Risks of long-acting beta-agonists in achieving asthma control

Boxed Warnings and Off-Label Use of Allergy Medications: Risks, Benefits, and Shared Decision Making

The Food and Drug Administration is tasked with evaluating the efficacy and safety of a drug. Despite having a regimented appraisal process in place, safety evidence can emerge during clinical trials as well as from observations and studies conducted after the drug has been on the market, which might require a boxed warning. The boxed warning is the most severe warning that the Food and Drug Administration can give to an approved drug. It is commonly referred to as a Black Box Warning because it is outlined in the package insert by a thick black box to garner the attention of prescribers and patients. There are currently more than 400 medications that have boxed warnings, and the information addressing major risks associated with a particular drug may, appropriately or inappropriately, influence patient and clinician decision making. Health care professionals must use the best evidence and clinical judgment in determining whether to prescribe medications with these warnings. Use of an approved drug at dosages or for indications other than what it was originally licensed for is referred to as "off-label" and is legal, commonplace, and may be evidence-based. All drugs may expose patients to possible harm, so prescribers have an obligation to discuss the best available evidence regarding benefits and harms so that patients can participate in shared decision making.

Genome-wide association studies of exacerbations in children using long-acting beta2-agonists

BACKGROUND

Some children with asthma experience exacerbations despite long-acting beta2-agonist (LABA) treatment. While this variability is partly caused by genetic variation, no genome-wide study until now has investigated which genetic factors associated with risk of exacerbations despite LABA use in children with asthma. We aimed to assess whether genetic variation was associated with exacerbations in children treated with LABA from a global consortium.

METHODS

A meta-analysis of genome-wide association studies (meta-GWAS) was performed in 1,425 children and young adults with asthma (age 6-21 years) with reported regular use of LABA from six studies within the PiCA consortium using a random effects model. The primary outcome of each study was defined as any exacerbation within the past 6 or 12 months, including at least one of the following: 1) hospital admissions for asthma, 2) a course of oral corticosteroids or 3) emergency room visits because of asthma.

RESULTS

Genome-wide association results for a total of 82 996 common single nucleotide polymorphisms (SNPs, MAF ≥1%) with high imputation quality were meta-analysed. Eight independent variants were suggestively (P-value threshold ≤5 × 10^-6 ) associated with exacerbations despite LABA use.

CONCLUSION

No strong effects of single nucleotide polymorphisms (SNPs) on exacerbations during LABA use were identified. We identified two loci (TBX3 and EPHA7) that were previously implicated in the response to short-acting beta2-agonists (SABA). These loci merit further investigation in response to LABA and SABA use.

Pharmacogenetics of inhaled long-acting beta2-agonists in asthma: A systematic review

BACKGROUND

Long-acting beta2-agonists (LABA) are recommended in asthma therapy; however, not all asthma patients respond well to LABA. We performed a systematic review on genetic variants associated with LABA response in patients with asthma.

METHODS

Articles published until April 2017 were searched by two authors using PubMed and EMBASE. Pharmacogenetic studies in patients with asthma and LABA response as an outcome were included.

RESULTS

In total, 33 studies were included in this systematic review; eight focused on children (n = 6051). Nineteen studies were clinical trials, while 14 were observational studies. Studies used different outcomes to define LABA response, for example, lung function measurements (FEV₁ , PEF, MMEF, FVC), exacerbations, quality of life, and asthma symptoms. Most studies (n = 30) focused on the ADRB2 gene, encoding the beta2-adrenergic receptor. Thirty studies (n = 14 874) addressed ADRB2 rs1042713, 7 ADRB2 rs1042714 (n = 1629), and 3 ADRB2 rs1800888 (n = 1892). The association of ADRB2 rs1042713 and rs1800888 with LABA response heterogeneity was successfully replicated. Other variants were only studied in three studies but not replicated. One study focused on the ADCY9 gene. Five studies and a meta-analysis found an increased risk of exacerbations in pediatrics using LABA carrying one or two A alleles (OR 1.52 [1.17; 1.99]). These results were not confirmed in adults.

CONCLUSIONS

ADRB2 rs1042713 variant is most consistently associated with response to LABA in children but not adults. To assess the clinical value of ADRB2 rs1042713 in children with asthma using LABA, a randomized clinical trial with well-defined outcomes is needed.

Therapeutic Effects of a Long-Acting Cholinergic Receptor Blocker, Tiotropium Bromide, on Asthma

Background

The aim of this study was to evaluate the therapeutic effects of tiotropium bromide on asthma.

Material/Methods

A total of 160 patients with moderate persistent asthma were randomly divided into 4 groups (n=40): the 3 control groups were given fluticasone propionate aerosol (group A), salmeterol-fluticasone propionate inhalant (group B), and tiotropium bromide inhalation powder combined with salmeterol-fluticasone propionate inhalant (group C), respectively, and the experimental group received tiotropium bromide inhalation powder combined with fluticasone propionate aerosol (group D) and salbutamol was used to relieve symptoms when necessary.

