-fold increase in mean PC20 by 1 h. Tiotropium still provided statistically significant protection at 7 days (p = 0.0282) while glycopyrronium provided bronchoprotection until day 7 (p = 0.0590). Tiotropium provided statistically superior bronchoprotection at 24 and 72 h compared to glycopyrronium. To minimize the occurrence of false negatives, MCT guidelines should be updated to recommend a minimum one-week abstinence period from all LAMA's. MCT was also able to statistically differentiate between tiotropium and glycopyrronium with respect to the degree and duration of bronchoprotection provided by each.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02622243.

Antileukotriene Agents Versus Long-Acting Beta-Agonists in Older Adults with Persistent Asthma: A Comparison of Add-On Therapies

OBJECTIVES

To compare the effectiveness and cardiovascular safety of long-acting beta-agonists (LABAs) with those of leukotriene receptor antagonists (LTRAs) as add-on treatments in older adults with asthma already taking inhaled corticosteroids (ICSs).

DESIGN

Retrospective cohort study.

SETTING

Medicare fee-for-service (FFS) claims (2009-10) for a 10% random sample of beneficiaries continuously enrolled in Parts A, B, and D in 2009.

PARTICIPANTS

Medicare beneficiaries aged 66 and older continuously enrolled in FFS Medicare with Part D coverage with a diagnosis of asthma before 2009 treated exclusively with ICSs plus LABAs or ICSs plus LTRAs (N = 14,702).

MEASUREMENTS

The augmented inverse propensity-weighted estimator was used to compare the effect of LABA add-on therapy with that of LTRA add-on therapy on asthma exacerbations requiring inpatient, emergency, or outpatient care and on cardiovascular (CV) events, adjusting for demographic characteristics, comorbidities, and county-level healthcare-access variables.

RESULTS

The primary analysis showed that LTRA add-on treatment was associated with greater odds of asthma-related hospitalizations or emergency department visits (odds ratio (OR) = 1.4, P < .001), as well as outpatient exacerbations requiring oral corticosteroids or antibiotics (OR = 1.41, P < .001) than LABA treatment. LTRA add-on therapy was also less effective in controlling acute symptoms, as indicated by greater use of short-acting beta agonists (rate ratio = 1.58, P < .001). LTRA add-on treatment was associated with lower odds of experiencing a CV event than LABA treatment (OR = 0.86, P = .006).

CONCLUSION

This study provides new evidence specific to older adults to help healthcare providers weigh the risks and benefits of these add-on treatments. Further subgroup analysis is needed to personalize asthma treatments in this high-risk population.

Impact of the Arg 16 allele of the B2AR gene on the effect of withdrawal of LABA in patients with moderate to severe asthma

INTRODUCTION

Long-acting beta agonists (LABAs) are effective for controlling asthma, however questions about their safety have led to concerns over use. Genetic polymorphisms at the 16 amino acid position of the beta-2 adrenergic receptor gene (B2AR) may be associated with increased risk.

METHODS

A randomized, double blind study was conducted in patients with moderate to severe asthma being treated with combined inhaled corticosteroids/LABA (ICS/LABA), comparing the effect of LABA continuation versus withdrawal on asthma outcomes among patients stratified by B2AR genotype (Arg/Arg vs. Gly/Gly at the 16th amino acid position).

RESULTS

67 participants (31 Arg/Arg, 36 Gly/Gly) were randomized to receive fluticasone alone (F) or continue combined fluticasone/salmeterol (F/S) after a run-in period on F/S. Among Gly/Gly subjects, those in the F/S treatment group showed improvement in AM PEFR (+ 8.4 L/s) whereas those receiving F alone experienced a reduction in AM PEFR over the study period (-14.4 L/s), (p = 0.06). There was no significant difference in morning peak expiratory flow rate (AM PEFR) in Arg/Arg participants randomized to receive F/S (-15.7L) vs F alone (-5.6 L/s) (p = 0.61). There was no significant difference in exacerbations in the Arg/Arg subjects treated with F/S compared with those treated with F (p = 0.65).

CONCLUSIONS

Withdrawal of LABA therapy in asthmatics with the Arg/Arg genotype at the 16th amino acid position of B2AR did not lead to significant improvement in AM PEFR. LABA withdrawal in the Gly/Gly genotype however led to a borderline significant decline in AM PEFR.

