Formoterol compared with beclomethasone and placebo on allergen-induced asthmatic responses

Impact of Ongoing Treatment With Inhaled Corticosteroids During Specific Inhalation Challenges for Diagnosing Occupational Asthma

BACKGROUND

Specific inhalation challenge (SIC) tests are still the reference test for diagnosing sensitizer-induced occupational asthma (SIOA). The European Respiratory Society recommends the cessation of inhaled corticosteroids (ICS) 72 hours before SIC.

OBJECTIVE

To assess the effect of an ongoing ICS treatment during SIC on the maximum fall in forced expiratory volume in 1 second (FEV1), the change in methacholine provocative concentration of methacholine inducing a 20% fall in FEV1 (PC20), and sputum eosinophil counts after exposure to the suspected agent.

METHODS

We performed a retrospective analysis using a database of cases referred to our center for suspected SIOA from 1999 to 2022. The results of the SIC were compared between subjects treated with ICS during SIC and steroid-naïve subjects.

RESULTS

Six hundred and seventy-one individuals underwent SIC in the laboratory. Three hundred and eighteen were treated with ICS, whereas 353 were steroid naïve. The proportion of subjects with a positive SIC was greater among ICS-treated subjects (39. 6%) compared with steroid-naïve subjects (27.5%, P < .001). A treatment with ICS did not influence the outcome of the SIC. There was no difference in the change in PC20 or the percentage of sputum eosinophils after SIC between steroid-treated and steroid-naïve subjects.

CONCLUSIONS

An ongoing ICS treatment during an SIC did not affect the occurrence of an asthmatic reaction, the change in airway responsiveness, or eosinophilic inflammation after exposure to the suspected agent in subjects who have been treated with ICS for a long period of time.

Inhaled allergen bronchoprovocation tests

The allergen bronchoprovocation test is a long-standing exacerbation model of allergic asthma that can induce several clinical and pathophysiologic features of asthma in sensitized subjects. Standardized allergen challenge is primarily a research tool, and when properly conducted by qualified and experienced investigators, it is safe and highly reproducible. In combination with validated airway sampling and sensitive detection techniques, allergen challenge allows the study of several features of the physiology of mainly TH2 cell-driven asthma in relation to the kinetics of the underlying airway pathology occurring during the allergen-induced late response. Furthermore, given the small within-subject variability in allergen-induced airway responses, allergen challenge offers an adequate disease model for the evaluation of new (targeted) controller therapies for asthma in a limited number of subjects. In proof-of-efficacy studies thus far, allergen challenge showed a fair positive predicted value and an excellent negative predictive value for the actual clinical efficacy of new antiasthma therapies, underscoring its important role in early drug development. In this review we provide recommendations on challenge methods, response measurements, sample size, safety, and harmonization for future applications.

Regular treatment with formoterol for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta(2)-agonists and increases in asthma mortality. There has been much debate about possible causal links for this association, and whether regular (daily) long-acting beta(2)-agonists are safe.

OBJECTIVES

The aim of this review is to assess the risk of fatal and non-fatal serious adverse events in trials that randomised patients with chronic asthma to regular formoterol versus placebo or regular short-acting beta(2)-agonists.

SEARCH METHODS

We identified trials using the Cochrane Airways Group Specialised Register of trials. We checked websites of clinical trial registers for unpublished trial data and Food and Drug Administration (FDA) submissions in relation to formoterol. The date of the most recent search was January 2012.

SELECTION CRITERIA

We included controlled, parallel design clinical trials on patients of any age and severity of asthma if they randomised patients to treatment with regular formoterol and were of at least 12 weeks' duration. Concomitant use of inhaled corticosteroids was allowed, as long as this was not part of the randomised treatment regimen.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review. One author extracted outcome data and the second author checked them. We sought unpublished data on mortality and serious adverse events.

MAIN RESULTS

The review includes 22 studies (8032 participants) comparing regular formoterol to placebo and salbutamol. Non-fatal serious adverse event data could be obtained for all participants from published studies comparing formoterol and placebo but only 80% of those comparing formoterol with salbutamol or terbutaline.Three deaths occurred on regular formoterol and none on placebo; this difference was not statistically significant. It was not possible to assess disease-specific mortality in view of the small number of deaths. Non-fatal serious adverse events were significantly increased when regular formoterol was compared with placebo (Peto odds ratio (OR) 1.57; 95% CI 1.06 to 2.31). One extra serious adverse event occurred over 16 weeks for every 149 people treated with regular formoterol (95% CI 66 to 1407 people). The increase was larger in children than in adults, but the impact of age was not statistically significant. Data submitted to the FDA indicate that the increase in asthma-related serious adverse events remained significant in patients taking regular formoterol who were also on inhaled corticosteroids.No significant increase in fatal or non-fatal serious adverse events was found when regular formoterol was compared with regular salbutamol or terbutaline.

AUTHORS' CONCLUSIONS

In comparison with placebo, we have found an increased risk of serious adverse events with regular formoterol, and this does not appear to be abolished in patients taking inhaled corticosteroids. The effect on serious adverse events of regular formoterol in children was greater than the effect in adults, but the difference between age groups was not significant.Data on all-cause serious adverse events should be more fully reported in journal articles, and not combined with all severities of adverse events or limited to those events that are thought by the investigator to be drug-related.

Genomic and non-genomic actions of glucocorticoids in asthma

Glucocorticoids are the mainstay of asthma therapy. They are primarily used to suppress airway inflammation, which is the central pathological change in asthmatic patients’ airways. This is achieved by many different mechanisms. The classical mechanism is by suppression of the genetic transcription of many inflammatory cytokines that are key in asthma pathophysiology (transrepression). On the other hand, the transcription of certain inhibitory cytokines is activated by glucocorticoids (transactivation), a mechanism that also mediates many of the adverse effects of glucocorticoids. The onset of action through these mechanisms is often delayed (4-24 hours). Other mechanisms mediated through non-genomic pathways are increasingly appreciated. These are delivered in part by binding of glucocorticoids to nonclassical membrane-bound glucocorticoid receptors or by potentiating the α1-adrenergic action on the bronchial arterial smooth muscles, in addition to other mechanisms. These effects are characterized by their rapid onset and short duration of action. Understanding these different mechanisms will help in the development of new and better drugs to treat this common disease and to develop new improved strategies in our approach to its management. Here, the genomic and non-genomic mechanisms of actions of glucocorticoids in asthma are briefly reviewed, with special emphasis on the current updates of the non-genomic mechanisms.

Rapid onset of bronchodilation with formoterol/beclomethasone Modulite and formoterol/budesonide Turbuhaler as compared to formoterol alone in patients with COPD

In the present study, we examined whether there is a difference in the onset of bronchodilatation between formoterol/beclomethasone 12/200 μg Modulite and formoterol/budesonide 9/320 μg Turbuhaler in patients with COPD. We enrolled 28 patients with stable COPD. Both formoterol/beclomethasone and formoterol/budesonide elicited a larger mean FEV₁-AUC₀₋₁₅min than formoterol alone, whereas there was no significant difference between their FEV₁-AUC₀₋₁₅min. Also the change in FEV₁ 15 min after inhalation of formoterol/beclomethasone combination or formoterol/budesonide combination was greater than that induced by formoterol alone. This study confirms the rapid effect of the inhaled corticosteroid component when combined with formoterol and indicates that the onset of bronchodilation of formoterol/beclomethasone Modulite and formoterol/budesonide Turbuhaler are similar and greater than formoterol alone in patients with COPD.

Addition of long-acting beta2-agonists to inhaled corticosteroids versus same dose inhaled corticosteroids for chronic asthma in adults and children

BACKGROUND

Long-acting inhaled ss(2)-adrenergic agonists (LABAs) are recommended as 'add-on' medication to inhaled corticosteroids (ICS) in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of LABAs to ICS in patients insufficiently controlled on ICS alone.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

We included RCTs if they compared the addition of inhaled LABAs versus placebo to the same dose of ICS in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the relative risk (RR) of asthma exacerbations requiring rescue oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), rescue beta2-agonist use, symptoms, withdrawals and adverse events.