Results

After 8 weeks of treatment, the pulmonary function of group D, which was significantly better than those of group A (P<0.05), was similar to those of groups B and C (P>0.05). Group D had significantly better asthma control test scores and nighttime symptom scores than in group A (P<0.05), without significant differences from those of group B or group C (P>0.05). The number of times salbutamol was used to alleviate symptoms was significantly different (P<0.05) between group D and group A (P<0.05), as well as between group C and group D (P<0.05). Groups D and B had similar results (P>0.05). IL-13 levels in induced sputum had significant differences (P<0.05). The levels in group D, which were higher than those of groups A and B (P<0.05), were similar to those of group C (P>0.05).

Conclusions

Tiotropium bromide combined with fluticasone propionate improved the respiratory function and quality of life, and is a new therapy for moderate, persistent asthma.

Routine Use of Budesonide/Formoterol Fixed Dose Combination in Elderly Asthmatic Patients: Practical Considerations

Asthma has been demonstrated to be as common in the elderly as in younger age groups. Although no specific recommendations exist to manage the disease differently in older individuals, functional features and clinical presentations may be affected by age per se, and by age-related conditions, such as comorbidities and polypharmacy. In this review article, we aimed to explore the efficacy and safety in elderly asthmatic patients of one of the most currently used inhaled treatments for asthma, that is, the fixed-dose combination of budesonide/formoterol. We attempted to address some practical questions that are relevant to the daily practice of clinicians. We focused on the efficacy and real-world effectiveness of inhaled corticosteroids and long-acting β-adrenergic bronchodilators (ICS/LABA) as treatment in the elderly population, since data are extrapolated from younger populations. We investigated whether a maintenance and reliever therapy approach is more effective in the elderly as opposed to maintenance regimens, from both the general practitioner's and the pulmonologist's perspective. To address these questions, we scanned electronic databases (PubMed, MEDLINE, Embase, Scopus and Google Scholar) from the date of inception up to October 2016 with a cross-search using the following keywords: 'asthma', 'elderly', 'SMART therapy', 'MART therapy', 'Turbuhaler', and 'budesonide/formoterol'. The available literature on the topic confirms that when the age-associated changes are properly managed in clinical practice, asthma in older populations can be optimally controlled with inhaled treatment including ICS/LABA. This also applies for the budesonide/formoterol fixed combination, thus allowing for the maintenance and reliever therapy approach.

The evidence on tiotropium bromide in asthma: from the rationale to the bedside

Severe and poorly controlled asthma still accounts for a great portion of the patients affected. Disease control and future risk management have been identified by international guidelines as the main goals in patients with asthma. The need for new treatment approaches has led to reconsider anticholinergic drugs as an option for asthma treatment. Tiotropium is the first anticholinergic drug that has been approved for children and adults with poorly controlled asthma and is currently considered as an option for steps 4 and 5 of the Global Initiative for Asthma. In large randomized clinical trials enrolling patients with moderate to severe asthma, add-on therapy with tiotropium has demonstrated to be efficacious in improving lung function, decreasing risk of exacerbation and slowing the worsening of disease; accordingly, tiotropium demonstrated to be non inferior compared to long acting beta-agonists in the maintenance treatment along with medium to high inhaled corticosteroids. In view of the numerous ancillary effects acting on inflammation, airway remodeling, mucus production and cough reflex, along with the good safety profile and the broad spectrum of efficacy demonstrated in different disease phenotypes, tiotropium can represent a beneficial alternative in the therapeutic management of poorly controlled asthma. The present extensive narrative review presents the pharmacological and pathophysiological basis that guided the rationale for the introduction of tiotropium in asthma treatment algorithm, with a particular focus on its conventional and unconventional effects; finally, data on tiotropium efficacy and safety. from recent randomized clinical trials performed in all age categories will be extensively discussed.

Addressing unmet needs in understanding asthma mechanisms: From the European Asthma Research and Innovation Partnership (EARIP) Work Package (WP)2 collaborators

Asthma is a heterogeneous, complex disease with clinical phenotypes that incorporate persistent symptoms and acute exacerbations. It affects many millions of Europeans throughout their education and working lives and puts a heavy cost on European productivity. There is a wide spectrum of disease severity and control. Therapeutic advances have been slow despite greater understanding of basic mechanisms and the lack of satisfactory preventative and disease modifying management for asthma constitutes a significant unmet clinical need. Preventing, treating and ultimately curing asthma requires co-ordinated research and innovation across Europe. The European Asthma Research and Innovation Partnership (EARIP) is an FP7-funded programme which has taken a co-ordinated and integrated approach to analysing the future of asthma research and development. This report aims to identify the mechanistic areas in which investment is required to bring about significant improvements in asthma outcomes.

