Comparison of the effects of salmeterol and formoterol on airway tone and responsiveness over 24 hours in bronchial asthma

The Relevance of Small Airway Dysfunction in Asthma with Nocturnal Symptoms

Rationale

Small airway dysfunction (SAD) is a frequent feature of asthma that has been linked to disease severity and poor symptom control. However, little is known about the role of SAD in nocturnal asthma.

Objective

To study the association between the severity of SAD and frequency of nocturnal symptoms compared to conventional lung function testing.

Methods

We assessed the frequency of self-reported nocturnal symptoms through the asthma control test. We studied the impact of nocturnal asthma using the Asthma Quality of Life Questionnaire (AQLQ) and the Multidimensional Fatigue Inventory (MFI-20). We assessed the lung function using spirometry, body plethysmography, impulse oscillometry, single and multiple inert gas washout and measured markers of T2-inflammation (blood and sputum eosinophils; fractional exhaled nitric oxide (FeNo)). We stratified the patients according to the presence and frequency of nocturnal asthma.

Results

A total of 166 asthma patients were enrolled in the analysis. Eighty-seven patients (52%) reported to have nocturnal symptoms at least once in the last four weeks. The odds ratio of nocturnal asthma correlated with the severity of all non-spirometric measures of SAD, yet neither with airflow obstruction (FEV1 and FEV/FVC) nor with large airway resistance (R20). Patients with frequent nocturnal asthma (n = 29) had a numerical increase of T2 markers and more severe SAD, as indicated by all non-spirometric measures of SAD (all p-values < 0.05), worse overall asthma control, increased fatigue and reduced quality of life (all p-values < 0.01) compared to patients with infrequent nocturnal asthma (n = 58) or patients without nocturnal asthma (n = 79). We identified 63 patients without airflow obstruction, nearly 43% of them (n = 27) had nocturnal asthma. In this subgroup, only markers of air trapping and ventilation heterogeneity were significantly elevated and correlated with the frequency of nocturnal symptoms: LCI (Spearman’s coefficient = −0.42, p < 0.001), RV% (−0.32, p = 0.02).

Conclusion

SAD is closely associated to asthma with nocturnal symptoms. Spirometry might underestimate the broad spectrum of distal lung function impairments in this population of patients.

Considering Circadian Pattern of Blood Pressure in the Treatment of Hypertension via Chronotherapy: A Conducive or Maladroit Approach

Medical chronobiology deals with the way body's rhythm influences a person's health and disease states. To match body rhythms, deliberate alteration of drug concentration is done to optimize therapeutic outcomes and minimize size effects and this approach is known as Chronotherapeutics. In general the concept of homeostasis has been the base for the treatment of diseases. Little importance has been given in understanding biologic rhythms and their underlying mechanisms. Designing of cardiovascular drug is done to achieve a constant or near-constant effect throughout the 24-hour with the prescribed dose. However in many cases, medication requirement during night and day time are not the same. Body rhythms may have profound effect on the treatment outcomes. It is a wrongful approach to assume that a drug dosed in the morning or evening will have the same antihypertensive effect. The vast literature record of circadian variations in Blood Pressure (BP), heart rate, hormone secretion, and platelet aggregation are examples of the impact of chronobiology. In this study we analyze the effect of circadian pattern of blood pressure on action of various antihypertensives and investigate the perspective of chronotherapeutics- whether it is a fruitful approach and rationalize its utility in the treatment of hypertension.

Methacholine bronchial provocation test in patients with asthma: serial measurements and clinical significance

BACKGROUND/AIMS

The methacholine bronchial provocation test (MBPT) is used to detect and quantify airway hyper-responsiveness (AHR). Since improvements in the severity of asthma are associated with improvements in AHR, clinical studies of asthma therapies routinely use the change of airway responsiveness as an objective outcome. The aim of this study was to assess the relationship between serial MBPT and clinical profiles in patients with asthma.

METHODS

A total of 323 asthma patients were included in this study. The MBPT was performed on all patients beginning at their initial diagnosis until asthma was considered controlled based on the Global Initiative for Asthma guidelines. A responder was defined by a decrease in AHR while all other patients were considered non-responders.

RESULTS

A total of 213 patients (66%) were responders, while 110 patients (34%) were non-responders. The responder group had a lower initial PC20 (provocative concentration of methacholine required to decrease the forced expiratory volume in 1 second by 20%) and longer duration compared to the non-responder group. Members of the responder group also had superior qualities of life, compared to members of the non-responder group. Whole blood cell counts were not related to differences in PC20; however, eosinophil concentration was. No differences in sex, age, body mass index, smoking history, serum immunoglobulin E, or frequency of acute exacerbation were observed between responders and non-responders.

CONCLUSIONS

The initial PC20, the duration of asthma, eosinophil concentrations, and quality-of-life may be useful variables to identify improvements in AHR in asthma patients.

Randomised, double-blind, placebo-controlled, cross-over single dose study of the bronchodilator duration of action of combination fluticasone furoate/vilanterol inhaler in adult asthma

BACKGROUND

Fluticasone furoate (FF)/vilanterol (VI) is a once-daily maintenance treatment for asthma and chronic obstructive pulmonary disease. The duration of bronchodilation beyond 24 h has not been determined previously.

METHODS

Adults aged 18-65 (n = 32), with asthma and reversibility to salbutamol (≥15% and ≥200 mL increase in forced expiratory volume in 1 s [FEV₁]) participated in a double-blind, placebo-controlled, crossover study. Patients were admitted to a clinical trials unit for 72 h, and inhaled, in random order, placebo or FF/VI 100/25 mcg via ELLIPTA dry powder inhaler on two occasions 7-14 days apart. FEV₁ was measured at baseline, 15 and 30 min, 1, 2, 4, 12, 24, 36, 48, 60, and 72 h. The differences in change in FEV₁ from baseline between treatments and corresponding two-sided 95% confidence intervals (CI) were calculated at each time point.

FINDINGS

FF/VI produced a rapid onset of bronchodilation (adjusted mean difference in change from baseline in FEV₁ versus placebo at 15 min, 252 mL [95% CI 182-322]). Maximum bronchodilation was observed at 12 h (adjusted mean difference in the change from baseline in FEV₁, 383 mL [95% CI 285-481]). Bronchodilation was maintained throughout the 72-h assessment period (adjusted mean difference in the change in FEV₁ from baseline at 72 h, 108 mL (95% CI 15-200]). FF/VI was well tolerated and no serious side effects were reported.

INTERPRETATION

A single dose of FF/VI 100/25 mcg showed evidence of a 72-h bronchodilator duration of action in adults with asthma.

Bronchial hyperresponsiveness in childhood: A narrative review

Bronchial hyperresponsiveness (BHR) is an important but not asthma-specific characteristic and can be assessed by direct and indirect methods, based on the stimulus causing airway obstruction. BHR has been proposed as a prognostic marker of asthma severity and persistence, and may also be used to control pharmacological management of asthma. The most recent data on the prevalence and development of BHR in childhood and its predictive value for subsequent asthma development in late adolescence and adulthood is discussed in this review. According to the BHR-related scientific articles written in the English language and indexed in the publicly searchable PubMed database, the prevalence of BHR varies based upon the methods used to assess it and the population examined. In general, however, BHR prevalence is reduced as children grow older, in both healthy and asthmatic populations. While asthma can be predicted by BHR, the predictive value is limited. Reduced lung function, allergic sensitization, female sex, and early respiratory illness have been identified as risk factors for BHR. The collective studies further indicate that BHR is a dynamic feature related to asthma, but asymptomatic BHR is also common. Ultimately, the prevalence of BHR varies depending on the population, the environment, and the evaluation methods used. While both the methacholine challenge and the exercise test may predict asthma in adolescence or early adulthood, the predictive value is higher for the methacholine challenge compared to the exercise test. The collective data presented in the present study demonstrate how BHR develops through childhood and its relation to bronchial asthma.

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.

Comparison of the effectiveness and safety of formoterol versus salmeterol in the treatment of patients with asthma: A systematic review and meta-analysis

BACKGROUND

Formoterol and salmeterol are two long-acting β2-agonists given by inhalation, with bronchodilating effects lasting for at least 12 h after a single administration. Formoterol has a faster onset of action compared with salmeterol. The aim of this study was to perform a systematic review and meta-analysis on the data published from previous review in order to calculate pooled estimates of effectiveness and safety assessment of formoterol and salmeterol in treatment of patients with asthma.

