An inhaled glucocorticoid does not prevent tolerance to the bronchoprotective effect of a long-acting inhaled beta 2-agonist. Long-term effects of a long-acting beta 2-adrenoceptor agonist, salmeterol, on airway hyperresponsiveness in patients with mild asthma. Changes in methacholine induced bronchoconstriction with the long acting beta 2 agonist salmeterol in mild to moderate asthmatic patients. Effects of the long acting beta agonist formoterol on asthma control in asthmatic patients using inhaled corticosteroids. The Netherlands and Canadian Formoterol Study Investigators. Use of a long-acting inhaled beta2-adrenergic agonist, salmeterol xinafoate, in patients with chronic obstructive pulmonary disease. Beta2-agonist tolerance and exercise-induced bronchospasm. A placebo-controlled clinical trial of regular monotherapy with short-acting and long-acting beta(2)-agonists in allergic asthmatic patients. The effects of fluticasone with or without salmeterol on systemic biomarkers of inflammation in chronic obstructive pulmonary disease. Is the increase in bronchial responsiveness or FEV1 shortly after cessation of beta2-agonists reflecting a real deterioration of the disease in allergic asthmatic patients? A comparison between short-acting and long-acting beta2-agonists. Effect of inhaled fluticasone with and without salmeterol on airway inflammation in asthma. Effects of salmeterol on arterial oxyhemoglobin saturations in patients with cystic fibrosis. Cost effectiveness of leukotriene receptor antagonists versus long-acting beta-2 agonists as add-on therapy to inhaled corticosteroids for asthma: a pragmatic trial. Subsensitivity of bronchodilator and systemic beta 2 adrenoceptor responses after regular twice daily treatment with eformoterol dry powder in asthmatic patients. Regular inhaled salbutamol and airway responsiveness to allergen. Tolerance to the nonbronchodilator effects of inhaled beta 2-agonists in asthma. An antiinflammatory effect of salmeterol, a long-acting beta(2) agonist, assessed in airway biopsies and bronchoalveolar lavage in asthma. Adding salmeterol to an inhaled corticosteroid: long term effects on bronchial inflammation in asthma. Short-term regular beta 2-adrenergic agonists treatment is safe in mild asthmatics taking low doses of inhaled steroids. The effect of regular inhaled albuterol on exercise-induced bronchoconstriction. Effect of feedback letters to physicians and pharmacists on the appropriate use of medication in the treatment of asthma. Acute response to bronchodilator. An imperfect guide for bronchodilator therapy in chronic airflow limitation. Effects of terbutaline and budesonide on sputum cells and bronchial hyperresponsiveness in asthma. Effects of treatment with formoterol on bronchoprotection against methacholine. Added salmeterol versus higher-dose corticosteroid in asthma patients with symptoms on existing inhaled corticosteroid. Allen & Hanburys Limited UK Study Group. Poor adherence with inhaled corticosteroids for asthma: can using a single inhaler containing budesonide and formoterol help? The long-acting beta2-agonist salmeterol xinafoate: effects on airway inflammation in asthma. A 3-month comparison of formoterol with terbutaline via turbuhaler. A placebo-controlled study.
There is increasing evidence for the development of tolerance to the protective effects of inhaled beta 2-agonists against bronchoconstrictor stimuli. Animal studies have suggested that glucocorticoids protect against the down-regulation of beta 2-receptors after chronic exposure to beta 2-agonists. In a double-blind placebo-controlled crossover study in 12 patients with mild asthma, we investigated the effect of inhaled budesonide or identical placebo on the protection conferred by albuterol (200 micrograms) against methacholine-induced bronchoconstriction before and after treatment with the long-acting beta 2-agonist salmeterol. Patients were randomized to be treated for 3 wk with inhaled budesonide (800 micrograms twice a day) or placebo; salmeterol (50 micrograms twice a day) was added during the third week. Airway responsiveness to methacholine was measured 15 min after albuterol, both before and exactly 12 h [corrected] after the last salmeterol dose. Mean FEV1 increased significantly after 2 wk of budesonide (p < 0.05) and increased further after salmeterol (p < 0.05) compared with placebo. After 2 wk, the bronchoprotective effect of albuterol against methacholine was significantly greater with budesonide than with placebo (3.4 versus 2.4 doubling dilutions; p < 0.05), consistent with an improvement in airway hyperresponsiveness with budesonide therapy. However, regular salmeterol treatment for 1 wk significantly diminished the protection conferred by albuterol against methacholine challenge, both with budesonide and with placebo (-1.1 +/- 0.42 and -1.41 +/- 0.30 doubling dilutions, respectively). There was no significant difference in the loss of bronchoprotection seen with salmeterol between budesonide and placebo treatment periods. Our study suggests that even a high dose of an inhaled glucocorticoid fails to prevent the loss of bronchoprotection produced by regular beta 2-agonist therapy. Asthma is characterized by hyperresponsiveness of the airways to bronchoconstrictive stimuli. Long-acting beta 2-adrenoceptor agonists have been introduced as a new therapeutic approach, but there is growing concern about whether control of asthma may deteriorate with the regular use of these agents. We investigated the long-term effects of the beta 2 agonist salmeterol on bronchodilation and on airway hyperresponsiveness to the bronchoconstrictive agent methacholine in mild asthma.
                In a parallel, double-blind study, 24 patients with mild asthma were randomly assigned to treatment with either inhaled salmeterol (50 micrograms, twice daily) (n = 12) or placebo (n = 12) during an eight-week trial. Methacholine challenge was performed before, during, and after the treatment period. Methacholine responsiveness was measured as the provocative concentration (PC20) that caused a 20 percent decrease in the forced expiratory volume in one second (FEV1).
