The effect of salmeterol on nocturnal symptoms, airway function, and inflammation in asthma

Factors responsible for poor sleep quality in patients with chronic obstructive pulmonary disease

Background

Sleep disturbance is a common complaint in patients with chronic obstructive lung disease (COPD). However, the factors resulting in sleep disturbance remain unclear. This retrospective, observational, multicenter study aimed to identify the factors associated with sleep disturbance in patients with COPD.

Methods

The study was a retrospective, observational, and multicenter research. Data including age, sex, body mass index, smoking status, COPD inhaler prescribed, clinical symptoms, pulmonary function tests, medical history of comorbidities, and questionnaires were collected. Parameters including demographics, symptoms, medication, severity, functional classification, and comorbidities were correlated with sleep quality scores.

Results

Among 377 patients with COPD, 200 (53 %) patients experienced poor sleep quality (Pittsburg Sleep Quality Index scores > 5). A significant difference in sleep quality, as measured by PSQI scores, was noted between groups based on the 2011 Global Initiatives for Chronic Obstructive Lung Disease (GOLD) classification system. The most common sleep disturbances included “getting up to use the bathroom” (70.3 %), “wake up at night or early morning” (40.3 %), and “cough and snore loudly at night” (15.9 %). The use of inhaled corticosteroids, the presence of wheezing, COPD Assessment Test (CAT) scores, and Modified Medical Research Council (mMRC) dyspnea scale scores positively correlated with poor sleep quality (odds ratio: 1.51, 1.66, 1.09, and 1.30, respectively). Upon multivariate analysis, the CAT score was an independent factor for poor sleep quality in these patients. With the exception of sleep problem items, based on the CAT questionnaire, phlegm was significantly higher in COPD patients with poor sleep quality.

Conclusions

Poor sleep quality is common among patients with COPD and symptoms including wheeze, phlegm, and inhaled corticosteroid use may contribute to poor sleep quality. The CAT score is a good indicator of poor sleep quality in patients with COPD.

Most nocturnal asthma symptoms occur outside of exacerbations and associate with morbidity

BACKGROUND

Although nocturnal awakenings help categorize asthma severity and control, their clinical significance has not been thoroughly studied.

OBJECTIVE

We sought to determine the clinical consequences of nocturnal asthma symptoms requiring albuterol (NASRAs) in children with mild-to-moderate persistent asthma outside of periods when oral corticosteroids were used for worsening asthma symptoms.

METHODS

Two hundred eighty-five children aged 6 to 14 years with mild-to-moderate persistent asthma were randomized to receive one of 3 controller regimens and completed daily symptom diaries for 48 weeks. Diary responses were analyzed for the frequency and consequences of NASRAs.

RESULTS

NASRAs occurred in 72.2% of participants at least once, and in 24.3% of participants, they occurred 13 or more times. The majority (81.3%) of nocturnal symptoms occurred outside of exacerbation periods and were associated the next day with the following events: albuterol use (56.9% of days preceded by nocturnal symptoms vs 18.1% of days not preceded by nocturnal symptoms; relative risk [RR], 2.3; 95% CI, 2.2-2.4), school absence (5.0% vs 0.3%; RR, 10.6; 95% CI, 7.8-14.4), and doctor contact (3.7% vs 0.2%; RR, 8.8; 95% CI, 6.1-12.5). Similar findings were noted during exacerbation periods (RRs of 1.7 for albuterol use, 5.5 for school absence, and 4.9 for doctor contacts). Nocturnal symptoms did not predict the onset of exacerbations.

CONCLUSION

Nocturnal symptoms requiring albuterol in children with mild-to-moderate persistent asthma receiving controller therapy occurred predominantly outside of exacerbation periods. Despite being poor predictors of exacerbations, they were associated with increases in albuterol use, school absences, and doctor contacts the day after nocturnal symptom occurrences.

Polymorphisms of the β2-adrenergic receptor correlated to nocturnal asthma and the response of terbutaline nebulizer

BACKGROUND

Inhaled β(2)-adrenergic receptor (β(2)-AR) agonists are the mainstay of treatment of acute asthma. Polymorphisms of the β(2)-AR, especially codons 16, 27, and 164, may affect the functions of the receptor. This study was conducted to investigate whether different polymorphisms of the β(2)-AR are related to the treatment responses of an inhaled β(2)-AR agonist in children with nocturnal and nonnocturnal asthma in Taiwan.

METHODS

The nocturnal asthma group consisted of 27 children (mean age of 10.3±2.4 years), and the nonnocturnal asthma group consisted of 24 patients (mean age of 9.9±3.0 years). Allele-specific polymerase chain reaction was performed to determine 16, 27, and 164 loci alleles of β(2)-AR genetic polymorphisms, and peak expiratory flow (PEF) was measured before and 1 hour after inhalation of 0.2mg/kg/dose of terbutaline to determine the treatment response in these patients.

RESULTS

The polymorphisms of β(2)-AR 27 but not 16 or 164 were significantly associated with the response to terbutaline nebulizer (p<0.05). The polymorphism of β(2)-AR 16 was associated with nocturnal asthma (p=0.027). The Gly16 allele was more prevalent in the nocturnal asthma group (9/27; 33.3%) than in the nonnocturnal asthma group (3/24; 12.5%). Arg16 allele was less prevalent in the nocturnal asthma (3/27; 11.1%) than in the nonnocturnal asthma group (10/24; 41.7%). There was also a linkage disequilibrium found between β(2)-AR 16 (Arg/Arg) and β(2)-AR 27 (Gln/Gln).

CONCLUSION

These findings suggest that polymorphisms of β(2)-AR 16 are related to nocturnal asthma and polymorphisms of β(2)-AR 27 are associated with the variable responses to the inhaled terbutaline in children with nocturnal and nonnocturnal asthma.

