Effects of montelukast on surrogate inflammatory markers in corticosteroid-treated patients with asthma

Current state and future prospect of the therapeutic strategy targeting cysteinyl leukotriene metabolism in asthma

Asthma is an allergic disorder with dominant type 2 airway inflammation, and its prevalence is increasing worldwide. Inhalation of corticosteroids is the primary treatment for asthma along with add-on drugs, including long-acting β2 agonists and/or cysteinyl leukotriene (cys-LT) receptor antagonists, in patients with poorly controlled asthma. Cys-LTs are composed of leukotriene C4 (LTC₄), LTD₄, and LTE₄, which are enzymatically metabolized from arachidonic acid. These molecules act as inflammatory mediators through different types of high-affinity receptors, namely, CysLT₁, CysLT₂, and CysLT₃ (also named as GPR99). CysLT₁ antagonists possessing anti-inflammatory and bronchodilatory effects can be orally administered to patients with asthma. Recently, molecular biology-based studies have revealed the mechanism of inflammatory responses via other receptors, such as CysLT₂ and CysLT₃, as well as the importance of upstream inflammatory regulators, including type 2 cytokines (e.g., interleukins 4 and 5), in controlling cys-LT metabolism. These findings indicate the therapeutic potential of pharmacological agents targeting cys-LT metabolism-related receptors and enzymes, and antibody drugs neutralizing or antagonizing type 2 cytokines. This review focuses on the current state and future prospect of the therapeutic strategy targeting cys-LT metabolism.

Comparison between montelukast and tiotropium as add-on therapy to inhaled corticosteroids plus a long-acting β2-agonist in for patients with asthma

Objective: Asthma often remains uncontrolled despite treatment with inhaled corticosteroids (ICS) alone or with ICS plus a long-acting β₂-agonist (LABA). The recommended alternative is the addition of either montelukast or tiotropium. The aim of this study was to compare the effects of montelukast and tiotropium on airway inflammation and remodeling in persistent asthma. Methods: Eighty-seven patients with asthma were treated with budesonide and formoterol (640/18 μg); then, the patients were randomly allocated to three groups to receive oral montelukast (10 mg/day), inhaled tiotropium (5 μg/day), or no add-on to the maintenance therapy for 48 weeks. Fractional exhaled nitric oxide (FeNO) and pulmonary function were measured, and quantitative computed tomography was performed. Results: Compared to the maintenance therapy, add-on montelukast significantly decreased FeNO (p < 0.05) and improved airflow obstruction (p < 0.05), whereas airway dimensions remained unchanged. Changes in FeNO were significantly correlated with changes in FEV₁ (r = -0.71, p < 0.001). In contrast, the addition of tiotropium significantly decreased airway wall area corrected for body surface area (WA/BSA) (p < 0.05), decreased wall thickness (T/√BSA) (p < 0.05) and improved airflow obstruction (p < 0.05) with no change in FeNO. Changes in WA/BSA and T/√BSA were significantly correlated with the change in percentage predicted FEV₁ (r = -0.84, p < 0.001 and r = -0.59, p < 0.01, respectively). Conclusions:Adding either montelukast or tiotropium to ICS/LABA may provide additive benefits with respect to the pulmonary function and airway inflammation or remodeling in patients with asthma.

Childhood asthma exacerbations and the Arg16 β2-receptor polymorphism: A meta-analysis stratified by treatment

BACKGROUND

The Gly-to-Arg substitution at the 16 position (rs1042713) in the β2-adrenoceptor gene (ADRB2) is associated with enhanced downregulation and uncoupling of β2-receptors.

OBJECTIVES

We sought to undertake a meta-analysis to test the hypothesis that there is an interaction between the A allele of rs1042713 (Arg16 amino acid) and long-acting β-agonist (LABA) exposure for asthma exacerbations in children.

METHODS

Children with diagnosed asthma were recruited in 5 populations (BREATHE, Genes-Environments and Admixture in Latino Americans II, PACMAN, the Paediatric Asthma Gene Environment Study, and the Pharmacogenetics of Adrenal Suppression with Inhaled Steroid Study). A history of recent exacerbation and asthma treatment was determined from questionnaire data. DNA was extracted, and the Gly16Arg genotype was determined.

RESULTS

Data from 4226 children of white Northern European and Latino origin were analyzed, and the odds ratio for exacerbation increased by 1.52 (95% CI, 1.17-1.99; P = .0021) for each copy of the A allele among the 637 children treated with inhaled corticosteroids (ICSs) plus LABAs but not for treatment with ICSs alone (n = 1758) or ICSs plus leukotriene receptor antagonist (LTRAs; n = 354) or ICSs plus LABAs plus LTRAs (n = 569).

CONCLUSIONS

The use of a LABA but not an LTRA as an "add-on controller" is associated with increased risk of asthma exacerbation in children carrying 1 or 2 A alleles at rs1042713. Prospective genotype-stratified clinical trials are now required to explore the potential role of rs1042713 genotyping for personalized asthma therapy in children.

Effect of beta2-adrenergic agonists on eosinophil adhesion, superoxide anion generation, and degranulation

BACKGROUND

Eosinophils play important roles in the development of asthma exacerbation. Viral infection is a major cause of asthma exacerbation, and the expression of IFN-γ-inducible protein of 10 kDa (IP-10) and cysteinyl leukotrienes (cysLTs) is up-regulated in virus-induced asthma. As β2-adrenergic agonists, such as formoterol or salbutamol, are used to treat asthma exacerbation, we examined whether formoterol or salbutamol could modify eosinophil functions such as adhesiveness, particularly those activated by cysLTs or IP-10.

METHODS

Eosinophils were isolated from the blood of healthy subjects and were pre-incubated with either formoterol or salbutamol, and subsequently stimulated with IL-5, LTD4, or IP-10. Adhesion of eosinophils to intercellular cell adhesion molecule (ICAM)-1 was measured using eosinophil peroxidase assays. The generation of eosinophil superoxide anion (O2(-)) was examined based on the superoxide dismutase-inhibitable reduction of cytochrome C. Eosinophil-derived neurotoxin (EDN) release was evaluated by ELISA as a marker of degranulation.

RESULTS

Neither formoterol nor salbutamol suppressed the spontaneous adhesion of eosinophils to ICAM-1. However, when eosinophils were activated by IL-5, LTD4, or IP-10, formoterol, but not salbutamol, suppressed the adhesion to ICAM-1. Formoterol also suppressed IL-5, LTD4, or IP-10 induced eosinophil O2(-) generation or EDN release.

CONCLUSIONS

These findings suggest that formoterol, but not salbutamol, suppresses eosinophil functions enhanced by IL-5, LTD4, or IP-10. As these factors are involved in the development of asthma exacerbation, our results strongly support the hypothesis that administration of formoterol is a novel strategy for treating asthma exacerbation.

Effect of montelukast on clinical score and cytokine levels of infants for clinically diagnosed acute bronchiolitis

BACKGROUND

Acute bronchiolitis comprises a major cause for morbidity in infants with viral infection which induces an immune inflammatory response that may produce long lasting harmful effects. Currently, there is no effective therapy for bronchiolitis.

OBJECTIVE

Our aim was to investigate the efficacy of five-day montelukast therapy in acute bronchiolitis management.

METHODS

The study included 50 infants with acute bronchiolitis. The infants with first episode of acute bronchiolitis were randomly assigned to receive daily montelukast dose of 4mg over five days after admission or no treatment. Plasma eotaxin, IL-4, IL-8 and IFN-gamma levels were evaluated before and after treatment by ELISA method. In the present study, the primary outcome measure was change in clinical severity score, whilst secondary outcome measures were changes in plasma eotaxin, IL-4, IL-8, IFN-gamma levels.

RESULTS

No significant differences was found in clinical severity score with five-day montelukast treatment (p>0.05, Mann-Whitney U test). There were no significant differences in plasma eotaxin, IL-4, IL-8, IFN-gamma levels between the groups (p>0.05 Mann-Whitney U test). There was significant decrease in plasma IFN-gamma levels following five-day montelukast treatment (p=0.027, Wilcoxon). There were no significant differences in plasma IL-4, IL-8, IFN-gamma levels between the groups after five-day montelukast treatment (p>0.05, Wilcoxon). There was significant increase in eotaxin levels after five-day montelukast treatment (p=0.009, Wilcoxon).

CONCLUSION

Our study showed that montelukast affected plasma IFN-gamma and eotaxin levels after five days of treatment. Further studies are needed to demonstrate effects of montelukast on chemokine levels in bronchiolitis.

Addition to inhaled corticosteroids of long-acting beta2-agonists versus anti-leukotrienes for chronic asthma

BACKGROUND

Asthma patients who continue to experience symptoms despite taking regular inhaled corticosteroids (ICS) represent a management challenge. Long-acting beta2-agonists (LABA) and anti-leukotrienes (LTRA) are two treatment options that could be considered as add-on therapy to ICS.

OBJECTIVES

To compare the safety and efficacy of adding LABA versus LTRA to the treatment regimen for children and adults with asthma who remain symptomatic in spite of regular treatment with ICS. We specifically wished to examine the relative impact of the two agents on asthma exacerbations, lung function, symptoms, quality of life, adverse health events and withdrawals.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register until December 2012. We consulted reference lists of all included studies and contacted pharmaceutical manufacturers to ask about other published or unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) conducted in adults or children with recurrent asthma that was treated with ICS along with a fixed dose of a LABA or an LTRA for a minimum of four weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the risk of bias of included studies and extracted data. We sought unpublished data and further details of study design when necessary.

MAIN RESULTS

We included 18 RCTs (7208 participants), of which 16 recruited adults and adolescents (6872) and two recruited children six to 17 years of age (336) with asthma and significant reversibility to bronchodilator at baseline. Fourteen (79%) trials were of high methodological quality.The risk of exacerbations requiring systemic corticosteroids (primary outcome of the review) was significantly lower with the combination of LABA + ICS compared with LTRA + ICS-from 13% to 11% (eight studies, 5923 adults and 334 children; risk ratio (RR) 0.87, 95% confidence interval (CI) 0.76 to 0.99; high-quality evidence). The number needed to treat for an additional beneficial outcome (NNTB) with LABA compared with LTRA to prevent one additional exacerbation over four to 102 weeks was 62 (95% CI 34 to 794). The choice of LTRA, the dose of ICS and the participants' age group did not significantly influence the magnitude of effect. Although results were inconclusive, the effect appeared stronger in trials that used a single device rather than two devices to administer ICS and LABA and in trials of less than 12 weeks' duration.The addition of LABA to ICS was associated with a statistically greater improvement from baseline in lung function, as well as in symptoms, rescue medication use and quality of life, although the latter effects were modest. LTRA was superior in the prevention of exercise-induced bronchospasm. More participants were satisfied with the combination of LABA + ICS than LTRA + ICS (three studies, 1625 adults; RR 1.12, 95% CI 1.04 to 1.20; moderate-quality evidence). The overall risk of withdrawal was significantly lower with LABA + ICS than with LTRA + ICS (13 studies, 6652 adults and 308 children; RR 0.84, 95% CI 0.74 to 0.96; moderate-quality evidence). Although the risk of overall adverse events was equivalent between the two groups, the risk of serious adverse events (SAE) approached statistical significance in disfavour of LABA compared with LTRA (nine studies, 5658 adults and 630 children; RR 1.33, 95% CI 0.99 to 1.79; P value 0.06; moderate-quality evidence), with no apparent impact of participants' age group.The following adverse events were reported, but no significant differences were demonstrated between groups: headache (11 studies, N = 6538); cardiovascular events (five studies, N = 5163), osteopenia and osteoporosis (two studies, N = 2963), adverse events (10 studies, N = 5977 adults and 300 children). A significant difference in the risk of oral moniliasis was noted, but this represents a low occurrence rate.