                There was a significant increase in FEV1 one hour after the inhalation of salmeterol (P = 0.006), which did not differ significantly on days 0, 28, and 56 of the treatment period (increase, 9.8, 9.4, and 8.8 percent of predicted FEV1, respectively; P = 0.91). On the first treatment day, salmeterol afforded significant protection against methacholine-induced bronchoconstriction, as shown by a 10-fold increase in the PC20 as compared with the value at entry (P less than 0.001). After four and eight weeks of treatment, however, the salmeterol-induced change in the PC20 was significantly attenuated (P less than 0.001) to only a twofold increase. Two and four days after treatment ended, the PC20 was not significantly different from the value before treatment (P = 0.15).
                Regular treatment of patients with mild asthma with salmeterol leads to tolerance to its protective effects against a bronchoconstrictor stimulus, in this case inhaled methacholine, despite well-maintained bronchodilation. This finding raises concern about the effectiveness of prolonged therapy with long-acting beta 2-adrenoceptor agonists in asthma. Beta-2 agonists protect against non-specific bronchoconstricting agents such as methacholine, but it has been suggested that the protection afforded by long acting beta 2 agonists wanes rapidly with regular treatment.
                The changes in airway responsiveness were investigated during and after eight weeks of regular treatment with salmeterol 50 micrograms twice daily in 26 adult asthmatic patients, 19 of whom were receiving maintenance inhaled corticosteroids. The study was of a randomised, placebo controlled, double blind design. Airway responsiveness to methacholine was measured as PD20 by a standardised dosimeter technique 12 hours after the first dose, at four weeks and eight weeks during treatment (12 hours after the last dose of test medication), and at 60 hours, one week and two weeks after stopping treatment.
                There were no significant differences between the baseline characteristics of the two groups. A significant improvement in PD20 was seen at all points during treatment with salmeterol compared with the placebo group, with no significant fall off with time. PD20 measurements returned to baseline values after cessation of treatment with no significant difference from the placebo group.
                Salmeterol gave significant protection against methacholine induced bronchoconstriction 12 hours after administration. This protection was of small magnitude, but there was no significant attenuation with eight weeks of regular use and no rebound increase in airway responsiveness on stopping treatment in a group of moderate asthmatic patients, the majority of whom were receiving inhaled corticosteroids. The long acting beta 2 agonist formoterol has proved to be an effective bronchodilator with a prolonged action of 12-14 hours. However, the precise role of formoterol in the maintenance treatment of asthma is still under debate. A study was performed to investigate the efficacy and safety of treatment with formoterol for six months in subjects with asthma.
                In a multicentre double blind, placebo controlled, parallel group study 239 subjects with mild to moderate asthma were randomly assigned to treatment with either inhaled formoterol 24 micrograms twice daily (n = 125) or placebo (n = 114) during eight months. The study consisted of a four week run in period, a 24 week treatment period, and a four week washout period. All subjects were using regular inhaled corticosteroids (100-3200 micrograms daily) but were still needing at least five inhalations of short acting beta 2 agonist per week for symptom relief. The study was performed in 10 outpatient clinics in Canada, and five outpatient clinics and one coordinating centre for 44 Dutch general practitioners in The Netherlands. Twice daily self-reported peak expiratory flow (PEF) measurements, symptom scores, and rescue beta 2 agonist use during the last 28 treatment days compared with baseline values were used as main outcome measures. Spirometric values were measured at entry, at the start of treatment, after four, 12 and 24 weeks of treatment, and after four weeks washout.
                One hundred and twenty five subjects received formoterol 24 micrograms twice daily via Turbohaler and 114 received placebo. Baseline FEV1 was 67.1% predicted and mean bronchodilator reversibility was 26%. The mean total asthma symptom score was 3.6 (maximum possible 21). A significant decrease in symptoms in favour of formoterol (difference from placebo -0.64, 95% CI -0.04 to -1.23, p = 0.04) was observed. Compared with placebo, morning PEF increased (difference from placebo 28 l/min, 95% CI 18.3 to 37.7, p = 0.0001) and the use of short acting beta 1 agonists decreased (daytime difference from placebo -1.1 inhalation, 95% CI -1.4 to -0.7, p = 0.0001) in the formoterol group. PEF returned to baseline following discontinuation of formoterol, as did asthma symptom scores. Thirty three patients treated with formoterol and 32 treated with placebo required treatment with prednisolone during the study (58 and 55 courses, respectively).