Tiotropium bromide as add-on therapy to inhaled corticosteroids for treating asthma

INTRODUCTION

Bronchial asthma is becoming increasingly prevalent worldwide. Although first-line therapy with inhaled corticosteroids (ICS) with or without long-acting β2 agonists (LABA) has significantly improved the clinical outcomes of asthma, they cannot provide all asthmatics with good control and thus alternatives or add-on drugs are required. Tiotropium is a long-acting muscarinic antagonist that has been used to treat chronic obstructive pulmonary disease and it has been approved for treating asthma in some countries. This agent has similar bronchodilatory effects to those of LABA and might also have anti-inflammatory and anti-remodeling effects.

AREAS COVERED

Some pivotal clinical trials have found tiotropium effective as an add-on medication for low-to-medium doses of ICS for treating symptomatic asthma and asthma that remains uncontrolled despite ICS plus LABA therapy.

EXPERT OPINION

Whether or not tiotropium has anti-inflammatory and anti-remodeling effects in humans with asthma is an important issue. Predictors that would identify patients who would derive the maximal potential benefit from treatment with tiotropium in addition to their current therapy are also needed. Although the cardiovascular toxicity of tiotropium is less remarkable in asthma than in chronic obstructive pulmonary disease, longer and larger studies are still needed to confirm the safety of tiotropium for treating asthma.

Practical guidance on the recognition of uncontrolled asthma and its management

PURPOSE

To highlight the significance of asthma in primary care and offer a practitioner-friendly interpretation of the asthma guidelines for the busy provider, while introducing new treatment options currently in clinical trials, such as the once-daily long-acting anticholinergic bronchodilator tiotropium Respimat.

DATA SOURCES

Articles with relevant adult data published between 2004 and 2015 were identified via PubMed. Additional references were obtained by reviewing bibliographies from selected articles.

CONCLUSIONS

In the United States, uncontrolled or symptomatic asthma is common, with rates of 46%-78% in primary care. Uncontrolled asthma has a substantial impact on patients' quality of life and represents a significant healthcare burden. Nurse practitioners can improve patients' asthma control through education, monitoring, assessment, and treatment. Although asthma management guidelines are readily available, the authors recognize that nurse practitioners see patients with multiple comorbidities, all of which have treatment guidelines of their own.

IMPLICATIONS FOR PRACTICE

Nurse practitioners have a compelling opportunity as frontline caregivers and patient educators to recognize and assess uncontrolled asthma, along with determining the steps necessary to help patients gain and maintain symptom control.

Asthma

Asthma is a heterogeneous group of conditions that result in recurrent, reversible bronchial obstruction. Although the disease can start at any age, the first symptoms occur during childhood in most cases. Asthma has a strong genetic component, and genome-wide association studies have identified variations in several genes that slightly increase the risk of disease. Asthma is often associated with increased susceptibility to infection with rhinoviruses and with changes in the composition of microbial communities colonising the airways, but whether these changes are a cause or consequence of the disease is unknown. There is currently no proven prevention strategy; however, the finding that exposure to microbial products in early life, particularly in farming environments, seems to be protective against asthma offers hope that surrogates of such exposure could be used to prevent the disease. Genetic and immunological studies point to defective responses of lung resident cells, especially those associated with the mucosal epithelium, as crucial elements in the pathogenesis of asthma. Inhaled corticosteroids continue to be the mainstay for the treatment of mild and moderate asthma, but limited adherence to daily inhaled medication is a major obstacle to the success of such therapy. Severe asthma that is refractory to usual treatment continues to be a challenge, but new biological therapies, such as humanised antibodies against IgE, interleukin 5, and interleukin 13, offer hope to improve the quality of life and long-term prognosis of severe asthmatics with specific molecular phenotypes.

Accuracy of patient self-report as a measure of inhaled asthma medication use

BACKGROUND AND OBJECTIVE

Measuring adherence to inhaled asthma treatment is a key priority for asthma care. The aim of this study was to determine the relationship between self-report and actual medication use as measured by electronic monitoring for single and combination inhaled corticosteroid (ICS) and long-acting beta-agonist (LABA) metered-dose inhaler therapy.

METHODS

In this retrospective analysis from a previously completed prospective 24-week randomized, controlled trial of single or combination ICS/LABA therapy, medication use in the week prior to study visits determined by self-report questionnaire and electronic monitoring was compared. One hundred eleven participants received 125 µg fluticasone dipropionate and 25 µg salmeterol, two actuations twice daily, by either separate or combination ICS/LABA inhalers. Paired data for self-report and electronic monitoring were analysed. Measurement of agreement was by Bland-Altman-like plots by visit with calculation of limits of agreement.