AUTHORS' CONCLUSIONS

In adults with asthma that is inadequately controlled by predominantly low-dose ICS with significant bronchodilator reversibility, the addition of LABA to ICS is modestly superior to the addition of LTRA in reducing oral corticosteroid-treated exacerbations, with an absolute reduction of two percentage points. Differences favouring LABA over LTRA as adjunct therapy were observed in lung function and, to a lesser extend, in rescue medication use, symptoms and quality of life. The lower overall withdrawal rate and the higher proportion of participants satisfied with their therapy indirectly favour the combination of LABA + ICS over LTRA + ICS. Evidence showed a slightly increased risk of SAE with LABA compared with LTRA, with an absolute increase of one percentage point. Our findings modestly support the use of a single inhaler for the delivery of both LABA and low- or medium-dose ICS. Because of the paucity of paediatric trials, we are unable to draw firm conclusions about the best adjunct therapy in children.

Leukotriene receptor antagonists pranlukast and montelukast for treating asthma

INTRODUCTION

The prevalence of bronchial asthma, which is a chronic inflammatory disorder of the airway, is increasing worldwide. Although inhaled corticosteroids (ICS) play a central role in the treatment of asthma, they cannot achieve good control for all asthmatics, and medications such as leukotriene receptor antagonists (LTRAs) with bronchodilatory and anti-inflammatory effects often serve as alternatives or add-on drugs.

AREAS COVERED

Clinical trials as well as basic studies of montelukast and pranlukast in animal models are ongoing. This review report clarifies the current status of these two LTRAs in the treatment of asthma and their future direction.

EXPERT OPINION

LTRAs could replace ICS as first-line medications for asthmatics who are refractory to ICS or cannot use inhalant devices. Further, LTRAs are recommended for asthmatics under specific circumstances that are closely associated with cysteinyl leukotrienes (cysLTs). Considering the low incidence of both severe adverse effects and the induction of tachyphylaxis, oral LTRAs should be more carefully considered for treating asthma in the clinical environment. Several issues such as predicted responses, effects of peripheral airway and airway remodeling and alternative administration routes remain to be clarified before LTRAs could serve a more effective role in the treatment of asthma.

Addition of anti-leukotriene agents to inhaled corticosteroids in children with persistent asthma

BACKGROUND

In the treatment of children with mild persistent asthma, low-dose inhaled corticosteroids (ICS) are recommended as the preferred monotherapy (referred to as step 2 of therapy). In children with inadequate asthma control on low doses of ICS (step 2), asthma management guidelines recommend adding an anti-leukotriene agent to existing ICS as one of three therapeutic options to intensify therapy (step 3).

OBJECTIVES

To compare the efficacy and safety of the combination of anti-leukotriene agents and ICS to the use of the same, an increased, or a tapering dose of ICS in children and adolescents with persistent asthma who remain symptomatic despite the use of maintenance ICS. In addition, we wished to determine the characteristics of people or treatments, if any, that influenced the magnitude of response attributable to the addition of anti-leukotrienes.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of Trials (CAGR), which were derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, AMED, and CINAHL; and the handsearching of respiratory journals and meeting abstracts, as well as the www.clinicaltrials.gov website. The search was conducted until January 2013.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) conducted in children and adolescents, aged one to 18 years, with asthma, who remained symptomatic despite the use of a stable maintenance dose of ICS and in whom anti-leukotrienes were added to the ICS if they were compared to the same, an increased, or a tapering dose of ICS for at least four weeks.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by The Cochrane Collaboration.

MAIN RESULTS

Five paediatric (parallel group or cross-over) trials met the inclusion criteria. We considered two (40%) trials to be at a low risk of bias. Four published trials, representing 559 children (aged ≥ six years) and adolescents with mild to moderate asthma, contributed data to the review. No trial enrolled preschoolers. All trials used montelukast as the anti-leukotriene agent administered for between four and 16 weeks. Three trials evaluated the combination of anti-leukotrienes and ICS compared to the same dose of ICS alone (step 3 versus step 2). No statistically significant group difference was observed in the only trial reporting participants with exacerbations requiring oral corticosteroids over four weeks (N = 268 participants; risk ratio (RR) 0.80, 95% confidence interval (CI) 0.34 to 1.91). There was also no statistically significant difference in percentage change in FEV₁ (forced expiratory volume in 1 second) with mean difference (MD) 1.3 (95% CI -0.09 to 2.69) in this trial, but a significant group difference was observed in the morning (AM) and evening (PM) peak expiratory flow rates (PEFR): N = 218 participants; MD 9.70 L/min (95% CI 1.27 to 18.13) and MD 10.70 (95% CI 2.41 to 18.99), respectively. One trial compared the combination of anti-leukotrienes and ICS to a higher-dose of ICS (step 3 versus step 3). No significant group difference was observed in this trial for participants with exacerbations requiring rescue oral corticosteroids over 16 weeks (N = 182 participants; RR 0.82, 95% CI 0.54 to 1.25), nor was there any significant difference in exacerbations requiring hospitalisation. There was no statistically significant group difference in withdrawals overall or because of any cause with either protocol. No trial explored the impact of adding anti-leukotrienes as a means to taper the dose of ICS.

AUTHORS' CONCLUSIONS

The addition of anti-leukotrienes to ICS is not associated with a statistically significant reduction in the need for rescue oral corticosteroids or hospital admission compared to the same or an increased dose of ICS in children and adolescents with mild to moderate asthma. Although anti-leukotrienes have been licensed for use in children for over 10 years, the paucity of paediatric trials, the absence of data on preschoolers, and the variability in the reporting of relevant clinical outcomes considerably limit firm conclusions. At present, there is no firm evidence to support the efficacy and safety of anti-leukotrienes as add-on therapy to ICS as a step-3 option in the therapeutic arsenal for children with uncontrolled asthma symptoms on low-dose ICS.

Tailored second-line therapy in asthmatic children with the Arg(16) genotype

The Arg(16) β(2) receptor genotype confers increased susceptibility to exacerbations in asthmatic children taking regular LABA (long-acting β(2) agonists). We therefore evaluated using montelukast as an alternative to salmeterol as tailored second-line asthma controller therapy in children expressing this susceptible genotype. A total of 62 persistent asthmatic children with the homozygous Arg16 genotype were randomized to receive salmeterol (50 μg, b.i.d.) or montelukast (5 or 10 mg, once daily) as an add-on to inhaled fluticasone for 1 year. School absences (the primary outcome) were reduced with montelukast compared with salmeterol {difference in score=-0.40 [95% CI (confidence interval), -0.22 to -0.58]; P=0.005}. Salbutamol use was also reduced with montelukast compared with salmeterol [difference in score=-0.47 (95% CI, -0.16 to -0.79); P<0.0001]. Greater improvements occurred in both symptom and quality of life scores with montelukast against salmeterol, whereas there was no difference in FEV(1) (forced expiratory volume in 1 s). In conclusion, montelukast may be suitable as tailored second-line controller therapy instead of salmeterol in asthmatic children expressing the susceptible Arg(16) genotype, a move towards a personalized medicine approach to management.

Role of leukotriene receptor antagonists in the management of pediatric asthma: an update

At present, the main indications for leukotriene receptor antagonists (LTRA) in pediatric asthma are as add-on therapy to inhaled corticosteroids (ICS) and as initial controller therapy in children with mild asthma, especially those who cannot or will not use ICS. LTRA are also useful for patients who have concomitant rhinitis, and patients with viral-induced wheeze and exercise-induced asthma. It should be noted that the benefits of LTRA therapy have been demonstrated in children as young as 6 months of age and recent clinical trials have further proven the benefits of LTRA in acute asthma exacerbations. However, considering the important pro-inflammatory effects that leukotrienes (LT) have in experimental models of asthma, it may seem surprising that LTRA treatment outcomes are not better and that in some clinical trials only a minority of patients could be classified as full responders. This could be explained by potential additional LT receptors that are not affected by LTRA. Such receptors could represent new therapeutic targets in asthma. Furthermore, progress in differentiating between asthma phenotypes that result from different pathogenic mechanisms, some of which may involve LT to a lesser degree, should lead to an improved, personalized use of LTRA for treating asthma.

Anti-leukotriene agents compared to inhaled corticosteroids in the management of recurrent and/or chronic asthma in adults and children

BACKGROUND

Anti-leukotrienes (5-lipoxygenase inhibitors and leukotriene receptors antagonists) serve as alternative monotherapy to inhaled corticosteroids (ICS) in the management of recurrent and/or chronic asthma in adults and children.

OBJECTIVES

To determine the safety and efficacy of anti-leukotrienes compared to inhaled corticosteroids as monotherapy in adults and children with asthma and to provide better insight into the influence of patient and treatment characteristics on the magnitude of effects.

SEARCH METHODS

We searched MEDLINE (1966 to Dec 2010), EMBASE (1980 to Dec 2010), CINAHL (1982 to Dec 2010), the Cochrane Airways Group trials register, and the Cochrane Central Register of Controlled Trials (Dec 2010), abstract books, and reference lists of review articles and trials. We contacted colleagues and the international headquarters of anti-leukotrienes producers.

SELECTION CRITERIA

We included randomised trials that compared anti-leukotrienes with inhaled corticosteroids as monotherapy for a minimum period of four weeks in patients with asthma aged two years and older.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the methodological quality of trials and extracted data. The primary outcome was the number of patients with at least one exacerbation requiring systemic corticosteroids. Secondary outcomes included patients with at least one exacerbation requiring hospital admission, lung function tests, indices of chronic asthma control, adverse effects, withdrawal rates and biological inflammatory markers.

