Safety of regular use of long-acting beta agonists as monotherapy or added to inhaled corticosteroids in asthma. A systematic review

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Asthma in Pregnancy

Asthma is a common chronic respiratory condition that affects approximately 10% of adult women in the United States. Pregnancy can present unique challenges for women with asthma, as changes in the body can alter the severity and management of asthma-related respiratory symptoms. In this article, we review the current understanding of asthma during pregnancy, including the direct effects of the disease state on the pregnant woman and fetus, risk factors for poor control of disease, as well as current treatment recommendations.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

Assessing the viability of long-acting β2-agonists in paediatric asthma patients: a pharmacokinetic/pharmacodynamic perspective

INTRODUCTION

Long-acting β₂-agonists (LABAs) combined with inhaled corticosteroids (ICSs) are still commonly prescribed to asthmatic children. Unfortunately, pediatric LABA use is based primarily on data from adults, despite the fact that children are not simply small adults and the magnitude of changes in dose exposure and/or exposure response may not be solely reflected by differences in body weight. Areas covered: The differences in pharmacokinetics (PK) and pharmacodynamics (PD) of LABAs are described and discussed with reference children and adults. Expert opinion: Data on the PK behavior of LABAs is very limited and there is almost no data on once-daily LABAs available in the pediatric population. We do not believe that this is due to a fundamental lack of information because therapeutic response and adverse effects are more useful for the optimization of β₂-agonist treatment than measurement of plasma drug concentrations per se. Nevertheless, population PK-PD studies in children are needed according to the European rules in order to define rational, patient-tailored dosing schemes. Population PK-PD modeling and simulation using non-linear mixed effect modeling should be considered as the preferred tool to develop effective and safe dosing regimens for children because they present an opportunity to analyze sparse and unbalanced datasets, thereby minimizing the burden for each child.

Pharmacogenomics of long-acting β2-agonists

INTRODUCTION

Long-acting β2-agonists are an effective class of drugs, when combined with inhaled corticosteroids, for reducing symptoms and exacerbations in patients with asthma that is not adequately controlled by inhaled corticosteroids alone. However, because this class of drugs has been associated with severe adverse events, including hospitalization and death in small numbers of patients, efforts to identify a pharmacogenetic profile for patients at risk has been diligently investigated.

AREAS COVERED

The PubMed search engine of the National Library of Medicine was used to identify English-language and non-English language articles published from 1947 to March 2015 pertinent to asthma, pharmacogenomics, and long-acting β2-agonists. Keywords and topics included: asthma, asthma control, long-acting β2-agonists, salmeterol, formoterol, pharmacogenetics, and pharmacogenomics. This strategy was also used for the Cochrane Library Database and CINAHL. Reference types were randomized controlled trials, reviews, and editorials. Additional publications were culled from reference lists. The publications were reviewed by the authors and those most relevant were used to support the topics covered in this review.

EXPERT OPINION

Children, who carry the ADRB2 Arg16Arg genotype, may be at greater risk than adults for severe adverse events. Rare ADRB2 variants appear to provide better clues for identifying the at-risk population of asthmatics.

Turning a molecule into a medicine: the development of indacaterol as a novel once-daily bronchodilator treatment for patients with COPD

Indacaterol is the first once-daily, long-acting β2-adrenergic agonist (LABA) approved for the treatment of chronic obstructive pulmonary disease (COPD). Indacaterol was developed using a combination of informed drug design and molecular chemistry to generate a β2-adrenergic agonist with a fast onset and long duration of action, enabling once-daily dosing with an acceptable safety profile. Early preclinical studies with indacaterol demonstrated these characteristics, and this promising molecule was taken into clinical development, originally for asthma treatment. Subsequent safety concerns over LABA monotherapy in patients with asthma redirected indacaterol's development to centre on COPD, where a good evidence base and guideline recommendations for bronchodilator monotherapy existed. Clinical development was initially complicated by different inhaler devices and differing doses of indacaterol. Using a phase III innovative adaptive-design clinical trial (INHANCE), indacaterol 150 and 300 μg once-daily doses were selected to be taken forward into the phase III INERGIZE programme. This programme delivered placebo-controlled and active-comparator data, including comparisons with formoterol, tiotropium and salmeterol/fluticasone, as well as the use of indacaterol in combination with tiotropium. Together, these studies provided a comprehensive assessment of the benefit-risk profile of indacaterol, allowing for regulatory submission. Indacaterol was first approved at once-daily doses of 150 and 300 μg in the European Union in 2009, followed by 150 µg in Japan (2011) and China (2012), and 75 μg in the United States (2011). To date, indacaterol is approved and marketed in more than 100 countries worldwide for once-daily maintenance treatment of COPD.

Application of multicategory exposure marginal structural models to investigate the association between long-acting beta-agonists and prescribing of oral corticosteroids for asthma exacerbations in the Clinical Practice Research Datalink

OBJECTIVE

To examine the comparative effectiveness of inhaled long-acting beta-agonist (LABA), inhaled corticosteroid (ICS), and ICS/LABA combinations.

METHODS

We used a retrospective cohort design of patients older than 12 years with asthma diagnosis in the Clinical Practice Research Datalink to evaluate asthma-related morbidity measured by oral corticosteroid (OCS) initiation within 12 months of initiating LABAs, ICSs, or ICSs/LABAs. Asthma severity 12 months before drug initiation (use of OCSs, asthma-related hospital or emergency department visits, and number of short-acting beta-agonist prescriptions) and during follow-up (short-acting beta-agonist prescriptions and total number of asthma drug classes) was adjusted as a time-varying variable via marginal structural models.