MATERIALS AND METHODS

In this study, we conducted an electronic search for medical citation databases including Cochrane, PubMed, Scopus, PsycInfo, and IranMedex. Besides manual search of the databases that record randomized clinical trials, conference proceedings, and journals related to asthma were included. Studies were evaluated by two independent people based on inclusion and exclusion criteria, and the common outcomes of studies were entered into the RevMan 5.0.1 software, after evaluation of studies and extraction of data from them; and in cases where there were homogeneous studies, meta-analysis was performed, and for heterogeneous studies, the results were reported qualitatively.

RESULTS

Of the 1539 studies initially found, 13 were included in the study. According to the meta-analysis conducted, no significant difference was found between the inhalation of formoterol 12 μg and salmeterol 50 μg in the two outcomes of mean forced expiratory volume 1 s (FEV1), 12 h after inhalation of medication and Borg score (A frequently used scale for quantifying breathlessness) after inhalation of medication. In addition, salmeterol was more effective than formoterol in the two outcomes of percent decrease in FEV1 after inhalation of methacholine and the number of days without an attack. Since the two outcomes of FEV1 30-60 min after inhalation of medication and morning peak expiratory flow after inhalation of medication were heterogeneous, they had no meta-analysis capabilities, and its results were reported qualitatively.

CONCLUSION

The data from included studies shows that, more efficacy has been achieved with Salmeterol, especially in some outcomes such as the percent decrease in FEV1 after inhalation of Methacholine, and the number of days without an attack; and therefore, the administration of Salmeterol seems to be beneficial for patients, compared with Formoterol.

Review of the management of childhood asthma in Tasmania

AIM

To review the supply of medications to children with asthma and parent-reported management of childhood asthma in Tasmania and highlight evidence-practice gaps for future interventions.

METHODS

Participating pharmacies ran a software application that extracted data from dispensing records and helped to identify children with asthma. Parents of identified children were mailed a survey evaluating components of asthma management. Dispensing and survey data were analysed.

RESULTS

A total of 939 children from 23 pharmacies were identified by the software and deemed eligible for inclusion. Surveys were received from 353 (37.6%) parents. In the past year, short-acting beta-2 agonists were supplied to 56.1% of the cohort, preventers to 76.5% (inhaled corticosteroids 52.3%; leukotriene receptor antagonists 31.3%; inhaled cromones 0.6%), long-acting beta-2 agonists (LABAs) to 25.7% and oral corticosteroids to 21.5%. Approximately half of the children receiving inhaled corticosteroids were concurrently receiving a LABA. Among children with indicators of inadequately controlled asthma, up to 73.7% of their parents reported that their asthma was adequately controlled, up to 38.2% did not possess an Asthma Action Plan, up to 36.8% were not regularly using a spacer and up to 22.8% had not received a preventer.

CONCLUSION

These results indicate gaps in childhood asthma management, in particular, undersupply of preventers in high-risk patient groups, high supply of LABAs and insufficient spacer and asthma action plan usage. These areas should be targeted for interventions to improve childhood asthma management.

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.

Controversies regarding long-acting β2-agonists

PURPOSE OF REVIEW

This review examines the literature regarding the efficacy and safety of long-acting β2-agonists as add-on therapy to inhaled corticosteroids.

RECENT FINDINGS

The Global Initiative for Asthma (GINA) 2009 guidelines and the National Heart, Lung, and Blood Institute (NHLBI) 2007 asthma guidelines recommend adding long-acting β2-agonists to patients inadequately controlled on inhaled corticosteroids. These recommendations must be balanced against published data which demonstrate a signal of increased morbidity and mortality with use of long-acting β2-agonists. These conflicting data raise the question of whether or not there may be genotypic or phenotypic discriminators leading to disparate responses to long-acting β2-agonists.

SUMMARY

The combination of long-acting β2-agonists and inhaled corticosteroids demonstrates improvement in asthma control and exacerbation rates; however, long-acting β2-agonists are not recommended for use as monotherapy or without optimization of inhaled corticosteroid dose. Although the majority of asthmatic patients appear to benefit from the addition of long-acting β2-agonists, there are concerns that a small proportion of patients, including steroid-naïve patients and African Americans, may not obtain such benefits. Thus far, studies have not clearly demonstrated genotypic or phenotypic differences explaining the variability in response.

Indacaterol: a new once daily long-acting beta(2) adrenoceptor agonist

INTRODUCTION

Indacaterol is a novel once daily long-acting beta agonist (LABA) developed for the treatment of chronic obstructive pulmonary disease (COPD) and asthma.

AIMS

This review summarizes preclinical and clinical data of indacaterol, including all data generated during the phase II trial program, and further discusses the outlook and potential of the drug in the future treatment of COPD and asthma.

EVIDENCE REVIEW

Clinical studies suggest that indacaterol produces rapid and sustained bronchodilation in COPD patients and asthmatics of different severities. Until now, clinical studies of up to 28 days' duration have been published that have confirmed the suitability of indacaterol for once daily dosing, along with a favorable overall safety and tolerability profile.

OUTCOMES SUMMARY

Indacaterol monotherapy has potential in COPD, where antiinflammatory treatment is not fully established and issues about a potential risk of LABA use causing excess mortality have not been raised. In addition, indacaterol represents an option for future combination therapies in both asthma and COPD. However, more data are required, particularly in COPD, to fully assess the therapeutic potential of indacaterol in improving symptoms, quality of life, exacerbation rates, disease progression, exercise capacity, and hyperinflation. The currently ongoing phase III clinical trial program will add knowledge in respect to many long-term efficacy outcomes and gather further safety and tolerability data in both asthma and COPD.

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.

Inhaled corticosteroids or long-acting beta-agonists alone or in fixed-dose combinations in asthma treatment: a systematic review of fluticasone/budesonide and formoterol/salmeterol

BACKGROUND

Inhaled corticosteroids (ICSs) and long-acting inhaled beta(2)-agonists (LABAs) are recommended treatment options for asthma.

OBJECTIVE

This review compares the clinical effectiveness and tolerability of the ICSs fluticasone propionate and budesonide and the LABAs formoterol fumarate and salmeterol xinafoate administered alone or in combination.

METHODS

A systematic review of the clinical studies available on MEDLINE (database period, 1950-September 2009) was conducted to assess English-language randomized controlled trials in children and adults with asthma. Treatment outcomes included lung function, symptom-free days (SFDs), use of rescue/reliever medications, asthma exacerbations, and tolerability profile.

RESULTS

Use of fluticasone was associated with significantly greater improvement in lung function and better asthma symptom control than budesonide. Similarly, formoterol was associated with significantly greater improvement in lung function and better asthma symptom control (as measured by less rescue medication use and more SFDs) compared with salmeterol. Single inhaler combination regimens (budesonide/ formoterol and fluticasone/salmeterol) were frequently more effective in improving all treatment outcomes than either monotherapy alone. Across all comparisons, a review of studies in adults and children did not find statistically significant differences in outcomes between the ICS and LABA therapies considered in this research. In general, no differences in tolerability profiles were reported between the ICS and LABA options, although the risk for growth retardation was lower with fluticasone than budesonide and with budesonide/formoterol than with budesonide monotherapy.

CONCLUSIONS

In this systematic review, fluticasone and formoterol appear to provide improved therapeutic benefits versus budesonide and salmeterol, respectively. Both fluticasone/salmeterol and budesonide/ formoterol combination therapies appeared to be associated with greater improvements in outcomes measures than the corresponding ICS and LABA monotherapies.

Prolonged bronchoprotection against inhaled methacholine by inhaled BI 1744, a long-acting beta(2)-agonist, in patients with mild asthma

BACKGROUND

Long-acting ss(2)-agonists are an established controller medication in asthma. BI 1744 is a novel L\long-acting ss(2)-agonist with a preclinical profile that suggests 24-hour bronchodilation and bronchoprotection may be achieved.

OBJECTIVE

To examine the bronchoprotective effects of single doses of BI 1744 against methacholine provocation in subjects with mild asthma.

METHODS

Thirty-one subjects with mild asthma were randomized to receive single doses of BI 1744 (2, 5, 10, 20 microg) or placebo on separate days according to a double-blind, 5-way crossover design. Methacholine challenges were performed at 30 minutes and at 4, 8, 24, and 32 hours after each single dose of medication, and the results were expressed as PC(20) FEV(1).

RESULTS

All doses of BI 1744 produced statistically significant increases in the methacholine PC(20) compared with placebo as long as 32 hours. The mean (geometric SEM) methacholine PC(20) 24 hours after dosing with placebo was 1.73 (1.13) mg/mL, which increased after 2 microg to 3.86 (1.14) mg/mL, after 5 microg to 5.67 (1.14) mg/mL, after 10 microg to 9.42 (1.13) mg/mL, and after 20 microg to 13.71 (1.14) mg/mL (all P < .0001). After 32 hours, the methacholine PC(20) value remained significantly increased for all doses. No safety or tolerability concerns were identified.