Antiinflammatory effects of long-acting beta2-agonists in patients with asthma: a systematic review and metaanalysis

BACKGROUND

Long-acting beta(2)-agonists (LABAs) are recommended as add-on therapy to antiinflammatory treatment in patients with chronic persistent asthma. Results from individual studies evaluating the in vivo antiinflammatory effect of LABAs are conflicting. The purpose of this metaanalysis was to determine whether LABAs have an in vivo antiinflammatory effect compared to placebo and whether the addition of a LABA to therapy with inhaled corticosteroids (ICSs) has a synergistic or additive antiinflammatory effect.

METHODS

A systematic search was performed of online databases for randomized controlled trials evaluating the antiinflammatory effects of the following: (1) LABAs compared to placebo; and (2) a LABA plus ICS vs ICS alone in adults and children with asthma. Inflammatory outcome measures included cell counts and markers of cell activation in sputum, BAL fluid, bronchial biopsy specimens, serum, and exhaled nitric oxide (ENO). Data were independently extracted by two study investigators and analyzed to generate standardized mean differences using either a fixed or random-effects metaanalysis depending on the degree of heterogeneity.

RESULTS

Thirty-two studies (n = 1,105 participants) met the inclusion criteria. The mean number of participants and mean number of studies for each inflammatory outcome in the metaanalysis was 113.1 (SD, 46.2) and 3.5 (SD, 1.3), respectively. There was no effect of LABA therapy on sputum, BAL fluid, or mucosal inflammatory cells in adults or in children. LABA therapy decreased ENO levels and BAL fluid albumin levels in adults. In children, LABA therapy was associated with a small decrease in serum eosinophils and interleukin-4.

CONCLUSION

LABA therapy does not appear to have any clinically important antiinflammatory or proinflammatory effect. LABA therapy decreases BAL fluid albumin levels, suggesting a possible modulating effect on microvascular leakage.

Beta2-agonists potentiate corticosteroid-induced neutrophil survival

Neutrophils are considered to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD) and severe asthma. Recent guidelines recommend the use of a combination of inhaled corticosteroids (ICS) and long-acting beta2-agonists (LABA) in the treatment of COPD with exacerbations and asthma not adequately controlled by ICS alone. LABA have been proposed to have a synergistic effect with corticosteroids by activating glucocorticoid receptors. The aim of this study was to investigate the effect of beta2-agonists on the inhibitory effects of corticosteroids on human neutrophil apoptosis. In addition, the effects of beta2-agonists on spontaneous neutrophil apoptosis and on GM-CSF- and LTB4-afforded survival were also evaluated. Neutrophils were isolated from human blood under sterile conditions and cultured for 16 hours. Apoptosis was assessed by relative DNA fragmentation assay. Morphological analysis was used as a control method to confirm the occurrence of apoptosis. Salbutamol, formoterol and salmeterol prolonged the lifespan of budesonide- and fluticasone propionate-treated neutrophils by inhibiting apoptosis. Formoterol and salbutamol partly reversed the inhibitory effect of GM-CSF on neutrophil apoptosis. In contrast, the effects of beta(2)-agonists on spontaneous neutrophil apoptosis and on LTB(4)-afforded survival were negligible. beta2-agonists potentiate corticosteroid-induced neutrophil survival at clinically relevant drug concentrations. Whether these effects translate into clinically relevant changes in lung neutrophil numbers remains to be demonstrated.

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.

Effects of salmeterol in patients with persistent asthma receiving inhaled corticosteroid plus theophylline

BACKGROUND

Patients with severe asthma require multiple therapies to improve lung function and reduce symptoms. The use of long-acting inhaled beta(2)-agonists plus theophylline in addition to high doses of inhaled corticosteroids (ICSs) for the treatment of severe asthma has not been extensively studied.

OBJECTIVE

The purpose of this study was to investigate the efficacy and safety of salmeterol combined with high-dose ICSs plus theophylline in severe asthma.

METHODS

We undertook a randomized, placebo-controlled, crossover study to compare the effect of a single dose of inhaled salmeterol (50 microg) or a placebo in patients with severe asthma whose conditions were not being adequately controlled by therapies with high-dose ICSs plus oral theophylline with or without leukotriene receptor antagonists.

RESULTS

Twenty patients took part in the trial. Compared with the placebo, the inhalation of salmeterol significantly increased the FEV(1). Even in the 9 patients treated with high-dose ICSs plus theophylline plus a leukotriene receptor antagonist, the FEV(1) increased significantly more after salmeterol than after the placebo.

CONCLUSION

Patients with severe asthma receiving high-dose ICSs plus theophylline may benefit from the addition of salmeterol.

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.

Bronchoprotective Effects of Single Doses of Salmeterol Combined With Montelukast in Thermally Induced Bronchospasm

STUDY OBJECTIVES

Salmeterol (S) and montelukast (M) individually inhibit the obstructive consequences of thermal stimuli such as exercise and hyperventilation (HV), but there is no information on whether these drugs can interact positively.

DESIGN

Randomized trial.

SETTING

University teaching hospital.

PARTICIPANTS

Atopic asthmatic patients with sensitivity to thermal provocations.

INTERVENTIONS

Eleven asthmatic patients generated stimulus-response curves to isocapnic HV while breathing frigid air without any interventions and then after pretreatment with 42 mug of S, 10 mg of M, and the combination. The order of testing was randomly determined.