RESULTS

A total of 51,103 patients with asthma were followed for 12 months after receiving first prescription for study drugs from 1993 to 2010. About 92% initiated ICSs, 1% initiated LABAs, and 7% initiated ICSs/LABAs. Compared with ICSs, LABAs were associated with a 10% increased risk of asthma exacerbations requiring short courses of OCSs (hazard ratio [HR] 1.10; 95% confidence interval [CI] 1.07-1.18). ICS/LABA initiators were 62% less likely than ICS initiators (HR 0.38; 95% CI 0.12-0.66) and 50% less likely than LABA initiators to receive OCS prescriptions for asthma exacerbations (HR 0.50; 95% CI 0.14-0.78).

CONCLUSIONS

In concordance with current asthma management guidelines, inhaled LABAs should not be prescribed as monotherapy to patients with asthma. The findings suggest the presence of time-dependent confounding by asthma severity, which was accounted for by the marginal structural model.

Do genetic polymorphisms alter patient response to inhaled bronchodilators?

INTRODUCTION

Short- and long-acting β agonists (SABA and LABA) are bronchodilators for treating asthma. Bronchodilator response (BDR) is quantified by measuring air expired in the first second during a forced expiratory maneuver, prior to and following inhalation of SABA. BDR has been associated with a significant degree of heterogeneity, in part attributable to genetic variation. Heritability, the proportion of phenotypic variability accounted for by genetic variation is estimated to account for 50% of pulmonary function and 28.5% for BDR.

AREAS COVERED

A MEDLINE search for English articles published from January 1990 to June 2014 was completed using the terms: bronchodilator, bronchodilator response, short-acting bronchodilator, long-acting bronchodilator, β2 adrenergic receptor gene (ADRB2), asthma and pharmacogenomics. The effects of ADRB2 variants on BDR and the safety of SABA and LABA + inhaled corticosteroids have been studied with equivocal results. Single and candidate gene studies have identified variants in other genes that alter response to bronchodilators. Associations were recently observed between hospital admission rates and two rare ADRB2 polymorphisms: Thr164Ile and a 25 base pair insertion-deletion at nucleotide -376. This was the first report of life-threatening events associated with LABA being linked to rare ADRB2 variants.

EXPERT OPINION

Pharmacogenomic studies over the last two decades clearly demonstrate that polymorphisms alter patient response to bronchodilators in patients with asthma.

[A new fixed dose combination of fluticasone and formoterol in a pressurised metered-dose inhaler for the treatment of asthma]

The combination of an inhaled corticosteroid and a long acting beta-2 agonist is indicated for the regular treatment of persistent moderate-to-severe asthmatics whose asthma is not controlled by inhaled corticosteroids and the occasional use of a short acting beta-2 agonist. The aim of this review is to give an overview of the rationale of combining formoterol and fluticasone and to analyze the clinical data concerning a new fixed combination of fluticasone and formoterol in a pressurised metered-dose inhaler with a dose counter (Flutiform(®)) that was approved for the treatment of asthma in France in 2013. The clinical studies provide evidence that combined fluticasone/formoterol is more efficacious than fluticasone or formoterol given alone, and provides similar improvements in lung function to fluticasone (Flixotide(®)) and formoterol (Foradil(®)) administered concurrently. The combination of fluticasone/formoterol gave a more rapid bronchodilatation than the combination fluticasone/salmeterol. As a whole, the combination of fluticasone/formoterol had similar efficacy and tolerability profiles to the combinations of either budesonide/formoterol or fluticasone/salmeterol.

Safety of long-acting beta agonists and inhaled corticosteroids in children and adolescents with asthma

The introduction of long-acting beta agonists (LABAs) was considered a major advance in bronchodilator therapy for adult, as well as pediatric, patients with asthma. However, the use of LABAs has raised safety concerns, especially the potential for severe asthma exacerbations (SAEs) resulting in hospitalizations or even death. Meanwhile, the use of inhaled corticosteroids (ICSs), a cornerstone in the treatment of mild-to-severe persistent asthma, has been associated with growth suppression in children. The purpose of this review was to identify and discuss the major published safety studies surrounding LABA, ICS, and combined LABA/ICS usage in children. By way of a critical search for influential published clinical trials, meta-analyses, and observational studies, six studies relevant to the safety of LABA monotherapy, seven studies relevant to ICS monotherapy, and four studies on the subject of LABA/ICS combination usage were identified and reviewed. Based on the reviewed literature, the controversy surrounding these anti-asthma medications was clearly exposed. On the one hand, there is some evidence that LABA monotherapy may be associated with SAEs and asthma-related death, while ICS monotherapy may be associated with a higher risk of growth suppression. On the other hand, the concurrent use of a LABA with an ICS has been associated with positive outcomes including symptom reduction and reduced rate and severity of exacerbations. Further clinical research is warranted and has been called for by the US Food and Drug Administration.

Cardiovascular safety of long acting beta agonist-inhaled corticosteroid combination products in adult patients with asthma: a systematic review

INTRODUCTION

Long-acting beta agonists and inhaled corticosteroids combination products (LABA-ICS) are widely used in the treatment of asthma. However, there appears to be little data on their cardiovascular safety. The purpose of this study was to conduct a systematic review of the available studies and trials on the cardiovascular safety of LABA-ICS in adults with asthma.

METHODS

Two independent reviewers screened citations from PubMed and National Clinical Trials registry to identify studies and trials on the cardiovascular effects of LABA-ICS in patients with asthma.

RESULTS

A total of 15 studies (with 17 cohorts on LABA-ICS to compare with a comparator or placebo) with 5,440 total study participants met the inclusion criteria. Two studies on budesonide-formoterol and one on fluticasone-salmeterol reported treatment emergent cardiovascular adverse events, all of which were dysrhythmias. For comparison, the pooled estimate of the Peto odds ratio (0.72; 95 % confidence interval [CI] 0.17-3; p = 0.65) and the summary risk ratio (0.77; 95 % CI 0.26-2.3; p = 0.64) indicated a nonsignificant difference between LABA-ICS and comparator/placebo groups.