MAIN RESULTS

Sixty-five trials met the inclusion criteria for this review. Fifty-six trials (19 paediatric trials) contributed data (representing total of 10,005 adults and 3,333 children); 21 trials were of high methodological quality; 44 were published in full-text. All trials pertained to patients with mild or moderate persistent asthma. Trial durations varied from four to 52 weeks. The median dose of inhaled corticosteroids was quite homogeneous at 200 µg/day of microfine hydrofluoroalkane-propelled beclomethasone or equivalent (HFA-BDP eq). Patients treated with anti-leukotrienes were more likely to suffer an exacerbation requiring systemic corticosteroids (N = 6077 participants; risk ratio (RR) 1.51, 95% confidence interval (CI) 1.17, 1.96). For every 28 (95% CI 15 to 82) patients treated with anti-leukotrienes instead of inhaled corticosteroids, there was one additional patient with an exacerbation requiring rescue systemic corticosteroids. The magnitude of effect was significantly greater in patients with moderate compared with those with mild airway obstruction (RR 2.03, 95% CI 1.41, 2.91 versus RR 1.25, 95% CI 0.97, 1.61), but was not significantly influenced by age group (children representing 23% of the weight versus adults), anti-leukotriene used, duration of intervention, methodological quality, and funding source. Significant group differences favouring inhaled corticosteroids were noted in most secondary outcomes including patients with at least one exacerbation requiring hospital admission (N = 2715 participants; RR 3.33; 95% CI 1.02 to 10.94), the change from baseline FEV(1) (N = 7128 participants; mean group difference (MD) 110 mL, 95% CI 140 to 80) as well as other lung function parameters, asthma symptoms, nocturnal awakenings, rescue medication use, symptom-free days, the quality of life, parents' and physicians' satisfaction. Anti-leukotriene therapy was associated with increased risk of withdrawals due to poor asthma control (N = 7669 participants; RR 2.56; 95% CI 2.01 to 3.27). For every thirty one (95% CI 22 to 47) patients treated with anti-leukotrienes instead of inhaled corticosteroids, there was one additional withdrawal due to poor control. Risk of side effects was not significantly different between both groups.

AUTHORS' CONCLUSIONS

As monotherapy, inhaled corticosteroids display superior efficacy to anti-leukotrienes in adults and children with persistent asthma; the superiority is particularly marked in patients with moderate airway obstruction. On the basis of efficacy, the results support the current guidelines' recommendation that inhaled corticosteroids remain the preferred monotherapy. 

A randomized primary care trial of steroid titration against mannitol in persistent asthma: STAMINA trial

BACKGROUND

We compared titrating inhaled corticosteroid (ICS) against mannitol airway hyperresponsiveness (AHR) or a reference strategy (control) based on symptoms, reliever use, and lung function in primary care.

METHODS

One hundred sixty-four patients with persistent asthma were randomized in parallel group fashion following an initial ICS tapering. Subsequent ICS doses (as ciclesonide) were titrated against either the provocative dose of mannitol causing a 10% fall in FEV(1) (PD(10)) (AHR strategy) or a control group (reference strategy) over a 1-year period.

RESULTS

One hundred nineteen participants (n = 61 AHR, n = 58 control) completed the study. Time to first mild exacerbation was not significantly different: hazard ratio, 1.29; 95% CI, 0.716-2.31; P = .40. Although there were 27% fewer total number of mild exacerbations over 12 months in AHR vs control groups (n = 84 vs n = 115, P = .03), there was no difference in severe exacerbations (n = 12 vs n = 13). No other significant differences were seen between groups with the exception of mannitol PD(10) and ICS dose. There was a 1.52 (95% CI, 0.61-2.42; P = .001) doubling dose difference in mannitol PD(10) between AHR vs control groups. The final mean daily ciclesonide dose was higher (P < .0001) in AHR vs control groups (514 μg vs 208 μg), with no associated significant suppression of overnight urinary cortisol/creatinine. Significant improvements were seen within the AHR group but not the control group for the provocative concentration of methacholine causing a 20% fall in FEV(1) (P < .05), salivary eosinophilic cationic protein (P < .05), exhaled nitric oxide (P < .05), symptoms (P < .005), and reliever use (P < .001).

CONCLUSIONS

Mannitol challenge was well tolerated in a primary care setting. Using mannitol resulted in exposure to a higher dose of ciclesonide, which was associated with equivocal effects on exacerbations without associated adrenal suppression. Large-scale trials using mannitol in patients with more severe disease may now be warranted to further define its role.

TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01216579; URL: www.clinicaltrials.gov.

The role of measuring airway hyperresponsiveness and inflammatory biomarkers in asthma

Asthma is characterized by inflammation and airway hyperresponsiveness, which results in episodic airflow obstruction. It is diagnosed once a compatible clinical history plus objective evidence of diurnal variability in peak expiratory flow or significant reversibility to inhaled bronchodilator is documented. In accordance with current guidelines, measures of airway calibre and symptoms allow patients and clinicians to assess the degree of asthma control and titrate pharmacotherapy. However, these parameters fail to reflect the extent of underlying endobronchial inflammation and airway hyperresponsiveness, which in turn suggests that additional measures of asthma control may be of benefit. This evidence-based review highlights ways by which inflammation and airway hyperresponsiveness can be assessed and how they may provide additional useful information in the diagnosis and management of asthmatic patients.

[Montelukast in the treatment of mild to moderate persistent asthma]

INTRODUCTION

Anti-inflammatory preventive treatment is recommended in cases of persistent asthma. Besides inhaled corticosteroids (ICS), which represent the mainstay of treatment, other therapeutic options are available, of which only antileukotrienes are approved for all age groups.

BACKGROUND

Given as a substitute of low-dose ICS, montelukast prevents exacerbations as efficiently and for a longer period than long-acting β2-agonists. Montelukast is as efficient as doubling the dose of ICS on asthma symptoms in cases of inadequate control with low-dose ICS. Combined with ICS, it can lead to better control of asthma and potentially to ICS sparing.

CONCLUSIONS

Given the efficacy, tolerance and long-term treatment compliance of montelukast in mild persistent asthma in adults and children, montelukast, given as a substitute or combined with ICS, could contribute to enhanced control of asthma, especially in children.

Addition to inhaled corticosteroids of long-acting beta2-agonists versus anti-leukotrienes for chronic asthma

BACKGROUND

Asthma patients who continue to experience symptoms despite being on regular inhaled corticosteroids (ICS) represent a management challenge. Long-acting beta(2)-agonists (LABA) or anti-leukotrienes (LTRA) are two treatment options that could be considered as add-on therapy to ICS.

OBJECTIVES

We compared the efficacy and safety profile of adding either daily LABA or LTRA in adults and children with asthma who remain symptomatic on ICS.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register (up to and including March 2010). We consulted reference lists of all included studies and contacted authors and pharmaceutical manufacturers for other published or unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) conducted in adults or children with recurrent asthma that was treated with ICS and where a fixed dose of a long-acting beta(2)-agonist or leukotriene agent was added for a minimum of 28 days.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias of included studies and extracted data. We sought unpublished data and further details of study design, where necessary.

MAIN RESULTS

We included 17 RCTs (7032 participants), of which 16 recruited adults and adolescents (6850) and one recruited children aged 6 to 17 years (182). Participants demonstrated substantial reversibility to short-acting beta-agonist at baseline. The studies were at a low risk of bias. The risk of exacerbations requiring systemic corticosteroids was lower with the combination of LABA and ICS compared with LTRA and ICS, from 11% to 9% (RR 0.83, 95% CI 0.71 to 0.97; six studies, 5571 adults). The number needed to treat (NNT) with LABA compared to LTRA to prevent one exacerbation over 48 weeks was 38 (95% CI 22 to 244). The choice of LTRA did not significantly affect the results. The effect appeared stronger in the trials using a single device to administer ICS and LABA compared to those using two devices. In the absence of data from the paediatric trial and the clinical homogeneity of studies, we could not perform subgroup analyses. The addition to ICS of LABA compared to LTRA was associated with a statistically greater improvement from baseline in several of the secondary outcomes, including lung function, functional status measures and quality of life. Serious adverse events were more common with LABA than LTRA, although the estimate was imprecise (RR 1.35, 95% CI 1.00 to 1.82), and the NNT to harm for one additional patient to suffer a serious adverse event on LABA over 48 weeks was 78 (95% CI 33 to infinity). The risk of withdrawal for any reason in adults was significantly lower with LABA and ICS compared to LTRA and ICS (RR 0.84, 95% CI 0.74 to 0.96).

AUTHORS' CONCLUSIONS

In adults with asthma that is inadequately controlled on low doses of inhaled steroids and showing significant reversibility with beta(2)-agonists, LABA is superior to LTRA in reducing oral steroid treated exacerbations. Differences favouring LABA in lung function, functional status and quality of life scores are generally modest. There is some evidence of increased risk of SAEs with LABA. The findings support the use of a single inhaler for the delivery of LABA and inhaled corticosteroids. We are unable to draw conclusions about which treatment is better as add-on therapy for children.

Pathogenesis of airway inflammation in bronchial asthma

Bronchial asthma is a chronic disorder characterized by airway inflammation, reversible airway obstruction, and airway hyperresponsiveness. Eosinophils are believed to play important roles in the pathogenesis of asthma through the release of inflammatory mediators. In refractory eosinophilic asthma, anti-IL-5 mAb reduces exacerbations and steroid dose, indicating roles of eosinophils and IL-5 in the development of severe eosinophilic asthma. Even in the absence of IL-5, it is likely that the "Th2 network", including a cascade of vascular cell adhesion molecule-1/CC chemokines/GM-CSF, can sufficiently maintain eosinophilic infiltration and degranulation. Cysteinyl leukotrienes can also directly provoke eosinophilic infiltration and activation in the airways of asthma. Therefore, various mechanisms would be involved in the eosinophilic airway inflammation of asthma. In the pathogenesis of severe asthma, not only eosinophils but also mast cells or neutrophils play important roles. Mast cells are much infiltrated to smooth muscle in severe asthma and induce airway remodeling by release of inflammatory mediators such as amphiregulin. Treatment with anti-IgE Ab, which neutralizes circulating IgE and suppresses mast cell functions, reduces asthma exacerbations in severe asthmatic patients. Furthermore, infiltration of neutrophils in the airway is also increased in severe asthma. IL-8 plays an important role in the accumulation of neutrophils and is indeed upregulated in severe asthma. In the absence of chemoattractant for eosinophils, neutrophils stimulated by IL-8 augment the trans-basement membrane migration of eosinophils, suggesting that IL-8-stimulated neutrophils could lead eosinophils to accumulate in the airways of asthma. In view of these mechanisms, an effective strategy for controlling asthma, especially severe asthma, should be considered.