MAIN RESULTS

Seventy-seven studies met the entry criteria and randomised 21,248 participants (4625 children and 16,623 adults). Participants were generally symptomatic at baseline with moderate airway obstruction despite their current ICS regimen. Formoterol or salmeterol were most frequently added to low-dose ICS (200 to 400 microg/day of beclomethasone (BDP) or equivalent) in 49% of the studies. The addition of a daily LABA to ICS reduced the risk of exacerbations requiring oral steroids by 23% from 15% to 11% (RR 0.77, 95% CI 0.68 to 0.87, 28 studies, 6808 participants). The number needed to treat with the addition of LABA to prevent one use of rescue oral corticosteroids is 41 (29, 72), although the event rates in the ICS groups varied between 0% and 38%. Studies recruiting adults dominated the analysis (6203 adult participants versus 605 children). The subgroup estimate for paediatric studies was not statistically significant (RR 0.89, 95% CI 0.58 to 1.39) and includes the possibility of the superiority of ICS alone in children.Higher than usual dose of LABA was associated with significantly less benefit. The difference in the relative risk of serious adverse events with LABA was not statistically significant from that of ICS alone (RR 1.06, 95% CI 0.87 to 1.30). The addition of LABA led to a significantly greater improvement in FEV(1) (0.11 litres, 95% 0.09 to 0.13) and in the proportion of symptom-free days (11.88%, 95% CI 8.25 to 15.50) compared to ICS monotherapy. It was also associated with a reduction in the use of rescue short-acting ss(2)-agonists (-0.58 puffs/day, 95% CI -0.80 to -0.35), fewer withdrawals due to poor asthma control (RR 0.50, 95% CI 0.41 to 0.61), and fewer withdrawals due to any reason (RR 0.80, 95% CI 0.75 to 0.87). There was no statistically significant group difference in the risk of overall adverse effects (RR 1.00, 95% 0.97 to 1.04), withdrawals due to adverse health events (RR 1.04, 95% CI 0.86 to 1.26) or any of the specific adverse health events.

AUTHORS' CONCLUSIONS

In adults who are symptomatic on low to high doses of ICS monotherapy, the addition of a LABA at licensed doses reduces the rate of exacerbations requiring oral steroids, improves lung function and symptoms and modestly decreases use of rescue short-acting ss(2)-agonists. In children, the effects of this treatment option are much more uncertain. The absence of group difference in serious adverse health events and withdrawal rates in both groups provides some indirect evidence of the safety of LABAs at usual doses as add-on therapy to ICS in adults, although the width of the confidence interval precludes total reassurance.

Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled ss2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine the effect of the combination of long-acting ss(2) agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the risk of asthma exacerbations, pulmonary function and on other measures of asthma control, and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs, clinical trial registries and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

RCTs that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the number of patients experiencing one or more asthma exacerbations requiring oral corticosteroids.

MAIN RESULTS

This review included 48 studies (15,155 participants including 1155 children and 14,000 adults). Participants were inadequately controlled on their current ICS regimen, experiencing ongoing symptoms and with generally moderate (FEV1 60% to 79% of predicted) airway obstruction. The studies tested the combination of salmeterol or formoterol with a median dose of 400 mcg/day of beclomethasone or equivalent (BDP-eq) compared to a median of 1000 mcg/day of BDP-eq, usually for 24 weeks or less. There was a statistically significantly lower risk of exacerbations requiring systemic corticosteroids in patients treated with LABA and ICS (RR 0.88, 95% CI 0.78 to 0.98, 27 studies, N = 10,578) from 11.45% to 10%, with a number needed to treat of 73 (median study duration: 12 weeks). The study results were dominated by adult studies; trial data from three paediatric studies showed a trend towards increased risk of rescue oral steroids (RR 1.24, 95% CI 0.58 to 2.66) and hospital admission (RR 2.21, 95% CI 0.74 to 6.64) associated with combination therapy. Overall, there was no statistically significant difference in the risk ratios for either hospital admission (RR 1.02, 95% CI 0.67 to 1.56) or serious adverse events (RR 1.12, 95% CI 0.91 to 1.37). The combination of LABA and ICS resulted in significantly greater but modest improvement from baseline in lung function, symptoms and rescue medication use than with higher ICS dose. Despite no significant group difference in the risk of overall adverse events (RR 0.99, 95% CI 0.95 to 1.03), there was an increase in the risk of tremor (RR 1.84, 95% CI 1.20 to 2.82) and a lower risk of oral thrush (RR 0.58, 95% CI 0.40 to 0.86)) in the LABA and ICS compared to the higher ICS group. There was no significant difference in hoarseness or headache between the treatment groups. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS (RR 0.65, 95% CI 0.51 to 0.83).

AUTHORS' CONCLUSIONS

In adolescents and adults with sub-optimal control on low dose ICS monotherapy, the combination of LABA and ICS is modestly more effective in reducing the risk of exacerbations requiring oral corticosteroids than a higher dose of ICS. Combination therapy also led to modestly greater improvement in lung function, symptoms and use of rescue ss(2) agonists and to fewer withdrawals due to poor asthma control than with a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor and less oral candidiasis with combination therapy, the two options appear relatively safe in adults although adverse effects associated with long-term ICS treatment were seldom monitored. In children, combination therapy did not lead to a significant reduction, but rather a trend towards an increased risk, of oral steroid-treated exacerbations and hospital admissions. These trends raised concern about the safety of combination therapy in view of modest improvement in children under the age of 12 years.

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults and children

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled ss2-agonists (LABA) only in asthmatic patients who are inadequately controlled on inhaled corticosteroids (ICS). It is not uncommon for some patients to be commenced on ICS and LABA together as initial therapy.

OBJECTIVES

To compare the efficacy of combining inhaled corticosteroids with long-acting ss2-agonists (ICS+LABA) with inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma. We assessed two protocols: (1) LABA + ICS versus a similar dose of ICS (comparison 1) and (2) LABA + ICS versus a higher dose of ICS (comparison 2).

SEARCH STRATEGY

We identified randomised controlled trials through electronic database searches (May 2008).

SELECTION CRITERIA

Randomised trials comparing ICS + LABA with ICS alone in children and adults with asthma who had no inhaled corticosteroids in the preceding 28 days prior to enrolment.

DATA COLLECTION AND ANALYSIS

Each author assessed studies independently for risk of bias and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was rate of patients with one or more asthma exacerbations requiring rescue systemic corticosteroids. Results are expressed as relative risks (RR) for dichotomous data and as mean differences (MD) or standardised mean differences (SMD) for continuous data.

MAIN RESULTS

Twenty-eight study comparisons drawn from 27 trials (22 adult; five paediatric) met the review entry criteria (8050 participants). Baseline data from the studies indicated that trial populations had moderate or mild airway obstruction (FEV1>/=65% predicted), and that they were symptomatic prior to randomisation. In comparison 1, the combination of ICS and LABA was not associated with a significantly lower risk of patients with exacerbations requiring oral corticosteroids (RR 1.04; 95% confidence interval (CI) 0.73 to 1.47) or requiring hospital admissions (RR 0.38; 95% CI 0.09 to 1.65) compared to a similar dose of ICS alone. The combination of LABA and ICS led to a significantly greater improvement from baseline in FEV1 (0.12 L/sec; 95% CI 0.07 to 0.17), in symptoms (SMD -0.26; 95% CI -0.37 to -0.14) and in rescue ss2-agonist use (-0.41 puffs/day; 95% CI -0.73 to -0.09) compared with a similar dose of ICS alone. There was no significant group difference in the risk of serious adverse events (RR 1.15; 95% CI 0.64 to 2.09), any adverse events (RR 1.02; 95% CI 0.96 to 1.09), study withdrawals (RR 0.95; 95% CI 0.82 to 1.11), or withdrawals due to poor asthma control (RR 0.94; 95% CI 0.63 to 1.41).In comparison 2, the combination of LABA and ICS was associated with a higher risk of patients requiring oral corticosteroids (RR 1.24; 95% CI 1 to 1.53) and study withdrawal (RR 1.31; 95% CI 1.07 to 1.59) than a higher dose of ICS alone. For every 100 patients treated over 43 weeks, nine patients using a higher dose ICS compared to 11 (95% CI 9 to 14) on LABA and ICS suffered one or more exacerbations requiring rescue oral corticosteroids. There was a high level of statistical heterogeneity for FEV1 and morning peak flow. There was no statistically significant group difference in the risk of serious adverse events. Due to insufficient data we could not aggregate results for hospital admission, symptoms and other outcomes.