CONCLUSIONS

Our systematic review found that few studies and trials reported treatment emergent cardiovascular adverse events with LABA-ICS. However, the Peto odds ratio and risk ratio for these outcomes was statistically nonsignificant. This suggests that LABA-ICS products may have a safe cardiovascular profile in asthma patients.

US Food and Drug Administration-mandated trials of long-acting β-agonists safety in asthma: will we know the answer?

For 2 decades, long-acting β-agonists (LABAs) have been associated with increased asthma-related death risks in several randomized trials, even when added to inhaled corticosteroids (ICSs). In reaction, the US Food and Drug Administration (FDA) recently mandated that the manufacturers of LABAs conduct five large, noninferiority, randomized trials of the LABA+ICS combination in 53,000 patients with asthma. Three methodologic issues in these trials could lead to masking of or falsely detecting elevated risks. First, the effect of LABA discontinuation among the many patients already using these drugs at enrollment can result in an underestimation of the relative risk by a factor of around 20%. This effect will bias downward the upper bound of the resulting CI away from the preset noninferiority margin of 2.0 for the relative risk, artificially making it more difficult to detect a risk increase. Second, the composite asthma outcome will be dominated by asthma hospitalization, possibly dwarfing an increased risk of asthma-related death, with differences as wide as seven deaths under the LABA+ICS combination vs one death under ICS alone remaining statistically uncertain. Finally, because of the multiple identical trials being requested from the different manufacturers of LABAs, even if each trial is powered at 90%, there is a 41% likelihood that at least one of the trials will not rule out a risk increase when, in truth, there is no risk increase. In view of these impediments, the FDA should preempt such complexities by establishing decision rules regarding the interpretation of the results from these momentous safety trials before their completion, expected in 2017.

The pharmacists' potential to provide targets for interventions to optimize pharmacotherapy in patients with asthma

BACKGROUND

Despite of pharmacists' specialized knowledge of medication and his/her regular contact with patients, the expertise of the pharmacist may not be used enough yet. Furthermore, the potential of pharmacy dispensing data is underestimated.

OBJECTIVE

To provide targets for tailored interventions in asthma patients and to illustrate the potential value of pharmacists in the identification of these targets using individual pharmacy dispensing data.

SETTING

We performed a cross sectional retrospective analysis assessing the quality of asthma patients' pharmacotherapeutic treatment.

METHOD

Drug dispensing data from 2008 to 2009 were retrieved from a Dutch pharmacy database. All asthma patients were screened for potential suboptimal pharmacotherapy in 2009. Results were projected to a single community pharmacy to provide an estimate of the number of patients eligible for potential interventions.

MAIN OUTCOME MEASURES

(1) frequent use of short-acting β-agonists without preventive medication, (2) concomitant use of β-blockers, (3) multiple short courses of oral corticosteroids without using inhaled corticosteroids and 4) use of long-acting β-agonist without inhaled corticosteroids.

RESULTS

A total of 8,504 patients were eligible for analysis of the quality of their asthma treatment. 20.9 % of all asthma patients used >100 DDD short-acting β-agonists per year, whereas between 21.2 % (≥ 400 DDD) and 31.4 % (100-199 DDD) of these patients did not receive preventive medication. Approximately 5.2 % of the asthma patients are using β-blockers concomitantly and 21.8 % of them received non-cardioselective β-blockers. 6.3 % of the asthma patients received two or more oral courses of corticosteroids in 2008 and 17.4 % of these patients did not receive inhaled corticosteroids in 2009. 2.9 % of the patients used a long-acting β-agonists without inhaled corticosteroids. 8.4 % of the asthma patients using both long-acting β-agonists and inhaled corticosteroids received these drugs in two separate inhalers. We estimated that about 400 asthma patients could be identified in an average pharmacy population (8,000 patients) and 33 (95 % CI 22-44) of these patients would be eligible for interventions.

CONCLUSION

This study shows the potential for pharmacists to use their own pharmacy records to identify suboptimal therapy of asthma patients, who may be targets for tailored interventions.

Treatment of exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) describes the transient narrowing of the airways during, and particularly after exercise and occurs commonly in asthmatic individuals. Limitation of exercise capacity is a frequent complaint in all age groups, and severity of EIB ranges from mild impairment of performance to severe bronchospasm and a large reduction in FEV1. Treatment of EIB varies from daily to less frequent therapy, depending on the level of activity. In this article, the authors evaluate the treatment possibilities before, during, and after exercise. They also review medications currently used to treat EIB.

Pharmacotherapy for exercise-induced asthma: allowing normal levels of activity and sport

Exercise-induced bronchoconstriction (EIB) is experienced by the majority of an estimated 300 million individuals who have asthma, a condition that affects all ages and is increasing globally. Respiratory water loss with dehydration of the airways causing mediator release and airway narrowing is considered the cause of EIB, the severity of which will be increased if the inhaled air is cold or polluted. Adequate control of asthma is essential to minimize or prevent EIB and permit normal levels of physical activity and sport. This is important because exercise is a necessary component of daily living, assists in obtaining and maintaining a healthy body and has been demonstrated to benefit asthmatics. Inhaled glucocorticosteroids and inhaled β(2)-adrenoceptor agonists (IβA) are the pharmacological agents of choice to manage asthma and minimize EIB, assisted when necessary, by other drugs including leukotriene receptor antagonists and chromones. Tolerance from daily use of IβA is of concern and more flexible drug therapy needs to be considered. Optimal use of inhalers to deliver drugs effectively requires closer attention. Pharmacogenetics may hold the key to future drug therapy.