Role of eosinophils and their clinical significance in allergic inflammation

Eosinophils are believed to play roles in the pathophysiology of allergic inflammation, such as bronchial asthma. However, recent studies on anti-interleukin-5 monoclonal antibody treatment of asthmatic patients raised the possibility that eosinophils may play only a limited role. More recent studies established that eosinophils are essentially involved in the development of airway remodeling. Moreover, it is theoretically conceivable that eosinophils are a cellular source of lipid mediators, such as cysteinyl leukotrienes or platelet-activating factor in asthma. Even in the absence of interleukin-5, it is likely that the 'T-helper Type 2 network', including a cascade of vascular cell adhesion molecule-1, intercellular cell adhesion molecule-1, CC chemokines, granulocyte-macrophage colony-stimulating factor, for example, can maintain sufficient eosinophilic infiltration and effector functions, such as superoxide anion generation and degranulation. Long-term studies, wherein tissue eosinophils are eliminated effectively will be required to establish the exact roles of these cells in asthma. Finally, the authors will demonstrate that eosinophils have the potential for not only playing detrimental roles but also beneficial ones.

Effects of asthma treatment: the present and future

The increasing burden of asthma in both primary and secondary care has led to extensive research into its genetics, pathophysiology and treatment over the past few decades. Inhaled corticosteroids remain an integral component in all but the mildest disease, although despite a low-to-moderate dose, many individuals remain symptomatic. In patients with persistent symptoms despite inhaled corticosteroids, a variety of different nonsteroidal second-line therapies are available as add-on therapy. In this review, existing and potential future pharmacological strategies involved in the management of asthma will be highlighted.

Acute additive effect of montelukast and beclomethasone on AMP induced bronchoconstriction

Bronchial hyperresponsiveness to 5-adenosine mono-phosphate (AMP) is a marker of airway inflammation. Inhaled corticosteroids and antileukotrienes are used as anti-inflammatory drugs for the treatment of asthma. To find out if these two drugs exert their protection in an additive fashion, we compared the effects of acute treatment with inhaled beclomethasone (BDP) and montelukast (ML), alone or in combination, on methacholine and AMP induced bronchoconstriction. 15 asthmatic patients undertook methacholine and AMP challenges at baseline and after receiving ML or BDP, alone or in combination, in a randomized, double-blind, double-dummy placebo-controlled, crossover design. BDP pretreatment significantly increased the AMP PC(20) value (68.34+/-15.9mg/mL) as compared to placebo (22.87+/-5.7mg/mL). Combined treatment, BDP plus ML, afforded a further significant increase of AMP PC(20) (154.57+/-55.0mg/mL) as compared to each single treatment. The significant protection exerted by combined treatment as compared to each single active treatment was also demonstrated by the change of AMP PC(20) doubling dose as compared to placebo and each single active treatment. Our findings suggest that these two agents exert their acute additive protection against AMP induced bronchoconstriction acting on distinct inflammatory pathways and their combined use might provide greater protection against inflammatory response elicited by AMP than either drug alone.

Addition of long-acting beta2-agonists to inhaled corticosteroids versus same dose inhaled corticosteroids for chronic asthma in adults and children

BACKGROUND

Long-acting inhaled ss(2)-adrenergic agonists (LABAs) are recommended as 'add-on' medication to inhaled corticosteroids (ICS) in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of LABAs to ICS in patients insufficiently controlled on ICS alone.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

We included RCTs if they compared the addition of inhaled LABAs versus placebo to the same dose of ICS in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the relative risk (RR) of asthma exacerbations requiring rescue oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), rescue beta2-agonist use, symptoms, withdrawals and adverse events.

MAIN RESULTS

Seventy-seven studies met the entry criteria and randomised 21,248 participants (4625 children and 16,623 adults). Participants were generally symptomatic at baseline with moderate airway obstruction despite their current ICS regimen. Formoterol or salmeterol were most frequently added to low-dose ICS (200 to 400 microg/day of beclomethasone (BDP) or equivalent) in 49% of the studies. The addition of a daily LABA to ICS reduced the risk of exacerbations requiring oral steroids by 23% from 15% to 11% (RR 0.77, 95% CI 0.68 to 0.87, 28 studies, 6808 participants). The number needed to treat with the addition of LABA to prevent one use of rescue oral corticosteroids is 41 (29, 72), although the event rates in the ICS groups varied between 0% and 38%. Studies recruiting adults dominated the analysis (6203 adult participants versus 605 children). The subgroup estimate for paediatric studies was not statistically significant (RR 0.89, 95% CI 0.58 to 1.39) and includes the possibility of the superiority of ICS alone in children.Higher than usual dose of LABA was associated with significantly less benefit. The difference in the relative risk of serious adverse events with LABA was not statistically significant from that of ICS alone (RR 1.06, 95% CI 0.87 to 1.30). The addition of LABA led to a significantly greater improvement in FEV(1) (0.11 litres, 95% 0.09 to 0.13) and in the proportion of symptom-free days (11.88%, 95% CI 8.25 to 15.50) compared to ICS monotherapy. It was also associated with a reduction in the use of rescue short-acting ss(2)-agonists (-0.58 puffs/day, 95% CI -0.80 to -0.35), fewer withdrawals due to poor asthma control (RR 0.50, 95% CI 0.41 to 0.61), and fewer withdrawals due to any reason (RR 0.80, 95% CI 0.75 to 0.87). There was no statistically significant group difference in the risk of overall adverse effects (RR 1.00, 95% 0.97 to 1.04), withdrawals due to adverse health events (RR 1.04, 95% CI 0.86 to 1.26) or any of the specific adverse health events.

AUTHORS' CONCLUSIONS

In adults who are symptomatic on low to high doses of ICS monotherapy, the addition of a LABA at licensed doses reduces the rate of exacerbations requiring oral steroids, improves lung function and symptoms and modestly decreases use of rescue short-acting ss(2)-agonists. In children, the effects of this treatment option are much more uncertain. The absence of group difference in serious adverse health events and withdrawal rates in both groups provides some indirect evidence of the safety of LABAs at usual doses as add-on therapy to ICS in adults, although the width of the confidence interval precludes total reassurance.

Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled ss2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine the effect of the combination of long-acting ss(2) agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the risk of asthma exacerbations, pulmonary function and on other measures of asthma control, and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs, clinical trial registries and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

RCTs that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the number of patients experiencing one or more asthma exacerbations requiring oral corticosteroids.

MAIN RESULTS

This review included 48 studies (15,155 participants including 1155 children and 14,000 adults). Participants were inadequately controlled on their current ICS regimen, experiencing ongoing symptoms and with generally moderate (FEV1 60% to 79% of predicted) airway obstruction. The studies tested the combination of salmeterol or formoterol with a median dose of 400 mcg/day of beclomethasone or equivalent (BDP-eq) compared to a median of 1000 mcg/day of BDP-eq, usually for 24 weeks or less. There was a statistically significantly lower risk of exacerbations requiring systemic corticosteroids in patients treated with LABA and ICS (RR 0.88, 95% CI 0.78 to 0.98, 27 studies, N = 10,578) from 11.45% to 10%, with a number needed to treat of 73 (median study duration: 12 weeks). The study results were dominated by adult studies; trial data from three paediatric studies showed a trend towards increased risk of rescue oral steroids (RR 1.24, 95% CI 0.58 to 2.66) and hospital admission (RR 2.21, 95% CI 0.74 to 6.64) associated with combination therapy. Overall, there was no statistically significant difference in the risk ratios for either hospital admission (RR 1.02, 95% CI 0.67 to 1.56) or serious adverse events (RR 1.12, 95% CI 0.91 to 1.37). The combination of LABA and ICS resulted in significantly greater but modest improvement from baseline in lung function, symptoms and rescue medication use than with higher ICS dose. Despite no significant group difference in the risk of overall adverse events (RR 0.99, 95% CI 0.95 to 1.03), there was an increase in the risk of tremor (RR 1.84, 95% CI 1.20 to 2.82) and a lower risk of oral thrush (RR 0.58, 95% CI 0.40 to 0.86)) in the LABA and ICS compared to the higher ICS group. There was no significant difference in hoarseness or headache between the treatment groups. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS (RR 0.65, 95% CI 0.51 to 0.83).

AUTHORS' CONCLUSIONS

In adolescents and adults with sub-optimal control on low dose ICS monotherapy, the combination of LABA and ICS is modestly more effective in reducing the risk of exacerbations requiring oral corticosteroids than a higher dose of ICS. Combination therapy also led to modestly greater improvement in lung function, symptoms and use of rescue ss(2) agonists and to fewer withdrawals due to poor asthma control than with a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor and less oral candidiasis with combination therapy, the two options appear relatively safe in adults although adverse effects associated with long-term ICS treatment were seldom monitored. In children, combination therapy did not lead to a significant reduction, but rather a trend towards an increased risk, of oral steroid-treated exacerbations and hospital admissions. These trends raised concern about the safety of combination therapy in view of modest improvement in children under the age of 12 years.

Regulation of PC12 cell survival and differentiation by the new P2Y-like receptor GPR17

The P2Y-like receptor GPR17 has been reported to respond to both uracil nucleotides and cysteinyl-leukotrienes (cysLTs), such as UDP-glucose and LTD(4). Our previous data suggest a potential role for GPR17 in regulation of both cell viability and differentiation state of central nervous system cells. On this basis, in the present paper we investigated the effect of GPR17 receptor ligands on PC12 cell viability, following induction of morphological differentiation by nerve growth factor (NGF). In addition, the role of GPR17 ligands, either alone or in combination with growth factors, on the degree of PC12 cell differentiation was investigated. GPR17, which was not basally expressed in undifferentiated PC12 cells, was specifically induced by a 10day-treatment with NGF, suggesting a role in the control of neuronal specification. Both UDP-glucose and LTD(4), agonists at the nucleotide and cysLT GPR17 binding sites, respectively, induced a significant pro-survival effect on PC12 cells after priming with NGF. By in vitro silencing experiments with specific small interfering RNAs and by using receptor antagonists, we confirmed that the agonist effects are indeed mediated by the selective activation of GPR17. We also demonstrated that GPR17 agonists act, both alone and synergistically with NGF, to promote neurite outgrowth in PC12 cells. In addition, GPR17 ligands were able to confer an NGF-like activity to the epidermal growth factor (EGF), that, under these experimental conditions, also promoted cell differentiation and neurite elongation. Finally, we show that GPR17 ligands activate the intracellular phosphorylation of both ERK 1/2 and p38 kinases, that have been identified as important signalling pathways for neurotrophins in PC12 cells. Our results establish GPR17 as a neurotrophic regulator for neuronal-like cells and suggest a possible interplay between endogenous uracil derivatives, cysLTs and NGF in the signalling pathways involved in neuronal survival and differentiation. They also represent the first direct demonstration, in a native system, that GPR17 can indeed be activated by uracil nucleotides and cysLTs, in line with what previously demonstrated in recombinant expression systems.

Effects of the addition of Beta2-agonist tulobuterol patches to inhaled corticosteroid in patients with asthma

BACKGROUND

Whether the additive effects of the tulobuterol patch (TP), the world's first transdermal beta2-agonist preparation, are useful in asthma patients receiving inhaled corticosteroid (ICS) is unclear. To examine the add-on effects of TP on bronchial hyperresponsiveness and reduction of the percentage of sputum eosinophils, and to compare add-on effects of TP, slow-release theophylline (SRT), and a leukotriene receptor antagonist (LTRA) in patients with asthma receiving ICS.