RESULTS

For single and combination ICS/LABA therapy, self-report consistently overestimated actual inhaler use assessed by electronic monitoring by a mean of 2.2-8.4 inhalations over a 1-week period, with limits of agreement ranging from ±15.8 to 25.6 inhalations. Participants who underused their inhalers tended to overreport their use, while those who overused tended to underreport their medication use. The greater the degree of underuse, the greater the magnitude of overreport, and likewise, the greater the degree of overuse, the greater the magnitude of underreport.

CONCLUSIONS

Self-report is inaccurate in measuring actual use of inhaled asthma treatment with patients who underuse their maintenance therapy overreporting their use and those who overuse their therapy underreporting their use.

Socioeconomic status and the quality of prescribing asthma drugs in Sweden

INTRODUCTION

Socioeconomic status (SES) is strongly associated with morbidity as well as with health care utilization and expenditure. The association between SES and quality of prescribing of asthma drugs is less studied.

OBJECTIVES

The aim of this study was to examine the association between socioeconomic factors, i.e. education, income and country of birth, and the prevalence, incidence and adherence to guidelines for antiasthmatic drugs.

METHODS

This registry study includes all Swedish citizens aged 25-44 years who redeemed at least one prescription of an antiasthmatic drug during 2010. Incidence and prevalence was calculated. The adherence to guidelines was studied using two defined quality indicators. Heavy users were also assessed.

RESULTS

Incidence for antiasthmatic drugs was 18.4 per 1000 person-years and the prevalence 50.9 per 1000 inhabitants. Previously untreated patients who redeemed fixed combination ranged from 45% to 49%. Patients who purchase long-acting beta-2-adrenoceptor agonists (LABA) without inhaled corticosteroid ranged from 43% to 59%. Six percent of the population was classified as heavy users.

CONCLUSION

The study showed a high incidence and prevalence of asthma drug use with a poor adherence to guidelines for rational drug prescribing. Fixed combination as first line asthma treatment as well as purchasing LABA without concomitant ICS was more common in patients born outside Scandinavia. Heavy users of short-acting bronchodilators were associated with male sex, high age, low income levels and low levels of education.

The β-2 agonist debate: is there still a problem?

PURPOSE OF REVIEW

To present an evidence-based review of the US Food and Drug Administration (FDA) recommendations for long-acting β agonist (LABA) use in asthma.

RECENT FINDINGS

The FDA recommendation contraindicating the use of LABAs without a concomitant asthma-controller medication such as an inhaled corticosteroid (ICS) is supported, with the caveat that concomitant use of an asthma-controller medication applies only to ICS therapy and not other asthma controller medications (such as leukotriene receptor antagonist therapy or theophylline). The recommendation that LABA therapy be stopped once asthma control is achieved is restrictive. Although downtitration of therapy should be considered in patients with asthma, who are well controlled, other options such as reducing the dose of ICS may be preferable to stopping LABA therapy. In patients who are at risk of unstable asthma or severe exacerbations, maintaining the ICS/LABA therapy without downtitration may be required. The recommendation against LABA use in patients whose asthma is adequately controlled with a low or medium dose ICS is supported. The recommendation that fixed-dose combination ICS/LABA products should be the only form in which LABAs are prescribed in adolescents and paediatric patients should be extended to all asthma patients.

SUMMARY

The current β agonist debate focuses on the optimal management approaches for the use of LABA therapy to both minimize risk and maximize clinical efficacy.

The safety of long-acting β2-agonists in the treatment of stable chronic obstructive pulmonary disease

BACKGROUND

Inhaled long-acting bronchodilators are the mainstay of pharmacotherapy for chronic obstructive pulmonary disease (COPD). Both the twice-daily long-acting β(2)-adrenoceptor agonists (LABAs) salmeterol and formoterol and the once-daily LABA indacaterol are indicated for use in COPD. This review examines current evidence for the safety of LABAs in COPD, focusing on their effect on exacerbations and deaths.

METHODS

We searched PubMed for placebo-controlled studies evaluating long-term (≥24 weeks) use of formoterol, salmeterol, or indacaterol in patients with stable COPD, published between January 1990 and September 2012. We summarized data relating to exacerbations and adverse events, particularly events related to COPD.