                Adding formoterol 24 micrograms twice daily by Turbohaler to inhaled corticosteroids was effective in improving symptom scores and morning PEF, and decreasing the use of rescue beta 2 agonists. There was no apparent loss of asthma control during 24 weeks of treatment with formoterol. Chronic obstructive pulmonary disease (COPD) is a condition in which continuous bronchodilation may have clinical advantages. This study evaluated salmeterol, a beta-agonist bronchodilator with a duration of action substantially longer than that of short-acting beta-agonists, compared with ipratropium, an anticholinergic bronchodilator, and placebo in patients with COPD. Four hundred and five patients with COPD received either salmeterol 42 microg twice daily, ipratropium bromide 36 microg four times daily, or placebo for 12 wk in this randomized, double-blind, parallel-group study. Patients were stratified on the basis of bronchodilator response to albuterol (> 12% and > 200-ml improvement) and were randomized within each stratum. Bronchodilator response was measured over 12 h four times during the treatment period. Salmeterol provided similar maximal bronchodilatation to ipratropium but had a longer duration of action and a more constant bronchodilatory effect with no evidence of bronchodilator tolerance. Both active treatments were well tolerated. Salmeterol was an effective bronchodilator with a consistent effect over this 12-wk study in patients with COPD, including those "unresponsive" to albuterol. The long duration of action of salmeterol offers the advantage of twice daily dosing compared with the required four times a day dosing with ipratropium. The effect of regular inhaled beta-agonist on the treatment of exercise-induced bronchoconstriction was studied. Eight subjects with exercise-induced bronchoconstriction took 1 week each of salbutamol 200 microg qid or placebo in a random-order, double-blind, crossover study. They then withheld this treatment for 8 hours before performing a dry-air, sub-maximal exercise challenge at a work-rate previously shown to induce a 15% fall in forced expiratory volume in 1 second (FEV1). Five minutes after exercise, they inhaled salbutamol 100, 100, and 200 microg at 5-minute intervals. The mean pre-exercise FEV1 was similar on both study days. However, pretreatment for 1 week with salbutamol led to a significantly greater fall in FEV1 after exercise. The FEV1 remained lower than during the placebo arm despite the administration of salbutamol after exercise. This difference persisted 25 minutes after exercise. It is concluded that regular beta-agonist treatment leads to increased exercise-induced bronchoconstriction and a suboptimal bronchodilator response to beta-agonist. The data suggest that previous regular beta-agonist treatment may lead to a failure to respond to emergency bronchodilator treatment during an acute asthma attack and support current opinion that regular short-acting beta-agonist therapy should not be used to treat asthma. Some recent studies suggest that regular beta(2)-agonist use may result in inadequate control of asthma. It has been hypothesized that this occurs particularly in allergic asthmatic patients exposed to relevant allergens. Moreover, it is still unclear whether this occurs during the use of both short-acting and long-acting beta(2)-agonists.
                Asthmatic patients (n = 145) allergic to house dust mite (HDM) were randomly allocated to monotherapy with a short-acting beta(2)-agonist (SA; n = 48), a long-acting beta(2)-agonist (LA; n = 50), or placebo (n = 47), double blind, double dummy. The study covered three periods: (1) a 4-week run-in period, in which no changes took place; followed by (2) cessation of treatment with asthma medication including inhaled corticosteroids, introduction of allergen avoidance measures (active/placebo treatment) to lower HDM exposure in the active group, and an 8-week washout period to adjust patients to these changes; followed by (3) a 12-week study medication period. At the start of the 12-week medication period, and every 4 weeks thereafter, spirometric measurements (FEV(1) and provocative concentration of histamine causing a 20% fall in FEV(1) [PC(20)]) were performed. Peak flow and asthma symptoms were recorded daily. Additionally, at the start and every 6 weeks thereafter, dust samples were collected from mattresses and living room and bedroom floors to assess HDM (der p 1) concentrations. Effects on FEV(1), PC(20), peak flow, and asthma symptoms were analyzed with repeated-measurement analysis and corrected for the exposure to HDM allergens.
                There were no significant differences among the three medication groups after 12 weeks for FEV(1). However, a significant decrease in mean FEV(1) percent predicted (95% confidence interval [CI]) was observed within the SA group: - 6.6 (- 10.4 to - 2.8) (p = 0.0002). A decrease in geometric mean PC(20) (95% CI) of - 1.2 (- 1.96 to - 0.44) doubling concentration was observed within the SA group (p = 0.05). No significant changes in FEV(1) and PC(20) were observed > 12 weeks within the LA group or the placebo group. There were neither changes in peak flow and asthma symptom scores among the three medication groups nor within the groups. Moreover, none of the parameters showed interactive effects with allergen exposure.
                There were no significant differences among the three medication groups for FEV(1) and PC(20). The within-treatment group comparison showed a significant small decline in FEV(1) for the SA group (but not for the LA group), which could indicate that monotherapy with SAs might have negative effects on FEV(1). This was not seen during regular use of LAS: No clear pathophysiologic mechanism can explain these findings at the moment. Relatively high or low exposure to allergens did not alter these findings. Small studies have suggested that inhaled corticosteroids can suppress systemic inflammation in chronic obstructive pulmonary disease (COPD).
                To determine the effect of inhaled corticosteroids with or without long-acting beta(2)-adrenergic agonist on systemic biomarkers of inflammation.
                We conducted a double-blind randomized placebo-controlled trial across 11 centers (n = 289 patients with FEV(1) of 47.8 +/- 16.2% of predicted) to compare the effects of inhaled fluticasone alone or in combination with salmeterol against placebo on circulating biomarkers of systemic inflammation over 4 weeks. The primary endpoint was C-reactive protein (CRP) level. Secondary molecules of interest were IL-6 and surfactant protein D (SP-D).
                Neither fluticasone nor the combination of fluticasone/salmeterol had a significant effect on CRP or IL-6 levels. There was, however, a significant reduction in SP-D levels with fluticasone and fluticasone/salmeterol compared with placebo (P = 0.002). Health status also improved significantly in both the fluticasone and fluticasone/salmeterol groups compared with placebo, driven mostly by improvements in the symptom scores. Changes in the circulating SP-D levels were related to changes in health status scores. FEV(1) improved significantly only in the fluticasone/salmeterol group compared with placebo.