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the combination of ICS and LABA does not significantly reduce the risk of patients with exacerbations requiring rescue oral corticosteroids over that achieved with a similar dose of ICS alone. However, it significantly improves lung function, reduces symptoms and marginally decreases rescue ss2-agonist use. Initiation of a higher dose of ICS is more effective at reducing the risk of exacerbations requiring rescue systemic corticosteroids, and of withdrawals, than combination therapy. Although children appeared to respond similarly to adults, no firm conclusions can be drawn regarding combination therapy in steroid-naive children, given the small number of children contributing data.

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

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

Allergen-induced airway inflammation and its therapeutic intervention

Allergen inhalation challenge has been useful for examining the mechanisms of allergen-induced airway inflammation and the associated physiological changes and for documenting the efficacy of drugs to treat asthma. Allergen inhalation by a sensitized subject results in acute bronchoconstriction, beginning within 15-30 min and lasting 1-3 hr, which can be followed by the development of a late asthmatic response. Individuals who develop both an early and late response after allergen have more marked increases in airway hyperresponsiveness, and greater increases in allergen-induced airway inflammation, particularly in airway eosinophils and basophils. All of the currently available and effective treatments for asthma modify some aspects of allergen-induced responses. These medications include short-acting and long-acting inhaled β₂-agonists, inhaled corticosteroids, cromones, methylxanthines, leukotriene inhibitors, and anti-IgE monoclonal antibody. In addition, allergen inhalation challenge has become a useful method which can, in a very limited number of patients, provide key information on the therapeutic potential of new drugs being developed to treat asthma.

Regular treatment with formoterol for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta-agonists and increases in asthma mortality. There has been much debate about possible causal links for this association, and whether regular (daily) long-acting beta(2)-agonists are safe.

OBJECTIVES

The aim of this review is to assess the risk of fatal and non-fatal serious adverse events in trials that randomised patients with chronic asthma to regular formoterol versus placebo or regular short-acting beta(2)-agonists.

SEARCH STRATEGY

Trials were identified using the Cochrane Airways Group Specialised Register of trials. Web sites of clinical trial registers were checked for unpublished trial data and Food and Drug Administration (FDA) submissions in relation to formoterol were also checked. The date of the most recent search was July 2008.

SELECTION CRITERIA

Controlled parallel design clinical trials on patients of any age and severity of asthma were included if they randomised patients to treatment with regular formoterol and were of at least 12 weeks duration. Concomitant use of inhaled corticosteroids was allowed, as long as this was not part of the randomised treatment regimen.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review. Outcome data were extracted by one author and checked by the second author. Unpublished data on mortality and serious adverse events were sought.

MAIN RESULTS

The review includes 22 studies (8,032 participants) comparing regular formoterol to placebo and salbutamol. Non-fatal serious adverse event data could be obtained for all participants from published studies comparing formoterol and placebo but only 80% of those comparing formoterol with salbutamol or terbutaline.Three deaths occurred on regular formoterol and none on placebo; this difference was not statistically significant. It was not possible to assess disease specific mortality in view of the small number of deaths. Non-fatal serious adverse events were significantly increased when regular formoterol was compared with placebo (Odds Ratio 1.57 [95% CI: 1.05 to 2.37]). One extra serious adverse event occurred over 16 weeks for every 179 people treated with regular formoterol [95% CI: 75 to 2022]. The increase was larger in children than in adults, but the impact of age was not statistically significant. Data submitted to the FDA indicates that the increase in asthma-related serious adverse events remained significant in patients taking regular formoterol who were also on inhaled corticosteroids.No significant increase in fatal or non-fatal serious adverse events was found when regular formoterol was compared with regular salbutamol or terbutaline.

AUTHORS' CONCLUSIONS

In comparison with placebo, we have found an increased risk of serious adverse events with regular formoterol, and this does not appear to be abolished in patients taking inhaled corticosteroids. The effect on serious adverse events of regular formoterol in children was greater than the effect in adults, but the difference between age-groups was not significant.Data on all-cause serious adverse events should be more fully reported in journal articles, and not combined with all adverse events or limited to those events that are thought by the investigator to be drug-related.

The allergen bronchoprovocation model: an important tool for the investigation of new asthma anti-inflammatory therapies

Allergen bronchoprovocation tests have been used for more than two decades in the investigation of respiratory allergic diseases such as asthma and rhinitis. These bronchial challenges are now well standardized and can offer key information on the therapeutic potential of new agents and on their anti-inflammatory effects on the airways. Both standard and low-dose allergen provocations are safe when performed by experienced investigators and do not lead to persistent worsening of asthma or change in airway function. The evaluation of new therapeutic agents by these methods can also provide important information on the mechanisms of development and persistence of airway diseases.

The effects of inhaled budesonide and formoterol in combination and alone when given directly after allergen challenge

BACKGROUND

The use of combination inhaled budesonide and formoterol as maintenance and reliever therapy significantly improves the risk and the time to exacerbations in asthma.

OBJECTIVES

To explore the mechanisms underlying the effect of the reliever dose on exacerbations by examining the effect of combination therapy on the allergen challenge model when given after allergen exposure.

METHODS

In a randomized, double-blind crossover study, single doses of budesonide/formoterol (400/12 mug), formoterol (12 mug), budesonide (400 mug), or placebo were administered during the acute bronchoconstriction response (early airway response) immediately after allergen inhalation in 15 patients with mild asthma. Allergen-induced late airway response (LAR), sputum inflammatory markers, airway hyperresponsiveness, and exhaled nitric oxide were measured.

RESULTS

All active treatments significantly attenuated the LAR, with budesonide/formoterol significantly better than its monocomponents (maximum FEV(1) fall: placebo, [mean +/- SEM] 21.2% +/- 3.1%; budesonide/formoterol, 4.2% +/- 1.4%; formoterol, 7.5% +/- 1.7%; budesonide, 10.4% +/- 1.6%). Allergen-induced change in methacholine PC(20) was significantly attenuated by budesonide/formoterol, but not by its monocomponents. Sputum cell counts and exhaled nitric oxide increased significantly after all allergen challenges, with no significant attenuation by any of the treatments. Therapy with combination and formoterol alone, but not budesonide, significantly reduced the early airway response.

CONCLUSION

A single dose of budesonide/formoterol was superior to its monocomponents in attenuating the allergen-induced LAR and airway hyperresponsiveness. These effects may represent the contribution of the reliever dose to the budesonide/formoterol maintenance and reliever regimen.

CLINICAL IMPLICATIONS

The protective effect against allergic airway responses with a single reliever dose of budesonide/formoterol is predominantly related to greater functional antagonism of airway smooth muscles.