CONCLUSION

BI 1744 provides significant bronchoprotection against inhaled methacholine for up to 32 hours after single-dose administration.

[Long-acting beta(2)-adrenoceptor agonists for asthma and COPD]

The introduction of long-acting beta(2)-adrenoceptor agonists such as salmeterol and formoterol has opened new perspectives for the treatment of asthma and, possibly, also COPD. These drugs are particularly useful in bronchial asthma and meet the requirements of several treatment guidelines to combine long-acting bronchodilator therapy with inhaled corticosteroids in patients with persistent asthma. The role of long-acting beta(2)-adrenoceptor agonists for management of COPD is less clear. While effects on lung function will be small, parameters of improved quality of life and exercise tolerance may verify the clinical role of long-acting beta(2)-adrenoceptor agonists for COPD treatment in the future.

Indacaterol, a novel inhaled, once-daily, long-acting beta2-agonist for the treatment of obstructive airways diseases

Indacaterol is a novel once-daily, long-acting beta(2)-agonist developed for the treatment of chronic obstructive pulmonary disease (COPD) and asthma. The present review summarizes the preclinical and clinical data of indacaterol, including recent data from phase II and III trials. These clinical studies suggest that indacaterol produces rapid and sustained bronchodilation in patients with COPD, and asthma of different severities. Until now, clinical studies of up to 1-year's duration have been at least partially published, which have confirmed the suitability of indacaterol for once-daily dosing, along with a favorable overall safety and tolerability profile in the long-term treatment of COPD. Data on relevant outcomes in asthma are more limited, especially with regard to chronic treatment. Therefore, it appears that indacaterol monotherapy will have its therapeutic potential primarily in COPD, where anti-inflammatory treatment is not fully established and issues about a potential risk of long-acting beta(2)-agonist use causing increased mortality have not been raised. As data from more advanced clinical trials have been published, a more complete picture of the full therapeutic potential of indacaterol in COPD has emerged, including patient-reported outcomes (eg, symptoms and quality of life) or additional pivotal outcomes (eg, exacerbation rates, disease progression, exercise capacity, and the development of hyperinflation). Finally, the pharmacological profile of indacaterol makes it an attractive partnering agent for future fixedcombination therapies in both asthma and COPD, eg, with once-daily inhaled corticosteroids or long-acting antimuscarinergic bronchodilators. The outlook and potential of indacaterol are further discussed.

Salmeterol/fluticasone propionate via Diskus once daily versus fluticasone propionate twice daily in patients with mild asthma not previously receiving maintenance corticosteroids

BACKGROUND AND OBJECTIVE

The efficacy and safety of twice-daily inhaled salmeterol/fluticasone propionate combination (SFC) therapy have been well established in the treatment of adults and adolescents with asthma. Once-daily administration of SFC could also be appropriate in patients with mild persistent asthma. This study aimed to investigate whether once-daily SFC 50 microg/100 microg was at least as effective as fluticasone propionate (FP) 100 microg twice daily, and more effective than twice-daily placebo, over 52 weeks as initial maintenance therapy in patients with mild persistent asthma.

METHODS

This was a randomized, double-blind, double-dummy, placebo-controlled, multicentre, parallel-group study carried out in primary and secondary care. Patients aged between 12 and 79 years with a documented clinical history of asthma for > or =6 months who were currently receiving inhaled short-acting beta(2)-adrenoceptor agonists only were enrolled. Patients were randomized to receive either once-daily inhaled SFC 50 microg/100 microg, twice-daily inhaled FP 100 microg (i.e. twice the dose of FP compared with SFC) or placebo for 52 weeks. The primary efficacy endpoints were mean morning peak expiratory flow (PEF), as recorded by patients prior to the use of bronchodilator or study medication, and the rate of investigator-recorded asthma exacerbations.

RESULTS

Patients receiving twice-daily FP and once-daily SFC showed greater improvements in mean morning PEF compared with those receiving placebo (FP, difference in means 20.1 L/min; 95% CI 14.7, 25.5; p < 0.001; SFC, difference in means 14.8 L/min; 95% CI 9.4, 20.2; p < 0.001). The difference in adjusted mean PEF between once-daily SFC and twice-daily FP was -5.3 L/min (95% CI -9.1, -1.6). PEF results showed that once-daily SFC was non-inferior to twice-daily FP. Over 52 weeks, there was a 35% reduction in exacerbation rates with once-daily SFC, which in this respect demonstrated superiority over placebo (p < 0.001). Non-inferiority between once-daily SFC and twice-daily FP with respect to exacerbation rates was not shown. Once-daily SFC significantly improved clinic forced expiratory flow between 25% and 75% of forced vital capacity (difference in means 0.129 L/s; p < 0.001) and clinic PEF (difference in means 10.8 L/min; p < 0.001) compared with twice-daily FP. Both treatments were well tolerated and the safety profile of each was similar to that seen with placebo.

CONCLUSION

In patients with mild persistent asthma not previously receiving maintenance therapy, once-daily SFC 50 microg/100 microg is an effective treatment compared with placebo, and was non-inferior to twice-daily FP 100 microg with respect to mean morning PEF. However, in this study, once-daily SFC was not as efficacious as twice-daily FP in reducing asthma exacerbation rates. This study confirms the benefits of regular maintenance treatment in patients with mild persistent asthma.

Combined salmeterol/fluticasone propionate versus fluticasone propionate alone in mild asthma : a placebo-controlled comparison

BACKGROUND AND OBJECTIVE

Combined therapy with inhaled corticosteroids (ICSs) and long-acting beta(2)-adrenoceptor agonists (LABAs) is the recommended approach for the treatment of patients with asthma that is uncontrolled on ICSs alone. Additional studies are needed to assess the safety and efficacy of combination treatment with ICSs and LABAs in patients with mild asthma. The aim of this study was to compare the efficacy and tolerability of once-daily salmeterol/fluticasone propionate combination (SFC) with once-daily fluticasone propionate (FP) over a 12-week treatment period in patients with mild persistent asthma.

METHODS

This was a randomized, double-blind, placebo-controlled, parallel-group, multicentre study carried out in primary care or at a hospital outpatient department and included patients 12-79 years of age with mild persistent asthma (n = 458). After a 2-week run-in period, patients were randomized to receive SFC 50 microg/100 microg (n = 149), FP 100 microg (n = 154) or placebo (n = 155) once daily in the morning for 12 weeks. The primary efficacy endpoint was patient-recorded pre-dose mean morning peak expiratory flow (PEF). Other assessments included asthma symptom scores, use of rescue medication and investigator-recorded exacerbations. Lung function was measured and assessed during clinic visits.

RESULTS

For the primary efficacy endpoint of mean change in morning PEF, SFC achieved significantly greater increases from baseline than both placebo (difference in adjusted means 23 L/min; 95% CI 15.0, 30.3; p < 0.001) and FP (difference in adjusted means 14 L/min; 95% CI 6.3, 21.7; p < 0.001). Compared with those who received FP, patients in the SFC group demonstrated significantly greater improvements in mean evening PEF (95% CI 11.7, 28.1; p < 0.001), forced expiratory volume in 1 second (95% CI 0.093, 0.257; p < 0.001), forced expiratory flow between 25% and 75% of forced vital capacity (95% CI 0.242, 0.617; p < 0.001), the percentage of symptom-free days (95% CI 0.34, 0.87; p = 0.011), and the percentage of rescue medication-free days (95% CI 0.34, 0.90; p = 0.018). During weeks 5-12, 52% of patients in the SFC group achieved 'well controlled' asthma, compared with 42% and 26% of patients in the FP and placebo groups, respectively. Only one patient (receiving placebo) had a severe asthma exacerbation during the study; the frequency of adverse events was similar across the three treatment groups.

CONCLUSION

Once-daily SFC 50 microg/100 microg provided significantly greater improvements in lung function and in asthma symptoms than once-daily FP 100 microg alone in patients with mild persistent asthma. However, twice-daily treatment with either SFC or ICSs plus short acting beta(2)-adrenoceptor agonists could be required to achieve guideline-defined asthma control in some patients.

Efficacy and safety of fluticasone propionate/salmeterol 250/50 mcg Diskus administered once daily

BACKGROUND

The twice daily administration of an inhaled corticosteroid (ICS) and long-acting beta(2)-agonist (LABA) has been shown to be effective in achieving asthma control. The once daily administration of an ICS/LABA may be a treatment option for some patients.