                ICS in conjunction with long-acting beta(2)-adrenergic agonist do not reduce CRP or IL-6 levels in serum of patients with COPD over 4 weeks. They do, however, significantly reduce serum SP-D levels. These data suggest that these drugs reduce lung-specific but not generalized biomarkers of systemic inflammation in COPD. Regular use of beta2-agonists might result in increased bronchial hyper-responsiveness (BHR) and decreased forced expiratory volume in 1 sec (FEV1). It has been suggested that these possible detrimental effects are not a real deterioration of the disease, but that it might be only a transient (rebound) effect shortly after discontinuing this regular use. Moreover, these effects are thought to occur especially during short-acting and not during long-acting beta2-agonists use. The aim of this study was to invest gate whether a rebound effect (a pharmacological deterioration effect diminishing after several hours) in FEV1 and PC20 (concentration of histamine causing a 20% fall in FEV1 with regard to baseline) occurred after cessation of regular use of beta2-agonists, and whether this occurred both after short-acting and long-acting beta2-agonists. Allergic asthmatic patients (n = 134) were randomly allocated to the use of a short-acting (salbutamol), a long-acting beta2-agonist (formoterol) or placebo for 12 weeks (double-blind, double-dummy). No other asthma medication was allowed, including inhaled corticosteroids. At the start and every 4 weeks later FEV and PC20 were measured, each time at least 12 h after the last doses of study medication, which is in the possible rebound period. To investigate whether a (transient) rebound effect occurred, parameters were additionally measured at least 72 h later after discontinuation of the study medication. After 12 weeks of short-acting beta2-agonist use, a drop was seen in FEV1 from 85.6 (+/- 2.21)% predicted to 78.8 (+/- 2.9)% predicted, measured 15 h (median) after the last doses of medication. This was significantly different compared to placebo. When measured 168 h (median) later FEV1 recovered to 85.5 (+/- 2.4)% predicted, comparable to baseline. PC20 decreased with -1.17 (+/- 0.44) doubling dose after 12 weeks of short-acting beta2-agonist use, measured 15 h after the last doses of medication, which was significantly different compared to placebo. However, 168 h later PC20 recovered slightly with +0.55 (+/- 0.34) doubling dose, but this value was still lower compared to placebo. In contrast, during long-acting beta2-agonist and placebo use no significant changes were seen. In conclusion, the use of short-acting beta2-agonists resulted in a transient (rebound) effect in FEV while the effects on PC20 may point to a real deterioration of the disease. Long-acting beta2-agonist and placebo use showed no changes. We conclude that a mono-therapy of short-acting and not of long-acting beta2-agonists might have deleterious effects in asthma. The clinical benefit of combining long-acting beta(2)-agonists with inhaled corticosteroids rather than doubling the dose of corticosteroid has been well-documented. However, there are concerns that this might result in a masking of underlying airway inflammation.
                The aim of this study was to test the hypothesis that the addition of the long-acting beta(2)-agonist salmeterol (SALM) to a low dose of the inhaled corticosteroid fluticasone propionate (FP) has a steroid-sparing effect and does not result in a worsening of bronchial inflammation compared to doubling the dose of inhaled corticosteroid.
                Fifty-six asthmatic subjects, previously not well-controlled on inhaled corticosteroids, were randomized to receive 3 months of treatment with inhaled FP 500 microg twice a day (FP 1000) or FP 200 microg twice a day plus SALM 50 microg twice a day (FP 400 + SALM). Fluticasone propionate 200 microg twice a day served as the control (FP400). Bronchial mucosal biopsy specimens, bronchial washings (BW), and bronchoalveolar lavage were obtained before and after treatment. The primary end points for the study were submucosal mast cell and eosinophil counts.
                There was a significant improvement in FEV(1) in the FP400 + SALM group compared to both the FP400 and FP1000 groups. This was accompanied by a significant improvement in peak expiratory flow in the FP400 + SALM group in both the morning and evening compared to the FP1000 group. There were no significant between treatment differences in the change in the number of submucosal mast cells or eosinophils. However, in the FP400 + SALM group there was a significant decrease in submucosal mast cells after 12 weeks of treatment. The addition of SALM to FP was not associated with any increases in airway inflammation in the biopsy specimens, bronchoalveolar lavage, or bronchial washings.
                These findings confirm that addition of SALM to FP has clinical benefits but does not mask or exacerbate airway inflammation and suggest that long-acting beta(2)-adrenoceptor agonists might influence mast cell numbers. Sleep-related oxygen desaturation has been described in patients with cystic fibrosis (CF). Thus we studied the effects of inhaled Salmeterol xinafoate, a long-acting beta-2 agonist, on transcutaneous oxyhemoglobin saturation in sleeping, stable CF patients. Patients with stable CF (n = 23) were divided into responders and nonresponders to beta-2 agonists, based on an albuterol challenge during daytime testing, and then they received salmeterol before sleep, in a double-blind crossover design. Overnight oxyhemoglobin saturation measurements and spirometry on awakening were performed. Salmeterol administration before sleep resulted in statistically significant increases in mean arterial oxyhemoglobin saturation and in FEV(1) and FEF(25-75) on awakening compared to placebo values, but only in patients responding to daytime albuterol inhalation by showing improvement in lung function. We conclude that salmeterol inhalation at bedtime could prevent or reduce nocturnal hypoxemia in daytime albuterol-responsive CF patients, thus improving the long-term clinical outcome of CF lung disease.
                Copyright 2002 Wiley-Liss, Inc. Information is lacking on the relative effectiveness and cost effectiveness--in a real-life primary-care setting--of leukotriene receptor antagonists (LTRAs) and long-acting beta2 adrenergic receptor agonists (beta2 agonists) as add-on therapy for patients whose asthma symptoms are not controlled on low-dose inhaled corticosteroids (ICS).
                To estimate the cost effectiveness of LTRAs compared with long-acting beta2 agonists as add-on therapy for patients whose asthma symptoms are not controlled on low-dose ICS.
                An economic evaluation was conducted alongside a 2-year, pragmatic, randomized controlled trial set in 53 primary-care practices in the UK. Patients aged 12-80 years with asthma insufficiently controlled with ICS (n = 361) were randomly assigned to add-on LTRAs (n = 176) or long-acting beta2 agonists (n = 185). The main outcome measures were the incremental cost per point improvement in the Mini Asthma Quality of Life Questionnaire (MiniAQLQ), per point improvement in the Asthma Control Questionnaire (ACQ) and per QALY gained from perspectives of the UK NHS and society.