The effect of a single inhaled dose of a VLA-4 antagonist on allergen-induced airway responses and airway inflammation in patients with asthma

Adhesion molecule very late antigen-4 (VLA-4) is implicated in the recruitment and activation of inflammatory cells in asthma, including eosinophils, T cells and mast cells. VLA-4 antagonists have been proposed as a new anti-inflammatory treatment modality for asthma. Therefore, we investigated whether a single inhaled dose of VLA-4 antagonist GW559090X could protect against allergen-induced changes in airway responses and airway inflammation in patients with asthma. We performed a randomized, double-blind, three-way crossover study with single inhaled doses of 3 mg of GW559090X, 500 microg of fluticasone propionate (FP) or placebo in 15 patients with mild intermittent asthma, controlled with short-acting beta(2)-agonists only. All patients developed a late asthmatic response (LAR) after allergen inhalation during screening. Study medication was administered 30 min prior to allergen challenge. Pre-dose and 24 h post-dose PC20 methacholine and levels of exhaled nitric oxide (eNO) were determined. At the given dose, VLA-4 antagonist GW559090X did not attenuate the early asthmatic response (EAR) when compared with placebo: mean AUC0-2 h(+/-SEM) (%fall h): 27.2+/-3.7 and 21.9+/-3.0 respectively (P=0.33); nor the LAR: mean AUC3-8 h(+/-SEM) (%fall h): 98.8+/-12.9 and 94.8+/-6.8 respectively (P=0.84). However, pretreatment with FP did attenuate both EAR and LAR when compared with placebo: mean AUC0-2 h11.6+/-3.3 (P=0.024) and mean AUC3-8 h 6.3+/-7.6 (P<0.001). None of these treatments had an effect on allergen-induced changes in airway hyper-responsiveness or eNO levels. These findings suggest that VLA-4 may not play a major role in allergen-induced airway responses and inflammation in asthma.

Long-acting beta2-agonists versus placebo in addition to inhaled corticosteroids in children and adults with chronic asthma

BACKGROUND

Long-acting inhaled beta2-adrenergic agonists are recommended as 'add-on' medication to inhaled corticosteroids in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of long-acting beta2-agonists to inhaled corticosteroids on the incidence of asthma exacerbations, pulmonary function and other measures of asthma control.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers, until April 2004.

SELECTION CRITERIA

RCTs were included that compared the addition of inhaled long-acting beta2-agonists to corticosteroids with inhaled corticosteroids alone for asthma therapy in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by two review authors for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of asthma exacerbations requiring systemic corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptom scores, adverse events and withdrawal rates.

MAIN RESULTS

Of 594 identified citations, 49 trials met the inclusion criteria: 27 full-text publications, one unpublished full-text report and 21 abstracts. Twenty-three citations (21 abstracts and two full-text publications) provided data in insufficient detail, 26 trials contributed to this systematic review. All but three trials were of high methodological quality. Most interventions (N = 26) were of four-month duration or less. Eight trials focused on children and 18 on adults, with participants generally symptomatic with moderate airway obstruction despite their current inhaled steroid regimen. If a trial had more than one intervention or control group, additional control to intervention comparisons were considered separately. Formoterol (N = 17) or salmeterol (N = 14) were most frequently added to low-dose inhaled corticosteroids (200 to 400 microg/day of beclomethasone (BDP) or equivalent). The addition of a daily long-acting beta2-agonist (LABA) reduced the risk of exacerbations requiring systemic steroids by 19% (relative risk (RR) 0.81, 95% CI 0.73 to 0.90). The number needed to treat for one extra patient to be free from exacerbation for one year was 18 (95% CI 13 to 33). The addition of LABA significantly improved FEV1 (weighted mean difference (WMD) 170 mL, 95% CI 110 to 240) using a random-effects model, increased the proportion of symptom-free days (WMD 17%, 95% CI 12 to 22, N = 6 trials) and rescue-free days (WMD 19%, 95% CI 12 to 26, N = 2 trials). The group treated with LABA plus inhaled corticosteroid showed a reduction in the use of rescue short-acting beta2-agonists (WMD -0.7 puffs/day, 95% CI -1.2 to -0.2), experienced less withdrawals due to poor asthma control (RR 0.5, 95% CI 0.4 to 0.7) and less withdrawals due to any reason (RR 0.9, 95% CI 0.8 to 0.98), using a random-effects model. There was no group difference in risk of overall adverse effects (RR 0.98, 95% CI 0.92 to 1.05), withdrawals due to adverse health events (RR 1.29, 95% CI 0.96 to 1.75) or specific adverse health events.

AUTHORS' CONCLUSIONS

In patients who are symptomatic on low to high doses of inhaled corticosteroids, the addition of a long-acting beta2-agonist reduces the rate of exacerbations requiring systemic steroids, improves lung function, symptoms and use of rescue short-acting beta2-agonists. The similar number of serious adverse events and withdrawal rates in both groups provides some indirect evidence of the safety of long-acting beta2-agonists as add-on therapy to inhaled corticosteroids.

Combination of inhaled long-acting beta2-agonists and inhaled steroids versus higher dose of inhaled steroids in children and adults with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled beta2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine, in asthmatic patients, the effect of the combination of long-acting beta2 agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the incidence of asthma exacerbations, on pulmonary function and on other measures of asthma control and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomized controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until April 2004.

SELECTION CRITERIA

RCTs were included that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children aged 2 years and older, and in adults with asthma.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by two authors for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of patients experiencing one or more asthma exacerbations requiring oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptoms, use of rescue beta2 agonists, adverse events and withdrawal rates. The meta-analysis was done with RevMan Analyses and the meta-regression, with Stata.

MAIN RESULTS

Of 593 citations identified, 30 (three pediatric; 27 adult) trials were analysed recruiting 9509 participants, including one study providing two control-intervention comparisons. Only one trial included corticosteroid-naive patients. Participants were symptomatic, generally (N=20 trials) presenting with moderate (FEV1 60-79% of predicted) rather than mild airway obstruction. Trials tested the combination of salmeterol (N=22) or formoterol (N=8) with a median of 400 mcg of beclomethasone or equivalent (BDP-eq) compared to a median of 800 to 1000 mcg/day of BDP-eq. Trial duration was 24 weeks or less in all but four trials. There was no significant group difference in the rate of patients with exacerbations requiring systemic corticosteroids [N=15, RR=0.88 (95% CI: 0.77, 1.02)]. The combination of LABA and ICS resulted in greater improvement from baseline in FEV1 [N=7, WMD=0.10 L (95% CI: 0.07, 0.12)], in symptom-free days [N=8 , WMD=11.90% (95% CI:7.37, 16.44), random effects model], and in the daytime use of rescue beta2 agonists than a higher dose of ICS [N=4, WMD= -0.99 puffs/day (95% CI: -1.41, -0.58), random effects model]. There was no significant group difference in the rate of overall adverse events [N=15, RR=0.93 (95% CI: 0.84, 1.03), random effects model], or specific side effects, with the exception of a three-fold increase rate of tremor in the LABA group [N= 10, RR=2.96 (95%CI: 1.60, 5.45)]. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS [N=20, RR=0.69 (95%CI: 0.52, 0.93)].

AUTHORS' CONCLUSIONS

In adult asthmatics, there was no significant difference between the combination of LABA and ICS and a higher dose of ICS for the prevention of exacerbations requiring systemic corticosteroids. Overall, the combination therapy led to greater improvement in lung function, symptoms and use of rescue beta2 agonists, (although most of the results are from trials of up to 24 weeks duration). There were less withdrawals due to poor asthma control in this group than when using a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor, the two options appear safe although adverse effects associated with long-term ICS treatment were seldom monitored.

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.

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled beta2-agonists only in asthmatic patients who are inadequately controlled on inhaled corticosteroids.

OBJECTIVES

To compare the efficacy of initiating anti-inflammatory therapy using the combination of inhaled corticosteroids and long-acting beta2-agonists (ICS+LABA) as compared to inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (Cochrane Airways Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL) until April 2004, bibliographies of identified RCTs and correspondence with manufacturers.

SELECTION CRITERIA

RCTs comparing the combination of inhaled corticosteroids and long-acting beta2-agonists (ICS + LABA) to inhaled corticosteroids (ICS) alone in steroid-naive children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by each reviewer for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of asthma exacerbations requiring systemic corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptoms, use of other measures of asthma control, adverse events, and withdrawal rates.