The effect of budesonide/formoterol maintenance and reliever therapy on the risk of severe asthma exacerbations following episodes of high reliever use: an exploratory analysis of two randomised, controlled studies with comparisons to standard therapy

BACKGROUND

Divergent strategies have emerged for the management of severe asthma. One strategy utilises high and fixed doses of maintenance treatment, usually inhaled corticosteroid/long-acting β2-agonist (ICS/LABA), supplemented by a short-acting β2-agonist (SABA) as needed. Alternatively, budesonide/formoterol is used as both maintenance and reliever therapy. The latter is superior to fixed-dose treatment in reducing severe exacerbations while achieving similar or better asthma control in other regards. Exacerbations may be reduced by the use of budesonide/formoterol as reliever medication during periods of unstable asthma. We examined the risk of a severe exacerbation in the period after a single day with high reliever use.

METHODS

Episodes of high reliever use were quantified and exacerbations occurring post-index day with these episodes were examined post hoc in two double-blind studies comparing the efficacy and safety of budesonide/formoterol maintenance and reliever therapy (Symbicort SMART™, Turbuhaler®) 160/4.5 μg twice daily plus as needed with similar or higher maintenance doses of ICS/LABA plus SABA or formoterol.

RESULTS

Budesonide/formoterol maintenance and reliever therapy significantly reduced the risk of episodes of high reliever use (>6 inhalations/day) vs. all alternative ICS/LABA regimens. With conventional fixed-dose treatment the need for exacerbation treatment within 21 days ranged from 6.0-10.1% of days post-index for all regimens compared with 2.5-3.4% of days with budesonide/formoterol maintenance and reliever therapy.

CONCLUSIONS

Budesonide/formoterol maintenance and reliever therapy reduces the incidence of high reliever episodes and the exacerbation burden immediately following these episodes vs. alternative ICS/LABA plus SABA regimens at up to double the maintenance dose of ICS.

TRIAL REGISTRATION

These studies do not have registration numbers as they were conducted before clinical trial registration was required.

Salmeterol and fluticasone in young children with multiple-trigger wheeze

BACKGROUND

Treatment guidelines recommend using an inhaled corticosteroid (ICS) plus a long-acting β(2)-agonist (LABA) for childhood asthma when the symptoms are not controlled by ICS alone, but the appropriate use of LABAs in children continues to be debated.

OBJECTIVE

To compare the efficacy of an inhaled salmeterol and fluticasone propionate combination, 50/100 μg twice daily, with fluticasone propionate, 100 μg twice daily, or salmeterol, 50 μg twice daily, in children with multiple-trigger wheeze.

METHODS

A total of 105 children 4 to 7 years of age with multiple-trigger wheezing based on respiratory symptoms and bronchodilator responsiveness and/or exercise-induced bronchoconstriction without a viral cold were randomized to salmeterol-fluticasone, fluticasone propionate alone, or salmeterol alone via a metered-dose inhaler and a spacer device for 8 weeks. The primary efficacy outcome was exhaled nitric oxide level. Secondary outcomes were lung function measurements via impulse oscillometry, respiratory symptoms, and rescue medication use.

RESULTS

The exhaled nitric oxide levels decreased after all treatments, significantly more so after salmeterol-fluticasone and fluticasone than with salmeterol (adjusted geometric means at 8 weeks: salmeterol-fluticasone, 9.4 ppb; fluticasone, 9.3 ppb; salmeterol, 13.9 ppb; salmeterol-fluticasone vs salmeterol, P = .02; fluticasone vs salmeterol, P = .01). No treatment differences were found with respect to respiratory symptoms or median rescue use. Salmeterol-fluticasone resulted in a small but statistically significant improvement in baseline lung function compared with fluticasone. All treatments were equally well tolerated.

CONCLUSION

The effects of salmeterol-fluticasone and fluticasone were comparable, although lung function improvement was better with salmeterol-fluticasone than with fluticasone alone. There is no obvious benefit in initiation therapy with salmeterol-fluticasone rather than fluticasone alone in the treatment of steroid-naive children with multiple-trigger wheeze.

TRIAL REGISTRATION

Pathway of clinical trial registry of Helsinki University:http://www.hus.fi/?Path=1;28;2530;9899;9900;23618;23903;33578.

Pharmacology and therapeutics of bronchodilators

Bronchodilators are central in the treatment of of airways disorders. They are the mainstay of the current management of chronic obstructive pulmonary disease (COPD) and are critical in the symptomatic management of asthma, although controversies around the use of these drugs remain. Bronchodilators work through their direct relaxation effect on airway smooth muscle cells. at present, three major classes of bronchodilators, β(2)-adrenoceptor (AR) agonists, muscarinic receptor antagonists, and xanthines are available and can be used individually or in combination. The use of the inhaled route is currently preferred to minimize systemic effects. Fast- and short-acting agents are best used for rescue of symptoms, whereas long-acting agents are best used for maintenance therapy. It has proven difficult to discover novel classes of bronchodilator drugs, although potential new targets are emerging. Consequently, the logical approach has been to improve the existing bronchodilators, although several novel broncholytic classes are under development. An important step in simplifying asthma and COPD management and improving adherence with prescribed therapy is to reduce the dose frequency to the minimum necessary to maintain disease control. Therefore, the incorporation of once-daily dose administration is an important strategy to improve adherence. Several once-daily β(2)-AR agonists or ultra-long-acting β(2)-AR-agonists (LABAs), such as indacaterol, olodaterol, and vilanterol, are already in the market or under development for the treatment of COPD and asthma, but current recommendations suggest the use of LABAs only in combination with an inhaled corticosteroid. In addition, some new potentially long-acting antimuscarinic agents, such as glycopyrronium bromide (NVA-237), aclidinium bromide, and umeclidinium bromide (GSK573719), are under development, as well as combinations of several classes of long-acting bronchodilator drugs, in an attempt to simplify treatment regimens as much as possible. This review will describe the pharmacology and therapeutics of old, new, and emerging classes of bronchodilator.