                Over 2 years, the societal cost per patient receiving LTRAs was pounds sterling 1157 versus pounds sterling 952 for long-acting beta2 agonists, a (significant, adjusted) increase of pounds sterling 214 (95% CI 2, 411) [year 2005 values]. Patients receiving LTRAs experienced a non-significant incremental gain of 0.009 QALYs (95% CI -0.077, 0.103). The incremental cost per QALY gained from the societal (NHS) perspective was pounds sterling 22,589 (pounds sterling 11,919). Uncertainty around this point estimate suggested that, given a maximum willingness to pay of pounds sterling 30,000 per QALY gained, the probability that LTRAs are a cost-effective alternative to long-acting beta2 agonists as add-on therapy was approximately 52% from both societal and NHS perspectives.
                On balance, these results marginally favour the repositioning of LTRAs as a cost-effective alternative to long-acting beta2 agonists as add-on therapy to ICS for asthma. However, there is much uncertainty surrounding the incremental cost effectiveness because of similarity of clinical benefit and broad confidence intervals for differences in healthcare costs.
                UK National Research Register N0547145240; Controlled Clinical Trials ISRCTN99132811. There is controversy as to the role of long acting beta 2 agonists such as eformoterol and, in particular, whether bronchodilator tolerance occurs during continuous therapy. The purpose of this study was to extend previous observations of bronchodilator subsensitivity with metered dose eformoterol aerosol in order to assess whether tolerance also occurs with a dry powder formulation of the same drug.
                Sixteen asthmatic patients of mean age 33 (range 18-53) years and FEV1 (% predicted) of 64 (3)%, of whom 13 were receiving inhaled corticosteroids, received regular treatment with eformoterol 24 micrograms twice daily or placebo twice daily (without beta 2 agonists) given concurrently for four weeks in a randomised double blind cross-over design. An initial two week run-in was used when beta 2 agonists were withdrawn and substituted with ipratropium bromide. Dose-response curves to eformoterol (cumulative dose 6-102 micrograms) for airways and systemic beta 2 responses were constructed at the end of each treatment period.
                Baseline values for airways and systemic responses were similar. The peak delta FEV1 response from the dose-response curve (as change from baseline) and the delta response for FEV1 and FEF25-75 at six hours after the last dose were attenuated after eformoterol compared with placebo: peak delta FEV1 response 1.001 with placebo v 0.841 with eformoterol (95% CI 0.04 to 0.28); at six hours 0.931 with placebo v 0.581 with eformoterol (95% CI 0.20 to 0.50); and for delta FEF25-75 at six hours 1.29 1/s with placebo v 0.87 1/s with eformoterol (95% CI 0.15 to 0.69). Morning peak expiratory flow rate was significantly improved during treatment with eformoterol (451 1/min) compared with placebo (399 1/min) (95% CI 21 to 82). Systemic beta 2 responses were blunted after eformoterol, together with a reduction in lymphocyte beta 2 receptor binding density.
                Regular twice daily eformoterol dry powder may produce bronchodilator subsensitivity in terms of both peak and duration of response to cumulative repeated doses of eformoterol. Systemic beta 2-mediated adverse effects also showed tolerance, which was mirrored by downregulation of lymphocyte beta 2 adrenoceptors. Regular inhaled beta 2 agonist causes tolerance to the acute protective effect of beta 2 agonist against bronchoconstriction induced by chemical stimuli such as AMP, histamine, and methacholine. We examined a more clinically relevant stimulus, inhaled allergen, in a double-blind, cross-over, random-order trial in 13 mild atopic asthmatics, who had not used beta 2 agonist for at least 4 weeks. We compared regular inhaled salbutamol (200 micrograms four times daily for 2 weeks) with placebo (2 weeks) for effects on bronchodilator response, baseline methacholine, and allergen airway responsiveness, and on the acute protective effect of salbutamol against both stimuli. Baseline forced expiratory volume in 1 s (FEV1), bronchodilator response, and methacholine responsiveness were the same during both treatment periods. After regular salbutamol, the allergen PC20 (provocation concentration producing a 20% FEV1 decrease) fell by 0.91 (SD 0.66) (p = 0.0009) doubling doses, and the protective effects of salbutamol on methacholine and allergen were both significantly reduced (p = 0.026 and 0.025, respectively). Taking into account the reduced baseline allergen PC20, the post-salbutamol allergen PC20 was almost 2 doubling doses (1.94 [1.43], p < 0.01) lower during salbutamol treatment. Thus, 2 weeks of regular inhaled salbutamol increased airway responsiveness to allergen but not to methacholine, and caused tolerance to the protective effect of salbutamol on bronchoconstriction induced by both stimuli. These effects of inhaled beta 2 agonist provide further evidence to support detrimental effects of their regular use. Tolerance to the direct bronchodilator effects of beta 2-agonists does not appear to occur in asthma. However, it is not known whether this is true for the nonbronchodilator effects of these agents, which protect the airways against bronchoconstrictive stimuli.
                We investigated whether tolerance develops to the protective effect of inhaled terbutaline on airway responsiveness to the bronchoconstrictors methacholine (which acts directly on airway smooth muscle) and AMP (which acts indirectly by stimulating the release of mediators from mast cells) during sustained treatment with terbutaline. In a randomized, double-blind, crossover study, 12 patients with mild asthma each inhaled a single dose of terbutaline (500 micrograms) or placebo before a challenge with a series of doubling doses of inhaled methacholine or AMP, before and after treatment for seven days with 500 micrograms of terbutaline four times daily or placebo.