MAIN RESULTS

Eighteen trials met the inclusion criteria; nine (totaling 1061 adults) contributed sufficient data to be analysed. Baseline forced expiratory volume in one minute (FEV1) was less than 80% predicted value in four trials and equal to or greater than 80% in five trials. The long-acting beta2-agonists (LABA) formoterol (N=2) or salmeterol (N=7) were added to a dose of at least 800 microg/day of beclomethasone dipropionate (BDP) equivalent of inhaled corticosteroids (ICS) in three trials and to at least 400 microg/day in the six remaining trials. Treatment with ICS plus LABA was not associated with a lower risk of exacerbations requiring oral corticosteroids than ICS alone (relative risk (RR) 1.2; 95% confidence interval (CI) 0.8 to 1.9). FEV1 improved significantly with LABA (weighted mean difference (WMD) 210 ml; 95% CI 120 to 300), as did symptom-free days (WMD 10.74%; 95% CI 1.86 to 19.62), but the change in use of rescue fast-acting beta2-agonists was not significantly different between the groups (WMD -0.4 puff/day, 95% CI -0.9 to 0.1). There was no significant group difference in adverse events (RR 1.1; 95% CI 0.8 to 1.5), withdrawals (RR 0.9; 95% CI 0.6 to 1.2), or withdrawals due to poor asthma control (RR 1.3; 95% CI 0.5 to 3.4).

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the initiation of inhaled corticosteroids in combination with long-acting beta2-agonists does not significantly reduce the rate of exacerbations over that achieved with inhaled corticosteroids alone; it does improve lung function and symptom-free days but does not reduce rescue beta2-agonist use as compared to inhaled steroids alone. Both options appear safe. There is insufficient evidence at present to recommend use of combination therapy rather than ICS alone as a first-line treatment.

The use of sputum eosinophils in the evaluation of occupational asthma

PURPOSE OF REVIEW

The diagnosis of occupational asthma needs to be made objectively using as many criteria as possible. These include laboratory exposure tests with occupational agent(s), which are only available in specialized centres. Another approach is to monitor peak expiratory flow or methacholine airway responsiveness during periods at work and away from work. However, these measurements are open to misinterpretation when they are not performed optimally. Airway inflammation is one of the main characteristics of occupational asthma, but is not often assessed during its investigation. The purpose of this work was to review recent studies that have investigated and characterized the changes in sputum cell counts occurring in patients with occupational asthma, in order to evaluate the role of the analysis of sputum cell counts.

RECENT FINDINGS

There is evidence that monitoring sputum eosinophils can help in the management of asthma. In the majority of cases of occupational asthma, the percentage of sputum eosinophils increases after exposure to occupational agents in the laboratory compared with baseline, but an increase in sputum neutrophils has also been observed. The changes in airway inflammation occurring at the workplace have been less investigated, but indicate that there are significant changes in airway inflammation and especially sputum eosinophils when workers are exposed to a sensitizer at their workplace compared with periods away from the workplace.

SUMMARY

Induced sputum has successfully been used to manage patients with mild to moderate asthma. Its use is promising in occupational asthma, and its role in the investigation of occupational asthma needs to be better defined.

Biological markers in diagnosing, monitoring, and treating asthma: a focus on noninvasive measurements

Asthma is a major concern for society, healthcare professionals, and individuals and families directly affected by asthma due to rising morbidity rates and costs associated with the disease. The pathological hallmark of asthma is airway inflammation that is considered to be a major cause of exacerbations and persistent structural alterations of the airways. Assessing airway inflammation is important for investigating the underlying mechanisms of the disease and possibly for following the progression and resolution of the disease. The presence and type of airway inflammation can be difficult to detect clinically, and may result in delays in initiating appropriate therapy. The purpose of this article is to review noninvasive methods for assessing biological markers of airway inflammation and their potential role in the future for diagnosing, monitoring, and treating asthma. The article reviews the noninvasive measurements of induced sputum and exhaled nitric oxide as indicators of airway inflammation.

Bronchodilation by an inhaled VPAC(2) receptor agonist in patients with stable asthma

BACKGROUND

The synthetic vasoactive intestinal peptide (VIP) analogue Ro 25-1553 is a selective VIP-PACAP type 2 (VPAC(2)) receptor agonist that causes a bronchodilatory effect in guinea pigs in vivo. The effect of Ro 25-1553 given by inhalation to patients with asthma was studied and compared with that of a long acting beta(2) adrenoceptor agonist.

METHODS

Twenty four patients with moderate stable asthma participated in a double blind, randomised, placebo controlled, crossover study. The primary variable was bronchodilatory effect (increase in forced expiratory volume in 1 second, FEV(1)) after inhalation of Ro 25-1553 (100 microg or 600 microg) and formoterol (4.5 microg), respectively. Putative side effects were characterised by monitoring sitting blood pressure, serum potassium, electrocardiography and echocardiography.

RESULTS

Inhalation of 600 microg Ro 25-1553 caused a rapid bronchodilatory effect (geometric mean increase in FEV(1) compared with placebo) within 3 minutes of 6% (95% CI 4 to 9), as did inhalation of formoterol (8% (95% CI 5 to 10)). The corresponding maximum bronchodilatory effect during 24 hours was similar for 600 microg Ro 25-1553 (7% (95% CI 4 to 10)) and the reference bronchodilator formoterol (10% (95% CI 7 to 12)). However, for both doses of Ro 25-1553 the bronchodilatory effect was attenuated 5 hours after inhalation whereas formoterol still had a bronchodilatory effect 12 hours after inhalation. Neither Ro 25-1553 nor formoterol produced any clinically relevant side effects. No drug related difference in adverse events was observed.

CONCLUSION

Inhalation of a synthetic selective VPAC(2) receptor agonist constitutes a promising approach for bronchodilation in patients with asthma.

Creatininuria in asthmatic children treated with a combination of glucocorticoid and beta-agonist

We examined whether a combination of glucocorticoids and beta-agonists inhaled by asthmatics had an influence on the metabolism of L-arginine, an amino acid involved in the production of urea, creatinine, and NO that is known to play a significant role in asthma. After lung function tests, we assayed nitrates, urea, and creatinine and determined urinary osmolality in urine samples taken from groups of 129 children (10+/-3 years old) with mild-to-moderate asthma treated with different regimens of drugs. No significant differences in urinary urea levels were noted between the groups. On the other hand, the children treated by the combination of glucocorticoid and beta-agonist (n = 52) had a higher level of urinary creatinine (+40%, P < .001, and a higher creatinine/urea ratio (C/U) expressed as % mass= 5.98 +/- 2.44, P < .001) than did the untreated children (n = 43, C/U = 4.03 +/- 1.24), those treated with glucocorticoid (n = 23, C/U = 4.01 +/- 1.32) or beta-agonist alone (n = 11, C/U = 4.09 +/- 1.01) or control children of the same age (n = 20, C/U = 4.81 +/- .90). Children treated with beta-agonist alone had the lowest mean levels of urinary nitrates (P < .05). The children in group 1 whose C/U ratio was above 6 (n = 24) had a higher FVC (P < .02) and FEV1 (not significant (NS)). However, an overly high C/U may also be indicative of a deleterious influence on the biosynthesis of NO from arginine. Further investigations will be required to determine whether there is a relationship between C/U ratios and lung function parameters, and whether the urinary C/U ratio could be employed as a simple and noninvasive parameter for assessment of treatment in asthmatics.

Effects of cysteinyl leukotrienes and leukotriene receptor antagonists on markers of inflammation

The understanding that asthma pathophysiology includes an inflammatory component has spurred the more aggressive use of anti-inflammatory therapies and created a need for effective tools to measure inflammation. Biomarkers of airway inflammation proposed are obtained by methods that are direct but highly invasive (bronchial biopsy, bronchoalveolar lavage), moderately direct, and less invasive (indirect sputum, exhaled air, breath condensate) or indirect and least invasive (blood, urine). Several studies described in this review have implicated the cysteinyl leukotrienes (CysLTs) as inflammatory mediators in a wide range of diseases, implying that their biological activities reach far beyond acute bronchoconstriction, the activity traditionally ascribed to them. The validity of examining sputum for "biomarkers" has improved the understanding of asthma pathophysiology, optimization of asthma treatment and management, and investigation of the relation between CysLTs and airway inflammation in asthma. Nitric oxide is also a surrogate marker of asthma and reflects airway inflammation. The anti-inflammatory effects of the leukotriene receptor antagonists and the markers of their activity continue to grow.