RESULTS

From 20 studies examined (8774 LABA-treated patients), there was no evidence of an association between LABA treatment and increased exacerbations, COPD-related adverse events, or deaths. Where analyzed as an efficacy outcome, LABA treatment was generally associated with significant or numerical reductions in COPD exacerbations compared with placebo. Incidences of COPD-related adverse events were similar for active and placebo treatments. The incidence of adverse events typically associated with the β(2)-agonist drug class such as skeletal muscle tremors and palpitations was low (often <1% of patients), and there were no reports of increased incidence of cardiac arrhythmias. The systemic effects of β(2)-adrenoceptor stimulation, such as high glucose and potassium levels, were considered minor.

CONCLUSION

Current evidence from clinical studies of the safety and tolerability profile of LABAs supports their long-term use in COPD.

The role of tiotropium in the management of asthma

Asthma is a chronic respiratory disease characterized by reversible airway obstruction that is secondary to an allergic inflammation and excessive smooth muscle contraction. Cholinergic signals were known to contribute significantly to the pathophysiology of asthma. However, the use of anti-cholinergic agents in asthma has been justified only in acute asthma exacerbations, until tiotropium bromide, a long-acting anti-cholinergic agent was introduced. Recent reports showing a promising role of tiotropium in the treatment of asthma have aroused interest of the use of anti-cholinergic agent for the management of asthma. This report describes pharmacological characteristics, potential effects on inflammatory cells, and the current status of tiotropium in the treatment of asthma.

Asthma mortality in Serbia: a 30-year analysis

INTRODUCTION

The asthma mortality pattern differs among countries. No published evidence is currently available on asthma mortality in a European low-middle-income country in socioeconomic transition. We analyzed the trend of asthma mortality rate in Serbia during the period 1980-2009.

MATERIALS AND METHODOLOGY

a descriptive study; source of data: Republic of Serbia Institute of Statistics Death Registry. We analyzed asthma mortality data in the total population, including gender specific analysis, and in the selected ≥ 5-34 year age group. The International Classification of Diseases codes for asthma 493 (1980-1996) and J45 + J46 (1997-2009) were included. Population estimates were based on 1991 and 2002 census data, with extrapolation.

RESULTS

The over-all average mortality rate was 7.27 ± 2.14/100,000 inhabitants. The mortality rate peaked in 1981 at 11.3/100,000 but was 4.45/100,000 in the last year of analysis. While both overall mortality rate, as well as gender specific rates, showed clear decreases over the observed 30-year period (average absolute annual decrease of 0.195/100,000 inhabitants, 0.241/100,000 men and 0.149/100,000 women; p < 0.001) with corresponding relative annual decreases of 2.9% for the whole population, 3.0% for men and 2.8% for women, a stable trend of the rate was found in the age group ≥ 5-34 years. Male-to-female ratio was 1.59 ± 0.186, on average and it showed a stable trend over the observed period.

CONCLUSION

Although the failure of the health care system during the socioeconomic crisis of the 1990s might have transiently affected asthma mortality rates, the overall mortality rate for the disease shows a favorable decreasing trend.

β2-Agonists upregulate PDE4 mRNA but not protein or activity in human airway smooth muscle cells from asthmatic and nonasthmatic volunteers

β(2)-Adrenergic receptor (β2AR) agonists induce airway relaxation via cAMP. Phosphodiesterase (PDE)s degrade and regulate cAMP, and in airway smooth muscle (ASM) cells PDE4D degrades cAMP. Long-acting β(2)-agonists are now contraindicated as monotherapy for asthma, and increased PDE4D has been speculated to contribute to this phenomenon. In this study we investigated the expression of PDE4D in asthmatic and nonasthmatic ASM cells and its regulation by formoterol and budesonide. Primary ASM cells from people with or without asthma were stimulated with transforming growth factor (TGF)-β(1), formoterol, and/or budesonide. PDE4D mRNA was assessed by real-time PCR, or PCR to assess splice variant production. PDE4D protein was assessed by Western blotting, and we investigated the effect of formoterol on cAMP production and PDE activity. Interleukin (IL)-6 was assessed using ELISA. PDE4D mRNA was dose dependently upregulated by formoterol, with a single splice variant, PDE4D5, present. Formoterol did not induce PDE4D protein at time points between 3 to 72 h, whereas it did induce and increase IL-6 secretion. We pretreated cells with actinomycin D and a proteasome inhibitor, MG132, and found no evidence of alterations in mRNA, protein expression, or degradation of PDE4D. Finally PDE activity was not altered by formoterol. This study shows, for the first time, that PDE4D5 is predominantly expressed in human ASM cells from people with and without asthma and that formoterol does not upregulate PDE4D protein production. This leads us to speculate that continual therapy with β2AR agonists is unlikely to cause PDE4-mediated tachyphylaxis.