Paradoxical and bidirectional drug effects

A paradoxical drug reaction constitutes an outcome that is opposite from the outcome that would be expected from the drug's known actions. There are three types: 1. A paradoxical response in a condition for which the drug is being explicitly prescribed. 2. Paradoxical precipitation of a condition for which the drug is indicated, when the drug is being used for an alternative indication. 3. Effects that are paradoxical in relation to an aspect of the pharmacology of the drug but unrelated to the usual indication. In bidirectional drug reactions, a drug may produce opposite effects, either in the same or different individuals, the effects usually being different from the expected beneficial effect. Paradoxical and bidirectional drug effects can sometimes be harnessed for benefit; some may be adverse. Such reactions arise in a wide variety of drug classes. Some are common; others are reported in single case reports. Paradoxical effects are often adverse, since they are opposite the direction of the expected effect. They may complicate the assessment of adverse drug reactions, pharmacovigilance, and clinical management. Bidirectional effects may be clinically useful or adverse. From a clinical toxicological perspective, altered pharmacokinetics or pharmacodynamics in overdose may exacerbate paradoxical and bidirectional effects. Certain antidotes have paradoxical attributes, complicating management. Apparent clinical paradoxical or bidirectional effects and reactions ensue when conflicts arise at different levels in self-regulating biological systems, as complexity increases from subcellular components, such as receptors, to cells, tissues, organs, and the whole individual. These may be incompletely understood. Mechanisms of such effects include different actions at the same receptor, owing to changes with time and downstream effects; stereochemical effects; multiple receptor targets with or without associated temporal effects; antibody-mediated reactions; three-dimensional architectural constraints; pharmacokinetic competing compartment effects; disruption and non-linear effects in oscillating systems, systemic overcompensation, and other higher-level feedback mechanisms and feedback response loops at multiple levels. Here we review and provide a compendium of multiple class effects and individual reactions, relevant mechanisms, and specific clinical toxicological considerations of antibiotics, immune modulators, antineoplastic drugs, and cardiovascular, CNS, dermal, endocrine, musculoskeletal, gastrointestinal, haematological, respiratory, and psychotropic agents.

Long-acting β-agonists in asthma management: what is the current status?

Large surveillance studies or phase IV clinical studies of long-acting β-agonists (LABA) compared with placebo in asthma patients using variable (from nil to regular) doses of inhaled corticosteroids (ICS) have raised the issue of mortality risk in patients with asthma taking regular LABA. There have been a number of meta-analyses and systematic reviews that have examined the risk of LABA in asthma patients, and the general conclusion is that LABA added to ICS reduces asthma-related hospitalizations compared with ICS alone and there is no statistical increase in mortality. However, LABA without ICS do increase mortality risk in asthma. All reviews and analyses show a greater number of LABA deaths, but not all are statistically significant. A recent meta-analysis found LABA with concomitant ICS had a higher mortality rate in asthma than ICS alone. The flaw in the study is the higher doses of ICS in the control arms, but the implicit message remains: the essential need for enough ICS to control airway inflammation. We suggest that the pragmatic solution is to have LABA only available in the same device as ICS for asthma treatment. We do not think that a study comparing the safety of LABA plus ICS versus ICS alone in asthma is necessary. If such a study is conducted, the measurement of morbidity from increased doses of ICS is an essential design consideration. Furthermore, the critical focus in asthma management should not be forgotten - education of health professionals and the community of the critical role of ICS, and the need for good communication between health professionals and the asthma patient to facilitate good asthma control. The same arguments apply to the asthma-with-chronic obstructive pulmonary disease overlap syndrome in older patients. There is an urgent need to provide medical practitioners with the capability to diagnose the overlap syndrome.

[Asthma exacerbations: pharmacological prevention]

Asthma exacerbations are responsible for many emergency medical interventions and account for a significant proportion of the health costs of the disease. Increased airway inflammation is a key feature of exacerbations in asthma and therefore inhaled corticosteroids (ICS) are considered as first-line therapy for long-term asthma control. ICS have been demonstrated to reduce the risk of asthma exacerbations, as well as improving lung function. Oral leukotriene receptor antagonists also reduce the incidence of asthma exacerbations but are less effective than ICS. In patients with inadequately controlled persistent asthma despite low-dose ICS, the addition of a long-acting inhaled beta-agonist (LABA) should be considered. LABA should not be given alone and should always be associated with ICS in asthma. The anti-immunoglobulin E antibody, omalizumab, reduces severe exacerbations and emergency visits in patients with severe allergic asthma. In clinical trials measurement of the inflammatory response in induced sputum could provide information concerning appropriate drug therapy. Asthma-associated comorbidities should be investigated and treated, particularly in severe asthma. Despite a high prevalence of both gastro-oesophageal reflux and allergic rhinitis among patients with asthma, treatment with proton-pump inhibitors or nasal corticosteroids does not reduce the rate of asthma exacerbations.

Comparative effectiveness of asthma interventions within a practice based research network

BACKGROUND

Asthma is a chronic lung disease that affects more than 23 million people in the United States, including 7 million children. Asthma is a difficult to manage chronic condition associated with disparities in health outcomes, poor medical compliance, and high healthcare costs. The research network coordinating this project includes hospitals, urgent care centers, and outpatient clinics within Carolinas Healthcare System that share a common electronic medical record and billing system allowing for rapid collection of clinical and demographic data. This study investigates the impact of three interventions on clinical outcomes for patients with asthma. Interventions are: an integrated approach to care that incorporates asthma management based on the chronic care model; a shared decision making intervention for asthma patients in underserved or disadvantaged populations; and a school based care approach that examines the efficacy of school-based programs to impact asthma outcomes including effectiveness of linkages between schools and the healthcare providers.