MEASUREMENTS AND RESULTS

Minute ventilation (Ve) was increased in 20-L increments until FEV(1) fell >or= 15%. Measurements were obtained before and 1 h after drug administration, and then again 5 min after each bout of HV. In the nonintervention trial, the provocation commenced after the patients presented to the laboratory. In the control challenge, the mean (+/- SEM) FEV(1) decreased 24.6 +/- 1.7% from baseline. S and M both increased the mean prechallenge FEV(1) significantly (S, 10.4 +/- 1.7% [p < 0.01]; M, 4.1 +/- 1.3% [p = 0.02]; S + M, p = 0.01). The combination of S + M produced greater bronchodilatation (mean improvement, 12.4 +/- 2.3%) than M alone (p = 0.004), but not greater than S alone (p = 0.80). Both drugs blunted the obstructive response similarly (protection: M, 34.6 +/- 15.1%; S, 60 +/- 8.7%; p = 0.13). The benefits added arithmetically with the combined regimen (protection with S + M, 84.9 +/- 5.5%; p = 0.01 vs S alone; p = 0.003 vs M alone).

CONCLUSION

These data indicate that the concurrent administration of single standard doses of S and M appears to provide greater protection against thermal stimuli than does either drug alone. Further experimentation will be required to ascertain whether the combination will provide additional clinical benefits to patients over those of the single agents.

Combination therapy of long-acting beta2-adrenoceptor agonists and corticosteroids for asthma

Twice-daily combination therapy of inhaled corticosteroids and long-acting beta2-adrenoceptor agonists (LABA) is now established as a most effective treatment for moderate to severe asthma and is available in a combined single inhaler. The benefits of combination therapy include better day-to-day control and a reduction in exacerbations compared with monotherapy with inhaled corticosteroids at a lower dose. Total control of asthma, defined as no daytime or night-time symptoms, no use of rescue beta2-adrenoceptor agonists (beta2-agonists), no exacerbations and a peak flow rate of >80% predicted, may be achieved with the use of combined salmeterol/fluticasone in up to 41% of patients with moderate to severe asthma, compared with only 28% of patients treated with fluticasone alone. Adjustable maintenance dosing with budesonide/formoterol may provide better control when compared with fixed-dosing combination regimens. Other therapies combining effectively with inhaled corticosteroids include slow-release theophylline and leukotriene inhibitors, montelukast and zafirlukast, but LABA are the most efficacious. Molecular interactions between corticosteroids and beta2-adrenoceptors may underlie the clinical added benefits of combination therapy. Corticosteroids may increase the number of beta2-adrenoceptors and their coupling with Gs proteins, while beta2-agonists may induce glucocorticoid receptor nuclear translocation, activate transcription factor/enhancer binding protein C/EBPalpha together with corticosteroids, or phosphorylate corticosteroid receptors. The combination of corticosteroids and LABA potentiates inhibition of interleukin-8 and eotaxin release from human airway smooth muscle cells and granulocyte-macrophage colony-stimulating factor release from epithelial cells, and also the inhibition of airway smooth muscle cell proliferation. It is important to determine whether there is a potentiating effect of combination therapy compared with corticosteroid treatment alone on airway inflammation and airway wall remodelling. Improvements in combination therapy include a once-daily preparation and possible combination of inhaled corticosteroids with newer drugs such as phosphodiesterase IV inhibitors.

A benefit-risk assessment of inhaled long-acting beta2-agonists in the management of obstructive pulmonary disease

The two inhaled long-acting beta2-adrenoceptor agonists, salmeterol and formoterol, have been studied extensively since their introduction in the early 1990s. In this review we consider the evidence for their efficacy and safety in adults with asthma and chronic obstructive pulmonary disease (COPD), by reviewing long-term prospective studies in which these drugs have been compared with placebo or an alternative bronchodilator. We have also assessed safety, including data from postmarketing surveillance studies and case-control studies using large databases. In patients with asthma, salmeterol and formoterol increase lung function, reduce asthmatic symptoms and improve quality of life when compared with placebo. Both drugs protect against exercise-induced asthma, although some tolerance develops with regular use. Tolerance to the bronchodilator effects of formoterol has also been seen, although this is small and most of the beneficial effects are maintained long-term. Both drugs have been shown to reduce asthma exacerbations but only in studies in which most patients were taking an inhaled corticosteroid. Adding a long-acting beta2-agonist provided better control than increasing the dose of inhaled corticosteroid in several studies. Long-acting beta2-agonists also provide better asthma control than use of regular short-acting beta2-agonists and theophylline. Their relative efficacy compared with leukotriene antagonists is uncertain as yet. Formoterol appears to be at least as safe and effective as a short-acting beta2-agonist when used on an 'as required' basis. In patients with COPD, both salmeterol and formoterol offer improved lung function and reduced COPD symptoms compared with placebo, and quality of life has been improved in some studies. Some tolerance to the bronchodilating effect of salmeterol was seen in one study. Most studies have not found a significant reduction in exacerbations in COPD. Both drugs have provided greater benefit than ipratropium bromide or theophylline; there are limited data on tiotropium bromide. The long-acting beta2-agonists cause predictable adverse effects including headache, tremor, palpitations, muscle cramps and a fall in serum potassium concentration. Salmeterol can also cause paradoxical bronchospasm. There is some evidence that serious adverse events including dysrhythmias and life-threatening asthma episodes can occur; however, the incidence of such events is very low but may be increased in patients not taking an inhaled corticosteroid. Salmeterol 50 microg twice daily and formoterol 12 microg twice daily are effective and safe in treating patients with asthma and COPD. Higher doses cause more adverse effects, although serious adverse events are rare.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

Salmeterol resolves airway obstruction but does not possess anti-eosinophil efficacy in newly diagnosed asthma: a randomized, double-blind, parallel group biopsy study comparing the effects of salmeterol, fluticasone propionate, and disodium cromoglycate

BACKGROUND

Salmeterol (SLM) is a long-acting beta(2)-receptor agonist that produces bronchodilatation for 12 hours in asthmatic subjects. The effects of the regular use of long-acting beta(2)-agonists on airway inflammation are largely unknown.

OBJECTIVES

We examined the effects of 16 weeks of treatment with 50 microg SLM bid, 250 microg fluticasone propionate (FP) bid,5 mg disodium cromoglycate (DSCG) qid, or placebo on airway inflammation in bronchial mucosa.