Tiotropium is noninferior to salmeterol in maintaining improved lung function in B16-Arg/Arg patients with asthma

BACKGROUND

The efficacy and safety of inhaled long-acting β(2)-adrenergic agonists in asthmatic patients with the B16-Arg/Arg genotype has been questioned, and the use of antimuscarinics has been proposed as an alternative in patients whose symptoms are not controlled by inhaled corticosteroids (ICSs).

OBJECTIVE

We compared the efficacy and safety of the long-acting anticholinergic tiotropium with salmeterol and placebo added to an ICS in B16-Arg/Arg patients with asthma that was not controlled by ICSs alone.

METHODS

In a double-blind, double-dummy, placebo-controlled trial, after a 4-week run-in period with 50 μg of twice-daily salmeterol administered through a metered-dose inhaler, 388 asthmatic patients were randomized 1:1:1 to 16 weeks of treatment with 5 μg of Respimat tiotropium administered daily in the evening, 50 μg of salmeterol administered twice daily through a metered-dose inhaler, or placebo. Patients aged 18 to 67 years demonstrated reversibility to bronchodilators, and their symptoms were uncontrolled by regular ICSs (400-1000 μg of budesonide/equivalent). ICS regimens were maintained throughout the trial. The mean weekly morning peak expiratory flow (PEF) before randomization was 358 ± 115.7 L/min (range, 80.3-733.0 L/min).

RESULTS

Changes in weekly PEF from the last week of the run-in period to the last week of treatment (primary end point: change in PEF) were -3.9 ± 4.87 L/min (n = 128) for tiotropium and -3.2 ± 4.64 L/min (n = 134) for salmeterol, and these were superior to placebo (-24.6 ± 4.84 L/min, n = 125, P < .05). Tiotropium was noninferior to salmeterol (estimated difference, -0.78 L/min [95% CI, -13.096 to 11.53]; P = .002; α = .025, 1-sided; noninferiority, 20 L/min). Tiotropium and salmeterol were numerically superior to placebo in some patient-reported secondary outcomes. Adverse events were comparable across treatments.

CONCLUSION

Tiotropium was more effective than placebo and as effective as salmeterol in maintaining improved lung function in B16-Arg/Arg patients with moderate persistent asthma. Safety profiles were comparable.

Animal models of asthma: value, limitations and opportunities for alternative approaches

Asthma remains an area of considerable unmet medical need. Few new drugs have made it to the clinic during the past 50 years, with many that perform well in preclinical animal models of asthma, failing in humans owing to lack of safety and efficacy. The failure to translate promising drug candidates from animal models to humans has led to questions about the utility of in vivo studies and to demand for more predictive models and tools based on the latest technologies. Following a workshop with experts from academia and the pharmaceutical industry, we suggest here a disease modelling framework designed to better understand human asthma, and accelerate the development of safe and efficacious new asthma drugs that go beyond symptomatic relief.

Safe use of long-acting β-agonists: what have we learnt?

INTRODUCTION

Long-acting β-agonists (LABAs) added to inhaled corticosteroids (ICS) reduce symptoms, improve lung function and enhance overall asthma control. However, several studies have indicated an increased risk of asthma mortality and asthma-related serious adverse events and the FDA recently mandated restrictions to the use of LABAs in asthma.

AREAS COVERED

This review highlights the clinical studies on which safety analyses pertaining to salmeterol and formoterol have been based and then focuses on recent meta-analyses of safety outcomes with and without consideration of concomitant ICS.

EXPERT OPINION

The phenomenon of masking of inflammation by LABA if ICS dose is insufficient underscores the potential for confounding in determining real safety risks. Under-treatment with ICS and differential dosing of ICS in many trials are major factors driving the LABA safety concern. The FDA meta-analysis, when stratified for mandatory ICS use, found no significant increase in the composite outcome of asthma mortality, intubations and hospitalizations. Add-on therapy with LABA is effective and safe if the dose of ICS is adequate to treat airway inflammation. LABA and ICS given in a single device will negate the possibility of LABA monotherapy which is contraindicated. The FDA has recommended that LABAs be withdrawn when control is achieved with combination therapy but recent evidence suggests this may result in loss of symptom control.