OBJECTIVE

To assess the effectiveness of fluticasone propionate (FP)/salmeterol via a single inhaler (FSC) administered once daily compared with FP once daily, FSC twice daily, or placebo.

METHODS

A 12-week, randomized, double-blind multicenter study conducted in 844 patients > or = 12 years of age who were symptomatic while using a short-acting beta(2)-agonist alone. Blinded treatments included: FSC 250/50 mcg once daily in the evening (FSC 250/50 QD), FP 250 mcg once daily in the evening (FP 250 QD), FSC 100/50 mcg twice daily (FSC 100/50 mcg BID), or placebo. All treatments were delivered via the Diskus device.

RESULTS

All treatments demonstrated greater improvements in efficacy measures compared with placebo. Overall, the greatest improvements were observed in the patients receiving FSC, either once or twice daily, compared with the FP 250 QD group. The two FSC treatments were similar except that QD dosing did not maintain improvements in lung function for 24h compared with twice daily dosing. All treatments were well tolerated. No suppression of HPA axis, as assessed by 24-h urinary cortisol excretion, was observed in any of the active treatment groups.

CONCLUSION

In patients symptomatic on a short-acting beta(2)-agonist alone, FSC 100/50 mcg BID was shown to provide better efficacy than a higher strength (FSC 250/50 mcg) administered once daily. However, a once daily regimen was effective and may be a valuable treatment option for some patients. Registered at (http://ctr.gsk.co.uk/welcome.asp) (SAS30022).

Getting to the heart of asthma: can "beta blockers" be useful to treat asthma?

beta(2)-adrenoceptor agonists are the mainstay for the acute symptomatic treatment of asthma and provide effective bronchoprotection to a wide range of bronchoconstrictor agents. However, over the past 4 decades there has been a continuing debate concerning whether regular chronic treatment with these drugs may be doing more harm than good. The FDA's recent decision to add black box warnings concerning the regular use of salmeterol- and formoterol-containing compounds, as well as their decision not to recommend agents containing long-acting beta(2)-adrenoceptor agonists as first-line therapy, seems to confirm the concerns regarding the regular use of the long-acting beta(2)-adrenoceptor agonists. A similar debate arose in the late 1980s concerning the use of beta-adrenoceptor agonists in the treatment of heart failure. In this disease, short-term use of beta agonists is associated with increased cardiac index and stroke volume, yet their long-term use is associated with increased morbidity and mortality. Moreover, certain beta blockers that are initially detrimental when used short term are now considered beneficial in the treatment of this disease when used chronically. Here, there is a parallel, as beta blockers are contraindicated in patients with asthma but the use of beta blockers chronically has never been evaluated. This begs the question of whether a similar paradigm shift is applicable in the treatment of asthma and whether under certain circumstances the long-term use of certain beta blockers may be useful in the treatment of this disease.

Beta2-agonists and bronchial hyperresponsiveness

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, and individuals with this disease respond to a range of physiological and chemical insults that are otherwise innocuous to healthy subjects, suggesting that the mechanisms underlying this phenomenon are characteristic of the asthma phenotype. BHR can be increased following exposure to environmental allergens in suitably sensitized individuals, pollutants, and certain viruses and can also be exacerbated by exposure to certain drugs, including nonsteroidal anti-inflammatory agents and beta-blockers. Although beta2-agonists administered acutely remain the treatment for the symptoms of asthma, paradoxically, regular treatment with these drugs can result in an increase in BHR, and this has been suggested to contribute to the increase in asthma morbidity and mortality that has been reported by numerous investigators. This article highlights our current understanding of this phenomenon and examines the potential mechanisms responsible for this effect.

Long-acting beta2-agonists for chronic asthma in adults and children where background therapy contains varied or no inhaled corticosteroid

BACKGROUND

Asthma is a common respiratory disease among both adults and children and short acting inhaled beta-2 agonists are used widely for 'reliever' bronchodilator therapy. Long acting beta-2 agonists (LABA) were introduced as prospective 'symptom controllers' in addition to inhaled corticosteroid 'preventer' therapy (ICS). In this updated review we have included studies in which patients were either not on ICS as a group, or in which some patients, but not all, were on ICS to complement previous systematic reviews of studies where LABA was given in patients uniformly receiving ICS. We have focussed particularly on serious adverse events, given previous concerns about potential risks, especially of death, from regular beta-2 agonist use.

OBJECTIVES

This review aimed to determine the benefit or detriment on the primary outcome of asthma control with the regular use of LABA compared with placebo, in mixed populations in which only some were taking ICS and in populations not using ICS therapy.

SEARCH STRATEGY

We carried out searches using the Cochrane Airways Group trial register, most recently in October 2005. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least four weeks duration, comparing a LABA given twice daily with a placebo, in chronic asthma. Selection criteria to this updated review have been altered to accommodate recently published Cochrane reviews on combination and addition of LABA to ICS therapy. Studies in which all individuals were uniformly taking ICS were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.

MAIN RESULTS

Sixty-seven studies (representing 68 experimental comparisons) randomising 42,333 participants met the inclusion criteria. Salmeterol was used as long-acting agent in 50 studies and formoterol fumarate in 17. The treatment period was four to nine weeks in 29 studies, and 12 to 52 weeks in 38 studies. Twenty-four studies did not permit the use of ICS, and forty permitted either inhaled corticosteroid or cromones (in three studies this was unclear). In these studies between 22% and 92% were taking ICS, with a median of 62%. There were significant advantages to LABA treatment compared to placebo for a variety of measurements of airway calibre including morning peak expiratory flow (PEF), evening PEF and FEV1. They were associated with significantly fewer symptoms, less use of rescue medication and higher quality of life scores. This was true whether patients were taking LABA in combination with ICS or not. Findings from SMART (a recently published surveillance study) indicated significant increases in asthma related deaths, respiratory related deaths and combined asthma related deaths and life threatening experiences. The absolute increase in asthma-related mortality was consistent with an increase of around one per 1250 patients treated with LABA for six months, but the confidence intervals are wide (from 700 to 10,000). Post-hoc exploratory subgroups suggested that African-Americans and those not on inhaled corticosteroids were at particular risk for the primary end-point of death or life-threatening asthma event. There was also a suggestion of an increase in exacerbation rate in children. Pharmacologically predicted side effects such as headache, throat irritation, tremor and nervousness were more frequent with LABA treatment.

AUTHORS' CONCLUSIONS

LABA are effective in the control of chronic asthma in the "real-life" subject groups included. However there are potential safety issues which call into question the safety of LABA, particularly in those asthmatics who are not taking ICS, and it is not clear why African-Americans were found to have significant differences in comparison to Caucasians for combined respiratory-related death and life threatening experiences, but not for asthma-related death.

Duration of action of the salmeterol/fluticasone combination inhaler administered in the evening: a randomized controlled trial in childhood asthma

OBJECTIVE AND BACKGROUND

To investigate the duration of bronchodilator action of a salmeterol/fluticasone combination (SFC) inhaler when administered in the evening to children with asthma.

METHODOLOGY

DESIGN

A double-blind, placebo-controlled, cross-over study.

SETTING

Hospital inpatient.

SUBJECTS

Fourteen children aged between 4 and 11 years with mild to moderate asthma (FEV(1) > 60% predicted) who exhibited a 15% increase in FEV(1) with bronchodilator.

INTERVENTIONS

SUBJECTS inhaled, in random order, either SFC (100/50 microg) or placebo, via accuhaler, at 20.00 hours on two separate occasions with at least 3 days between study days.

OUTCOME MEASURES

Lung function measurements including FEV(1), PEF, specific airways conductance (sGaw) and maximum expiratory flow at 25-75% of vital capacity were measured at baseline, 2, 12, 16, 20 and 24 h.

RESULTS

For all lung function parameters SFC resulted in significantly greater bronchodilation than placebo for at least 20 h after inhalation. At 24 h, the increase in FEV(1) and PEF compared with placebo was 0.08 L (95% confidence interval: -0.18 to 0.02, P = 0.16) and 27 L/min (95% confidence interval: -47 to -6, P = 0.004), respectively.

CONCLUSIONS

The single administration of SFC via an accuhaler in the evening resulted in significant bronchodilation for at least 20 h in children with asthma.