METHODS

Airway inflammation was assessed in bronchial biopsy specimens before and after treatments and bronchial hyperresponsiveness (BHR) in 80 patients with newly diagnosed asthma. Inflammatory cells and tenascin in the basement membrane were studied with immunohistochemical methods. Peak expiratory flow rate (PEF), symptoms, and need for rescue medication were recorded.

RESULTS

SLM, FP, and DSCG reduced symptoms and need for rescue medication (P <.04). Both SLM and FP improved PEF and increased PD15FEV(1) to histamine by 2.8 and 5.2 doubling dose units, respectively. Both compounds reduced BHR more than placebo (P <.05). Both SLM and placebo had no effect on any inflammatory cell type. In both FP-treated and DSCG-treated patients, the number of EG2-positive eosinophils in the airway mucosa decreased (P =.002 and P <.05, respectively).

CONCLUSIONS

SLM showed no anti-eosinophil properties in this study, but it provided good symptom control. FP provided the best anti-eosinophil properties and symptom relief of the studied compounds.

Nocturnal asthma

Lung function in a healthy individual varies in a circadian rhythm, with peak lung function occurring near 4:00 PM (1600 hours) and minimal lung function occurring near 4:00 AM (0400 hours). An episode of nocturnal asthma is characterized by an exaggeration in this normal variation in lung function from daytime to nighttime, with diurnal changes in pulmonary function generally of > 15%. The occurrence of nocturnal asthma is associated with increased morbidity and inadequate asthma control, and has an important negative impact on quality of life (QOL). Newer data have shed light on physiologic and immunologic mechanisms that underlie the nocturnal development of airway obstruction. It remains controversial whether nocturnal asthma is a distinct entity or is a manifestation of more severe asthma. The current data do not resolve these two alternatives, as well-controlled studies have reached opposite conclusions. However, the clinical associations of gastroesophageal reflux disease and obesity appear to be strong. The treatment of asthma with effective controller agents can reduce nighttime symptoms, improve psychometric outcomes, and improve QOL.

Effect of montelukast added to inhaled budesonide on control of mild to moderate asthma

BACKGROUND

Proinflammatory leukotrienes, which are not completely inhibited by inhaled corticosteroids, may contribute to asthmatic problems [corrected]. A 16 week multicentre, randomised, double blind, controlled study was undertaken to study the efficacy of adding oral montelukast, a leukotriene receptor antagonist, to a constant dose of inhaled budesonide.

METHODS

A total of 639 patients aged 18-70 years with forced expiratory volume in 1 second (FEV(1)) > or =55% predicted and a minimum predefined level of asthma symptoms during a 2 week placebo run in period were randomised to receive montelukast 10 mg (n=326) or placebo (n=313) once daily for 16 weeks. All patients received a constant dose of budesonide (400-1600 microg/day) by Turbuhaler throughout the study.

RESULTS

Mean FEV(1) at baseline was 81% predicted. The median percentage of asthma exacerbation days was 35% lower (3.1% v 4.8%; p=0.03) and the median percentage of asthma free days was 56% higher (66.1% v 42.3%; p=0.001) in the montelukast group than in the placebo group. Patients receiving concomitant treatment with montelukast had significantly (p<0.05) fewer nocturnal awakenings and significantly (p<0.05) greater improvements in beta agonist use and morning peak expiratory flow rate (PEFR).

CONCLUSIONS

For patients with mild airway obstruction and persistent asthma symptoms despite budesonide treatment, concomitant treatment with montelukast significantly improves asthma control.

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.

Inhaled corticosteroids plus long-acting beta2-agonists as a combined therapy in asthma

Inhaled corticosteroids (ICS) are the mainstay of asthma treatment. Since 1994, when the first trial showed an equivalent effect of doubling the ICS dose or adding salmeterol, it has repeatedly been shown that the combinations of beclomethasone dipropionate and salmeterol, budesonide and formoterol, or fluticasone propionate and salmeterol have at least the same efficacy as doubling the dose of the ICS in adults, though a conclusive trial in asthmatic children is still lacking. The addition of a long-acting beta(2)-agonist (LABA) to ICS appears more efficacious than adding a short-acting beta(2)-agonist or an antileukotriene, even though available data are sparse. Concurrent (two inhalers) and combination (same inhaler) modes of administration are equivalent from the clinical point of view, as is also true regarding administration via metered dose inhaler or dry powder inhaler. Using a single inhaler might eventually have a positive effect on treatment compliance, but there are no confirmatory data yet. Despite some clues regarding a presumed agonist effect of ICS and LABAs, there are still more doubts than certainties. Even though there are still unanswered questions, the data available strongly suggest that the fixed combination of ICS and LABAs using the same inhaler is an efficacious, safe and practical approach for those asthmatic patients who are not well controlled with low doses of ICS alone.

Regular treatment with long acting beta agonists versus daily regular treatment with short acting beta agonists in adults and children with stable asthma

BACKGROUND

Selective beta-adrenergic agonists for use in asthma are: short acting (2-6 hours) and long acting (>12 hours). There has been little controversy about using short acting beta-agonists intermittently, but long acting beta-agonists are used regularly, and their regular use has been controversial.

OBJECTIVES

To determine the benefit or detriment of treatment with regular short- or long acting inhaled beta-agonists in chronic asthma.