Randomized controlled trial of adherence with single or combination inhaled corticosteroid/long-acting beta-agonist inhaler therapy in asthma

BACKGROUND

The inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA) combination inhaler has the potential to improve adherence with ICS therapy in asthma.

OBJECTIVE

To determine whether ICS/LABA combination inhaler therapy improves adherence compared with separate inhaler use.

METHODS

In a 24-week randomized controlled parallel group study, 111 subjects were prescribed 125 microg fluticasone dipropionate (FP) and 25 microg salmeterol, 2 actuations twice daily through either a combination inhaler or separate inhalers concurrently. Medication use was recorded by covert electronic monitors. The primary outcome variable was adherence during the final 6-week period, defined as the number of doses taken as a percentage of those prescribed.

RESULTS

Complete adherence data from the final 6-week period were available for 49 and 54 subjects in the separate and combination groups, respectively. The mean (SD) adherence was 73.7% (36.0) for FP, 76.7% (30.5) for salmeterol, and 82.4% (24.5) for FP/salmeterol. There were no significant differences in adherence between FP/salmeterol and FP (-8.7%; 95% CI, -10.6 to 3.3) and salmeterol (-5.6%; 95% CI, -16.4 to 5.1). There was no significant difference in overuse among the FP, salmeterol, or FP/salmeterol groups. In 2 (4%) of 49 subjects, salmeterol was effectively taken as monotherapy during a 6-week period.

CONCLUSION

In the setting of a randomized controlled trial, use of a combination ICS/LABA inhaler does not markedly increase adherence above that observed with separate inhaler use. LABA monotherapy was observed in a small proportion of patients prescribed ICS and LABA therapy via separate inhalers.

Salmeterol use and risk of hospitalization among emergency department patients with acute asthma

BACKGROUND

The safety of inhaled long-acting beta2-agonists (LABAs) in the treatment of chronic asthma remains controversial and has not been evaluated in emergency department (ED) patients with acute asthma.

OBJECTIVE

To determine whether ED patients undergoing long-term LABA therapy would have increased risk of asthma-related hospitalization compared with those not undergoing LABA therapy and whether concurrent long-term inhaled corticosteroid (ICS) therapy would mitigate this risk.

METHODS

Prospective cohort study of patients aged 12 to 54 years with acute asthma in 115 EDs. Four patient groups were created based on their asthma regimen: no ICS or salmeterol (group A), salmeterol monotherapy (group B), ICS monotherapy (group C), and combination ICS and salmeterol (group D).

RESULTS

Of the 2,236 included patients, group A had 1,221 patients (55%), group B had 48 patients (2%), group C had 787 patients (35%), and group D had 180 patients (8%); 489 patients (22%) required hospitalization. In a multivariable model controlling for 20 factors and using group A as the reference, group B had an increased risk of hospitalization (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.0-4.9), whereas groups C (OR, 1.1; 95% CI, 0.8-1.5) and D (OR, 1.2; 95% CI, 0.8-1.9) did not.

CONCLUSION

Among ED patients with acute asthma, those undergoing salmeterol monotherapy had an increased risk of hospitalization; however, this risk was not seen among patients undergoing combination ICS-salmeterol therapy. Our findings provide data from a unique ED population on clinical response to acute asthma treatment among patients undergoing long-term LABA therapy.

Long-acting beta-agonists and asthma death: how useful are different study designs to evaluate the potential association?

BACKGROUND AND OBJECTIVE

There is uncertainty whether long-acting beta-agonist (LABA) drugs may increase the risk of asthma mortality. This uncertainty is partly due to the difficulty in estimating the risk of rare adverse outcomes. The aim of this paper is to consider the utility of three approaches to determine the magnitude and statistical significance of this potential association.

METHODS

Using a death rate of 9 per 10,000 subjects with asthma, derived from a meta-analysis of randomized controlled trials (RCTs) of formoterol, power calculations for a single RCT, a case-control study, and a meta-analysis of RCTs were determined.

RESULTS

For each study design, the number of subjects and events required to have adequate statistical power to detect a 1.5- and 2.0-fold increased risk of death were calculated. For a single RCT, or meta-analyses of RCTs, very large sample sizes are required. In contrast, case-control methodology represents a realistic method of estimating the risk of rare serious adverse events.

CONCLUSIONS

Major practical limitations exist in the use of RCTs to determine the potential risk of death with LABAs in the treatment of asthma. Case-control methodology may be more effective in establishing causation; however, if selection bias occurs, estimates of risk may be inaccurate.