Safety of Adding Salmeterol to Fluticasone Propionate in Children with Asthma

BACKGROUND

Long-acting beta-agonists (LABAs) have been shown to increase the risk of asthma-related death among adults and the risk of asthma-related hospitalization among children. It is unknown whether the concomitant use of inhaled glucocorticoids with LABAs mitigates those risks. This trial prospectively evaluated the safety of the LABA salmeterol, added to fluticasone propionate, in a fixed-dose combination in children.

METHODS

We randomly assigned, in a 1:1 ratio, children 4 to 11 years of age who required daily asthma medications and had a history of asthma exacerbations in the previous year to receive fluticasone propionate plus salmeterol or fluticasone alone for 26 weeks. The primary safety end point was the first serious asthma-related event (death, endotracheal intubation, or hospitalization), as assessed in a time-to-event analysis. The statistical design specified that noninferiority would be shown if the upper boundary of the 95% confidence interval of the hazard ratio for the primary safety end point was less than 2.675. The main efficacy end point was the first severe asthma exacerbation that led to treatment with systemic glucocorticoids, as assessed in a time-to-event analysis.

RESULTS

Among the 6208 patients, 27 patients in the fluticasone-salmeterol group and 21 in the fluticasone-alone group had a serious asthma-related event (all were hospitalizations); the hazard ratio with fluticasone-salmeterol versus fluticasone alone was 1.28 (95% confidence interval [CI], 0.73 to 2.27), which showed the noninferiority of fluticasone-salmeterol (P=0.006). A total of 265 patients (8.5%) in the fluticasone-salmeterol group and 309 (10.0%) in the fluticasone-alone group had a severe asthma exacerbation (hazard ratio, 0.86; 95% CI, 0.73 to 1.01).

CONCLUSIONS

In this trial involving children with asthma, salmeterol in a fixed-dose combination with fluticasone was associated with the risk of a serious asthma-related event that was similar to the risk with fluticasone alone. (Funded by GlaxoSmithKline; VESTRI ClinicalTrials.gov number, NCT01462344 .).

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

OBJECTIVES

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

DESIGN

Retrospective cohort study.

SETTING

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

PARTICIPANTS

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

MEASUREMENTS

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

RESULTS

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

CONCLUSION

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

Cost-Utility Analysis of Long-Acting Beta Agonists versus Leukotriene Receptor Antagonists in Older Adults with Persistent Asthma Receiving Concomitant Inhaled Corticosteroid Therapy

BACKGROUND

Long-acting beta agonists (LABA) and leukotriene receptor antagonists (LTRA) are the major add-on treatments in older adults with persistent asthma when inhaled corticosteroids (ICS) fail to achieve adequate asthma control.

OBJECTIVES

To evaluate the cost-utility of ICS + LABA treatment compared with ICS + LTRA treatment in older adults with asthma.

METHODS

A Markov model was used to estimate the incremental costs and quality-adjusted life expectancy associated with ICS + LABA treatment versus ICS + LTRA treatment in older adults with asthma in the United States from the health system perspective. The HCUPnet 2010 national statistics were used to extract the costs associated with asthma and cardiovascular hospitalizations, and inpatient mortality associated with these events. Event probabilities were predicted using Medicare 2009-2010 claims for older adults with asthma. Treatment costs were estimated on the basis of average wholesale drug price listings, and utility estimates were extracted from the literature. To account for uncertainty, one-way sensitivity analysis and probabilistic sensitivity analysis were performed.

RESULTS

The model predicted that, compared with ICS + LTRA treatment, ICS + LABA treatment costs $5,823 more while gaining 0.03 quality-adjusted life-years (QALYs), resulting in an incremental cost-effectiveness ratio of $209,090 per QALY. Hospitalization probabilities and posthospitalization utilities were the most influential parameters in the one-way sensitivity analysis. Probabilistic uncertainty analysis using Monte-Carlo simulations showed that the probabilities that ICS + LTRA treatment is cost-effective compared with ICS + LABA treatment are 77% and 62% at $50,000 and $100,000 per QALY gained willingness-to-pay thresholds, respectively.

CONCLUSIONS

The cost-effectiveness of ICS + LABA treatment is economically unfavorable in older adults when compared with LTRA as add-on treatment.

Risk factors associated with 30-day asthma readmissions

OBJECTIVES

Assess factors that increase the odds of 30-day asthma readmissions to hospitals.

METHODS

Retrospective chart review between 1/1/2002 to 12/31/2012 of pediatric and adult patients with the primary diagnosis of asthma readmitted within 30 days after the index admission was performed. Patients were identified from billing database for asthma ICD 9 code (493.9). Inclusion criteria were: physician confirmed asthma diagnosis, one or more asthma admissions and accessible medical records.