SEARCH STRATEGY

A search was carried out using the Cochrane Airways Group register. Bibliographies of identified RCTs were searched for additional relevant RCTs. Authors of identified RCTs were contacted 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 any short acting inhaled beta-agonist of equivalent bronchodilator effectiveness given regularly in chronic asthma.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

31 studies met the inclusion criteria, 24 of parallel group and 7 cross over design. Salmeterol xinafoate was used as long acting agent in 22 studies and formoterol fumarate in 9. Salbutamol was the short acting agent used in 27 studies and terbutaline in 5. The treatment period was over 2 weeks in 29 studies, and at least 12 weeks in 20. 25 studies permitted a variety of co-intervention treatments, usually inhaled corticosteroid or cromones. One study did not permit inhaled corticosteroid. Long acting beta-agonists were significantly better than short acting for a variety of lung function measurements including morning PEF (Weighted Mean Difference (WMD) 33 l/min 95% CI 25, 42) or evening PEF (WMD 26 l/min 95% CI 18, 33); and had significantly lower scores for day and night time asthma symptom scores and percentage of days and nights without symptoms. They were also associated with a significantly lower use of rescue medication both during the day and night. Risk of exacerbations was not different between the two types of agent, but most studies were of short duration which limits the power to test for such differences.

REVIEWER'S CONCLUSIONS

Long acting inhaled beta-agonists have advantages across a wide range of physiological and clinical outcomes for regular treatment.

Nocturnal asthma uncontrolled by inhaled corticosteroids: theophylline or long-acting beta2 agonists?

Asthma is an inflammatory disease of the airways that is frequently characterised by marked circadian rhythm. Nocturnal and early morning symptoms are quite common among patients with asthma. Increased mortality and decreased quality of life are associated with nocturnal asthma. Although numerous mechanisms contribute to the pathophysiology of nocturnal asthma, increasing evidence suggests the most important mechanisms relate to airway inflammation. According to international guidelines, patients with persistent asthma should receive long term daily anti-inflammatory therapy. A therapeutic trial with anti-inflammatory therapy alone (without a long-acting bronchodilator) should be assessed to determine if this therapy will eliminate nocturnal and early morning symptoms. If environmental control and low to moderate doses of inhaled corticosteroids do not eliminate nocturnal symptoms, the addition of a long-acting bronchodilator is warranted. Long-acting inhaled beta2 agonists (e.g. salmeterol, formoterol) are effective in managing nocturnal asthma that is inadequately controlled by anti-inflammatory agents. In addition, sustained release theophylline and controlled release oral beta2 agonists are effective. In patients with nocturnal symptoms despite low to high doses of inhaled corticosteroids, the addition of salmeterol has been demonstrated to be superior to doubling the inhaled corticosteroid dose. In trials comparing salmeterol with theophylline, 3 studies revealed salmeterol was superior to theophylline (as measured by e.g. morning peak expiratory flow, percent decrease in awakenings, and need for rescue salbutamol), whereas 2 studies found the therapies of equal efficacy. Studies comparing salmeterol to oral long-acting beta2 agonists reveal salmeterol to be superior to terbutaline and equivalent in efficacy to other oral agents. Microarousals unrelated to asthma are consistently increased when theophylline is compared to salmeterol in laboratory sleep studies. In addition to efficacy data, clinicians must weigh benefits and risks in choosing therapy for nocturnal asthma. Long-acting inhaled beta2 agonists are generally well tolerated. If theophylline therapy is to be used safely, clinicians must be quite familiar with numerous factors that alter clearance of this drug, and they must be prepared to use appropriate doses and monitor serum concentrations. Comparative studies using validated, disease specific quality of life instruments (e.g. Asthma Quality of Life Questionnaire) have shown long-acting inhaled beta2 agonists are preferred to other long-acting bronchodilators. Examination of costs for these therapeutic options reveals that evening only doses of long-acting oral bronchodilators are less expensive than multiple inhaled doses. However, costs of monitoring serum concentrations, risks, quality of life and otheroutcome measures must also be considered. Long-acting inhaled beta2 agonists are the agents of choice for managing nocturnal asthma in patients who are symptomatic despite anti-inflammatory agents and other standard management (e.g. environmental control). These agents offer a high degree of efficacy along with a good margin of safety and improved quality of life.

Circadian differences among 4,096 emergency department patients with acute asthma

INTRODUCTION

In patients with asthma, airways narrow during the night. The clinical implications of a nocturnal presentation of patients with acute asthma to the emergency department (ED) are uncertain.

OBJECTIVE

Our objective was to determine whether patients with asthma who had ED visits during the night (midnight to 7:59 am) vs. other times were more severe, responded less well to ED therapy, and had worse clinical outcomes.

DESIGN AND SETTING

We performed a cohort study, as part of the Multicenter Airway Research Collaboration (n = 77 sites). ED patients with acute asthma, ages 2-54 yrs, underwent a structured interview in the ED. Chart review of missed/refusal patients created a truly consecutive case series.

MEASUREMENTS AND MAIN RESULTS

Among 1,602 children, 19% presented at night Nighttime patients were more likely to be younger, male, and have a shorter duration of symptoms; there were no other clinical differences noted. Among 2,494 adults, 20% presented at night, and they were more likely to be female and to have a history of steroid use for asthma. Nighttime adults also had a shorter duration of symptoms and slightly lower peak flows (mean, 45% vs. 49% of predicted; p = .006) and were more likely to receive steroids. They were more likely to be intubated (2.0% vs. 0.2%; p < .001), but, overall, they were equally likely to be admitted or relapse after ED discharge. In contrast to objective measures of acute asthma severity, both nighttime children and adults were significantly less likely to report their asthma symptoms as severe.

CONCLUSION

Except for endotracheal intubation (in adults only), circadian differences minimally affect ED presentation, therapy, or the outcomes of acute asthma. Nighttime asthmatics may be relatively insensitive to the symptoms of severe asthma.

Decreased steroid responsiveness at night in nocturnal asthma. Is the macrophage responsible?