METHODS/DESIGN

This study will include 95 Practices, 171 schools, and over 30,000 asthmatic patients. Five groups (A-E) will be evaluated to determine the effectiveness of three interventions. Group A is the usual care control group without electronic medical record (EMR). Group B practices are a second control group that has an EMR with decision support, asthma action plans, and population reports at baseline. A time delay design during year one converts practices in Group B to group C after receiving the integrated approach to care intervention. Four practices within Group C will receive the shared decision making intervention (and become group D). Group E will receive a school based care intervention through case management within the schools. A centralized database will be created with the goal of facilitating comparative effectiveness research on asthma outcomes specifically for this study. Patient and community level analysis will include results from patient surveys, focus groups, and asthma patient density mapping. Community variables such as income and housing density will be mapped for comparison. Outcomes to be measured are reduced hospitalizations and emergency department visits; improved adherence to medication; improved quality of life; reduced school absenteeism; improved self-efficacy and improved school performance.

DISCUSSION

Identifying new mechanisms that improve the delivery of asthma care is an important step towards advancing patient outcomes, avoiding preventable Emergency Department visits and hospitalizations, while simultaneously reducing overall healthcare costs.

β(2) -adrenoceptor agonists: current and future direction

Despite the passionate debate over the use of β(2) -adrenoceptor agonists in the treatment of airway disorders, these agents are still central in the symptomatic management of asthma and COPD. A variety of β(2) -adrenoceptor agonists with long half-lives, also called ultra long-acting β(2) -adrenoceptor agonists (ultra-LABAs; indacaterol, olodaterol, vilanterol, carmoterol, LAS100977 and PF-610355) are currently under development with the hopes of achieving once-daily dosing. It is likely that the once-daily dosing of a bronchodilator would be a significant convenience and probably a compliance-enhancing advantage, leading to improved overall clinical outcomes. As combination therapy with an inhaled corticosteroid (ICS) and a LABA is important for treating patients suffering from asthma, and a combination with an inhaled long-acting antimuscarinic agent (LAMA) is important for treating COPD patients whose conditions are not sufficiently controlled by monotherapy with a β(2) -adrenoceptor agonist, some novel once-daily combinations of LABAs and ICSs or LAMAs are under development.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

The addition of long-acting beta-agonists to inhaled corticosteroids in asthma

PURPOSE OF REVIEW

although long-acting beta-agonists (LABAs) have been used for two decades, with many studies showing benefit versus increasing inhaled corticosteroid (ICS), controversy regarding safety has resulted in the United States Food and Drug Administration (FDA) recently mandating label changes restricting LABA use. This review addresses these safety concerns together with clinical studies and meta-analyses assessing the appropriate use of LABAs.

RECENT FINDINGS

effective use of LABAs requires sufficient ICS to control inflammation. Underuse of ICS, which is often manifest by exacerbations, may reflect undue emphasis on alleged steroid-sparing effects of LABAs. The FDA meta-analysis found that LABA with mandatory ICS was not associated with increased risks of serious adverse events. The role of LABA with ICS as initial therapy in steroid-naïve patients is debated, as is LABA use in children, with data indicating less benefit than in adults. The FDA recommendation that LABA be withdrawn once control is achieved remains problematic, as greater ICS reduction can be achieved when LABA is continued.

SUMMARY

the safe use of LABAs, which are clearly effective in many patients with moderate to severe asthma, requires high compliance with ICS therapy, which is best assured if ICS and LABA are provided in a single inhaler.

[Asthma in the Archivos de Bronconeumología: a review of publications in the year 2009]

A total of 16 articles (Table 1), were published in the Archivos de Bronconeumología in the past year (December 2008 to November 2009), 9 of which were Originals, which was 17.6% of the originals published in that period. Fortunately, the tendency of a decreasing interest in asthma by pneumologists does not seem to have materialised as was feared a few years ago, on the contrary it seems that research is increasing. All articles that appeared in the journal during the period mentioned are reviewed.

Risk of serious asthma exacerbations associated with long-acting beta agonists among patients with asthma: a retrospective cohort study

BACKGROUND

After the Serevent Nationwide Surveillance clinical trial, controversy has surrounded the safety of long-acting beta agonists (LABAs).

OBJECTIVE

Examine the association between LABAs and severe asthma exacerbations (SAEs).

METHODS

From a multistate Medicaid database, for the years 2002-2007, a total of 940,449 patients (age <40) with asthma were selected and divided into a cohort with newly-diagnosed asthma and one with pre-existing asthma. SAEs included asthma-related emergency department (ED) visits, hospitalizations, and intubations. Patients' asthma severity was determined based on medication regimen as suggested by the 2002 National Asthma Guidelines. Specific use of inhaled corticosteroids (ICSs), LABAs, ICS/LABA combination drugs, short-acting beta agonists (SABAs), and other drugs was tracked. Cox proportional hazard regressions were estimated to assess the risk of SAEs associated with patient severity, drug use, and covariates.

RESULTS

Compared to patients taking a SABA only, estimated SAE hazard ratios for newly diagnosed and pre-existing-asthma patients were as follows: 0.63 (95% CI 0.58-0.69) and 0.74 (0.70-0.79) for patients on a LABA without ICS, and 0.79 (0.77-0.81) and 0.90 (0.87-0.92) for those on a LABA/ICS single inhaler. Although hazard ratios were estimated to be similar for ED visits, LABA use was found to be positively associated with hospitalizations and intubations. Other key risk factors (P < .0001) included being African American, an alcohol/substance use disorder, pregnancy, and obesity.

CONCLUSION

Relative to SABA-only therapy, LABA use is associated with a lower risk of ED visit. Certain patients with asthma, such as pregnant women and African Americans, are particularly vulnerable to SAE risk of all types.