METHODS

Study 1: We randomly allocated 24 patients with asthma receiving ICS alone in equal numbers to either control treatment (ICS alone at conventional doses) or TP treatment (ICS at conventional doses plus TP at 2mg/day). Following a 2-week observation period, patients received the allocated drug regimens for 4 weeks. Methacholine challenge test and measurement of percentage of eosinophils in hypertonic saline-induced sputum were performed before and after the treatment period. Study 2: We compared add-on effects of TP, SRT, and LTRA in 65 patients with asthma receiving ICS alone, using spirometry and peak expiratory flow (PEF). Participants in these studies had experienced decrease in morning PEF to <80% of the predicted value at least twice a week.

RESULTS

Study 1: In the TP group, improvement of bronchial hyperresponsiveness and decrease in percentage of sputum eosinophils both indicated a statistically significant difference (p < 0.01, and p < 0.05, respectively). These findings were not observed in the control group. Study 2: forced expiratory volume in 1 second (FEV(1)) and PEF markedly increased after treatment with TP compared with treatment with SRT or LTRA.

CONCLUSIONS

These findings suggest that TP can be used as a long-term add-on controller for patients with asthma receiving ICS.

Leukotriene modifiers in the treatment of asthma in children

Asthma is one of the most common respiratory disorders in clinical practice, affecting up to 13% of people worldwide. Inflammation is the most important component of asthma and inhaled corticosteroids (ICS) are recommended as the first line controller treatment for patients of all ages. Treatment with corticosteroids is often unable to fully control asthma symptoms and progression. Recently, leukotrienes have come to the forefront of research as they have been found play a pivotal role in the airway inflammatory process, and specific drugs have been developed to target them. Cysteiny leukotriene antagonists (LTRAs) have recently emerged as important therapeutic options that show a large potential clinical utility. Three specific LTRAs are licensed for clinical use: montelukast, zafirlukast and pranlukast, although montelukast is the only drug approved in the paediatric age range. It is well tolerated (although adverse effects such as headaches, abdominal pain, rashes, angioedema, pulmonary eosinophilia and arthralgia have been reported) and shows many positive effects in asthmatic patients. Current Global Initiative for Asthma guidelines recommend LTRAs as: (1) a second choice treatment to ICS for patients with mild persistent asthma, (2) an add-on therapy to reduce the dose of ICS in patients with moderate or severe asthma, due to the different and complementary mechanisms of action of these agents. LTRAs may be particularly appropriate choices in a number of clinical situations, including the following: patients with concomitant rhinitis; patients with viral-induced wheeze; patients with exercise-induced bronchoconstriction (EIB) and, in children aged 2-5 years, to reduce the frequency of asthma exacerbations.

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults and children

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled ss2-agonists (LABA) only in asthmatic patients who are inadequately controlled on inhaled corticosteroids (ICS). It is not uncommon for some patients to be commenced on ICS and LABA together as initial therapy.

OBJECTIVES

To compare the efficacy of combining inhaled corticosteroids with long-acting ss2-agonists (ICS+LABA) with inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma. We assessed two protocols: (1) LABA + ICS versus a similar dose of ICS (comparison 1) and (2) LABA + ICS versus a higher dose of ICS (comparison 2).

SEARCH STRATEGY

We identified randomised controlled trials through electronic database searches (May 2008).

SELECTION CRITERIA

Randomised trials comparing ICS + LABA with ICS alone in children and adults with asthma who had no inhaled corticosteroids in the preceding 28 days prior to enrolment.

DATA COLLECTION AND ANALYSIS

Each author assessed studies independently for risk of bias and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was rate of patients with one or more asthma exacerbations requiring rescue systemic corticosteroids. Results are expressed as relative risks (RR) for dichotomous data and as mean differences (MD) or standardised mean differences (SMD) for continuous data.

MAIN RESULTS

Twenty-eight study comparisons drawn from 27 trials (22 adult; five paediatric) met the review entry criteria (8050 participants). Baseline data from the studies indicated that trial populations had moderate or mild airway obstruction (FEV1>/=65% predicted), and that they were symptomatic prior to randomisation. In comparison 1, the combination of ICS and LABA was not associated with a significantly lower risk of patients with exacerbations requiring oral corticosteroids (RR 1.04; 95% confidence interval (CI) 0.73 to 1.47) or requiring hospital admissions (RR 0.38; 95% CI 0.09 to 1.65) compared to a similar dose of ICS alone. The combination of LABA and ICS led to a significantly greater improvement from baseline in FEV1 (0.12 L/sec; 95% CI 0.07 to 0.17), in symptoms (SMD -0.26; 95% CI -0.37 to -0.14) and in rescue ss2-agonist use (-0.41 puffs/day; 95% CI -0.73 to -0.09) compared with a similar dose of ICS alone. There was no significant group difference in the risk of serious adverse events (RR 1.15; 95% CI 0.64 to 2.09), any adverse events (RR 1.02; 95% CI 0.96 to 1.09), study withdrawals (RR 0.95; 95% CI 0.82 to 1.11), or withdrawals due to poor asthma control (RR 0.94; 95% CI 0.63 to 1.41).In comparison 2, the combination of LABA and ICS was associated with a higher risk of patients requiring oral corticosteroids (RR 1.24; 95% CI 1 to 1.53) and study withdrawal (RR 1.31; 95% CI 1.07 to 1.59) than a higher dose of ICS alone. For every 100 patients treated over 43 weeks, nine patients using a higher dose ICS compared to 11 (95% CI 9 to 14) on LABA and ICS suffered one or more exacerbations requiring rescue oral corticosteroids. There was a high level of statistical heterogeneity for FEV1 and morning peak flow. There was no statistically significant group difference in the risk of serious adverse events. Due to insufficient data we could not aggregate results for hospital admission, symptoms and other outcomes.

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the combination of ICS and LABA does not significantly reduce the risk of patients with exacerbations requiring rescue oral corticosteroids over that achieved with a similar dose of ICS alone. However, it significantly improves lung function, reduces symptoms and marginally decreases rescue ss2-agonist use. Initiation of a higher dose of ICS is more effective at reducing the risk of exacerbations requiring rescue systemic corticosteroids, and of withdrawals, than combination therapy. Although children appeared to respond similarly to adults, no firm conclusions can be drawn regarding combination therapy in steroid-naive children, given the small number of children contributing data.

Role of add-on zileuton on total exhaled, large airway, and small airway/alveolar nitric oxide in moderate-severe persistent adult asthmatics on fluticasone 250 microg/Salmeterol 50 microg

BACKGROUND

Measuring non-invasive exhaled biomarkers of inflammation may be important in monitoring asthma therapy.

OBJECTIVE

Evaluate exhaled nitric oxide with add-on leukotriene synthesis inhibitor in moderate-severe persistent asthmatics on combination controllers.

METHODS

In a non-randomized, non-placebo, single-blind, fixed sequence, pilot study, we evaluated 22 non-smoking, stable, moderate-severe adult asthmatics on maintenance inhaled fluticasone 250 microg/salmeterol 50 microg (F/S) via MDI bid> or =1 yr, with add-on oral zileuton 600 mg qid. Exhaled fractional nitric oxide (FENO) gas exchange, large airway NO, small airway/alveolar NO concentration (CANO), Juniper score and lung function were measured. Asthmatics were studied at baseline only on F/S bid (visit 1), on F/S bid pre and 2 h post first dose zileuton 600 mg (visit 2), and post 4 weeks (visit 3) F/S bid plus zileuton 600 mg qid. Values were compared at each visit and to healthy non-smoking age matched healthy controls with normal lung function.

RESULTS

Three asthmatics stopped zileuton prematurely (headache and/or nausea) and 19 (12F) age 55+/-17 yr (mean+/-SD) completed the 4-week study. Baseline forced expiratory lung volume in 1 sec (FEV(1)) was 1.6+/-0.7L (53+/-19% pred) (mean+/-SD), FEV(1) over FVC ratio was 64+/-11% and post 180 microg albuterol FEV(1) was 1.8+/-0.7L (56+/-21% pred), and FEV(1) over FVC ratio was 67+/-12%. Baseline Juniper scores were mild (10+/-10) and similar (p=ns) at all visits. Baseline FENO@50 mL/s was 48+/-27 ppb (mean+/-SD), and FENO@100 mL/s was 29+/-16ppb, and were similar (p=ns) at all visits. Large airway NO flux was 2.0+/-1.3 nL/s (52% asthmatics abnormal) and small airway/alveolar NO was 8.0+/-4.0 ppb (79% asthmatics abnormal) and were similar (p=ns) at all visits. Compared to baseline, post 26+/-6 days Zileuton, mean FEV(1) (L)% predicted increased 3.3% predicted (p=0.03), and FEV(1) over FVC ratio increased 2.2% (p=0.03).

CONCLUSION

In stable, moderate-severe persistent adult asthmatics, large airway NO flux, small airway/alveolar CANO, and Juniper airway scores, were not significantly different on F/S bid vs F/S bid plus Zileuton for 4 weeks, despite significant small increase in FEV(1) over FVC ratio and FEV(1)% predicted.

Rates of asthma attacks in patients with previously inadequately controlled mild asthma treated in clinical practice with combination drug therapy: an exploratory post-hoc analysis

Background

Differences could exist in the likelihood of asthma attacks in patients treated with inhaled corticosteroid (ICS), long-acting beta-agonist (LABA), and montelukast (MON) (ICS/LABA/MON) and patients treated with an inhaled corticosteroid (ICS) and montelukast (MON) (ICS/MON).

Methods

This was a post-hoc analysis of a pretest-posttest retrospective cohort study. Patients with mild persistent asthma and allergic rhinitis, who were taking an ICS either alone or in combination with a LABA, started concomitant MON treatment as part of their routine care. Rates of asthma- and allergic rhinitis-related medical resource use in the 12-months after the initial (index) MON prescription were compared in the ICS/MON and ICS/LABA/MON groups. An asthma attack was defined as an asthma-related hospitalization, ER visit, or use of an oral corticosteroid.

Results

Of the total of 344 patients, 181 (53%) received ICS/MON and 163 (47%) received ICS/LABA/MON in the post-index period for means of 10.5 and 11.4 months, respectively, (P < 0.05). Short-acting beta-agonists were used by 74.6% in the ICS/MON and 71.8% in the ICS/LABA/MON groups (P > 0.05). An asthma attack occurred in 4.4% of the ICS/MON group and 6.8% of the ICS/LABA/MON group (P > 0.05). The adjusted odds of an asthma attack in the post-index period in the ICS/LABA/MON group relative to the ICS/MON group was 1.24, 95% confidence interval 0.35–4.44.

Conclusion

In this observational study of combination drug treatment of mild persistent asthma and allergic rhinitis, no difference was observed between LABA/ICS/MON combination therapy and the ICS/MON combination without LABA use, for the rate of asthma attacks over one year.