RESULTS

A total of 95 patients with multiple asthma readmissions were included in the final analysis. Thirty-seven patients (39%) were readmitted for asthma within 30 days and 58 patients (61%) had readmission in a 30-365-day period. Demographic characteristics were not significantly different between groups. Bivariate analysis showed that factors associated with higher likelihood of readmissions were a higher frequency of previous admissions, ED visits, inpatient hospitalizations, ICU stays, intubations, chest X-rays, history of chronic sinusitis, gastroesophageal reflux disease, anxiety, and the use of tiotropium or a long-acting beta-agonist (LABA). Multivariable analysis confirmed that prior hospital admissions and a history of GERD are the strongest predictive factors for early asthma readmissions, yet a history of environmental allergies might be a protective factor (p = 0.053).

CONCLUSIONS

Non-allergic asthma patients with multiple prior admissions, ED visits and inpatient hospitalizations, on multiple medications with history of GERD, sinusitis, and anxiety are more likely to be readmitted within 30 days irrespective of other factors. Patients with these characteristics should be assessed for interventions in an effort to reduce early readmissions.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Increased Dose of Inhaled Corticosteroid versus Add-On Long-acting β-Agonist for Step-Up Therapy in Asthma

RATIONALE

Guidelines advocate adding long-acting β-agonist (LABA) to inhaled corticosteroid as the preferred step-up therapy to increasing inhaled corticosteroid dose for patients with uncontrolled asthma on inhaled corticosteroid monotherapy. However, less than 5% of patients with asthma qualify for the randomized controlled trials on which guidelines are based. Thus, real-world data are needed to complement the results of randomized trials with narrow entry criteria.

OBJECTIVES

To compare the effectiveness of stepping up asthma therapy with an increased dose of various types of inhaled corticosteroid as compared with add-on LABA.

METHODS

We performed a historical matched cohort study using large primary care databases to compare asthma step-up therapy with small- and standard size-particle inhaled corticosteroid versus added LABA for patients 12-80 years old. As outcomes, we examined a composite of asthma control and rates of severe exacerbations.

MEASUREMENTS AND MAIN RESULTS

The odds of asthma control and rates of severe exacerbations over one outcome year were comparable with increased inhaled corticosteroid dose versus added LABA. The adjusted odds ratios (95% confidence interval) for achieving asthma control with increased inhaled corticosteroid dose versus inhaled corticosteroid/LABA were 0.99 (0.88-1.12) for small-particle inhaled corticosteroid (n = 3,036 per cohort) and 0.85 (0.67-1.07) for standard size-particle inhaled corticosteroid (n = 809 per cohort). The adjusted rate ratios (95% confidence interval) for severe exacerbations, compared with inhaled corticosteroid/LABA combination inhaler, were 1.04 (0.91-1.20) and 1.18 (0.92-1.54), respectively. The results were not affected by smoking status.

CONCLUSIONS

When applied to a broad primary care population, antiinflammatory therapy using increased doses of small- or standard size-particle inhaled corticosteroid is as effective as adding LABA, as measured by outcomes important to both patients and providers. Real-world populations and outcomes need to be taken into consideration when formulating treatment recommendations.

Clinical efficacy of tiotropium in children with asthma

OBJECTIVE

To investigate the clinical efficacy of tiotropium in children with asthma.

METHODS

Eighty children with newly diagnosed moderate persistent asthma were enrolled into this study. The children were randomly assigned to the fluticasone propionate aerosol group or the fluticasone propionate aerosol plus tiotropium group for 12 weeks.

RESULTS

Lung function was significantly improved in both groups at 4, 8, and 12 weeks compared with baseline (P < 0.01). Moreover, lung function was significantly improved in the tiotropium group compared with the control group (P < 0.05). However, there was no significant difference in the incidence of severe asthma between the two groups (36.3% and 26.8%, respectively; P > 0.05). Compared with the control group, the number of days and frequency of short-acting beta2-adrenoceptor agonist use was significantly reduced in the tiotropium group (P < 0.05). Awakenings during the night were also significantly decreased (P < 0.00). There were no severe adverse reactions in either of the study groups.

CONCLUSION

Tiotropium could significantly improve lung function, reduce the use of short-acting beta2-adrenoceptor agonists, and improve sleep in children with asthma. Furthermore, few adverse reactions were reported.

Severe asthma in children

Severe asthma in children is characterized by sustained symptoms despite treatment with high doses of inhaled corticosteroids or oral corticosteroids. Children with severe asthma may fall into 2 categories, difficult-to-treat asthma or severe therapy-resistant asthma. Difficult-to-treat asthma is defined as poor control due to an incorrect diagnosis or comorbidities, or poor adherence due to adverse psychological or environmental factors. In contrast, treatment resistant is defined as difficult asthma despite management of these factors. It is increasingly recognized that severe asthma is a highly heterogeneous disorder associated with a number of clinical and inflammatory phenotypes that have been described in children with severe asthma. Guideline-based drug therapy of severe childhood asthma is based primarily on extrapolated data from adult studies. The recommendation is that children with severe asthma be treated with higher-dose inhaled or oral corticosteroids combined with long-acting β-agonists and other add-on therapies, such as antileukotrienes and methylxanthines. It is important to identify and address the influences that make asthma difficult to control, including reviewing the diagnosis and removing causal or aggravating factors. Better definition of the phenotypes and better targeting of therapy based upon individual patient phenotypes is likely to improve asthma treatment in the future.