Beclometasone dipropionate/formoterol: in an HFA-propelled pressurised metered-dose inhaler

A hydrofluoroalkane (HFA)-propelled pressurised metered-dose inhaler (pMDI) has been developed (using Modulite technology) for a new fixed combination of beclometasone dipropionate/formoterol fumarate (BDP/formoterol) 100 microg/6 microg. Each actuation of the BDP/formoterol HFA pMDI 100 microg/6 microg delivers 86.4 microg of BDP and 5 microg of formoterol. BDP/formoterol HFA pMDI was associated with significantly higher morning peak expiratory flow (PEF) values than BDP administered alone via a chlorofluorocarbon (CFC) pMDI (including when BDP was administered at a higher dosage) in well designed trials in adults with mild to moderate or moderate to severe asthma. In terms of morning PEF values, BDP/formoterol HFA pMDI was noninferior to BDP plus formoterol administered via separate inhalers in well designed trials in adults with moderate to severe asthma. BDP/formoterol HFA pMDI was noninferior to fixed-combination budesonide/formoterol (the daily dosage of BDP was half that of budesonide) in terms of lung function, asthma symptoms and use of rescue medications in adults with moderate to severe asthma. BDP/formoterol HFA pMDI was also noninferior to, and had a faster onset of bronchodilation than, fixed-combination fluticasone propionate/salmeterol. BDP/formoterol 200 microg/12 microg per day or 400 microg/24 microg per day administered by the HFA pMDI was generally well tolerated. Moreover, a single high dose of BDP/formoterol (1000 microg/60 microg) was generally well tolerated in patients with asthma.

Efficacy and safety of high-dose budesonide/formoterol (Symbicort) compared with budesonide administered either concomitantly with formoterol or alone in patients with persistent symptomatic asthma

OBJECTIVE AND BACKGROUND

Budesonide/formoterol 160/4.5 microg, two inhalations bd, is an effective and well-tolerated maintenance therapy for patients not controlled on inhaled corticosteroids alone. The authors assessed the efficacy and safety of a higher dose of budesonide/formoterol in patients with persistent symptomatic asthma.

METHODS

This was a 24-week, double-blind, double-dummy randomized study. Budesonide/formoterol 320/9 microg, two inhalations bd (1280/36 microg/day), was compared with corresponding doses of budesonide during weeks 1-12 and budesonide plus formoterol via separate inhalers during weeks 1-24. Efficacy was assessed during weeks 1-12; the primary variable was morning PEF. Safety was assessed over weeks 1-24.

RESULTS

Patients (n=456; aged 12-79 years) had a mean reversibility in FEV1 of 28% and mean pre-study inhaled corticosteroid dose of 1038 microg/day. Mean morning PEF increased by 37 L/min and 36 L/min with budesonide/formoterol and budesonide plus formoterol, respectively, versus an increase of 5 L/min with budesonide (P<0.001 for both vs. budesonide). Budesonide/formoterol increased time to first mild exacerbation (P<0.005) versus budesonide. Budesonide/formoterol and budesonide plus formoterol had similar efficacy. All treatments were well tolerated and the incidence of class-related adverse events was similarly low in all groups. Changes in serum potassium and plasma cortisol were comparable across treatments.

CONCLUSIONS

High-dose budesonide/formoterol (320/9 microg, two inhalations bd) is effective and well tolerated in patients with persistent symptomatic asthma. The findings also support the safety of regular high-dose formoterol (36 microg/day).

Inhaled steroid/long-acting beta 2 agonist combination products provide 24 hours improvement in lung function in adult asthmatic patients

Background

The combination of inhaled corticosteroids (ICS) and long-acting β2-agonists (LABA) is recommended by treatment guidelines for the treatment of persistent asthma. Two such combination products, salmeterol/fluticasone propionate (SFC, Seretide™ GSK, UK) and formoterol/budesonide (FBC, Symbicort™, AstraZeneca, UK) are commercially available.

Objectives

The purpose of these studies was to evaluate and compare the duration of bronchodilation of both combination products up to 24 hours after a single dose.

Methods

Two randomised, double blind, placebo-controlled, crossover studies were performed. Study A was conducted in 33 asthmatic adults receiving 400–1200 mcg of budesonide or equivalent. Serial forced expiratory volume in one second (FEV₁) was measured over 24 hours to determine the duration of effect of both SFC (50/100 mcg) and FBC (4.5/160 mcg). Study B was conducted in 75 asthmatic adults receiving 800–1200 mcg of budesonide or equivalent and comprised a 4 week run-in of 400 mcg bd Becotide™ followed by 4 weeks treatment with either SFC 50/100 mcg bd or FBC 4.5/160 mcg bd taken in a cross-over manner. Serial 24-hour FEV₁ was measured after the first dose and the last dose after each 4-weeks treatment period to determine the offset of action of each treatment.

Results

In study A, a single inhalation of SFC and FBC produced a sustained bronchodilation at 16 hours with an adjusted mean increase in FEV₁ from pre-dose of 0.22 L (95% CI 0.19, 0.35 L) for SFC and 0.25 L (95% CI 0.21, 0.37 L) for FBC, which was significantly greater than placebo for both treatments (-0.05 L; p < 0.001). In study B, the slope of decline in FEV₁ from 2–24 hours post dose was -16.0 ml/hr for SFC and -14.2 ml/hr for FBC. The weighted mean AUC over 24 hours was 0.21 Lxmin and 0.22 Lxmin and mean change from pre-dose FEV₁ at 12 hours was 0.21 L for SFC and 0.20 L for FBC respectively

Conclusion

Both SFC and FBC produced a similar sustained bronchodilator effect which was prolonged beyond 12 hours post dose and was clearly measurable at 24 h.

Once-daily dosing with budesonide/formoterol compared with twice-daily budesonide/formoterol and once-daily budesonide in adults with mild to moderate asthma

Adherence to maintenance therapy is often poor in patients with asthma. Simplifying dosing regimens has the potential to improve both adherence and asthma-related morbidity. In this 12-week, randomized, double-blind, double-dummy, parallel-group study, 617 patients with mild to moderate persistent asthma (mean forced expiratory volume in 1s [FEV1] 78.5% predicted) who were not optimally controlled on inhaled corticosteroids (200-500 microg/day) were randomized to once-daily budesonide/formoterol (80/4.5 microg, 2 inhalations in the evening), twice-daily budesonide/formoterol (80/4.5 microg, 1 inhalation), or a corresponding dose of budesonide once-daily (200 microg, 1 inhalation in the evening). All patients received budesonide (100 microg twice daily) during a 2-week run-in. Changes in mean morning peak expiratory flow (PEF) were similar for od budesonide/formoterol (23.4 l/min) and twice-daily budesonide/formoterol (24.1 l/min), and both were greater than with budesonide (5.5 l/min; both P<0.001). Evening PEF, symptom-free days, reliever-free days, and asthma control days were improved with budesonide/formoterol therapy vs. budesonide (P<0.05 vs. budesonide for all variables). All treatments were well tolerated. Budesonide/formoterol administered once daily in the evening is a convenient treatment regimen that is as effective in improving asthma control as twice-daily dosing in patients with mild to moderate persistent asthma.

Chronopharmacology and controlled drug release

Circadian rhythms in the body are well established and are an important factor to consider when administering drugs. Many diseases display symptoms and onset characteristics that are not randomly distributed within 24 h (e.g., coronary infarction, angina pectoris, asthmatic attacks and peptic ulcer perforations); therefore, it is not surprising that the effects and/or pharmacokinetics of drugs can display significant daily variations. Recent data, primarily concerned with the chronopharmacokinetics of antiasthmatics, histamine H2-blockers and cardiovascular active drugs (e.g., propanolol, organic nitrate and nifedipine) are described as representative examples in this review. The data demonstrate that biological rhythms should have been taken into account when evaluating drug delivery systems, galenic formulations and pharmacokinetics as a basis for drug treatment.

Effect of fluticasone propionate-salmeterol therapy on seasonal changes in airway responsiveness and exhaled nitric oxide levels in patients with pollen-induced asthma

BACKGROUND

There has been concern that in allergic asthmatic patients there might be an interactive effect on inflammation between regular salmeterol use and exposure to allergens, resulting in increased airway responsiveness.

OBJECTIVE

To determine the effects of salmeterol on allergen-induced changes in airway responsiveness and exhaled nitric oxide (ENO) levels in allergic asthmatic patients concomitantly taking inhaled corticosteroids.

METHODS

Forty-two asthmatic patients sensitized to pollen allergens were randomly allocated to treatment with fluticasone propionate-salmeterol (n=21) or fluticasone propionate alone (n=21). Spirometry, the methacholine provocation concentration causing a 20% decline in forced expiratory volume in 1 second (PC20), the adenosine 5'-monophosphate (AMP) PC20, and ENO levels were measured before and at the height of the pollen season after 6 weeks of treatment.