Molecular mechanism of the additive effects of leukotriene modifier in asthmatic patients receiving steroid therapy

BACKGROUND

The addition of leukotriene modifier (LM) may be a useful approach for uncontrollable asthma despite treatment with inhaled corticosteroid (ICS), especially in asthmatics comorbid with allergic rhinitis (AR), although little is known about its molecular mechanism. We evaluated the additive effects of LM with ICS on pulmonary function and airway inflammation in asthmatics with or without AR.

METHODS

Eighteen uncontrolled steroid-treated asthmatics, nine with and nine without AR, were enrolled. Spirometry, peak expiratory flow (PEF) measurements, and exhaled breath condensate sampling were performed before and 8 weeks after LM administration. The lowest PEF over the course of one week, expressed as a percentage of the highest PEF (Min%Max PEF), was used as an index of fluctuation of the airway caliber. Airway cytokine expression was analyzed with a protein array.

RESULTS

A significant improvement in forced expiratory volume in one second as a percentage of the predicted value (%FEV(1)) and Min%Max PEF was seen in the subgroup of asthma with AR. Although there was no significant difference in the baseline cytokine values between the groups, the exhaled RANTES level was significantly reduced by LM in the asthma with AR group. The changes in the RANTES level were significantly related to the changes in the %FEV(1) and Min%Max PEF values.

CONCLUSIONS

LM caused a greater improvement in pulmonary function and airway inflammation in asthmatics with AR. The RANTES-mediated pathway may be involved in the improvement of the airflow limitation and airway lability by LM additive therapy in asthmatics receiving steroid therapy.

Evaluating combination therapies for asthma: pros, cons, and comparative benefits

Combination therapies with inhaled corticosteroids (ICS) and either long-acting beta2 agonists (LABA) or leukotriene receptor antagonists (LTRA) are commonly used to help patients maintain control of their asthma. LABA and LTRA have different mechanisms of action and both provide complementary benefits when combined with ICS. This paper compares the two regimens based on recent clinical trial data, evaluates their efficacy on various clinical and quality of life outcomes, and discusses the importance of therapy choice in people with specific asthma phenotypes. The potential of new dosing strategies, including adjustable maintenance therapy and single-inhaler maintenance and reliever therapy is also reviewed. Given the variety of outcomes, phenotypes, and treatment strategies that must be considered, the importance of individualized management is emphasized.

Effect of fluticasone 250 microg/salmeterol 50 microg and montelukast on exhaled nitric oxide in asthmatic patients

BACKGROUND

Monitoring noninvasive biomarkers of inflammation is an important adjunct in asthma therapy.

OBJECTIVE

The goal of the present study was to identify airway and alveolar site(s) of inflammation using exhaled nitric oxide (NO) as a marker in asthmatic patients, and to evaluate the NO response to maintenance fluticasone 250 microg/salmeterol 50 microg (F/S) and add-on montelukast 10 mg (M).

METHODS

Thirty (24 women) nonsmoking, mild to moderate asthmatic patients were studied, mean age (+/- SD) 43+/-9 years, treated with F/S for more than one year. All were clinically stable for longer than eight weeks and had not taken oral corticosteroids and/or leukotriene antagonists for eight weeks before the present study. Spirometry, Juniper asthma symptom score, fractional exhaled NO (FENO) 100 mL/s, bronchial NO and alveolar NO concentration (CANO) were measured in a single-blind, nonrandomized crossover study.

PROTOCOL

Visit 1: baseline F/S; visit 2: after four weeks of F/S plus M; visit 3: after four weeks of S plus M; and visit 4: after four weeks of S only. Values in asthmatic patients were also compared with 34 nonsmoking age-matched healthy controls with normal lung function.

RESULTS

After 180 microg aerosolized metered dose inhaler albuterol, the forced expiratory volume in 1 s at baseline was 2.6+/-0.8 L (86%+/-16% of the predicted value) and the forced expiratory volume in 1 s over the forced vital capacity was 77%+/-9% (mean +/- SD), and was similar at visits 2 to 4. Juniper scores were mildly abnormal at visits 1 to 3, but significantly worse (P=0.03) at visit 4 versus visits 1 to 3. FENO values at visits 1 to 3 were similar but significantly increased (P=0.007) at visit 4. Bronchial NO was higher (P=0.03) at visit 4, versus visits 1 and 2, and was no different at visit 3. Compared with the healthy subjects, FENO and bronchial NO values were abnormal (greater than the normal mean plus 2 SD) in 33% of asthmatic patients at visits 1 to 3. CANO was similar for visits 1 to 4. CANO was abnormal (greater than the normal mean + 2 SD) in 20% of asthmatic patients.

CONCLUSION

In clinically stable asthmatic patients, despite controller treatment including moderate-dose inhaled corticosteroids and add-on M, 33% of mild to moderate asthmatic patients have ongoing nonsuppressed bronchial sites of increased NO production, compared with healthy control subjects. These controllers have no effect on CANO, which was abnormal in 20% of the asthmatic patients studied. The addition of add-on M to baseline moderate-dose inhaled corticosteroid did not further reduce total exhaled, bronchial and/or alveolar NO production.

The clinical significance of exhaled nitric oxide in asthma

Asthma is an inflammatory disease of the airways, for which many therapeutic options are available. Guidelines for the management of asthma suggest a stepwise approach to pharmacotherapy based on assessment of asthma severity and control. However, the assessment of asthma control presently relies on surrogate measures, such as the frequency of symptoms or the frequency of use of short-acting beta2-adrenergic agonists. There is no simple, noninvasive technique for the assessment of severity of actual airway inflammation in asthma. The collection and analysis of nitric oxide (NO) levels in exhaled breath has recently become feasible in humans. Based on increased exhaled NO (eNO) levels in patients with asthma, eNO analysis has been proposed as a novel, noninvasive approach to the assessment and monitoring of airway inflammation, and as a basis for adjustments in asthma therapy. In the present paper, the relationship of elevated eNO levels in asthma with inflammatory, physiological and clinical markers of asthma in adults was reviewed. Use of eNO is a promising tool for diagnosing asthma, for monitoring asthma control and for guiding optimal anti-inflammatory asthma therapy. However, because of many unresolved questions, eNO cannot be recommended at present for routine clinical management of adults with asthma.

Montelukast inhibits tumour necrosis factor-alpha-mediated interleukin-8 expression through inhibition of nuclear factor-kappaB p65-associated histone acetyltransferase activity

BACKGROUND

Montelukast is a potent cysteinyl leukotriene-1 receptor antagonist possessing some anti-inflammatory effects although the molecular mechanism of these anti-inflammatory effects is unknown. In this study, we aimed to investigate the effect of montelukast on nuclear factor (NF)-kappaB-associated histone acetylation activity in phorbol myristate acetate (PMA)-differentiated U937 cells.

METHODS

We examined the inhibitory effects of montelukast on TNF-alpha-induced IL-8 production in PMA-differentiated U-937 cells. U-937 cells were exposed to PMA (50 ng/mL) for 48 h to allow differentiation to macrophages. Macrophages were then exposed to TNF-alpha (10 ng/mL) in the presence or absence of montelukast (0.01-10 microm) for 24 h. After this time, the concentration of IL-8 in the culture supernatant was measured by sandwich-type ELISA kit. The effect of signalling pathways on TNF-alpha-induced IL-8 release was examined pharmacologically using selective NF-kappaB/IKK2 (AS602868, 3 microm), (PD98059, 10 microm) and p38 mitogen activated protein kinase (MAPK) (SB203580, 1 microm) inhibitors. NF-kappaB DNA binding activity was measured by a DNA-binding ELISA-based assay. NF-kappaB-p65-associated histone acetyltransferase (HAT) activity was measured by immunoprecipitation linked to commercial fluorescent HAT.

RESULTS

TNF-alpha-induced IL-8 release was suppressed by an NF-kappaB inhibitor but not by MEK or p38 MAPK inhibitors. Montelukast induced a concentration-dependent inhibition of TNF-alpha-induced IL-8 release and mRNA expression that reached a plateau at 0.1 microm without affecting cell viability. Montelukast did not affect NF-kappaB p65 activation as measured by DNA binding but suppressed NF-kappaB p65-associated HAT activity.

CONCLUSION

Montelukast inhibits TNF-alpha-stimulated IL-8 expression through changes in NF-kappaB p65-associated HAT activity. Drugs targeting these enzymes may enhance the anti-inflammatory actions of montelukast.

Tolerability profiles of leukotriene receptor antagonists and long-acting beta2-adrenoceptor agonists in combination with inhaled corticosteroids for treatment of asthma: a review

Inhaled corticosteroids, long-acting beta2-adrenoceptor agonists, and leukotriene receptor antagonists are widely used for treatment of asthma. Inhaled corticosteroids are recommended as first-line therapy, whereas long-acting beta2-adrenoceptor agonists and leukotriene receptor antagonists are indicated as add-on therapy in patients not adequately controlled with corticosteroids alone. A number of studies have investigated the efficacy of combinations of these drugs in asthma, but several issues concerning the safety of these treatments are highly debated. This review provides a critical appraisal of the tolerability profiles of long-acting beta2-agonists and leukotriene receptor antagonists used in combination with inhaled corticosteroids for the treatment of asthma.

Salmeterol plus fluticasone propionate versus fluticasone propionate plus montelukast: a randomised controlled trial investigating the effects on airway inflammation in asthma

Background

Few studies have compared treatment strategies in patients with asthma poorly controlled on low dose inhaled corticosteroids, and little is known about the effects of different treatments on airway inflammation. In this double-blind, placebo-controlled, parallel group study, we compared the effects of salmeterol plus fluticasone propionate (FP) (Seretide™; SFC) and FP plus montelukast (FP/M) on sputum inflammatory markers, airway responsiveness, lung function, and symptoms in adult asthmatics.

Methods

Sixty-six subjects were randomised to SFC or FP/M for 12 weeks. The primary outcome was changes in neutrophil, eosinophil, macrophage, lymphocyte, and epithelial cell levels in induced sputum. Additional outcomes included the change in other sputum markers of airway inflammation, airway responsiveness, symptom control, and lung function.

Results

Both treatments had no significant effect on induced sputum inflammatory cells, although there was a trend for a reduction in sputum eosinophils. Both treatments significantly improved airway responsiveness, whereas SFC generally led to greater improvements in symptom control and lung function than FP/M. FP/M led to significantly greater reductions in sputum cysteinyl leukotrienes than SFC (treatment ratio 1.80; 95% CI 1.09, 2.94).

Conclusion

Both treatments led to similar control of eosinophilic airway inflammation, although PEF and symptom control were better with SFC.