Anticholinergics/antimuscarinic drugs in asthma

Anticholinergic alkaloids have been used for thousands of years for the relief of bronchoconstriction and other respiratory symptoms, and their use in the treatment of chronic obstructive pulmonary disease is well established. Acetylcholine, acting through muscarinic receptor (M) receptor, modulates multiple physiologic functions pertinent to asthma including airway muscle tone, mucus gland secretion, and various parameters of inflammation and remodeling. In addition, activation of M receptors may inhibit beta2 adrenoreceptor. These observations offer the rationale for the use of M receptors antagonists in the treatment of asthma. Short-acting antimuscarinic agents may be effective alone or in combination with short-acting beta agonists for the relief of acute symptoms. Long-acting antimuscarinic agents have emerged as potentially useful in the long-term treatment of difficult-to-control asthma. This review will analyze the mechanisms of action and therapeutic role of antimuscarinic agents on asthma including current guidelines regarding antimuscarinic drugs, recent studies in asthma, special populations to consider, and possible predictors of response.

β₂-Adrenergic agonists augment air pollution-induced IL-6 release and thrombosis

Acute exposure to particulate matter (PM) air pollution causes thrombotic cardiovascular events, leading to increased mortality rates; however, the link between PM and cardiovascular dysfunction is not completely understood. We have previously shown that the release of IL-6 from alveolar macrophages is required for a prothrombotic state and acceleration of thrombosis following exposure to PM. Here, we determined that PM exposure results in the systemic release of catecholamines, which engage the β2-adrenergic receptor (β2AR) on murine alveolar macrophages and augment the release of IL-6. In mice, β2AR signaling promoted the development of a prothrombotic state that was sufficient to accelerate arterial thrombosis. In primary human alveolar macrophages, administration of a β2AR agonist augmented IL-6 release, while the addition of a beta blocker inhibited PM-induced IL-6 release. Genetic loss or pharmacologic inhibition of the β2AR on murine alveolar macrophages attenuated PM-induced IL-6 release and prothrombotic state. Furthermore, exogenous β2AR agonist therapy further augmented these responses in alveolar macrophages through generation of mitochondrial ROS and subsequent increase of adenylyl cyclase activity. Together, these results link the activation of the sympathetic nervous system by β2AR signaling with metabolism, lung inflammation, and an enhanced susceptibility to thrombotic cardiovascular events.

Effect of vitamin D3 on asthma treatment failures in adults with symptomatic asthma and lower vitamin D levels: the VIDA randomized clinical trial

IMPORTANCE

In asthma and other diseases, vitamin D insufficiency is associated with adverse outcomes. It is not known if supplementing inhaled corticosteroids with oral vitamin D3 improves outcomes in patients with asthma and vitamin D insufficiency.

OBJECTIVE

To evaluate if vitamin D supplementation would improve the clinical efficacy of inhaled corticosteroids in patients with symptomatic asthma and lower vitamin D levels.

DESIGN, SETTING, AND PARTICIPANTS

The VIDA (Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness in Asthma) randomized, double-blind, parallel, placebo-controlled trial studying adult patients with symptomatic asthma and a serum 25-hydroxyvitamin D level of less than 30 ng/mL was conducted across 9 academic US medical centers in the National Heart, Lung, and Blood Institute's AsthmaNet network, with enrollment starting in April 2011 and follow-up complete by January 2014. After a run-in period that included treatment with an inhaled corticosteroid, 408 patients were randomized.

INTERVENTIONS

Oral vitamin D3 (100,000 IU once, then 4000 IU/d for 28 weeks; n = 201) or placebo (n = 207) was added to inhaled ciclesonide (320 µg/d). If asthma control was achieved after 12 weeks, ciclesonide was tapered to 160 µg/d for 8 weeks, then to 80 µg/d for 8 weeks if asthma control was maintained.

MAIN OUTCOMES AND MEASURES

The primary outcome was time to first asthma treatment failure (a composite outcome of decline in lung function and increases in use of β-agonists, systemic corticosteroids, and health care).

RESULTS

Treatment with vitamin D3 did not alter the rate of first treatment failure during 28 weeks (28% [95% CI, 21%-34%] with vitamin D3 vs 29% [95% CI, 23%-35%] with placebo; adjusted hazard ratio, 0.9 [95% CI, 0.6-1.3]). Of 14 prespecified secondary outcomes, 9 were analyzed, including asthma exacerbation; of those 9, the only statistically significant outcome was a small difference in the overall dose of ciclesonide required to maintain asthma control (111.3 µg/d [95% CI, 102.2-120.4 µg/d] in the vitamin D3 group vs 126.2 µg/d [95% CI, 117.2-135.3 µg/d] in the placebo group; difference of 14.9 µg/d [95% CI, 2.1-27.7 µg/d]).