                Before the seven days of treatment with terbutaline, a single dose of terbutaline reduced airway responsiveness to methacholine by 2.7 doubling doses (95 percent confidence interval, 1.9 to 3.5), but it had an even greater protective effect against AMP, reducing airway responsiveness by 3.8 doubling doses (95 percent confidence interval, 2.7 to 4.9; P less than 0.001). After seven days of treatment with terbutaline, the protective effect of terbutaline against methacholine decreased to 2.2 doubling doses (95 percent confidence interval, 1.3 to 3.0; P = 0.04), and that against AMP decreased even more, to 1.7 doubling doses (95 percent confidence interval, 1.1 to 2.4; P less than 0.001). By contrast, the bronchodilator response to terbutaline was unchanged during seven days of treatment with this agent.
                We observed tolerance to the nonbronchodilator actions of the inhaled beta 2-agonist terbutaline in patients with mild asthma, an effect that may be more pronounced in mast cells than in bronchial smooth muscle. This property of beta-agonists may constitute a drawback to their regular use in patients with 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. Addition of the long acting beta2 agonist salmeterol to inhaled corticosteroids leads to better symptomatic asthma control than increasing the dose of inhaled corticosteroids. However, little is known about the long term effects of adding salmeterol on the asthmatic inflammatory process, control of which is considered important for the long term outcome of asthma.
                After a 4 week fluticasone run-in period, 54 patients with allergic asthma were randomised to receive twice daily treatment with fluticasone 250 microg with or without salmeterol 50 microg for 1 year in a double blind, parallel group design (total daily dose of fluticasone 500 microg in both treatment groups). Primary outcomes were sputum eosinophil numbers and eosinophil cationic protein concentrations. Secondary outcomes were neutrophil associated sputum parameters and a respiratory membrane permeability marker. The effects on allergen induced changes were determined before and at the end of the treatment period.
                Adding salmeterol to fluticasone resulted in improved peak expiratory flow, symptom scores, rescue medication usage, and bronchial hyperresponsiveness (p < 0.05 for all). There was no sustained effect on sputum cell differential counts and cytokine concentrations during the treatment period or on changes induced by allergen challenge at the end of treatment (p > 0.05). However, adding salmeterol significantly reduced sputum ratios of alpha2-macroglobulin and albumin during the treatment period (p = 0.001).
                The addition of salmeterol to fluticasone produces no sustained effect on allergen induced cellular bronchial inflammation but leads to a significant improvement in size selectivity of plasma protein permeation across the respiratory membrane. This may contribute to the improved clinical outcome seen in patients with allergic asthma when a long acting beta2 agonist is combined with inhaled corticosteroids. Regular treatment with beta 2-adrenergic agonists is controversial in bronchial asthma. To investigate whether beta 2-adrenergic agonists can be used safely if associated with low doses of inhaled steroids, for a short period, without a deterioration of asthma control, we have examined 24 mild asthmatics. In a parallel, double-blind, placebo-controlled study, 1 week of run-in and run-out period framed 3 weeks of treatment. All patients received inhaled beclomethasone dipropionate (BDP 250 micrograms t.i.d.); after 1 week, 12 patients inhaled 400 micrograms of broxaterol and 12 patients received placebo t.i.d. FVC, FEV1, PD20-FEV1 methacholine, morning and evening PEF, and PEF amplitude % mean were measured before, during, and after treatment. No significant changes were noted in patients receiving inhaled broxaterol. There were no differences in symptoms and the use of rescue medication (salbutamol spray). We conclude that short-term regular treatment with beta 2-adrenergic agonists is not associated with a deterioration in asthma control in mild asthmatics inhaling low doses of steroids. Pretreatment with inhaled beta 2-agonists is often recommended for the prevention of exercise-induced bronchoconstriction. Regular treatment with inhaled beta 2-agonists has been associated with worsened baseline airway caliber and increased airway responsiveness. In this study, we have investigated the effects of regular inhaled albuterol on the severity of exercise-induced bronchoconstriction using a double-blind, placebo-controlled, randomized, crossover design. Ten subjects inhaled either albuterol or placebo (2 x 100 micrograms, four times per day) for 7 d. On the eighth and ninth days of treatment periods, subjects performed 5-min constant work rate cycle ergometry exercise challenges after inhaling 200 micrograms of placebo (eighth day) or albuterol (ninth day). Forced expired volume in 1 s (FEV1) was measured on arrival in the laboratory as well as before and for 1 h after exercise. One week of regular inhaled albuterol compared with placebo resulted in: (1) a lower baseline FEV1 (mean difference, 230 ml) (p = 0.02); (2) a lower minimum postexercises FEV1 without inhaled albuterol pretreatment (mean difference, 390 ml; range, -50 ml to 1,250 ml) (p = 0.01); (3) a lower minimum postexercise FEV1 with inhaled albuterol pretreatment (p < 0.01). The smallest degree of exercise-induced bronchoconstriction occurred after a week of regular placebo and pretreatment with inhaled albuterol immediately before exercise. Inhalation of albuterol four times daily for 1 wk worsens exercise-induced bronchoconstriction; however, it remains extremely effective when used immediately before exercise for preventing bronchoconstriction. Suboptimal medication treatment of asthma has been reported. More specifically, short-acting beta 2-agonists are overused, while inhaled corticosteroids are underused. This can be related in part to poor adherence by patients to the prescribed regimen and to professionals' failure to comply with practice guidelines. Feedback seems to have an effect on professional practices related to medication use.
                To assess the impact of feedback letters to physicians and pharmacists on their patients' appropriate use of asthma medication.