RESULTS

Changes in the methacholine PC20, the AMP PC20, and ENO levels were not significantly different between treatment groups. No significant changes in the AMP PC20 were observed among the fluticasone propionate-salmeterol and fluticasone propionate groups during natural pollen exposure. However, a significant increase in the methacholine PC20 was observed in the fluticasone propionate-salmeterol group (P = .03) and in the fluticasone propionate group (P = .04); ENO concentrations decreased significantly in both groups during natural allergen exposure (P = .009 and .005).

CONCLUSIONS

In patients with pollen-induced asthma, treatment with either fluticasone propionate or fluticasone propionate-salmeterol is associated with significant reductions in methacholine responsiveness and ENO concentrations, even during natural pollen exposure. Furthermore, at least in patients with mild asthma, natural allergen exposure and the regular use of fluticasone propionate-salmeterol are not associated with a greater increase in ENO levels and airway responsiveness than natural allergen exposure and fluticasone propionate use alone.

Salmeterol Does Not Alter Increased Bronchial Responsiveness Caused by Organic Dust Exposure

BACKGROUND

Exposure in a swine house induces airway inflammation and increases bronchial responsiveness to methacholine in healthy subjects.

STUDY OBJECTIVES

The aim was to investigate whether a long-acting beta2-agonist, salmeterol, alters the increased bronchial responsiveness induced in healthy subjects following exposure to organic dust in a swine barn.

DESIGN AND SUBJECTS

The study includes three separate parts. In the first part (part 1), healthy subjects inhaled salmeterol (50 microg bid, n = 8) or placebo (n = 8) over 2 weeks. In part 2, healthy subjects inhaled one single dose of salmeterol (100 microg, n = 6) or placebo (n = 6) 1 h prior to exposure in a swine barn, which was followed by a bronchial methacholine challenge. In part 3, eight healthy individuals inhaled placebo or salmeterol (100 microg), 2 h or 8 h prior to a bronchial methacholine provocation, without being exposed in the swine barn.

RESULTS

Exposure caused an increase of bronchial responsiveness to methacholine by 3.2 doubling concentration steps (25 to 75th percentiles, 2.8 to 4.1) and 2.6 doubling concentration steps (25 to 75th percentiles, 1.4 to 3.7) in the placebo and salmeterol groups (2 weeks), respectively, with no significant differences between the groups (p = 0.3; part 1). Similar results were obtained when salmeterol was administered as a single dose (part 2) prior to exposure. However, salmeterol significantly attenuated the bronchial responsiveness to methacholine by 1.2 doubling concentration steps (0.8 to 1.7) 8 h after inhalation (part 3).

CONCLUSIONS

Salmeterol inhalation did not protect against the increased bronchial responsiveness induced in healthy subjects following exposure to organic dust when administered for 2 weeks or as a single dose prior to exposure. This lack of protection cannot be explained by homologous beta2-adrenoceptor desensitization. We hypothesize that exposure to organic material may alter the airway response to beta2-agonists.

Tolerance to bronchodilation during treatment with long-acting beta-agonists, a randomised controlled trial

BACKGROUND

Regular use of beta-agonists leads to tolerance to their bronchodilator effects. This can be demonstrated by measuring the response to beta-agonist following bronchoconstriction using methacholine. However most studies have demonstrated tolerance after a period of beta-agonist withdrawal, which is not typical of their use in clinical practice. This study assessed tolerance to the bronchodilator action of salbutamol during ongoing treatment with long-acting beta-agonist.

METHODS

Random-order, double-blind, placebo-controlled, crossover trial. After 1 week without beta-agonists, 13 asthmatic subjects inhaled formoterol 12 microg twice daily or matching placebo for 1 week. Eight hours after the first and last doses subjects inhaled methacholine to produce a 20% fall in FEV1. Salbutamol 100, 200 and 400 microg (cumulative dose) was then given at 5-minute intervals and FEV1 was measured 5 minutes after each dose. After a 1 week washout subjects crossed over to the other treatment. Unscheduled use of beta-agonists was not allowed during the study. The main outcome variable was the area under the salbutamol response curve.

RESULTS

The analysis showed a significant time by treatment interaction indicating that the response to salbutamol fell during formoterol therapy compared to placebo. After 1 week of formoterol the area under the salbutamol response curve was 48% (95% confidence interval 28 to 68%) lower than placebo. This reduction in response remained significant when the analyses were adjusted for changes in the pre-challenge FEV1 and dose of methacholine given (p = 0.001).

CONCLUSION

The bronchodilator response to salbutamol is significantly reduced in patients taking formoterol. Clinically relevant tolerance to rescue beta-agonist treatment is likely to occur in patients treated with long-acting beta-agonists.

Efficacy and safety of budesonide/formoterol compared with salbutamol in the treatment of acute asthma

This study compared the efficacy and safety of budesonide/formoterol (Symbicort) Turbuhaler)) with salbutamol pressurized metered-dose inhaler (pMDI) with spacer for relief of acute bronchoconstriction in patients with asthma. In this randomized, double-blind, parallel-group study, patients (n = 104 allocated to treatment; n = 103 received treatment; mean age 45 years) seeking medical attention for acute asthma (mean FEV(1) 43% of predicted) received two doses repeated at t = -5 and 0 min of either budesonide/formoterol (320/9 microg, two inhalations) or salbutamol (100 microg x eight inhalations); total doses 1280/36 microg and 1600 microg, respectively. All patients received prednisolone 60 mg at 90 min and FEV(1) was assessed over 3h. FEV(1) 90 min after dosing (primary variable) increased compared with pre-dose FEV(1) by an average of 30% and 32% for budesonide/formoterol and salbutamol, respectively (P = 0.66), with similar increases at all timepoints from 3 to 180 min for both groups. Mean pulse rate over 3h was significantly higher in the salbutamol group versus the budesonide/formoterol group (92 vs. 88 bpm; P < 0.01). No treatment differences were seen for other vital signs, including ECG. High-dose budesonide/formoterol was effective and well tolerated for the treatment of acute asthma, with rapid onset of efficacy and a safety profile over 3h similar to high-dose salbutamol.

Long-acting beta2-agonists in asthma: an overview of Cochrane systematic reviews

According to major asthma management guidelines, long-acting beta2-agonists (LABAs) should be used only when asthma remains symptomatic in patients already receiving regular inhaled corticosteroids (ICSs). A large Cochrane systematic review provides evidence that LABAs are safe and beneficial in control of asthma; sub-group analyses indicating that this is true when ICSs are used and in their absence. Two other Cochrane systematic reviews have found that LABAs are more effective than regular short-acting beta2-agonists, and are as effective as theophylline with fewer side-effects. These reviews support guidelines in the use of LABA as additional therapy when asthma is inadequately controlled by ICS at moderate dose. However, guidelines may be too conservative, and more studies in stable mild asthma comparing their use and safety with placebo and ICS are required.

The 24 h duration of bronchodilator action of the budesonide/formoterol combination inhaler

INTRODUCTION

The duration of bronchodilator action of the long-acting beta-agonist formoterol when administered in the evening has not been investigated. In this study we have investigated whether a single evening dose of formoterol, administered from the combination budesonide/formoterol (BUD/F) Turbuhaler significantly attenuates the circadian rhythm in airway tone over 24 h.

METHODS

Twenty subjects with mild to moderate asthma (mean FEV1 84% predicted) participated in a double-blind, placebo-controlled, cross-over study. Subjects inhaled, in random order, placebo or BUD/F (2x100/6 microg) administered in the evening (2000 h) on two separate occasions. Lung function measurements including FEV1, specific airways conductance (sGaw) and maximum expiratory flow at 25-75% of vital capacity (MEF(25-75%)) were assessed at baseline, at 1 h and subsequently every 4 h post-dose for 24 h.

RESULTS

Compared with placebo, BUD/F significantly improved the three measures of airways function throughout the 24 h period, with a difference in FEV1 at 24 h of 0.20L (0.04-0.35L). BUD/F attenuated the biphasic pattern of the circadian rhythm in airway tone.

CONCLUSION

The single evening administration of formoterol from the combination BUD/F inhaler resulted in a duration of bronchodilation of at least 24 h.