CONCLUSIONS AND RELEVANCE

Vitamin D3 did not reduce the rate of first treatment failure or exacerbation in adults with persistent asthma and vitamin D insufficiency. These findings do not support a strategy of therapeutic vitamin D3 supplementation in patients with symptomatic asthma.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01248065.

Fast beneficial systemic anti-inflammatory effects of inhaled budesonide and formoterol on circulating lymphocytes in asthma

BACKGROUND AND OBJECTIVE

Inhaled glucocorticoids and long acting β2 -agonists reduce airway inflammation. It is unclear if this effect is based on the local action of the drugs or is due to a systemic effect on circulating peripheral blood lymphocytes. We assessed whether inhaled budesonide and/or formoterol modify the activity of circulating peripheral blood lymphocytes.

METHODS

Placebo controlled crossover design, including healthy (n = 10) or mild asthmatic males (n = 8). Blood was collected in the morning at 08:00 before drug inhalation, and drugs (placebo, budesonide 400 μg, formoterol 12 μg) were inhaled alone or in combination at 08:30. Four more blood samples were collected after inhalation at 09:00, 09:30, 12:30 and at 09:30 am on the following day. The activity of the glucocorticoid receptor, NFκB and IκB was determined in isolated lymphocytes. Lymphocytes were stimulated with lipopolysaccharide (LPS 10 μg/mL) for 24 h and interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, eotaxin level were determined. Lymphocyte proliferation was induced by phytohaemagglutinin (PHA 10 μg/mL) over 24 h.

RESULTS

When combined, the drugs synergistically activated the glucocorticoid receptor within 30 min but did not modify NFκB or IκB activity. Inhaled budesonide significantly reduced LPS-induced IL-1β, IL-6, IL-8 and TNF-α secretion, while inhaled formoterol had no such effect; however when combined, the inhibitory effect of budesonide was significantly increased by formoterol. PHA-induced proliferation was reduced by both drugs alone and in combination.

CONCLUSIONS

Combined budesonide and formoterol may reduce airway inflammation and immune reactivity of circulating lymphocytes through its local and systemic effects.

Asthma

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

LABAs in asthmatic children: highlights and new inside

International asthma guidelines recommend increasing the dose of ICS or adding leukotriene modifiers or the use of long-acting inhaled beta2-agonists (LABAs) in combination with inhaled corticosteroids (ICS) when uncontrolled asthma occurs in adult and children in treatment with low-dose inhaled corticosteroids. However, in children, the effects of this last treatment option are unclear because there are few studies on the efficacy and safety of these drugs in pediatric age. Furthermore, salmeterol is licensed for use in children over 4 years and formoterol in children of more than 6 years. Finally, recent data provides evidence that repeated bronchoconstriction induces epithelial cell stress that may lead to remodeling and these findings may have potential implications for asthma management, particularly for LABAs treatment in the future.

[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.

Trends in preventive asthma medication use among children and adolescents, 1988-2008

OBJECTIVE

To examine trends in preventive asthma medication (PAM) use among children with current asthma in the United States from 1988 to 2008.

METHODS

We performed a cross-sectional analysis of PAM use among 2499 children aged 1 to 19 years with current asthma using nationally representative data from the National Health and Nutrition Examination Survey (NHANES) during 3 time periods: 1988-1994, 1999-2002, and 2005-2008. PAMs included inhaled corticosteroids, leukotriene receptor antagonists, long-acting β-agonists, mast-cell stabilizers, and methylxanthines.

RESULTS

Among children with current asthma, there was an increase in the use of PAMs from 17.8% (SE: 3.3) in 1988-1994 to 34.9% (SE: 3.3) in 2005-2008 (P < .001 for trend). Adjusting for age, gender, race/ethnicity, and health insurance status, the odds of PAM use were higher in 2005-2008 compared with 1988-1994 (adjusted odds ratio [aOR] = 2.6; 95% confidence interval [CI]: 1.5-4.5). A multivariate analysis, combining all 3 time periods, showed lower use of PAMs among non-Hispanic black (aOR = 0.5 [95% CI: 0.4-0.7]) and Mexican American (aOR = 0.6 [95% CI: 0.4-0.9]) children compared to non-Hispanic white children. PAM use was also lower in 12 to 19 year olds compared with 1 to 5 year olds and also in children who did not have health insurance compared with those who did.

CONCLUSIONS

Between 1988 and 2008, the use of PAM increased among children with current asthma. Non-Hispanic black and Mexican American children, adolescents aged 12 to 19 years, and uninsured children with current asthma had lower use of PAM.