                Two randomized trials were set up in the province of Quebec, Canada: one with physicians and another with pharmacists. A sample of voluntary physicians and pharmacists was randomly assigned to either the experimental group or to the control group. Those in the experimental groups received three consecutive feedback letters over a 9-month period summarizing the asthma medications acquired by their patients over the preceding year. The feedback focused on short-acting beta 2-agonists, long-acting beta 2-agonists and antileukotrienes and provided information on compliance with five appropriate-use criteria. Pharmacists received aggregate profiles and individual profiles with patients' names, while most physicians received aggregate profiles for all their eligible patients. Each mailing also included a pamphlet that summarized practice guidelines on asthma treatment.
                Seventy-one physicians and 60 pharmacists participated in the study. Physicians who received the feedback letters did not differ from those in the control group in terms of their proportion of prescriptions compliant with the criteria, either before the feedback or after it (p > 0.05). The before-after difference was also similar between groups. The same was true for pharmacists. However, although the before-after difference for criteria 1 (frequency of use of short-acting beta 2-agonists) and 2 (frequency of use of long-acting beta 2-agonists) did not reach the usual statistical significance threshold of 0.05, the p value was under 0.10.
                As designed in this study, feedback provided to physicians did not improve the appropriate use of asthma medication. However, feedback to pharmacists is promising, especially when including patients' names so that pharmacists can intervene more specifically. We conducted a four-period cross-over randomized trial in which we found that patients with chronic airflow limitation demonstrated symptomatic improvement with both inhaled albuterol and oral theophylline. The response, however, was not uniform. We therefore tested the ability of acute change in forced expired volume in one second (FEV1) following inhaled beta agonist to predict long-term symptomatic response to albuterol and theophylline. We found that the reproducibility of acute change in FEV1 over three repetitions was poor (intraclass correlation 0.17). Furthermore, the mean improvement FEV1 following inhaled albuterol across the three repetitions did not relate closely to symptomatic response to either albuterol or theophylline. We conclude that acute response to inhaled beta agonist is not useful for identifying patients with chronic airflow limitation who are likely to benefit from bronchodilator treatment. Previous studies have shown that the regular administration of short acting beta-agonists can be associated with adverse effects on airway caliber and bronchial hyperresponsiveness (BHR) and that this may occur through a proinflammatory mechanism. The aim was to explore possible adverse effects of high-dose beta-agonist therapy and to assess any adverse interaction with corticosteroids. We undertook a randomized, crossover study to investigate the effects of 6 wk of treatment with regular terbutaline (1 mg four times a day), regular budesonide (400 microg twice a day), combined treatment, and placebo in subjects with mild to moderate asthma. Major endpoints were PD(15) saline, PD(20) methacholine, and induced sputum differential cell counts. Thirty-four subjects were randomized and 28 completed the study. PD(15) saline decreased on terbutaline alone compared with placebo treatment and on combined treatment compared with budesonide alone (mean fold decrease of 0.57 [95% CI = 0.36, 0.90] and 0.65 [95% CI = 0.43, 0.97], respectively). PD(20) methacholine was not affected by the use of terbutaline either alone or in combination with budesonide. The percentage of eosinophils in induced sputum increased during terbutaline treatment alone compared with placebo (median 8.3% versus 4.4%, p = 0.049). The addition of terbutaline to budesonide did not affect the percentage of eosinophils compared with budesonide treatment alone. These findings support the hypothesis that short-acting beta-agonists have a permissive effect on airway inflammation and that when used in high dose there may be an unfavorable interaction with inhaled corticosteroids. In addition to their bronchodilatory effects, beta(2)-agonists protect against bronchoconstriction, such as that caused by methacholine challenge. However, tachyphylaxis to this beneficial effect develops after chronic use of beta(2)-agonists. We studied whether the frequency or dose of treatment with a long-acting beta(2)-agonist (formoterol) affects the degree of bronchoprotection afforded against methacholine challenge and to compare this with the effects of a short-acting beta(2)-agonist (terbutaline).
                In a randomized, parallel group, double-blind study at two centers, patients with stable asthma of mild to moderate severity who were treated with inhaled corticosteroids were treated with formoterol 6 micrograms twice daily, 24 micrograms twice daily, 12 micrograms once daily; terbutaline 500 micrograms four times daily; or placebo. Treatments were given by dry powder inhaler for a period of 2 weeks. Of the 72 patients who were enrolled, 67 completed the study. Methacholine challenge was performed to calculate the provocative dose that caused a 20% fall in forced expiratory volume in 1 second at baseline (unprotected) after an initial 1-week run-in without beta(2)-agonists, 1 hour after the first dose of study treatment, and again 1 hour after 7 and 14 days of study treatment.
                Each of the four active treatments exhibited significant tachyphylaxis (P < 0.05) to protection against methacholine challenge when comparing first/last dose (as geometric mean protection ratio versus baseline): formoterol 24 micrograms twice daily (9.6-fold/1.6-fold), 12 micrograms once daily (7.1-fold/2.2-fold), 6 micrograms twice daily (6.2-fold/2.3-fold), and terbutaline 500 micrograms four times daily (2.9-fold/2.0-fold). There were no significant differences among treatments after 2 weeks in bronchoprotection against methacholine challenge. For all formoterol regimens, the bronchodilator response 1 hour after inhalation was maintained over the 2-week treatment period. Diurnal control of morning and evening peak flow was significantly better with formoterol 24 micrograms twice daily than with terbutaline.