Combination therapy of long-acting beta agonists and inhaled corticosteroids in the management of chronic asthma

Both the Global Initiative for Asthma (GINA) and the National Heart, Lung and Blood Institute (NHLBI) Expert Panel guidelines recommend combination treatment with inhaled corticosteroids (ICSs) and inhaled long-acting beta-agonists (LABAs) for patients whose asthma is not adequately controlled by low doses of ICSs alone. Not only is this combination more effective than the combination of either theophylline or leukotriene modifiers with ICSs, there is suggestive evidence that the results with LABAs and ICSs may be more than additive. Through the effect of each one on the receptor for the other, they may have a synergistic action. This marked effectiveness of the combination, particularly when combined in the same device, has led to new objectives and novel applications. Therefore, for the first time, it appears that the Goals of Asthma Therapy, as outlined in the guidelines, are achievable for many patients with asthma. Also, at least for combination therapies including formoterol, adjustable dosing and perhaps even use as a rescue as well as a maintenance therapy may be possible.

Long-acting beta2-agonists: comparative pharmacology and clinical outcomes

Salmeterol and formoterol are both long-acting beta(2)-adrenoceptor agonists (beta(2)-agonists). They both provide excellent bronchodilating and bronchoprotective effects in patients with asthma but their are some differences between these two long-acting beta(2)-agonists in vitro and in vivo. Formoterol has a greater potency and intrinsic activity than salmeterol, which can become especially apparent at higher doses than that clinically recommended, and in contracted bronchi. Long-term use of long-acting beta(2)-agonists can induce tolerance, which can be partially reversed with corticosteroids. Long-acting beta(2)-agonists have some anti-inflammatory effects in vitro, but data in vivo are less convincing. Compared with doubling the dose of inhaled corticosteroids, the addition of inhaled long-acting beta(2)-agonists to inhaled corticosteroids improves symptom control in patients with asthma and reduces both the exacerbation rate of asthma and hospital admission rate. No enhanced airway responsiveness or loss of perception of dyspnea has been observed with the use of inhaled long-acting beta(2)-agonists. Monotherapy with long-acting beta(2)-agonists is not recommended.

The effect of formoterol over 24 h in patients with asthma: the role of enantiomers

The single-dose effect of formoterol racemate and enantiomers on bronchodilatation up to 24 h was determined. Forty-six reversible asthmatic patients were randomised to this double blind, crossover study. Formoterol was inhaled by nebulizer (HaloLite); 4.5 and 36 microg of the racemate (rac-formoterol), 2.25 and 18 microg of (R;R)-formoterol, 18 mirog of (S;S)-formoterol, or placebo. Airway and systemic effects were assessed by serial measurements of forced expiratory volume during the first second, FEV1 (24 h), and heart rate (4 h). Rac- and (R;R)-formoterol significantly and dose-dependently increased FEV1 with similar mean maximal effect. (S;S)-formoterol was without significant effects on FEV1 and heart rate. (R;R)- and rac-formoterol were still effective 22-24 h after single high doses, but this was associated with some systemic side effect (increased heart rate) initially. Average 22-24 h FEV1 was 8% (rac-formoterol 36 microg) and 11% ((R;R)-formoterol 18 microg) over placebo, respectively. No significant differences in effects were observed between rac- and (R;R)-formoterol. Thus, the single dose bronchodilatating effect of formoterol resides in (R;R)-formoterol. This study does not indicate a clinically important advantage of (R;R)-formoterol as acute bronchodilator compared to the racemate.

Rapid onset of tolerance to beta-agonist bronchodilation

INTRODUCTION

Regular use of beta-agonists leads to tolerance to their bronchodilator effects. This is easily demonstrated if dilation is tested following methacholine challenge. It is not known how quickly tolerance develops or how long it lasts after stopping beta-agonist therapy.

METHODS

Ten subjects with stable asthma were studied. Following 2 weeks without beta-agonists, methacholine was inhaled to induce a 20% reduction in FEV1. The response to inhaled salbutamol (100, 100, 200 microg at 5-min intervals) was then measured. This procedure was repeated 24 h after one dose and 24 h after 3, 7 and 14 days of inhaled formoterol 12 microg twice daily, and 3 and 5 days after formoterol was discontinued. Unscheduled use of beta-agonists was not permitted.

RESULTS

Bronchodilator tolerance, assessed by a reduction of the area under the salbutamol dose-response curve, occurred after 1 dose of formoterol (28% reduction, 95% CI 12, 45%), increased up to 1 week and plateaued between 1 and 2 weeks (58% reduction, 95% CI 38, 78%). Three days after stopping formoterol, the response to salbutamol was similar to baseline (12% reduction, 95% CI -9, 33%). The first dose of formoterol provided significant bronchoprotection to methacholine (1.6 doubling doses, P=0.007). This diminished with regular treatment and by 2 weeks the PD20 methacholine was not significantly different to baseline.

CONCLUSIONS

Bronchodilator tolerance occurs after a single dose and reaches a maximum after 1 week of regular formoterol. Sensitivity recovers 3 days after stopping treatment.

The 24 h duration of bronchodilator action of the salmeterol/fluticasone combination inhaler

INTRODUCTION

The duration of bronchodilator action of the long-acting beta agonist salmeterol when administered in the evening has not been investigated. In this study we have investigated whether a single evening dose of salmeterol, administered from the combination salmeterol/fluticasone (SFC) Accuhaler significantly attenuates the circadian rhythm in airway tone over 24 h.

METHODS

Eighteen subjects with mild to moderate asthma (mean FEV1 84% predicted) participated in a double-blind, double dummy, placebo controlled, cross-over study. Subjects inhaled, in random order, placebo, salbutamol (200 microg) or SFC (50/100 microg) administered in the evening (2000 h) on three separate occasions. Lung function measurements including FEV1, specific airways conductance (sGaw) and maximum expiratory flow at 25-75% of vital capacity (MEF(25-75%)) were assessed at baseline, at 1 h and subsequently every 4 h post-dose for 24 h.

RESULTS

Compared with placebo, SFC significantly improved the three measures of airways function throughout the 24 h period, with a difference in FEV1 at 24 h of 0.24 l (0.00-0.47 l). SFC abolished the biphasic pattern of the circadian rhythm in airway tone. In contrast, salbutamol had a significant bronchodilator action of 4-8 h, depending on the lung function parameter measured.

CONCLUSION

The single evening administration of SFC via the Accuhaler resulted in a duration of bronchodilation of at least 24 h, with the abolition of the accentuated biphasic circadian variation in airway tone observed in asthma.

Combination therapy in asthma--fixed or variable dosing in different patients?

The introduction of combination products, for the coadministration of an inhaled corticosteroid (ICS) with a long-acting beta2-agonist in a single inhaler, has greatly simplified asthma therapy. The two combination inhalers currently available, Symbicort (budesonide/formoterol in a single inhaler) and Seretide (salmeterol/fluticasone), comply with Step 3 of international guidelines that recommend the addition of a long-acting beta2-agonist to ICS in patients who are inadequately controlled on ICS alone. Importantly, combination inhalers ensure that patients cannot neglect their ICS maintenance therapy in favour of the long-acting beta2-agonist--which may improve adherence and overall asthma control. In vitro experiments suggest that ICS and long-acting beta2-agonists may interact beneficially when they are administered via one inhaler. The efficacy and tolerability of budesonide/formoterol and salmeterol/fluticasone have been demonstrated. There are currently two approaches for treating asthma using combination therapy--fixed and adjustable dosing. Fixed dosing with budesonide/formoterol or salmeterol/fluticasone provides effective asthma control in line with guideline goals. However, given the inherent variability of asthma, there is increasing evidence that adjusting the dose of ICS according to fluctuations in symptoms is beneficial. Findings from a series of studies comparing fixed and adjustable symptom-guided dosing regimens demonstrate that adjustable dosing may improve asthma control at an overall lower steroid dose. Ultimately, if adjustable dosing proves to be an effective treatment option, it may be possible to use budesonide/formoterol for both maintenance therapy and symptom relief, thereby overcoming the need for a separate reliever inhaler. This is because formoterol has a more rapid onset and greater dose-related effects than salmeterol in salmeterol/fluticasone. Given that all patients are different, with different disease severities and treatment preferences, both fixed and adjustable dosing strategies are likely to be important in the long-term management of asthma. It is possible that different treatment options will be used for different patients, depending on their disease severity, personality and ability to adhere to therapy.