Asthma: time to confront some inconvenient truths

Despite major advances in the understanding of the pathogenesis of asthma and improvements in management, the accompanying benefits from public health initiatives and clinical practice have arguably been less than expected. For example, there are no effective public health strategies or treatment regimes that reduce the risk of developing asthma or influence its natural history. These represent priority areas for future translational research, which would need to investigate genetic and environmental interactions and vaccine strategies. In terms of asthma management it is tempting to focus on novel drug therapies; however, a case can be made that the priority is to undertake research that leads to improvements in the use of existing treatments through public health and primary care initiatives. Guidelines represent an important component of this approach, with recommendations for asthma imbedded within respiratory guidelines that can be implemented in the developing world where other acute and chronic respiratory disorders are common. This approach offers the best opportunity to close the gap between what is currently achieved in asthma management and that which is potentially achievable.

Regional variation and adherence to guidelines for drug treatment of asthma

AIMS

To describe the utilization of antiasthmatic drugs in Sweden and to explore regional variations in drug utilization and adherence to guidelines for rational drug prescribing of antiasthmatics and their rationale.

METHODS

Data on antiasthmatic drugs dispensed between July 2005 and December 2008 to all Swedish citizens aged between 18 and 44 years were obtained from the Swedish National Prescribed Drug Register. The period prevalence was determined by analyzing the number of users/1000 inhabitants, and the incidence by analyzing the number of new users after an 18-month drug-free wash-out period. Three drug-related indicators were used to assess the adherence to guidelines. All measures were analyzed by gender and region.

RESULTS

A total of 161,000 patients were dispensed antiasthmatics in 2007, corresponding to a prevalence of 4 and 6% among men and women, respectively; the incidence rates were 2 and 3%, respectively. The total drug utilization and adherence to guidelines varied between regions. The total drug expenditures of antiastmatics were 258 million SEK (28 million euro), with fixed dose combinations accounting for 46% of the expenditure. No relation was found between models for allocating prescribing budgets or clear Drug and Therapeutics Committee recommendations and adherence to guidelines.

CONCLUSION

There are large regional variations in the utilization of antiasthmatics between Swedish regions, with substantial room for improvement in the adherence to guidelines. New methods of influencing physician behavior may be needed in the future to enhance adherence.

Safety of budesonide/formoterol maintenance and reliever therapy in asthma trials

BACKGROUND

The safety of long-acting beta(2)-agonists (LABAs) in asthma is debated. This study examined the safety of the inhaled corticosteroid (ICS)/LABA combination budesonide/formoterol dry powder inhaler used as maintenance and reliever therapy versus combination treatments based on guideline recommendations.

METHODS

Safety data from six double-blind, randomised clinical trials (RCTs) in asthma where budesonide/formoterol was used as maintenance and reliever therapy for at least 6 months were reviewed (N=14 346). All-cause mortality and asthma-related serious adverse events (SAEs) (co-primary endpoints), overall and cardiac SAEs, and discontinuations due to adverse events (DAEs) were assessed. Estimated Mantel-Haenszel (MH) relative risks (RR) with this regimen versus comparators were calculated.

RESULTS

There was no increase in all-cause mortality with budesonide/formoterol maintenance and reliever therapy (four deaths [0.07%] versus nine [0.10%]; pooled MH RR 0.70, 95% confidence interval [CI] 0.21-2.30). Asthma-related SAEs were reduced with budesonide/formoterol maintenance and reliever therapy: 41 (0.73%) versus 121 (1.38%); pooled MH RR 0.59, 95% CI 0.42-0.85. All-cause and asthma-related DAEs were also reduced with budesonide/formoterol maintenance and reliever therapy: pooled MH RR 0.60 (95% CI 0.46-0.79) and 0.43 (0.28-0.68), respectively. Overall and cardiac-related SAEs were comparable between treatment groups: pooled MH RR 0.96 (95% CI 0.82-1.14) and 1.26 (0.72-2.22), respectively.

CONCLUSION

Budesonide/formoterol dry powder inhaler maintenance and reliever therapy was well tolerated in RCTs versus fixed-dose alternatives and not associated with increased risk of death or cardiac-related SAEs and DAEs, and asthma-related SAEs and DAEs were significantly reduced. Given the limitations of RCTs, particularly exclusion of patients with co-morbidities, ongoing surveillance is appropriate.