Actions other than smooth muscle relaxation may play a role in the protective effects of formoterol on the allergen-induced late asthmatic reaction

Long-acting beta(2)-adrenoceptor agonists attenuate the allergen-induced late asthmatic reaction. We evaluated whether other mechanisms in addition to airway smooth muscle relaxation may be implicated in this protective effect. The effects of formoterol (Foradil Aerolizer(TM), 24 microg dry powder) on the late asthmatic reaction were assessed by a randomised crossover factorial study in 24 patients with asthma. Four challenge/treatment combinations were tested: (A) saline/placebo, (B) saline/formoterol, (C) allergen/placebo, (D) allergen/formoterol. Formoterol and placebo were administered double blind after the last inhalation of the allergen or saline. FEV(1) was measured up to 32 h. The bronchodilator effect of formoterol was estimated as (B-A) and the overall protective effect as (D-C). The effect not due to bronchodilation was estimated as [(D-C)-(B-A)]/2. The bronchodilator effect of formoterol was statistically significant up to 5h (all P< or =0.015). Formoterol significantly attenuated the late asthmatic reaction between 3 and 32 h after allergen inhalation (all P< or =0.0012). The difference between this protective effect and the bronchodilator effect was statistically significant at 5 h and between 7 and 28 h after allergen inhalation (all P< or =0.035). Our results suggest that functional antagonism may not be the sole mechanism by which formoterol attenuates the allergen-induced late asthmatic reaction.

Non-invasive assessment of airway inflammation in occupational lung diseases

The clinical investigation of occupational asthma is currently based on the demonstration of functional changes after exposure to occupational agents, but it does not yet include any monitoring of airway inflammation, one of the hallmarks of this disease. Methods permitting a non-invasive assessment of airway inflammation, such as induced sputum and exhaled nitric oxide, are currently under investigation for research purposes in occupational asthma. Their role in clinical practice has not yet been established. The advantages and limitations of these methods for occupational airway diseases, and more particularly occupational asthma, are discussed in this review.

The use of sputum cell counts to evaluate asthma medications

Total and differential cell counts from hypertonic-induced, dithiothreitol-dispersed sputum provide reproducible measurements of airway inflammatory cell counts, which are responsive to treatment with anti-inflammatory drugs. They have helped to understand the kinetics of inflammatory cell changes in asthma after the reduction of corticosteroids and the subsequent re-introduction of treatment. They have identified that the presence of sputum eosinophilia in asthma, chronic cough and chronic airflow limitation is a predictor of steroid-responsiveness and of lack of 'asthma control'. They can be used to study the dose-response effect of inhaled corticosteroids and may be useful to establish the relative potency of different corticosteroid formulations and delivery devices. Sputum cell counts are also useful to study the potential anti-inflammatory effects of drugs like theophylline, long-acting beta-adrenoceptor agonists, leukotriene antagonists and newer drugs in development. They may be helpful to select add-on therapy to corticosteroids in 'difficult-to-control' asthma.

Effects of budesonide and formoterol on eosinophil activation induced by human lung fibroblasts

Budesonide and formoterol are extensively used in current asthma therapy. Budesonide is known as potent antiinflammatory agent and formoterol also appears to have some antiinflammatory properties. We investigated inhibitory effects of these drugs on eosinophil activation in vitro as induced by fibroblast-conditioned medium (FCM). We measured the modulation of expression of clonal designator (CD)11b and L-selectin with flow cytometry after 4 h or 16 h of culture of eosinophils when budesonide or formoterol was applied either directly to the eosinophils while they were stimulated with FCM (direct method) or when each drug was applied to lung fibroblasts from which conditioned medium was then administered to eosinophils (indirect method). In the direct method, budesonide (10(-)(8) M) inhibited the modulation of CD11b (44 [25th to 75th percentiles: 26 to 66]% of control) and L-selectin (30 [-13 to 48]% of control) only after 16 h, and not after 4 h. Formoterol did not directly inhibit the modulation of eosinophil CD11b and L-selectin expression. In the indirect method, both budesonide and formoterol inhibited lung fibroblast activation, resulting in diminished eosinophil activation after 4 h. Budesonide or formoterol at 10(-)(8) M inhibited upregulation of CD11b to 26 [15 to 40]% and 38 [23 to 46]%, respectively, and inhibited L-selectin shedding to 14 [-3 to 50]% and 27 [2 to 62]%, respectively, of control values. These results show that budesonide inhibits eosinophil activation primarily through effects on lung fibroblasts, presumably by inhibiting production of granulocyte-macrophage colony-stimulating factor. After longer incubation periods, budesonide also directly inhibits eosinophil activation. In contrast, formoterol can inhibit eosinophil activation only via inhibitory effects on lung fibroblasts. We did not observe an additional effect of formoterol, beyond the effects induced by budesonide under any circumstance studied. Lung fibroblasts, in addition to eosinophils, may serve as important target cells for antiinflammatory treatment in asthma.

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.

A long-term study of the antiinflammatory effect of low-dose budesonide plus formoterol versus high-dose budesonide in asthma

Adding inhaled long-acting beta(2)-agonists to a low dose of inhaled corticosteroids (ICS), results in better clinical asthma control than increasing the dose of ICS. However, this approach may mask underlying airway inflammation. In a double-blind parallel-group study, we evaluated the effect of adding formoterol to a low dose of budesonide, compared with a higher dose of budesonide, on the composition of induced sputum. After a 4-wk run-in period of treatment with budesonide (800 microg, twice daily), 60 patients with moderate asthma were randomly assigned to a 1-yr treatment with 400 microg of budesonide plus placebo, twice daily (BUD800), or 100 microg of budesonide plus 12 microg of formoterol, twice daily (BUD200+F). All drugs were administered via Turbuhaler. Budesonide (800 microg, twice daily) during run-in significantly reduced median sputum eosinophils from 4.5 to 0.68%. No significant changes in the proportion of eosinophils, EG2(+) cells, other inflammatory cells, or ECP levels in sputum were observed over the ensuing 1-yr treatment with BUD200+F or BUD800. Clinical asthma control was not significantly different between both groups. In conclusion, no significant differences in sputum markers of airway inflammation were observed during a 1-yr treatment with a low dose of inhaled budesonide plus formoterol compared with a higher dose of budesonide.

Relationship between induced sputum cell counts and fluid-phase eosinophil cationic protein and clinical or physiologic profiles in mild asthma

BACKGROUND

Sputum analysis is the only non-invasive method to examine airway inflammatory processes in subjects with asthma. The aim of this study was to investigate the relationship between cell counts and fluid phase levels in induced sputum in subjects with mild asthma, and the severity of asthma as assessed by clinical, physiologic and blood measurements.

METHODS

Forty patients with mild asthma, aged 17 to 49 years were studied (good sputum sample only from 31). On the first day, spirometry and methacholine challenges were performed. After 2 to 4 days, venous blood for absolute eosinophil count and eosinophil cationic protein (ECP) measurement was obtained and sputum was induced by inhalation of hypertonic saline. For the next 15 days subjects recorded their peak expiratory flow (PEF), symptom scores, and beta2-agonist requirements twice daily. Differential counts of leukocytes were done on cytospin preparations of homogenized sputum and the supernatant was examined for eosinophil cationic protein (ECP).

RESULTS

Sputum eosinophil counts and not neutrophil, epithelial cells, macrophages, or lymphocytes, were inversely correlated to FEV1/FVC % (r = -.57, P = .0008) and to PC20-methacholine (r = -.40, P = .024). No statistical relationship was obtained between eosinophil counts and either symptom scores, bronchodilator requirements, or daily PEF variability. Sputum ECP values were correlated to FEV1/FVC% (r = -.41, P = .026) but not to PC20 (r = -.32, P = .08) or clinical scores or PEF variation. A trend to significance was appreciated between peripheral blood and sputum eosinophil counts (r = .34, P = .067) and no relationship was found between sputum and serum ECP values (r = .10, P = .38).