Study number

SAM40030 (SOLTA)

Effect of procaterol, a beta(2) selective adrenergic receptor agonist, on airway inflammation and hyperresponsiveness

BACKGROUND

beta-agonists are frequently used as bronchodilators for asthma as not only a reliever but also a controller, and their utility has increased with the development of long-acting beta(2) selective drugs. Although anti-inflammatory effects of beta(2) selective-agonists have been reported in vitro, side effects on augmentation of airway hyperresponsiveness by chronic use of beta(2) selective-agonists have been described in several reports. In this study, we investigated the effects of procaterol, a second-generation beta(2)-agonist, on airway inflammation in vivo using an antigen-specific murine model of asthma.

METHODS

Mice immunized with ovalbumin (OVA) + alum and challenged with inhaled ovalbumin were orally administered procaterol during the challenge. After inhalation, the mice were tracheostomized and placed in a body box under controlled ventilation to measure airway resistance before and after acetylcholine inhalation.

RESULTS

Administration of procaterol at a clinical dose equivalent did not augment airway hyperresponsiveness, inflammation of the airway wall, or subsequent airway wall thickening induced by OVA inhalation. BALF cell analysis revealed that the eosinophil number in the BALF was significantly reduced in procaterol-treated mice compared to untreated mice.

CONCLUSIONS

Oral administration of procaterol at a clinical dose did not augment airway responsiveness, but did reduce eosinophil inflammation.

Differential anti-inflammatory effects of large and small particle size inhaled corticosteroids in asthma

BACKGROUND

Extra-fine particle formulations of hydrofluoroalkane-134a beclometasone dipropionate (HFA-BDP) exhibit clinical effects comparable with conventional particle formulations of chlorofluorocarbon beclometasone dipropionate (CFC-BDP) at half the dose. There is little data comparing their effects on inflammation. We have evaluated the effects of HFA-BDP and CFC-BDP on pulmonary and systemic markers of asthmatic inflammation.

METHODS

A double-blind randomized crossover trial was undertaken comparing the anti-inflammatory effects of HFA-BDP (100 and 400 microg/day) and CFC-BDP (200 and 800 microg/day). Treatment with montelukast was evaluated as add-on to the higher dose of BDP.

RESULTS

Compared with baseline after withdrawal of usual asthma therapy, 100 microg of HFA-BDP significantly attenuated serum eosinophilic cationic protein levels (0.61-fold change, 95% CI 0.49-0.77; a 39% reduction, P < 0.001), but 200 microg of CFC-BDP did not (0.87-fold change, 95% CI 0.63-1.23; P = 1). A dose of 800 microg of CFC-BDP and 400 microg of HFA-BDP led to reductions in exhaled nitric oxide (0.57-fold change, 95% CI 0.44-0.73; a 43% reduction, P < 0.001 and 0.65-fold change, 95% CI 0.47-0.91; a 35% reduction, P = 0.008, respectively); and peripheral eosinophils (-74 cells/microl, 95% CI -146 to -2; P = 0.020 and -77 cells/microl, 95% CI -140 to -14; P = 0.012, respectively). Montelukast further reduced exhaled nitric oxide (0.81-fold change, 95% CI 0.66-0.98; P = 0.028) with 400 microg HFA-BDP and eosinophils (-44 cells/microl, 95% CI -80 to -8; P = 0.012) with 800 microg CFC-BDP, but not vice versa.

CONCLUSION

Chlorofluorocarbon beclometasone dipropionate and HFA-BDP have differential effects on pulmonary and systemic inflammation, which dictate the additive effects of montelukast.

Combination therapy with a long-acting beta-agonist and a leukotriene antagonist in moderate asthma

RATIONALE

Long-acting beta-agonists (LABAs) and inhaled corticosteroids administered together appear to be complementary in terms of effects on asthma control. The elements of asthma control achieved by LABAs (improved lung function) and leukotriene receptor antagonists (LTRAs; protection against exacerbations) may be complementary as well.

OBJECTIVE

We sought to determine whether the combination of the LTRA montelukast and the LABA salmeterol could provide an effective therapeutic strategy for asthma.

METHODS AND MEASUREMENTS

In a randomized, placebo-controlled, crossover study of 192 subjects with moderate asthma, we compared the clinical efficacy of regular treatment over 14 weeks with the combination of montelukast and salmeterol to that with the combination of beclomethasone and salmeterol in moderate asthma. The primary efficacy outcome was time to treatment failure.

MAIN RESULTS

Three months after the randomization of the last subject, the Data and Safety Monitoring Board determined that the primary research question had been answered and terminated the trial. The combination of montelukast and salmeterol was inferior to the combination of beclomethasone and salmeterol as judged by protection against asthma treatment failures (p = 0.0008), lung function (26 L/min difference in a.m. peak expiratory flow rate, p = 0.011), asthma control score (0.22 difference in Asthma Control Questionnaire score, p = 0.038), and markers of inflammation and airway reactivity.

CONCLUSIONS

Patients with moderate asthma similar to those we studied should not substitute the combination of an LTRA and an LABA for the combination of inhaled corticosteroid and an LABA.

The expanding role of leukotriene receptor antagonists in chronic asthma

OBJECTIVE

To provide a comprehensive review of studies that evaluate the effects of leukotriene receptor antagonists in adult chronic asthma.

DATA SOURCES

A literature search using MEDLINE, Clinical Evidence, and the Cochrane Library was performed using the following keywords: randomized controlled trial, asthma, cysteinyl leukotriene, leukotriene receptor antagonist, antileukotriene, montelukast, zafirlukast, pranlukast, inflammation, lung function, exacerbations, and symptoms.

STUDY SELECTION

Relevant peer-reviewed articles (mostly randomized controlled trials, meta-analyses, and reviews) published up to July 2006 were selected and extracted.

RESULTS

Leukotriene receptor antagonists are beneficial across a range of asthma severities and may have a particular role in exercise-induced asthma, aspirin-sensitive asthma, and individuals with concomitant allergic rhinitis.

CONCLUSION

In the management of chronic asthma, leukotriene receptor antagonists have emerged as a useful oral nonsteroidal anti-inflammatory adjunct both as monotherapy and in combination with other classes of drugs. Monitoring their effects in terms of lung function alone may result in clinicians missing beneficial effects on inflammatory biomarkers, airway hyperresponsiveness, and exacerbations.

Long-acting beta2-agonists in asthma: not so SMART?

Asthma is a worldwide chronic disorder that is characterised by airway inflammation and hyper-responsiveness, which results in intermittent airflow obstruction and subsequent perception of symptoms and exacerbations. Inhaled corticosteroids are a fundamental component in the prevention of the short- and long-term complications associated with inadequately controlled asthma. However, many individuals experience persistent symptoms and exacerbations despite receiving low-to-medium doses of an inhaled corticosteroid (400-800 microg/day of beclometasone or equivalent). In these symptomatic asthmatic patients, guidelines advocate the initiation of a long-acting beta2-adrenoceptor agonist (LABA) as additional second-line controller therapy. The recent SMART (Salmeterol Multi-centre Asthma Research Trial) study was designed to compare the effects of add-on salmeterol 42 microg (ex-actuator) twice daily with placebo over 28 weeks in a randomised, double-blind, parallel-group fashion, with the intention to enrol 60,000 asthmatic patients. However, the study was halted prematurely because preliminary data revealed an increased mortality associated with regular use of salmeterol. Moreover, concerning rates of respiratory-related deaths, asthma-related deaths and life-threatening events were observed among African Americans, who constituted up to 18% of the study population. This in turn prompted the US FDA to announce important safety information regarding inhalers containing LABAs and advise that new labelling be produced outlining the "small but significant risk in asthma-related deaths" associated with their regular use. This evidence-based review discusses the data from SMART and highlights potentially important drawbacks with regular use of LABAs in persistent asthma.

Long-acting beta2-agonists versus anti-leukotrienes as add-on therapy to inhaled corticosteroids for chronic asthma

BACKGROUND

Patients who continue to experience asthma symptoms despite taking regular inhaled corticosteroids (ICS) represent a management challenge. Leukotriene receptor antagonists (LTRA) and long-acting beta(2)-agonists (LABA) agents may both be considered as add-on therapy to inhaled corticosteroids (ICS).

OBJECTIVES

We compared the efficacy and safety profile of adding either daily LABA or LTRA in asthmatic patients who remained symptomatic on ICS.

SEARCH STRATEGY

The Cochrane Airways Group Specialised Register was searched for randomised controlled trials up to and including March 2006. Reference lists of all included studies and reviews were screened to identify potentially relevant citations. Inquiries regarding other published or unpublished studies supported by the authors of the included studies or pharmaceutical companies who manufacture these agents were made. Conference proceedings of major respiratory meetings were also searched.

SELECTION CRITERIA

Only randomised controlled trials conducted in adults or children with recurrent asthma where a LABA (for example, salmeterol or formoterol) or LTRA (for example, montelukast, pranlukast, zafirlukast) was added to ICS for a minimum of 28 days were considered for inclusion. Inhaled short-acting beta(2)-agonists and short courses of oral steroids were permitted as rescue medications. Other daily asthma treatments were permitted, providing the dose remained constant during the intervention period. Two reviewers independently reviewed the literature searches.

DATA COLLECTION AND ANALYSIS

Data extraction and trial quality assessment were conducted independently by two reviewers. Whenever possible, primary study authors were requested to confirm methodology and data extraction and to provide additional information and clarification when needed. Where necessary, expansion of graphic reproductions and estimation from other data presented in the paper was performed.

MAIN RESULTS

Fifteen randomised controlled trials met the inclusion criteria; eleven trials including 6,030 participants provided data in sufficient detail to permit aggregation. All eleven trials pertained to adults with moderate airway obstruction (% predicted FEV(1) 66-76%) at baseline. Montelukast (n=9) or Zafirlukast (n=2) was compared to Salmeterol (n=9) or Formoterol (n=2) as add-on therapy to 400-565 mcg of beclomethasone or equivalent. Risk of exacerbations requiring systemic corticosteroids was significantly lower with LABA+ICS when compared to LTRA+ICS (RR= 0.83, 95% Confidence Interval (95%CI): 0.71, 0.97): the number needed to treat with LABA compared to LTRA, to prevent one exacerbation over 48 weeks, was 38 (95% CI: 23 to 247). The following outcomes also improved significantly with the addition of LABA compared to LTRA to inhaled steroids (Weighted Mean Difference; 95%CI): morning PEFR (16 L/min; 13 to 18), evening PEFR (12 L/min; 9 to 15), FEV(1) (80 mL; 60 to 100), rescue-free days (9%; 5% to 13%), symptom-free days (6%; 2 to 11), rescue beta(2)-agonists (-0.5 puffs/day; -0.2 to -1), quality of life (0.1; 0.05 to 0.2), symptom score (Standard Mean Difference -0.2; -0.1 to -0.3), night awakenings (-0.1/week; -0.06 to -0.2) and patient satisfaction (RR 1.12; 1.07 to 1.16). Risk of withdrawals due to any reason was significantly lower with LABA+ICS compared to LTRA+ICS (Risk Ratio 0.83, 95% CI 0.73 to 0.95). Withdrawals due to adverse events or due to poor asthma control, hospitalisation, osteopenia, serious adverse events, overall adverse events, headache or cardiovascular events were not significantly different between the two study groups.