Achieving symptom control in patients with moderate asthma

Disease severity in asthma can be classified as mild, moderate or severe based upon the frequency of symptoms or the severity of airflow obstruction. This review will focus on the treatment of youths greater than 12 years of age and adults with moderate persistent asthma. Moderate asthmatics may have daily symptoms that cause some limitation with normal daily activities and require use of a rescue inhaled short-acting beta(2)-agonist inhaler or experience nocturnal awakenings secondary to asthma that occur more than once per week. Furthermore, spirometry may reveal airflow obstruction with a reduction in FEV(1) to between 60% and 80% of predicted. Although inhaled corticosteroids (ICS) are the primary controller medication used to modify symptoms in moderate asthmatics, additional controller medications, such as inhaled long-acting beta(2)-agonists (LABA), leukotriene receptor antagonists (LTRA) or theophylline, are often needed to obtain optimal disease control. While the addition of an inhaled LABA to an ICS is very effective at improving disease control in moderate asthma, concerns have arisen over the safety of LABAs, in particular the risk of asthma-related death. Therefore, consideration may be given to initially adding a LTRA, rather than a LABA, to ICS when asthma symptoms are not adequately controlled by ICS alone. Furthermore, individualization of medication regimens, treatment of co-morbid conditions, and patient education are crucial to optimizing compliance with therapy, improving disease control, and reducing the risk of exacerbations. Lastly, the development of new asthma treatments, perhaps based upon personalized medicine, may revolutionize the future treatment of moderate asthma.

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.

Uniform definition of asthma severity, control, and exacerbations: document presented for the World Health Organization Consultation on Severe Asthma

Asthma is a global health problem affecting around 300 million individuals of all ages, ethnic groups and countries. It is estimated that around 250,000 people die prematurely each year as a result of asthma. Concepts of asthma severity and control are important in evaluating patients and their response to treatment, as well as for public health, registries, and research (clinical trials, epidemiologic, genetic, and mechanistic studies), but the terminology applied is not standardized, and terms are often used interchangeably. A common international approach is favored to define severe asthma, uncontrolled asthma, and when the 2 coincide, although adaptation may be required in accordance with local conditions. A World Health Organization meeting was convened April 5-6, 2009, to propose a uniform definition of severe asthma. An article was written by a group of experts and reviewed by the Global Alliance against Chronic Respiratory Diseases review group. Severe asthma is defined by the level of current clinical control and risks as "Uncontrolled asthma which can result in risk of frequent severe exacerbations (or death) and/or adverse reactions to medications and/or chronic morbidity (including impaired lung function or reduced lung growth in children)." Severe asthma includes 3 groups, each carrying different public health messages and challenges: (1) untreated severe asthma, (2) difficult-to-treat severe asthma, and (3) treatment-resistant severe asthma. The last group includes asthma for which control is not achieved despite the highest level of recommended treatment and asthma for which control can be maintained only with the highest level of recommended treatment.

Long-acting beta-agonists in the management of chronic obstructive pulmonary disease: current and future agents

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and debilitating symptoms. For patients with moderate-to-severe COPD, long-acting bronchodilators are the mainstay of therapy; as symptoms progress, guidelines recommend combining bronchodilators from different classes to improve efficacy. Inhaled long-acting β2-agonists (LABAs) have been licensed for the treatment of COPD since the late 1990s and include formoterol and salmeterol. They improve lung function, symptoms of breathlessness and exercise limitation, health-related quality of life, and may reduce the rate of exacerbations, although not all patients achieve clinically meaningful improvements in symptoms or health related quality of life. In addition, LABAs have an acceptable safety profile, and are not associated with an increased risk of respiratory mortality, although adverse effects such as palpitations and tremor may limit the dose that can be tolerated. Formoterol and salmeterol have 12-hour durations of action; however, sustained bronchodilation is desirable in COPD. A LABA with a 24-hour duration of action could provide improvements in efficacy, compared with twice-daily LABAs, and the once-daily dosing regimen could help improve compliance. It is also desirable that a new LABA should demonstrate fast onset of action, and a safety profile at least comparable to existing LABAs.A number of novel LABAs with once-daily profiles are in development which may be judged against these criteria. Indacaterol, a LABA with a 24-hour duration of bronchodilation and fast onset of action, is the most advanced of these. Preliminary results from large clinical trials suggest indacaterol improves lung function compared with placebo and other long-acting bronchodilators. Other LABAs with a 24-hour duration of bronchodilation include carmoterol, vilanterol trifenatate and oldaterol, with early results indicating potential for once-daily dosing in humans.The introduction of once-daily LABAs also provides the opportunity to develop combination inhalers of two or more classes of once-daily long-acting bronchodilators, which may be advantageous for COPD patients through simplification of treatment regimens as well as improvements in efficacy. Once-daily LABAs used both alone and in combination with long-acting muscarinic antagonists represent a promising advance in the treatment of COPD, and are likely to further improve outcomes for patients.