A comparison of salmeterol and formoterol in attenuating airway responses to short-acting beta2-agonists

In vitro data suggest that salmeterol, contrary to formoterol, can partly antagonise the effect of short-acting beta(2)-agonist rescue medication. To explore whether this occurs in vivo, we compared the effects of increasing doses (200-3200 microg) of fenoterol on the recovery of methacholine induced bronchoconstriction as well as PD(20) methacholine in 23 asthmatic patients, during two-week treatment periods with placebo, and standard doses of salmeterol or formoterol in a double blind, double-dummy, crossover study. Salmeterol showed a slightly higher propensity for the development of bronchodilator tolerance. The recovery of methacholine induced bronchoconstriction was more complete during regular use of formoterol relative to salmeterol. During regular use of both long-acting beta(2)-agonists the bronchoprotective efficacy of fenoterol was attenuated, but this was more pronounced during salmeterol than during formoterol. The mean maximum increase in PD(20) metacholine after the highest dose of fenoterol was 3.97 DD during placebo, 2.47 DD during formoterol (p<0.001) and 1.81 DD during salmeterol treatment (p<0.001). We conclude that in asthmatic patients the efficacy of short-acting beta(2)-adrenoceptor agonists can be significantly attenuated during regular use of long-acting beta(2)-agonists. In this respect, differences were observed between salmeterol and formoterol that may represent the expression of partial antagonism by salmeterol.

Beta-adrenergic agonists inhibit corticosteroid-induced apoptosis of airway epithelial cells

Airway epithelial damage is a feature of persistent asthma. Treatment with inhaled and oral corticosteroids may suppress inflammation and gain clinical control despite continued epithelial damage. We have previously demonstrated that corticosteroids elicit apoptosis of airway epithelial cells in culture. beta-Adrenergic receptor agonists are commonly used in asthma therapy and can inhibit corticosteroid-induced apoptosis of eosinophils. We tested the hypothesis that beta-adrenergic agonists would inhibit corticosteroid-induced airway epithelial cell apoptosis in cultured primary airway epithelial cells and in the cell line 1HAEo-. Albuterol treatment inhibited dexamethasone-induced apoptosis completely but did not inhibit apoptosis induced by Fas receptor activation. The protective effect of albuterol was duplicated by two different analogs of protein kinase A. The protective effect was not associated with increased translocation of the glucocorticoid receptor to the nucleus nor with changes in glucocorticoid receptor-mediated transcriptional activation or repression. We demonstrate that beta-adrenergic agonists can inhibit corticosteroid-induced apoptosis but not apoptosis induced by Fas activation. These data suggest that one potential deleterious effect of corticosteroid therapy in asthma can be prevented by concomitant beta-adrenergic agonist treatment.

A proof of concept study to evaluate putative benefits of montelukast in moderate persistent asthmatics

AIMS

Whether chronic dosing with montelukast confers benefit in patients with moderate to severe asthma remains to be fully established. A proof of concept study was performed evaluating putative benefits with montelukast in moderate persistent asthmatics who were taken off inhaled corticosteroids (ICS) and switched to salmeterol. The latter was done to dissociate the effects of montelukast from ICS.

METHODS

Twenty moderate to severe persistent asthmatics completed a randomized double-blind crossover study. Subjects received montelukast 10 mg daily or placebo for 2 weeks each. This was preceded by a 2-week run-in when ICS were discontinued and salmeterol started, and used on a regular basis throughout the study. Measurements were made after run-in and after both randomized treatments.

RESULTS

There were no significant sequence effects for responses as to whether placebo or montelukast were given first or second. Methacholine PD20 values after run-in, first and second placebo were 63 micro g, 60 micro g and 64 micro g, respectively (corresponding to 2, 4 and 6 weeks of ICS washout, respectively). Lung function deteriorated pre vs post run-in, which was significant (P < 0.05) for FEF25-75 % predicted. Montelukast conferred significant (P < 0.05) improvements as change from post run-in compared with placebo in methacholine PD20, FEV1 % predicted, FEF25-75 % predicted, diurnal peak expiratory flow, symptoms and salbutamol use. For the primary outcome of methacholine PD20, this amounted to a 1.6-fold difference (95% CI 1.1, 2.5).

CONCLUSIONS

In moderate persistent asthmatics switched from taking ICS to salmeterol alone, adding montelukast conferred significant benefits on all parameters of asthma control. Further studies are indicated to evaluate whether montelukast exhibits additive effects to ICS/long-acting beta2-adrenoceptor agonist combination inhalers upon clinically important outcomes.

The long and short of beta2-agonists

For patients whose asthma is not adequately controlled with inhaled corticosteroid (ICS) therapy alone, increasing the dose of ICS or the addition of a long-acting beta(2)-agonist is recommended. Greater improvements in lung function are achieved with the addition of a long-acting beta(2)-agonist to ICS therapy, rather than doubling the dose of ICS. Formoterol and salmeterol have a similarly long duration of effect (up to 12 h). However, as a result of their different chemical structures, there are marked pharmacological differences in the mechanism of action which affect their speeds of onset. These differences amount to a more rapid onset of effect for formoterol compared with salmeterol. Long-acting beta(2)-agonists appear to be well tolerated at elevated doses. These two features (tolerability at high doses and rapid onset of effect) support the use of formoterol as a reliever medication in addition to use in maintenance therapy. The long-acting beta(2)-agonists can be considered as beneficial additions to ICS therapy for the management of moderate-to-severe asthma.

Once-daily budesonide/formoterol in a single inhaler in adults with moderate persistent asthma

Patients with moderate persistent asthma (n = 523; mean FEV1 77.4%) not fully controlled with inhaled corticosteroids (ICS; 400-1000 microg/day) were randomized to receive either once-daily budesonide/formoterol (160/4.5 microg, two inhalations); or twice-daily budesonide/formoterol (160/4.5 microg, one inhalation); or budesonide (400 microg) once-daily for 12 weeks. Once-daily dosing was administered in the evening and twice-daily dosing was administered in the morning and evening. All patients received twice-daily budesonide (200 microg) during a 2-week run-in. Compared with budesonide alone, change in mean morning and evening peak expiratory flow was greater in the once-daily budesonide/formoterol group (27 and 171 min(-1), respectively; P < 0.001) and twice-daily budesonide/formoterol group (23 and 24 l min(-1), respectively; P < 0.001). Night awakenings, symptom-free days, reliever-use-free days and asthma-control days were all improved during once-daily budesonide/formoterol therapy vs. budesonide (P < or = 0.05). Similar improvements were also seen with twice-daily budesonide/formoterol (P < or = 0.05). The risk of a mild exacerbation was reduced after once- and twice-daily budesonide/formoterol vs. budesonide (38% and 35%, respectively; P < 0.002). All treatments were well tolerated. Budesonide/formoterol, once- or twice-daily, in a single inhaler improved asthma symptoms and exacerbations compared with budesonide. In the majority of patients with moderate persistent asthma requiring ICS and long-acting beta-agonists, once-daily formoterol/budesonide provided sustained efficacy over 24 h, similar to twice-daily dosing.

Inhaled long acting beta agonists for stable chronic asthma

BACKGROUND

Asthma is a common respiratory disease among both adults and children and short acting inhaled beta-2 agonists are used widely for 'reliever' bronchodilator therapy. Long acting beta-2 agonists were introduced as prospective 'symptom controllers' in addition to inhaled corticosteroid 'preventer' therapy (ICS).

OBJECTIVES

This review aimed to determine the benefit or detriment on the primary outcome of asthma control with the regular use of long acting inhaled beta-2 agonists compared with placebo.

SEARCH STRATEGY

We carried out searches using the Cochrane Airways Group trial register, most recently in October 2002. We searched bibliographies of identified RCTs for additional relevant RCTs and contacted authors of identified RCTs for other published and unpublished studies.

SELECTION CRITERIA

All randomised studies of at least two weeks duration, comparing a long acting inhaled beta-agonist given twice daily with a placebo, in chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers performed data extraction and study quality assessment independently. We contacted authors of studies for missing data.

MAIN RESULTS

Eighty five studies met the inclusion criteria, 56 parallel group and 29 cross over design. Salmeterol xinafoate was used as long acting agent in 60 studies and formoterol fumarate in 25. The treatment period was two to four weeks in 32 studies, and 12 to 52 weeks in 53 studies. 34 study groups used concurrent inhaled corticosteroid treatment, 21 studies did not permit their use and 35 permitted either inhaled corticosteroid or cromones. There were significant advantages to long acting beta-2 agonist treatment compared to placebo for a variety of measurements of airway calibre including morning peak expiratory flow (PEF) (weighted mean difference (WMD) 26.78 L/min 95%CI 20.36 to 33.20), evening PEF (WMD 19.17 L/min 95%CI 11.63 to 26.73). They were associated with significantly fewer symptoms, less use of rescue medication and higher quality of life scores. The risk of exacerbation was lower in adults using regular inhaled corticosteroids.

REVIEWER'S CONCLUSIONS

Long acting beta-2 agonists are effective in the control of chronic asthma, and the evidence supports their use in addition to inhaled corticosteroids, as emphasised in current guidelines. Further research is needed on their use in children under 12 and in mild asthmatics not taking ICS.