                Tachyphylaxis to bronchoprotection against methacholine challenge develops after 2 weeks of therapy with formoterol, a long-acting beta(2)-agonist, at all three dosage regimens that were tested. In contrast, the bronchodilator effects of formoterol were maintained during the 2 weeks of treatment. Guidelines on asthma management recommend that in patients who still have symptoms on treatment with low-dose inhaled corticosteroids the first step should be an increase in inhaled corticosteroid dose. The addition of long-acting inhaled beta 2-adrenoceptor agonists is another option. We have compared these two strategies in a randomised, double-blind, parallel-group trial. We studied 429 adult asthmatic patients who still had symptoms despite maintenance treatment with 200 micrograms twice daily inhaled beclomethasone dipropionate (BDP). 3 did not provide verifiable data. Of the others, 220 were assigned salmeterol xinafoate (50 micrograms twice daily) plus BDP and 206 were assigned higher-dose BDP (500 micrograms twice daily) for 6 months. The mean morning peak expiratory flow increased from baseline in both groups, but the increase was greater in the salmeterol/BDP group than in the higher-dose BDP group at all time points (differences 16-21 L/min, p < 0.05). Mean evening PEF also increased with salmeterol/BDP but not with higher-dose BDP. There were significant differences in favour of salmeterol/BDP in diurnal variation of PEF (all time points) and in use of rescue bronchodilator (salbutamol) and daytime and night-time symptoms (some time points). There was no significant difference between the groups in adverse effects or exacerbations of asthma, indicating that in this group of patients regular beta 2-agonist therapy was not associated with any risk of deteriorating asthma control over 6 months. This study suggests a need for a flexible approach to asthma management. Poor adherence with inhaled corticosteroids is an important problem in asthma management. Previous approaches to improving adherence have had limited success.
                To determine whether treatment with a single inhaler containing a long-acting beta(2)-agonist and a corticosteroid for maintenance treatment and symptom relief can overcome the problem of poor adherence with inhaled corticosteroids.
                Randomised, parallel group, open-label trial.
                Forty-four general practices in Nottinghamshire.
                Participants who used less than 70% of their prescribed dose of inhaled corticosteroid and had poorly controlled asthma were randomised to budesonide 200 microg one puff twice daily plus their own short-acting beta(2)-agonist as required (control group), or budesonide/formoterol 200/6 microg one puff once daily and as required (active group) for 6 months. The primary outcome was inhaled corticosteroid dose.
                Seventy-one participants (35 control, 36 active group) were randomised. Adherence with budesonide in the control group was approximately 60% of the prescribed dose. Participants in the active group used approximately 80% more budesonide than participants in the control group (448 versus 252 microg/day, mean difference 196 mug, 95% confidence interval 113 to 279; P<0.001) and were less likely to withdraw from the study (3 versus 13; P<0.01). No safety issues were identified.
                Using a single inhaler for both maintenance treatment and symptom relief approximately doubled the dose of inhaled corticosteroid taken, suggesting this could be a useful strategy to overcome the problems related to poor adherence with inhaled corticosteroids. Salmeterol xinafoate is an inhaled long-acting beta2-adrenoceptor agonist recently introduced for the treatment of asthma. Both in vitro and animal studies suggest that it may have anti-inflammatory activities of benefit in this disease. To assess this directly, the effects of 6 weeks' treatment with salmeterol on indices of clinical activity, airway dysfunction and inflammation in subjects with stable atopic asthma were investigated. In a double blind study, asthmatic patients were randomized to 6 weeks' treatment with either salmeterol 50 microg twice daily (n=14) or placebo (n=12). They underwent bronchoscopy with bronchoalveolar lavage (BAL) and bronchial biopsy immediately before starting treatment and again after 6 weeks. Treatment with salmeterol improved clinical indices of asthma activity, but there were no changes in BAL differential cell counts or mediator levels, and no change in T-cell numbers or activation status. In the biopsy specimens there were no changes in numbers of inflammatory cells, sub-basement membrane collagen deposition or mast cell degranulation. Regular treatment with salmeterol improves clinical indices of asthma but has no effect on the underlying inflammatory process. These findings strengthen guideline recommendations that long-acting beta2-agonists should not be prescribed as sole antiasthma medication. Oxis Turbuhaler is a new dry powder formulation of long-acting beta2-agonist formoterol. This study compared the efficacy and safety of regular use of the long-acting beta2-agonist formoterol and the short-acting terbutaline for 3 months in patients with asthma.
                After 1-week run-in, 343 patients received either formoterol 12 microg bid (F) (delivered dose of 9 microg), terbutaline 500 microg qid (T) or placebo qid, in a parallel-group, double-blind, randomized manner. They had a mean of 61% of predicted forced expiratory volume in 1 second (FEV1) and a mean reversibility of 26%. Eighty-nine percent used inhaled corticosteroids.
                During run-in mean morning peak expiratory flow (PEF L/min) for F was 366 and 348 for T, and 344 for placebo (P). The F group improved morning PEF significantly compared with P (P = .0022) and T (P = .0001). Changes from run-in were + 18, -1.5, and +5 L/min after F, T, and P, respectively. The F group was statistically significantly better than P and T in increasing evening PEF and in reducing night-time asthma. The F and T statistically significantly reduced the use of rescue medication compared with P. The bronchodilating response to the study drug and to an additional 1.25 mg terbutaline was of the same magnitude before and throughout the study. No statistically significant treatment-by-time interaction was observed (P > .20). There were no adverse effects of clinical relevance.
                Formoterol Turbuhaler, 12 microg bid, was more effective than terbutaline Turbuhaler, 0.5 mg qid, and placebo. Regular use of formoterol or terbutaline did not significantly influence the response to additional inhalation of terbutaline.
Long acting inhaled beta-agonists have advantages across a wide range of physiological and clinical outcomes for regular treatment.