AUTHORS' CONCLUSIONS

In asthmatic adults inadequately controlled on low doses of inhaled steroids, the addition of LABA is superior to LTRA for preventing exacerbations requiring systemic steroids, and for improving lung function, symptoms, and the use of rescue beta(2)-agonists.

Non-invasive measurement of airway inflammation in asthma

Assessing the severity and control of a patient's asthma is of great importance to ensure that pharmacotherapy is optimized. Measures such as lung function, symptoms, and reliever use have traditionally been used as objective means of undertaking this assessment, but until now the level of airway inflammation has not been quantified. As asthma is primarily an inflammatory disorder, it would be desirable to include a measure of this process when evaluating disease control. The following article outlines methods of non-invasively measuring asthmatic airway inflammation and highlights their potential role in clinical practice.

Adenosine receptors: promising targets for the development of novel therapeutics and diagnostics for asthma

Interest in the role of adenosine in asthma has escalated considerably since the early observation of its powerful bronchoconstrictor effects in asthmatic but not normal airways. A growing body of evidence has emerged in support of a proinflammatory and immunomodulatory role for the purine nucleoside adenosine in the pathogenic mechanisms of chronic inflammatory disorders of the airways such as asthma. The fact that adenosine enhances mast cell allergen-dependent activation, that elevated levels of adenosine are present in chronically inflamed airways, and that adenosine given by inhalation cause dose-dependent bronchoconstriction in subjects with asthma emphasizes the importance of adenosine in the initiation, persistence and progression of these common inflammatory disorders of the airways. These distinctive features of adenosine have been recently exploited in the clinical and research setting to identify innovative diagnostic applications for asthma. In addition, because adenosine exerts its multiple biological activities by interacting with four adenosine receptor subtypes, selective activation or blockade of these receptors may lead to the development of novel therapies for asthma.

Differential effects of salbutamol and montelukast on eosinophil adhesion and superoxide anion generation

BACKGROUND

Beta2-agonists, a representative class of bronchodilators used for asthma, have been shown to modulate some functions of eosinophils, including cell adhesion. Similarly, a leukotriene receptor antagonist (LTRA) may be beneficial in controlling inflammation in asthma, as cysteinyl leukotrienes (cysLTs) can cause accumulation or activation of eosinophils. Recent evidence suggests that the addition of an LTRA, but not a long-acting beta2-agonist, to inhaled corticosteroid additionally reduces the number of eosinophils in sputum and blood from patients with asthma. The present study examined whether a beta2-agonist and an LTRA differentially modify eosinophil adhesion and activation induced by cysLTs and other activators.

METHODS

Eosinophils were isolated from blood of healthy donors and then incubated in the presence or absence of salbutamol (albuterol) or montelukast. Eosinophils were then exposed to leukotriene D4 (LTD4) or another activator, and the generation of superoxide anion (O2-) was evaluated by cytochrome C reduction assay. Eosinophil adhesion was examined by an eosinophil peroxidase assay.

RESULTS

Montelukast, but not salbutamol (both at 1 microM), inhibited LTD4-induced (100 nM) eosinophil adhesion to recombinant human intercellular adhesion molecule 1. Both drugs similarly and partially inhibited the 100 pM interleukin-5-induced adhesive response of eosinophils to recombinant human intercellular adhesion molecule 1. Montelukast, but not salbutamol, blocked LTD4-induced eosinophil O2- generation of eosinophils. Finally, neither salbutamol nor montelukast modified phorbol myristate acetate (1 ng/ml)-induced O2- generation from eosinophils.

CONCLUSION

These results confirm that LTD4 directly induces activation of eosinophils via the cysLT1 receptor. Furthermore, the results suggest that a beta2-agonist has no effect on eosinophil adhesion and activation induced by cysLTs. These results explain the differential effects of an LTRA and a beta2-agonist in the treatment of eosinophilic inflammation in asthma.

Effect of montelukast on exhaled leukotrienes and quality of life in asthmatic patients

STUDY OBJECTIVES

In some patients with asthma treated with inhaled corticosteroids, suppression of inflammation is incomplete. This may be because the effect of corticosteroids on cysteinyl-leukotriene (cys-LT) biosynthesis is limited. Montelukast is a cys-LT antagonist that significantly improves asthma control in corticosteroid-treated asthmatic patients. However, not all patients treated with cys-LT antagonists show a clinical improvement.

DESIGN

We have studied the effect of treatment for 4 weeks with montelukast (10 mg/d) on exhaled cys-LTs and leukotriene B4 (LTB4), exhaled nitric oxide, asthma quality of life (AQL), and respiratory function in patients with stable asthma.

SETTING

Asthma clinics in general practice.

PATIENTS

We studied 50 patients (30 men; mean +/- SEM age, 53 +/- 2 years) who were treated with inhaled corticosteroids.

MEASUREMENTS AND RESULTS

We detected cys-LTs in exhaled breath condensate in 25 of 50 patients; however, in the normal nonasthmatic subjects, cys-LTs were below the limit of detection. After treatment with montelukast, there was a fall in cys-LT concentrations from 14.6 +/- 3.3 to 8.5 +/- 2.6 pg/mL after 2 weeks (p > 0.05) and to 3.9 +/- 1.3 pg/mL after 4 weeks (p < 0.01). Exhaled LTB4 levels were also elevated. After treatment with montelukast, LTB4 levels fell from 33.0 +/- 3.9 to 20.4 +/- 2.5 pg/mL after 2 weeks of treatment (p < 0.05), and to 17.0 +/- 2.2 pg/mL after 4 weeks of treatment (p < 0.01). These changes in exhaled cys-LT and LTB4 were associated with significant improvements in AQL scores.

CONCLUSIONS

It appears that in some patients with stable asthma treated with inhaled corticosteroids, the suppression of inflammation is incomplete. Adding a leukotriene receptor antagonist can provide a complementary effect of controlling inflammation, with a significant improvement in quality of life.

Addition of fexofenadine to inhaled corticosteroid therapy to reduce inflammatory biomarkers in atopic asthma

BACKGROUND

We previously showed that H1-antihistamines may shift the PC20 (provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20%) threshold to adenosine monophosphate (AMP) challenge but may paradoxically prolong recovery.

OBJECTIVES

To measure AMP recovery using a constant predetermined AMP PC20 and to evaluate whether fexofenadine use confers add-on effects to treatment with either fluticasone propionate alone or combined fluticasone propionate-salmeterol.

METHODS

Fourteen atopic patients with mild-to-moderate asthma (forced expiratory volume in 1 second of 76%) completed a double-blind, randomized, crossover study consisting of 3-week treatment blocks of either fluticasone propionate-salmeterol, 250 microg twice daily, or fluticasone propionate alone, 250 microg twice daily, in conjunction with either fexofenadine, 180 mg once daily, or matched placebo. Recovery after a predetermined AMP PC20 challenge was measured (primary outcome), along with exhaled nitric oxide levels, plasma eosinophil cationic protein levels, peripheral eosinophil counts, pulmonary function, diary card outcomes, and quality of life (all secondary outcomes).

RESULTS

There were no differences in any of the primary or secondary outcomes when fexofenadine was added to treatment with either fluticasone propionate-salmeterol or fluticasone propionate alone. The mean AMP recovery time was 25.0 vs 23.4 minutes for fexofenadine and placebo, respectively, as add-on to fluticasone-salmeterol and 22.5 vs 23.9 minutes, respectively, as add-on to fluticasone alone.

CONCLUSION

Fexofenadine did not affect recovery to a fixed dose of AMP challenge or any other surrogate inflammatory markers when given as add-on therapy to corticosteroid-treatedatopic asthmatic patients.

Long-acting beta2-agonists versus placebo in addition to inhaled corticosteroids in children and adults with chronic asthma

BACKGROUND

Long-acting inhaled beta2-adrenergic agonists are recommended as 'add-on' medication to inhaled corticosteroids in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of long-acting beta2-agonists to inhaled corticosteroids on the incidence of asthma exacerbations, pulmonary function and other measures of asthma control.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers, until April 2004.

SELECTION CRITERIA

RCTs were included that compared the addition of inhaled long-acting beta2-agonists to corticosteroids with inhaled corticosteroids alone for asthma therapy in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by two review authors for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of asthma exacerbations requiring systemic corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptom scores, adverse events and withdrawal rates.

MAIN RESULTS

Of 594 identified citations, 49 trials met the inclusion criteria: 27 full-text publications, one unpublished full-text report and 21 abstracts. Twenty-three citations (21 abstracts and two full-text publications) provided data in insufficient detail, 26 trials contributed to this systematic review. All but three trials were of high methodological quality. Most interventions (N = 26) were of four-month duration or less. Eight trials focused on children and 18 on adults, with participants generally symptomatic with moderate airway obstruction despite their current inhaled steroid regimen. If a trial had more than one intervention or control group, additional control to intervention comparisons were considered separately. Formoterol (N = 17) or salmeterol (N = 14) were most frequently added to low-dose inhaled corticosteroids (200 to 400 microg/day of beclomethasone (BDP) or equivalent). The addition of a daily long-acting beta2-agonist (LABA) reduced the risk of exacerbations requiring systemic steroids by 19% (relative risk (RR) 0.81, 95% CI 0.73 to 0.90). The number needed to treat for one extra patient to be free from exacerbation for one year was 18 (95% CI 13 to 33). The addition of LABA significantly improved FEV1 (weighted mean difference (WMD) 170 mL, 95% CI 110 to 240) using a random-effects model, increased the proportion of symptom-free days (WMD 17%, 95% CI 12 to 22, N = 6 trials) and rescue-free days (WMD 19%, 95% CI 12 to 26, N = 2 trials). The group treated with LABA plus inhaled corticosteroid showed a reduction in the use of rescue short-acting beta2-agonists (WMD -0.7 puffs/day, 95% CI -1.2 to -0.2), experienced less withdrawals due to poor asthma control (RR 0.5, 95% CI 0.4 to 0.7) and less withdrawals due to any reason (RR 0.9, 95% CI 0.8 to 0.98), using a random-effects model. There was no group difference in risk of overall adverse effects (RR 0.98, 95% CI 0.92 to 1.05), withdrawals due to adverse health events (RR 1.29, 95% CI 0.96 to 1.75) or specific adverse health events.

AUTHORS' CONCLUSIONS

In patients who are symptomatic on low to high doses of inhaled corticosteroids, the addition of a long-acting beta2-agonist reduces the rate of exacerbations requiring systemic steroids, improves lung function, symptoms and use of rescue short-acting beta2-agonists. The similar number of serious adverse events and withdrawal rates in both groups provides some indirect evidence of the safety of long-acting beta2-agonists as add-on therapy to inhaled corticosteroids.