CONCLUSIONS

Although sputum markers give some information about disordered lung function and physiologic changes in the airways, they are not the only factors concerned in the clinical expression of mild asthma.

The effects of regular inhaled formoterol, budesonide, and placebo on mucosal inflammation and clinical indices in mild asthma

The present study was designed to observe the effects of 8 wk of treatment with formoterol (Foradil) 24 microgram, budesonide 400 microgram, and matched placebo inhaled twice a day on inflammatory indices in the bronchial mucosa of 64 patients with mild atopic asthma. Biopsies were obtained at the start and 1 wk before stopping a 9-wk period of treatment, and inflammatory cell numbers were assessed in the submucosa and epithelium by immunohistochemistry. Regular formoterol significantly reduced the number of submucosal mast cells, with a similar trend for eosinophils but not activated T cells. A subgroup analysis conducted in biopsies with >= 10 eosinophils per mm2 revealed a significant reduction in eosinophil numbers when compared with both pretreatment baseline (p < 0.01) and changes after placebo (p < 0.01). Parallel, but less pronounced, effects were observed on mast cell but not on CD25(+) T cell numbers. There was no effect of any of the three treatments on BAL levels of mast cell or eosinophil mediators. We conclude that regular treatment with inhaled formoterol reduces rather than increases inflammatory cells in the mucosa of asthmatic patients. It is possible that these cellular effects of formoterol may contribute to the therapeutic efficacy of this drug when used regularly in the treatment

Comparison of 3 different doses of budesonide and placebo on the early asthmatic response to inhaled allergen

BACKGROUND

A simple laboratory method to evaluate relative potency of inhaled corticosteroids in asthma would be valuable. Single-dose studies with the allergen-induced late asthmatic response have failed to show a useful dose-response relationship. Treatment for several days with inhaled corticosteroids will also inhibit the allergen-induced early asthmatic response.

METHODS

Twelve atopic asthmatic subjects were studied during a season when no medications were required except ipratropium bromide as needed. These subjects had positive allergen and methacholine inhalation tests and FEV1 greater than 70% of predicted value. A double-blind, randomized, cross-over study compared placebo and budesonide 100, 200, and 400 microg administered by means of Turbuhaler twice daily for 7 days with 6-day washout periods. Methacholine PC20 was measured before and after 6 days of treatment, and allergen PC15 was measured after 7 days of treatment.

RESULTS

The allergen PC15 (n = 11) was significantly larger (P = .0001) for all doses of budesonide compared with placebo, but there was no significant difference between the 3 doses of budesonide, and no dose response was demonstrated. The methacholine PC20 was significantly larger after all budesonide treatments compared with placebo (P = .024), but there was no difference between the 3 doses. There was a progressive increase in the allergen PC15 chronologically (sequence effect) that was not explained by improvement in FEV1 or airway responsiveness; sequence effects were not seen for FEV1 or for pretreatment or posttreatment methacholine PC20. Statistical adjustment for sequence effect did not alter allergen PC15 statistics.

CONCLUSION

A 7-day course of budesonide administered by means of Turbuhaler at 200, 400, or 800 microg per day provided marked and significant inhibition of the allergen-induced early asthmatic response compared with placebo. There was, however, no difference between the 3 doses. Therefore this method with these doses is not useful for providing assessment of relative potency.

Potential masking effects of salmeterol on airway inflammation in asthma

We hypothesized that regular use of long-acting beta-agonists could delay recognition of ("mask") increasing airway inflammation. We studied steroid-sparing and "masking" effects of salmeterol versus placebo in 13 asthmatic individuals requiring >= 1,500 microgram inhaled corticosteroid daily. Corticosteroid doses were reduced weekly until criteria were met for an exacerbation or the corticosteroid was fully withdrawn. Subjects were restabilized on their original dose of inhaled corticosteroid for 4 wk before crossover to the alternative treatment. Subjects maintained symptom and peak expiratory flow (PEF) diaries, and underwent weekly spirometric, methacholine challenge, sputum eosinophil, and serum eosinophil cationic protein (ECP) measurements. Mean corticosteroid dose was reduced by 87% during salmeterol treatment, versus 69% with placebo (p = 0.04). Sputum eosinophils increased before exacerbation despite stable symptoms, FEV1, and PEF. In the week before clinical exacerbation, sputum eosinophil counts were higher in the salmeterol-treatment arm (19.9 +/- 29.8% [mean +/- SD], versus placebo 9.3 +/- 17.6%; p = 0.006). Five subjects showed > 10% sputum eosinophilia before exacerbation during salmeterol treatment, as compared with two receiving placebo. In this model, salmeterol controlled symptoms and lung function until inflammation became significantly more advanced. We conclude that the bronchodilating and symptom-relieving effects of salmeterol can mask increasing inflammation and delay awareness of worsening asthma.

Chemotherapy for malignancy induces a remission in asthma symptoms and airway inflammation but not airway hyperresponsiveness

Inflammation with infiltrations of eosinophils and mast cells into the walls of airways is considered to increase airway hyperresponsiveness (AHR), which in turn characterizes asthma. We present a child with AHR in whom the clinical course of asthma was related to eosinophilic bronchitis. Our patient was admitted at age 6 months with bronchiolitis and at age 4 years with asthma. Inhaled corticosteroids were begun at age 7 years. At age 8 he developed a meningeal sarcoma. While on chemotherapy, his asthma symptoms resolved and he no longer required prophylactic asthma treatment. After 14 months off all chemotherapy, he again had mild episodic asthma. While receiving chemotherapy for malignancy, he had an admission with a coagulase negative staphylococcal bacteremia. During sputum induction with 4.5% saline, he developed cough, wheeze, and a 20% reduction in peak expiratory flow (220 to 180 L/min) that reversed after treatment with salbutamol. The sputum cell count was 1.7 x 10(6)/ml with 1.1 x 10(6) being neutrophils. Two weeks later and prior to the induction of the second sputum, a 21% increase in FEV1 was recorded after bronchodilator inhalation (82% to 99% of predicted). The second sputum contained 2.7 x 10(6)/ml cells with 1.6 x 10(6)/ml neutrophils. Neither eosinophils nor mast cells were identified in the sputum. A third sputum obtained 14 months after the cessation of chemotherapy showed a sputum cell count of 16 x 10(6)/ml, with 11.6 x 10(6) neutrophils and 0.4 x 10(6) eosinophils; no mast cells were detected. A reversible 15% reduction in FEV1 was detected on hypertonic saline challenge testing. This boy had persistent airway hyperreactivity and reversible airways obstruction on three occasions during and following chemotherapy. When he developed asthma symptoms, his sputum contained neutrophils and eosinophils; while on chemotherapy his sputum did not contain eosinophils and he was symptom-free and off all asthma therapy. One can speculate that chemotherapy for malignancy can induce a remission in asthma symptoms but not AHR, and remission in symptoms is associated with a lack of eosinophilic or mast cell infiltrates in the sputum.

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.