Tiotropium bromide step-up therapy for adults with uncontrolled asthma

BACKGROUND

Long-acting beta-agonist (LABA) therapy improves symptoms in patients whose asthma is poorly controlled by an inhaled glucocorticoid alone. Alternative treatments for adults with uncontrolled asthma are needed.

METHODS

In a three-way, double-blind, triple-dummy crossover trial involving 210 patients with asthma, we evaluated the addition of tiotropium bromide (a long-acting anticholinergic agent approved for the treatment of chronic obstructive pulmonary disease but not asthma) to an inhaled glucocorticoid, as compared with a doubling of the dose of the inhaled glucocorticoid (primary superiority comparison) or the addition of the LABA salmeterol (secondary noninferiority comparison).

RESULTS

The use of tiotropium resulted in a superior primary outcome, as compared with a doubling of the dose of an inhaled glucocorticoid, as assessed by measuring the morning peak expiratory flow (PEF), with a mean difference of 25.8 liters per minute (P<0.001) and superiority in most secondary outcomes, including evening PEF, with a difference of 35.3 liters per minute (P<0.001); the proportion of asthma-control days, with a difference of 0.079 (P=0.01); the forced expiratory volume in 1 second (FEV1) before bronchodilation, with a difference of 0.10 liters (P=0.004); and daily symptom scores, with a difference of -0.11 points (P<0.001). The addition of tiotropium was also noninferior to the addition of salmeterol for all assessed outcomes and increased the prebronchodilator FEV1 more than did salmeterol, with a difference of 0.11 liters (P=0.003).

CONCLUSIONS

When added to an inhaled glucocorticoid, tiotropium improved symptoms and lung function in patients with inadequately controlled asthma. Its effects appeared to be equivalent to those with the addition of salmeterol. (Funded by the National Heart, Lung, and Blood Institute; ClinicalTrials.gov number, NCT00565266.).

FDA's recommendations on the use of long-acting {beta}2 agonists in the management of asthma

The revised labeling for long-acting β(2) agonists (LABAs) by the Food and Drug Administration (FDA) is controversial and in part is inconsistent with the 2007 National Asthma Education and Prevention Program asthma guidelines. Two large randomized controlled studies, the Serevent Nationwide Surveillance (SNS) study and the Salmeterol Multicenter Asthma Research Trial (SMART), and a 2008 meta-analysis conducted by the FDA were the main sources of information used to determine the label changes. A paucity of large, well-designed, controlled, prospective studies evaluating the asthma-related risks associated with LABAs makes it difficult to reach a consensus regarding how best to use LABAs in patients with asthma.

Management of severe asthma in children

Children who are referred to specialist care with asthma that does not respond to treatment (problematic severe asthma) are a heterogeneous group, with substantial morbidity. The evidence base for management is sparse, and is mostly based on data from studies in children with mild and moderate asthma and on extrapolation of data from studies in adults with severe asthma. In many children with severe asthma, the diagnosis is wrong or adherence to treatment is poor. The first step is a detailed diagnostic assessment to exclude an alternative diagnosis ("not asthma at all"), followed by a multidisciplinary approach to exclude comorbidities ("asthma plus") and to assess whether the child has difficult asthma (improves when the basic management needs, such as adherence and inhaler technique, are corrected) or true, therapy-resistant asthma (still symptomatic even when the basic management needs are resolved). In particular, environmental causes of secondary steroid resistance should be identified. An individualised treatment plan should be devised depending on the clinical and pathophysiological characterisation. Licensed therapeutic approaches include high-dose inhaled steroids, the Symbicort maintenance and reliever (SMART) regimen (with budesonide and formoterol fumarate), and anti-IgE therapy. Unlicensed treatments include methotrexate, azathioprine, ciclosporin, and subcutaneous terbutaline infusions. Paediatric data are needed on cytokine-specific monoclonal antibody therapies and bronchial thermoplasty. However, despite the interest in innovative approaches, getting the basics right in children with apparently severe asthma will remain the foundation of management for the foreseeable future.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND AND OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Asthma: time to confront some inconvenient truths

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

Asthma: clinical expression and molecular mechanisms

Asthma is a complex disorder that displays heterogeneity and variability in its clinical expression both acutely and chronically. This heterogeneity is influenced by multiple factors including age, sex, socioeconomic status, race and/or ethnicity, and gene by environment interactions. Presently, no precise physiologic, immunologic, or histologic characteristics can be used to definitively make a diagnosis of asthma, and therefore the diagnosis is often made on a clinical basis related to symptom patterns (airways obstruction and hyperresponsiveness) and responses to therapy (partial or complete reversibility) over time. Although current treatment modalities are capable of producing control of symptoms and improvements in pulmonary function in the majority of patients, acute and often severe exacerbations still occur and contribute significantly to both the morbidity and mortality of asthma in all age groups. This review will highlight some of the important clinical features of asthma and emphasize recent advances in both pathophysiology and treatment.

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.