[Impact of preventive treatment with long-acting beta(2)-adrenergic agonists and inhaled corticosteroids on the morbidity and mortality of severe asthma exacerbations in 1543 patients]

BACKGROUND AND OBJECTIVES

Recent systematic reviews and meta-analyses examining long-acting #b(2)-adrenergic agonists (LABA) as maintenance treatment for asthma have shown surprisingly conflicting results. The aim of the present study was to determine the impact, in terms of efficacy and safety, of previous maintenance treatment on severe asthma exacerbations.

PATIENTS AND METHODS

We retrospectively evaluated the clinical characteristics of exacerbations experienced by 1543 patients with moderate persistent and severe persistent asthma. Drug therapy was as follows: a combination of inhaled LABAs and corticosteroids (493 patients), an inhaled corticosteroid only (456 patients), and no maintenance treatment (594 patients).

RESULTS

Asthmatic patients taking LABAs did not show higher mortality, longer stay in the intensive care unit, longer hospital stay, lower pH, or worse airflow obstruction than the other 2 groups. On the contrary, they had a higher mean (SD) forced expiratory volume in 1 second at discharge (54% [16%]) than patients taking inhaled corticosteroids (48% [19%]) and patients taking no maintenance treatment (48% [20%]) (P=.009). Patients taking no maintenance treatment also had lower mean (SD) pH values (7.37 [0.11]) than patients taking LABAs (7.39 [0.09]) and patients taking inhaled corticosteroids (7.39 [0.08]) (P=.002), and more admissions to the intensive care unit (11.1% vs 6.5% and 7.7%; P=.002 and P=.018, respectively).

CONCLUSIONS

This study did not reveal higher morbidity or mortality in severe asthma exacerbations in patients with moderate persistent or severe persistent asthma who had received inhaled LABAs combined with inhaled corticosteroids. On the contrary, asthma patients who did not use maintenance treatment experienced more severe asthma exacerbations.

Safety of long-acting beta-agonists: are new data really required?

Despite 20 years of debate, several US Food and Drug Administration (FDA) hearings, black-box warnings, and many descriptive articles and metaanalyses, controversy regarding the safety of long-acting beta-agonist (LABA) treatment in asthma patients continues. This has resulted in a recent call for another large and definitive safety study. This commentary focuses first on data provided in the metaanalysis recently undertaken by the FDA of safety outcomes among 60,954 individuals in 110 LABA trials, and second on the sample size that would be required for a new definitive study of LABA safety in the presence of mandatory treatment with an inhaled corticosteroid (ICS). A critical stratified analysis in the FDA report involving 15,192 individuals indicates that a LABA used with mandatory ICS therapy was not associated with an increased risk of asthma-related mortality, intubations, or exacerbations (risk difference [RD], 0.25 per 1,000 individuals; 95% confidence interval [CI], -1.69 to 2.18). Using the same stratified data to calculate the sample size required to prove or disprove an association between the use of LABA with mandatory ICS therapy and adverse outcomes, assuming the RD is exactly 0.25, and ignoring the 95% CI, which includes 0.0 or even a negative risk, such a study is both logistically and scientifically impossible. A new study is not practicable, nor is one needed in the light of current analyses of existing data. It is time to learn from the past, to rigorously avoid LABA monotherapy in asthma, and to use a LABA (when indicated) always in mandatory combination with appropriate doses of an ICS.

The beta-agonist saga and its clinical relevance: on and on it goes

The decision by the Food and Drug Administration to issue a "black box" warning for long-acting beta-agonists has been followed by a series of pharmacoepidemiological studies focusing on the safety of these drugs. However, these provide the clinician with mixed messages and do not offer clear guidance as to whether adverse responses to beta-agonists are a relevant consideration in individual patients. Simultaneously, there is a growing body of evidence that continuous or high dose-beta-agonist exposure is proinflammatory and that, paradoxically, airway hyperresponsiveness is enhanced, not attenuated. Also, pharmacological theory regarding the pathophysiological function of the beta-adrenoceptor is having to be revised. A recent clinical study has even suggested that beta-blockers rather than beta-agonists may be beneficial in asthma. In practice, there are individuals in whom excessive beta-agonist use contributes adversely to poor asthma control. The recommendation that concomitant use of inhaled steroids will obviate any risks associated with beta-agonists is not in fact fool-proof. Clinicians need to be aware of how to identify and manage patients for whom beta-agonist treatment is a problem rather than a solution. They constitute a small but important subgroup of patients with difficult asthma.