Formoterol. An update of its pharmacological properties and therapeutic efficacy in the management of asthma

Formoterol, a selective beta 2-adrenoceptor agonist, produces effective dose-proportional bronchodilation, which persists for up to 12 hours, in patients with reversible obstructive respiratory disease. Bronchodilation is significant within minutes of inhalation, maximal within 2 hours, and at therapeutic doses is equivalent to that produced by standard doses of traditional beta 2-agonists. In single-dose studies comparing the two long-acting beta 2-agonists formoterol and salmeterol, significant bronchodilation is achieved more rapidly with formoterol than salmeterol. Duration of bronchodilation is similar with both drugs. The therapeutic efficacy of inhaled formoterol has been equal to or greater than that of salbutamol (albuterol), fenoterol and terbutaline in both short and long term clinical trials. Formoterol reduces symptoms of nocturnal asthma and reduces the need for rescue medication compared with salbutamol. Recent studies have shown that the addition of inhaled formoterol 12 or 24 micrograms twice daily to existing inhaled corticosteroid regimens improves lung function and reduces asthma symptoms compared with placebo. In one well designed study, the frequency of severe exacerbations of asthma over 12 months was decreased by adding formoterol to existing regimens of inhaled corticosteroids. Tolerance to the bronchodilator response of formoterol has not been observed in long term clinical trials. Because of its long duration of action, formoterol offers significant therapeutic advantages over shorter-acting beta 2-agonists in the treatment of nocturnal and exercise-induced asthma. Formoterol is effective in preventing exercise-induced asthma in adults and children and confers significantly more protection than salbutamol when administered 3 and 12 hours before exercise. In general, inhaled formoterol is well tolerated. The most commonly reported adverse effects, tremor and palpitations, are those traditionally associated with the use of beta 2-agonists. Oral formoterol and high doses of inhaled formoterol are associated with more adverse events than are the recommended doses of 6 to 24 micrograms. Formoterol is currently recommended for use as an alternative to increasing inhaled steroid dosage in patients whose symptoms are inadequately controlled despite therapy with low to moderate doses of inhaled steroids and intermittent short-acting beta 2-agonists, and results of recent studies support therapeutic guidelines. Long term clinical studies comparing formoterol and salmeterol have not yet been published. Further studies to evaluate the earlier use of formoterol in patients with mild to moderate asthma are needed to determine the role and long term safety of formoterol in the management of asthma.

Effect of beta 2-agonists on histamine-induced airway microvascular leakage in ozone-exposed guinea pigs

beta 2-adrenergic agonists exhibit antipermeability effects in the airways. However, it is not known whether beta 2-agonists have this beneficial effect in airway mucosa that is already inflamed. We evaluated the effects of two inhaled beta 2-agonists, salbutamol and formoterol, on the histamine-induced bronchoconstriction and plasma extravasation in the airways of guinea pigs with or without ozone exposure. Total pulmonary resistance (RL) was measured before and after histamine inhalation in anesthetized animals that were pretreated with inhaled salbutamol, formoterol, or saline. Plasma extravasation in the airways was measured using Evans blue dye. In the control animals not exposed to ozone, salbutamol and formoterol each significantly reduced both the histamine-induced bronchoconstriction and the plasma extravasation in the trachea and main bronchi. In the ozone-exposed animals, the increase in RL after histamine was greater than that in control animals. Salbutamol and formoterol each significantly reduced histamine-induced bronchoconstriction, even in the ozone-exposed animals. Salbutamol did not affect the histamine-induced plasma extravasation, whereas formoterol reduced the plasma extravasation in the main bronchi, but not in the trachea, of the animals exposed to ozone. These results suggest that the anti-inflammatory properties of formoterol in inflamed airways may contribute to the beneficial effects in the treatment of airway inflammation.

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

STUDY OBJECTIVE

To determine the efficacy of salmeterol alone in a group of patients with moderate asthma with nocturnal worsening of symptoms.

DESIGN

Double-blind, randomized, placebo-controlled crossover study.

SETTING

Tertiary care hospital specializing in respiratory diseases.

PARTICIPANTS

Ten patients with nocturnal asthma.

INTERVENTIONS

Subjects were randomized to salmeterol, 100 micrograms twice daily, or placebo for 6 weeks with a 1-week washout between treatment periods. Symptoms, nocturnal awakenings, and beta 2-agonist use were recorded daily. Spirometry was performed at weeks 1 and 6 of each period at bedtime and at 4 AM, and methacholine challenge was performed at 4 AM followed by bronchoscopy with BAL. BAL fluid analysis included cell count and differential count, eosinophil cationic protein, Charcot-Leyden crystal protein, leukotriene B4, and thromboxane B2.

RESULTS

The percentage of nights with awakenings decreased significantly with salmeterol (69.8 +/- 8.7% vs 30.6 +/- 10.8% for placebo and salmeterol, respectively; p = 0.02). The percentage of 24-h days with supplemental inhaled beta 2-agonist use significantly decreased with salmeterol (85.9 +/- 9.4% vs 70.4 +/- 10.1% for placebo and salmeterol, respectively; p = 0.04). There were no significant differences in bronchial reactivity, 4 AM FEV1, overnight percentage change in FEV1, or indexes of airway inflammation.

CONCLUSIONS

Salmeterol alone improves the number of nocturnal awakenings and supplemental 24-h beta 2-agonist use in nocturnal asthma without significantly altering lung function and airway inflammation.

Effects of salmeterol and terbutaline on IgE-mediated dermal reactions and inflammatory events in skin chambers in atopic patients

The objective of the present study was to investigate the potential of the long-acting beta 2-agonist salmeterol as an inhibitor of various components of IgE-mediated inflammatory in man. For this purpose, we measured gross skin reactivity (diameters of wheal and flare reaction [WFR] and late cutaneous reaction [LCR] as well as inflammatory cells, mediators, and protein in cutaneous suction blister chambers in eight subjects with allergic rhinitis. Blisters were induced, two on each forearm, by gentle suction and heating, and were unroofed 12 h later, after which plastic chambers were placed over the denuded area. The chambers were challenged for 2 h with antihuman IgE (titer 1:10) in the presence and absence of salmeterol or terbutaline. Normal goat IgG served as negative control. Chamber fluids were removed hourly for the first 4 h, and this followed by a 4-h incubation before final collection. Salmeterol (10(-6)M) and terbutaline (10(-5)M) injected intradermally 30 min before, aw well as together with anti-IgE (titer 1:100), inhibited the WFRs by up to 30%. The effect of salmeterol on the ensuing LCR (75% inhibition at 24 h) tended to be more pronounced than the corresponding inhibition by terbutaline. Both salmeterol and terbutaline very effectively inhibited the anti-IgE-induced extravasation of alpha 2-macroglobulin into skin chambers, with a significantly more sustained effect by salmeterol. Interestingly, only terbutaline reduced the histamine release evoked by anti-IgE. With the present experimental design, where both drugs were washed out from the chambers after 2 h, neither drug inhibited recruitment of leukocytes (including eosinophils). Taken together, salmeterol had a more sustained inhibitory effect than terbutaline on indices of IgE-mediated edema formation (late induration and plasma protein extravasation). On the other hand, under the present experimental conditions, salmeterol failed to reduce the histamine release (in contrast to terbutaline), and neither salmeterol nor terbutaline affected the recruitment of leukocytes.

Oral vs inhaled asthma therapy. Pros, cons and combinations

A number of oral and inhaled drugs are available for the long term management of patients with persistent asthma, yet the disease continues to be associated with significant morbidity and mortality. Over the past years, inhaled glucocorticoids have become established as a cornerstone of maintenance therapy because of their demonstrated clinical efficacy, ability to reduce bronchial inflammation and good tolerability. Other inhaled drugs (e.g. sodium cromoglycate, nedocromil, long-acting beta 2 agonists) also play a role in the long term treatment of patients with asthma. However, many patients (especially children and the elderly) find inhalers difficult to use, and poor inhalation technique can affect the amount of drug reaching the lungs and response to therapy. Oral drug administration is simple, but, until recently, oral asthma therapy has primarily consisted of sustained-release theophylline and glucocorticoids. Theophylline has a narrow therapeutic index, necessitating regular monitoring of serum drug concentrations, and long term oral glucocorticoid therapy is associated with potentially serious adverse events including osteoporosis with bone fracture. The recent development of orally administered leukotriene receptor antagonists (e.g. zafirlukast) and 5-lipoxygenase inhibitors (e.g. zileuton) offers novel mechanisms of action and potential solutions to compliance issues associated with regular administration of inhaled asthma therapy. These drugs have demonstrated efficacy as maintenance therapy in patients with asthma and, importantly, lack the adverse effects associated with long term systemic glucocorticoid therapy. Further clinical trials and the increasing use of these new therapies will help to establish the precise role of orally administered leukotriene receptor antagonists and 5-lipoxygenase inhibitors in the long term management of patients with asthma.