As peripheral blood mononuclear cells from patients with nocturnal asthma (NA) exhibit reduced steroid responsiveness at 4:00 A.M. as compared with 4:00 P.M., we hypothesized that NA is associated with increased nocturnal airway cell expression of GRbeta, an endogenous inhibitor of steroid action. Ten subjects with NA and seven subjects with nonnocturnal asthma (NNA) underwent bronchoscopy with bronchoalveolar lavage (BAL) at 4:00 P.M. and 4:00 A.M. BAL lymphocytes and macrophages were incubated with dexamethasone (DEX) at 10(-5) to 10(-8) M. DEX suppressed proliferation of BAL lymphocytes similarly at 4:00 P.M. and 4:00 A.M. in both groups. However, BAL macrophages from NA exhibited less suppression of IL-8 and TNF-alpha production by DEX at 4:00 A.M. as compared with 4:00 P.M. (p = 0.0001), whereas in the NNA group DEX suppressed IL-8 and TNF-alpha production equally at both time points. GRbeta expression was increased at night only in NA, primarily due to significantly increased expression by BAL macrophages (p = 0.008). IL-13 mRNA expression was increased at night, but only in the NA group and addition of neutralizing antibodies to IL-13 reduced GRbeta expression by BAL macrophages. We conclude that the airway macrophage may be the airway inflammatory cell driving the reduction in steroid responsiveness at night in NA, and this function is modulated by IL-13.

Sleep in patients with asthma and chronic obstructive pulmonary disease

Sleep abnormalities are common in patients with asthma and chronic obstructive pulmonary disease. Recent studies have provided new insight into the mechanisms involved in circadian changes in airway resistance, analyzed the effect of disease treatment on sleep quality, and re-examined issues relating to oxygen supplementation at night in patients with chronic obstructive pulmonary disease. Although providing new and useful information, some of these studies also raise new questions that will need answering in the future. This article reviews our current understanding of the complex interactions between sleep and lung disease in patients with asthma and chronic obstructive pulmonary disease.

The effect of salmeterol on markers of airway inflammation following segmental allergen challenge

Inflammation is a critical component of asthma. Drugs that control asthma generally reduce the degree of airway inflammation. There is theoretical controversy surrounding the effects of beta(2)-agonists on airway inflammation, with some studies suggesting an anti-inflammatory effect, and others predicting a proinflammatory influence. We conducted a double-blind, placebo-controlled, crossover study of the effect of the long-acting beta(2)-agonist salmeterol on airway inflammation induced by segmental allergen challenge (SAC). We studied 13 allergic asthmatics controlled with as needed inhaled short-acting beta(2)-agonists alone, and used bronchoalveolar lavage 5 min and 48 h after SAC to assess airway inflammation, and the effects of salmeterol on this process. Salmeterol therapy improved FEV(1), but had no significant effect on the immediate or late cellular response to SAC. One measure of superoxide production was reduced, and interleukin-4 (IL-4) was reduced in baseline samples, but other indices of airway inflammation were unchanged by salmeterol therapy. We conclude that salmeterol therapy alone does not meaningfully reduce airway inflammation induced by SAC, but equally importantly, does not result in amplified inflammation.

Advair: combination treatment with fluticasone propionate/salmeterol in the treatment of asthma

Several classes of medications are available for the treatment of asthma, and often they must be taken concurrently to achieve asthma control. Based on the understanding of asthma as an inflammatory disease, the National Heart Lung and Blood Institute guidelines provide a stepwise approach to pharmacologic therapy. Corticosteroid therapy, principally inhaled corticosteroid (ICS) therapy, is considered the most effective anti-inflammatory treatment. In cases of moderate-to-severe persistent asthma, the addition of a second long-term control medication to ICS therapy is one recommended treatment option. A combination-product inhaler (Advair, Seretide) was developed to treat both the inflammatory and bronchoconstrictive components of asthma by delivering a dose of the ICS, fluticasone propionate, and a dose of the long-acting beta2-adrenergic (LABA) bronchodilator, salmeterol. The Advair Diskus is available in 3 strengths of fluticasone propionate (100, 250, and 500 microg) and a fixed dose (50 microg) of salmeterol. Combination treatment with both ICS and LABA provides greater asthma control than increasing the ICS dose alone, while at the same time reducing the frequency and perhaps the severity of exacerbations. Furthermore, salmeterol added to ICS therapy provides superior asthma control compared with the addition of leukotriene modifiers or theophylline. The superior control is likely a consequence of the complementary actions of the drugs when taken together, including the activation of the glucocorticoid receptor by salmeterol. By combining anti-inflammatory treatment with a long-acting beta2-agonist in a single inhaler (1 inhalation twice daily), physicians can provide coverage for both the inflammatory and bronchoconstrictive aspects of asthma without introducing any new or unexpected adverse consequences. The most common drug-related adverse events were those known to be attributable to the constituent medications (ICS therapy and/or LABA therapy). Although the benefits of combined ICS plus LABA therapy can be achieved with separate inhalers, the convenience of the combination product may improve patient adherence and may therefore reduce the morbidity of asthma.

Serum potassium levels, CPK-MB and ECG in children suffering asthma treated with beclomethasone or beclomethasone-salmeterol