An update on the safety of long-acting beta-agonists in asthma patients using inhaled corticosteroids

IMPORTANCE OF THE FIELD

Pooled trial data have shown that long-acting beta-agonists increase the risk for asthma hospitalizations and deaths by two to fourfold compared with placebo. Until recently, it was unclear whether concomitant inhaled corticosteroids (ICSs) could eliminate this risk.

AREAS COVERED IN THIS REVIEW

This review summarizes the available data on the safety of long-acting beta-agonist use in asthma, with and without concomitant ICSs. The results from an updated meta-analysis are presented, with data through December 2008.

WHAT THE READER WILL GAIN

In pooled trial data, catastrophic asthma events (defined as asthma-related intubation or death) were increased fourfold for concomitant treatment with long-acting beta-agonists and ICSs compared with corticosteroids alone (odds ratio 3.7; 95% CI 1.4 - 9.6). It is estimated that the addition of long-acting beta-agonists to ICS therapy is associated with an absolute increase of one catastrophic event per 1500 patient-years.

TAKE HOME MESSAGE

When the available trial data are pooled together, it is clear that long-acting beta-agonists significantly increase the risk for asthma-related intubations and deaths, even when used in a controlled fashion with concomitant ICSs. Clinical guidelines should readdress the role long-acting beta-agonists have in the management of asthma.

Long-term safety of mometasone furoate/formoterol combination for treatment of patients with persistent asthma

Objective: The combination of inhaled corticosteroid (ICS) and long-acting β₂-agonist is recommended for treatment of patients with persistent asthma inadequately controlled on ICS monotherapy. This study was conducted to evaluate the long-term safety of mometasone furoate/formoterol (MF/F) administered through metered-dose inhaler (MDI) in patients with persistent asthma previously on medium- to high-dose ICS. Methods: This was a 52-week, randomized, multicenter, parallel-group, open-label, evaluator-blinded study. At baseline, 404 patients (aged >12 years) were stratified according to their previous ICS dose (medium or high), then randomized 2:1 to receive twice-daily treatment of MF/F (200/10 or 400/10 μg) or fluticasone propionate/salmeterol (FP/S; 250/50 or 500/50 μg). The primary endpoint was the number and percentage of patients reporting any adverse event (AE). Additional safety evaluations included plasma cortisol 24-hour area under the curve (AUC_0–24h) and ocular changes. Pulmonary function, asthma symptoms, and use of rescue medication were monitored. Results: The incidence of >1 treatment-emergent AE was similar across treatment groups (MF/F 200/10 μg, 77.3% [n = 109]; FP/S 250/50 μg, 82.4% [n = 56]; MF/F 400/10 μg, 79.2% [n = 103]; FP/S 500/50 μg, 76.9% [n = 50]). Rates of treatment-related AEs were also similar across treatment groups (MF/F 200/10 μg, 28.4%; FP/S 250/50 μg, 23.5%; MF/F 400/10 μg, 23.1%; FP/S 500/50 μg, 20.0%). Headache (3.7%) and dysphonia (2.7%) were the most common treatment-related AEs overall. The nature and frequency of AEs and the decreases in plasma cortisol AUC_{0–24 h} observed with MF/F treatment were similar to those observed with FP/S treatment. Ocular events were rare (2–6% overall incidence among treatment groups); in particular, no posterior subcapsular cataracts were reported. Only three patients discontinued the study because of treatment-related ocular AEs (two for lens disorders in the MF/F 400/10 μg group; one for reduced visual acuity in the FP/S 250/50 μg group) and no asthma-related deaths occurred. Furthermore, MF/F showed numerical improvement in lung function and clinical benefits by reducing asthma symptoms and rescue medication use. Conclusions: One-year treatment with the new combination therapies -twice-daily MF/F-MDI 200/10 and 400/10 μg — is safe and well tolerated in patients with persistent asthma.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Use and safety of long-acting β2-agonists for pediatric asthma

Asthma guidelines recommend the use of long-acting β2-agonists (LABAs) as the preferred add-on therapy for adults and children over 5 years of age when asthma is inadequately controlled by inhaled corticosteroids alone. It has been suggested that LABA use may be associated with an increased risk of morbidity and mortality; however, this view is controversial since study findings have been inconsistent. While the safety profile of LABA monotherapy has been questioned, the value of concomitant inhaled corticosteroids to eliminate possible risks remains unproven. There is a paucity of efficacy and safety data for LABA use in children, and existing evidence is not sufficiently convincing to demonstrate a clear position for LABAs in the management of childhood asthma. The main aims of this article are to place LABAs in context in the management of childhood asthma and evaluate the current evidence for safety and efficacy.

Long-acting beta-agonists with and without inhaled corticosteroids and catastrophic asthma events

BACKGROUND

It is unclear whether long-acting beta-agonists with concomitant inhaled corticosteroids increase asthma-related intubations and deaths. We pooled data on long-acting beta-agonists with variable and concomitant inhaled corticosteroids to evaluate the risk for catastrophic asthma events.

METHODS

We conducted searches of electronic databases, the US Food and Drug Administration website, clinical-trials registries, and selected references through December 2008. We analyzed randomized controlled trials in patients with asthma, which lasted at least 3 months, evaluated long-acting beta-agonists compared with placebo or long-acting beta-agonists with inhaled corticosteroids compared with corticosteroids alone, and included at least 1 catastrophic event, defined as asthma-related intubation or death.

RESULTS

In pooled trial data that included 36,588 participants, long-acting beta-agonists increased catastrophic events 2-fold (Peto odds ratio [OR] 2.10; 95% confidence interval [CI], 1.37-3.22). Statistically significant increases were seen for long-acting beta-agonists with variable corticosteroids compared with placebo (OR 1.83; 95% CI, 1.14-2.95) and for concomitant treatment with corticosteroids compared with corticosteroids alone (OR 3.65; 95% CI, 1.39-9.55). Similar increases in risk were seen for variable and concomitant corticosteroid use, salmeterol and formoterol, and children and adults. When the analysis was restricted to trials with controlled corticosteroid use, given as part of the study intervention, concomitant treatment still increased catastrophic events compared with corticosteroids alone (OR 8.19; 95% CI, 1.10-61.18).