Asthma morbidity and mortality has increased. One of the possible causes is the excessive use of beta agonists. The aim of this study is to compare the effects of six week treatment with beclomethasone alone (Ibec) or the combination of beclomethasone-salmeterol (Ibe + Isal) on serum potassium (K), CPK-MB and ECG in children suffering asthma. It was a prospective, randomised, open cross-over trial. Patients received either Ib2 (2 puff/12 hr, 100 micrograms per puff) or Ibe + Isal (B 2 puff/12 hr, 100 micrograms per puff and S 2 puff/12 hr, 25 micrograms per puff) with dose meter inhaler by 6 weeks, with a four-week wash-out period between the treatments. K, CPK-MB and ECG were assessed at baseline, and after each treatment period. There were 9 girls and 20 boys, aged 11 +/- 2.18 (mean +/- SD) years, baseline K was 4.57 +/- 0.43 mEq/l, after B K 4.38 +/- 0.39 IU and after BS K 4.38 +/- 0.40. The CPK-MB level were baseline 14.75 +/- 4.5, after B 20.10 +/- 6.9 and after BS 21 +/- 8.05 (p < 0.05). Baseline QTc was 0.416 +/- 0.02 msec, after B 0.425 +/- 0.027, and after BS 0.415 +/- 0.029. We conclude that the treatment of children with asthma with 400 micrograms per day of Ibec or concomitantly with 100 micrograms of Isal for 6 weeks does not alter the serum K+ or the QTc. However, the CPK-MB has a significant increment with both treatments but without clinical and/or ECG changes. We can't affirm that Ibec or Ibec plus Isal have a cardiotoxic side-effect by the only presence of high levels of CPK-MB. We agree that it is necessary a close follow up of these apparently asymptomatic patients not induce important cardiovascular changes although CPK-MB was increased.

The effect of long-acting beta2-agonists on airway inflammation in asthmatic patients

Early observations suggested that the inhibition by long-acting beta2-agonists (LABAs) of non-specific bronchial hyperresponsiveness following allergen challenge was unrelated to bronchodilation or functional antagonism and might be a reflection of anti-inflammatory activity. Investigation of the effect of LABAs on airway inflammatory responses has demonstrated an inhibition of eosinophil recruitment in allergen challenge studies. Nevertheless, results from biopsy and other studies suggest that the chronic inflammatory process in asthma patients is unaffected by these drugs. There is no evidence from biopsy studies that LABAs are pro-inflammatory or that they mask existing inflammation. The beneficial effects of LABAs in allergen challenge are probably mediated through stabilization of mast cells. Recent evidence suggests that LABAs may reduce numbers of neutrophils and their associated markers; this observation needs to be confirmed in future studies and its relevance to the treatment of asthma determined.

The pathobiologic implications for treatment. Old and new strategies in the treatment of chronic asthma

An increased understanding of the pathobiology of asthma has led to improved treatment for chronic asthma. This article discusses the old and new strategies of asthma therapy based on a pathobiologic approach. Therapeutic agents discussed include beta-adrenergic agonists, methylxanthines, corticosteroids, cromolyn, nedocromil, leukotriene modifiers, and new investigational agents.

Montelukast or salmeterol combined with an inhaled steroid in adult asthma: design and rationale of a randomized, double-blind comparative study (the IMPACT Investigation of Montelukast as a Partner Agent for Complementary Therapy-trial)

Asthma patients who continue to experience symptoms despite taking regular inhaled corticosteroids represent a management challenge. Leukotrienes play a key role in asthma pathophysiology, and since pro-inflammatory leukotrienes are poorly suppressed by corticosteroids it seems rational to add a leukotriene receptor antagonist (LTRA) when a low to moderate dose of inhaled corticosteroids does not provide sufficient disease control. Long acting beta2-agonist (LABA) treatment represents an alternative to LTRAs and both treatment modalities have been shown to provide additional disease control when added to corticosteroid treatment. To compare the relative clinical benefits of adding either a LTRA or a LABA to asthma patients inadequately controlled by inhaled corticosteroids, a randomized, double-blind, multi-centre, 48-week study will be initiated at approximately 120 centres throughout Europe, Latin America, Middle East, Africa and the Asia-Pacific region in early 2000. The study will compare the oral LTRA montelukast with the inhaled LABA salmeterol, each administered on a background of inhaled fluticasone, on asthma attacks, quality of life, lung function, eosinophil levels, healthcare utilization, and safety, in approximately 1200 adult asthmatic patients. The requirements for study enrollment include a history of asthma, FEV1 or PEFR values between 50% and 90% of the predicted value together with > or = 12% improvement in FEV1 after beta-agonist administration, a minimum pre-determined level of asthma symptoms and daily beta-agonist medication. The study will include a 4-week run-in period, during which patients previously taking inhaled corticosteroids are switched to open-label fluticasone (200 microg daily), followed by a 48-week double-blind, treatment period in which patients continuing to experience abnormal pulmonary function and daytime symptoms are randomized to receive montelukast (10 mg once daily) and salmeterol placebo, or inhaled salmeterol (100 microg daily) and montelukast placebo. All patients will continue with inhaled fluticasone (200 microg daily). During the study, asthma attacks, overnight asthma symptoms, and morning peak expiratory flow rate will be assessed using patient diary cards; quality of life will also be assessed using an asthma-specific quality-of life questionnaire. The results of this study are expected to provide physicians with important clinical evidence to help them make a rational and logical treatment choice for asthmatic patients experiencing breakthrough symptoms on inhaled corticosteroids.

Pharmacotherapy of asthma in children, with special reference to leukotriene receptor antagonists

Asthma in adults is generally recognized as a chronic inflammatory airway disease, although this association is less well established in childhood asthma. Thus, recent asthma guidelines have emphasized that asthma treatment should be directed toward the underlying inflammatory aspects of the disease. The prevalence of asthma and resultant hospitalizations and deaths have increased or remained stable over the past 10 years in the United States. In part, this appears to be caused by shortcomings of available antiasthma therapeutic agents. Because these trends are particularly troublesome in children and young adults, there is a need for effective anti-inflammatory therapies that are safe and tolerable. The leukotrienes are a family of lipid mediators that appear to play an important role in the symptomology and pathogenesis of asthma. The results of clinical trials in adults with asthma demonstrated that antileukotriene drugs such as zafirlukast, montelukast, and zileuton improve pulmonary function, decrease asthma symptoms, and decrease the concomitant use of other antiasthma drugs. Most antileukotriene agents are orally bioavailable and well tolerated, offering the potential for improved patient compliance. Montelukast and zafirlukast have received approval for use in pediatric asthma patients, and approval of zafirlukast in this patient population is pending.