CONCLUSION

Long-acting beta-agonists increase the risk for asthma-related intubations and deaths, even when used in a controlled fashion with concomitant inhaled corticosteroids.

Clinical implications of the intrinsic efficacy of beta-adrenoceptor drugs in asthma: full, partial and inverse agonism

PURPOSE OF REVIEW

beta2-Adrenoceptor (AR) agonists are the most effective bronchodilators known, and play important roles in every step of asthma therapy. Intrinsic efficacy is an important pharmacological property that differentiates the clinical effects and safety profile of beta2-AR agonists. We review the role of beta2-AR agonist intrinsic efficacy in asthma treatment focusing on recent literature.

RECENT FINDINGS

In acute asthma, a full agonist (high intrinsic efficacy) offers a clinical advantage over a partial agonist (low intrinsic efficacy) but with the potential of inducing dose-dependent adverse effects. The chronic use of beta2-AR agonists may be associated with several adverse outcomes including loss of asthma control and even increased mortality. Recently, the role of beta-AR inverse agonists (beta-blockers) which have a negative intrinsic efficacy was studied. Whereas contraindicated in acute asthma, preliminary data suggest that the chronic use of these agents may be associated with attenuation of airway hyper-responsiveness in patients with mild asthma. Studies in a murine model of asthma suggest that such effects may be related to decreased airway inflammation and mucous metaplasia.

SUMMARY

Rational choice among beta2-AR agonists in acute and chronic asthma should be influenced by differences in intrinsic efficacy among these agents. In acute severe asthma, a full agonist offers a clinical advantage over a partial agonist. Whereas the use of inverse agonists in the treatment of asthma is still experimental and needs further exploration in future trials, preliminary studies suggest that their chronic use is well tolerated and is associated with decreased airway hyper-responsiveness.

Optimizing maintenance therapy in pediatric asthma

PURPOSE OF REVIEW

There are different phenotypes of asthma, with phenotype-specific differences in medication response observed.

RECENT FINDINGS

Tobacco smoke exposure reduces corticosteroid responsiveness. Treatment for tobacco smoke-triggered asthma must start with treatment of tobacco dependence. Obesity-associated asthma responds to weight loss and treatment of comorbidities. Immunotherapy and omalizumab are specific therapies for atopic asthma, though its use is limited by expense, inconvenience, need for injections, and toxicities. Leukotriene modifier response is more prominent in viral-triggered asthma. Research on intermittent escalation of controller therapy for asthma shows best results when escalation is substantial and early. Inhaled corticosteroid medications in low-to-moderate doses remain the most important maintenance medication for a broad variety of asthma phenotypes, reducing both impairment and risk. When impairment is not fully controlled by an inhaled corticosteroid, combination with a long-acting beta-agonist, leukotriene modifier, or theophylline can be effective. Inhaled corticosteroid use in children does not appear to influence airway caliber or asthma severity after the medication is stopped.

SUMMARY

Optimizing maintenance therapy for asthma is not one size fits all. It is important to assess the asthma phenotype in addition to the symptom pattern, in determining optimal maintenance therapy.

Promoting effects of IL-13 on Ca2+ release and store-operated Ca2+ entry in airway smooth muscle cells

Th2 cytokine interleukin (IL)-13 plays a central role in the pathogenesis of allergic asthma. IL-13 exhibits a direct effect on airway smooth muscle cells (ASMCs) to cause airway hyperresponsiveness. IL-13 has been demonstrated to regulate Ca(2+) signaling in ASMCs, but the underlying mechanisms are not fully understood. Store-operated Ca(2+) entry (SOCE) plays an important role in regulating Ca(2+) signaling and cellular responses of ASMCs, whether IL-13 affects SOCE in ASMCs has not been reported. In this study, by using confocal Ca(2+) fluorescence imaging, we found that IL-13 (10 ng/ml) treatment increased basal intracellular Ca(2+) ([Ca(2+)](i)) level, Ca(2+) release and SOCE induced by SERCA inhibitor thapsigargin in rat bronchial smooth muscle cells. The glucocorticoid dexamethasone and the short-acting beta2 adrenergic agonist (beta2 agonist) salbutamol suppressed IL-13-augumented basal [Ca(2+)](i), Ca(2+) release and SOCE, whereas the long-acting beta2 agonist salmeterol had no effect on altered Ca(2+) signaling in IL-13-treated ASMCs. Membrane-permeable cAMP analog dibutyryl-cAMP (db-cAMP) similarly decreased Ca(2+) release and SOCE induced by thapsigargin in IL-13-treated ASMCs, confirmed a role of cAMP/PKA signaling pathway in the regulation of SOCE. IL-13 promoted the proliferation of ASMCs stimulated by serum; this effect was inhibited by nonspecific Ca(2+) channel blockers SKF-96365 and NiCl(2), by salmeterol, but not by salbutamol and dexamethasone. IL-13 treatment did not change the expression of SOC channel-associated molecules STIM1, Orai1 and TRPC1 at mRNA level. Our findings identified a promoting effect of IL-13 on Ca(2+) release and SOCE in ASMCs, which partially contributes to its effect on the proliferation of ASMCs; the differences of glucocorticoids and beta2 agonists in inhibiting Ca(2+) signal and proliferation potentiated by IL-13 suggest that these therapies of asthma may have distinct effect on the relief of airway contraction and remodeling in bronchial asthma.

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

BACKGROUND AND OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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