An antiinflammatory effect of salmeterol, a long-acting beta(2) agonist, assessed in airway biopsies and bronchoalveolar lavage in asthma

The addition of long-acting beta(2) agonists to inhaled corticosteroid (ICS) therapy in symptomatic patients with asthma improves clinical status more than increasing the dose of ICS. It has been suggested that these benefits could be at the cost of an increase in airway inflammation, but few histopathological studies have been performed in the relevant group. In a double-blind, parallel-group, placebo-controlled study, we randomly assigned 50 symptomatic patients with asthma who were receiving ICS (range, 100 -500 microgram/d) to 12 wk of supplementary treatment with salmeterol (50 microgram twice daily) or fluticasone (100 microgram twice daily) or placebo. Bronchial biopsies and BAL were obtained from 45 patients before and after treatment and analyzed. After treatment with salmeterol there was no deterioration of airway inflammation as assessed by mast cells, lymphocytes, or macrophages in BAL or biopsies, but rather a significant fall in EG1-positive eosinophils in the lamina propria (from a median 18.3 to 7.6 cells/mm, p = 0.01), which was not seen after treatment with fluticasone. The only cellular effect of added fluticasone was a decrease in BAL lymphocyte activation. There was a concurrent improvement in clinical status, more marked with salmeterol than with increased ICS. Thus, adding salmeterol to ICS is not associated with increased "allergic" airway inflammation, but conversely with a complementary antieosinophil effect.

Ten asthma pearls every primary care physician should know

Asthma is often easily identified and effectively treated. However, presenting symptoms are variable, and many cases of asthma may not be obvious or typical. Since asthma affects about 5% of the US population, primary care physicians should be prepared to identify and manage both atypical and classic types. Atypical symptoms include disturbed sleep, chest tightness, and persistent cough without audible wheezing. Occupational factors should be suspected in all cases of adult-onset asthma. The patient's history and results of simple pulmonary function tests are useful in diagnosing, staging, and managing asthma. A beta 2 agonist delivered by metered-dose inhaler (e.g., albuterol) should provide prompt relief of most exacerbations. Inhaled corticosteroid therapy delivered via a spacer helps prevent exacerbations and has an important role in long-term control of moderate and severe asthma. If symptoms do not improve with the use of standard asthma medications, alternative diagnoses should be considered.

Pathophysiology of nocturnal asthma

LEARNING OBJECTIVES

This article will focus on the pathophysiologic changes underlying the nocturnal worsening of asthma and the therapeutic approach to this disorder.

DATA SOURCES

Selected articles appearing since 1985 dealing specifically with the underlying pathologic features and therapy of nocturnal asthma.

STUDY SELECTION

Studies that aimed to elucidate the pathologic features, mechanisms, and therapeutic strategies for the treatment of nocturnal asthma are summarized.

RESULTS

Nocturnal asthma is associated with significant decline in pulmonary function and increase of airway inflammation at night. The administration of medications must be designed to achieve the maximal effect during the night in nocturnal asthma.

CONCLUSIONS

The further elucidation of the reasons underlying nocturnal asthma should lead to more specific therapeutic interventions with maximal effect at night.

Alternative agents for anti-inflammatory treatment of asthma

Recent guidelines for the management of asthma have emphasized the role of inflammation in persistent asthma. Medications with anti-inflammatory properties are recommended as the primary long-term-control medications. Of the available choices of long-term-control medications, inhaled corticosteroids are the preferred medication. A literature review of the available studies supports this recommendation of inhaled corticosteroids as the preferred agents for long-term control. Other long-term-control medications--specifically nedocromil, theophylline, and leukotriene modifiers, but not cromolyn--can supplement the beneficial effect of inhaled corticosteroids on pulmonary function and symptom control. Long-acting beta2-adrenergic agonists can also provide an additive clinical benefit to inhaled corticosteroids on symptom control and pulmonary function, but they do not provide additional anti-inflammatory effect. Extended long-term studies of each of the long-term-control medications with anti-inflammatory actions are needed to assess their specific effect on airway remodeling and on the natural history of asthma.

Long-acting inhaled beta2-agonists in asthma therapy

OBJECTIVE

To review the pharmacology of the long-acting inhaled beta2-agonists, salmeterol and formoterol, summarize results of their clinical trials, evaluate their safety records, and discuss their roles in the treatment of asthma.

DATA SOURCES

Preclinical and clinical studies involving salmeterol or formoterol were identified by a MEDLINE search, weekly computerized literature updates, and manual searches. Studies of satisfactory quality were chosen for review.

DATA SYNTHESIS

Salmeterol and formoterol are potent and selective beta2-adrenoceptor agonists with durations of action >12 h. Their major differences are that formoterol has a rapid onset of action and is a partial agonist of high intrinsic efficacy, whereas salmeterol has a delayed onset and is a partial agonist of low intrinsic efficacy. Twice daily use of either drug results in improved lung function, reduced symptoms, and a better quality of life. These agents protect against exercise-induced asthma for 12 h and eliminate nighttime awakening in most patients. Limited tolerance develops, especially to their bronchoprotective effects, but their improvement of lung function is sustained.

CONCLUSIONS

Regular use of salmeterol or formoterol provides subjective and objective amelioration of asthma in patients experiencing excessive symptoms or physiologic impairment despite the regular administration of low doses of inhaled corticosteroids (equivalent to approximately 500 microg/d of beclomethasone). Intermittent use of either long-acting beta2-agonist can provide prolonged protection against exercise-induced asthma or nighttime symptoms. Patients should be instructed to continue taking inhaled steroids when long-acting beta2-agonists are administered on a regular schedule and to not take long-acting beta2-agonists between regularly scheduled doses. Used properly, they are effective and safe adjunctive agents in the treatment of asthma.