Formoterol via Turbuhaler gave better protection than terbutaline against repeated exercise challenge for up to 12 hours in children and adolescents

Exercise-induced bronchoconstriction update-2016

The first practice parameter on exercise-induced bronchoconstriction (EIB) was published in 2010. This updated practice parameter was prepared 5 years later. In the ensuing years, there has been increased understanding of the pathogenesis of EIB and improved diagnosis of this disorder by using objective testing. At the time of this publication, observations included the following: dry powder mannitol for inhalation as a bronchial provocation test is FDA approved however not currently available in the United States; if baseline pulmonary function test results are normal to near normal (before and after bronchodilator) in a person with suspected EIB, then further testing should be performed by using standardized exercise challenge or eucapnic voluntary hyperpnea (EVH); and the efficacy of nonpharmaceutical interventions (omega-3 fatty acids) has been challenged. The workgroup preparing this practice parameter updated contemporary practice guidelines based on a current systematic literature review. The group obtained supplementary literature and consensus expert opinions when the published literature was insufficient. A search of the medical literature on PubMed was conducted, and search terms included pathogenesis, diagnosis, differential diagnosis, and therapy (both pharmaceutical and nonpharmaceutical) of exercise-induced bronchoconstriction or exercise-induced asthma (which is no longer a preferred term); asthma; and exercise and asthma. References assessed as relevant to the topic were evaluated to search for additional relevant references. Published clinical studies were appraised by category of evidence and used to document the strength of the recommendation. The parameter was then evaluated by Joint Task Force reviewers and then by reviewers assigned by the parent organizations, as well as the general membership. Based on this process, the parameter can be characterized as an evidence- and consensus-based document.

Beta₂-agonists for exercise-induced asthma

BACKGROUND

It is well known that physical exercise can trigger asthma symptoms and can induce bronchial obstruction in people without clinical asthma. International guidelines on asthma management recommend the use of beta2-agonists at any stage of the disease. At present, however, no consensus has been reached about the efficacy and safety of beta2-agonists in the pretreatment of exercise-induced asthma and exercise-induced bronchoconstriction. For the purpose of the present review, both of these conditions are referred to by the acronymous EIA, independently from the presence of an underlying chronic clinical disease.

OBJECTIVES

To assess the effects of inhaled short- and long-acting beta2-agonists, compared with placebo, in the pretreatment of children and adults with exercise-induced asthma (or exercise-induced bronchoconstriction).

SEARCH METHODS

Trials were identified by electronic searching of the Cochrane Airways Group Specialised Register of Trials and by handsearching of respiratory journals and meetings. Searches are current as of August 2013.

SELECTION CRITERIA

We included randomised, double-blind, placebo-controlled trials of any study design, published in full text, that assessed the effects of inhaled beta2-agonists on EIA in adults and children. We excluded studies that did not clearly state diagnostic criteria for EIA.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration.

MAIN RESULTS

We included 53 trials consisting of 1139 participants. Forty-eight studies used a cross-over design, and five were performed in accordance with a parallel-group design. Forty-five studies addressed the effect of a single beta2-agonist administration, and eight focused on long-term treatment. We addressed these two different intervention regimens as different comparisons.Among primary outcomes for short-term administration, data on maximum fall in forced expiratory volume in 1 second (FEV1) showed a significant protective effect for both short-acting beta-agonists (SABA) and long-acting beta-agonists (LABA) compared with placebo, with a mean difference of -17.67% (95% confidence interval (CI) -19.51% to -15.84%, P = 0.00001, 799 participants from 72 studies). The subgroup analysis of studies performed in adults compared with those performed in children showed high heterogeneity confined to children, despite the comparable mean bronchoprotective effect.Secondary outcomes on other pulmonary function parameters confirmed a more positive and protective effect of beta2-agonists on EIA compared with placebo. Occurrence of side effects was not significantly different between beta2-agonists and placebo.Overall evaluation of the included long-term studies suggests a beta2-agonist bronchoprotective effect for the first dose of treatment. However, long-term use of both SABA and LABA induced the onset of tolerance and decreased the duration of drug effect, even after a short treatment period.

AUTHORS' CONCLUSIONS

Evidence of low to moderate quality shows that beta2-agonists, both SABA and LABA, when administered in a single dose, are effective and safe in preventing EIA.Long-term regular administration of inhaled beta2-agonists induces tolerance and lacks sufficient safety data. This finding appears to be of particular clinical relevance in view of the potential for prolonged regular use of beta2-agonists as monotherapy in the pretreatment of EIA, despite the warnings of drug agencies (FDA, EMA) regarding LABA.

Use and safety of long-acting β2-agonists for pediatric asthma

Asthma guidelines recommend the use of long-acting β2-agonists (LABAs) as the preferred add-on therapy for adults and children over 5 years of age when asthma is inadequately controlled by inhaled corticosteroids alone. It has been suggested that LABA use may be associated with an increased risk of morbidity and mortality; however, this view is controversial since study findings have been inconsistent. While the safety profile of LABA monotherapy has been questioned, the value of concomitant inhaled corticosteroids to eliminate possible risks remains unproven. There is a paucity of efficacy and safety data for LABA use in children, and existing evidence is not sufficiently convincing to demonstrate a clear position for LABAs in the management of childhood asthma. The main aims of this article are to place LABAs in context in the management of childhood asthma and evaluate the current evidence for safety and efficacy.

Exercise-induced bronchoconstriction in asthmatic children: a comparative systematic review of the available treatment options

The aim of this article is to critically review the efficacy and safety data from randomized controlled trials (RCTs) using inhaled corticosteroids (ICSs), long- or short-acting beta(2)-adrenoceptor agonists (LABAs, SABAs), parasympatholytics and oral leukotriene receptor antagonists in the management of exercise-induced bronchoconstriction (EIB) in children with persistent asthma (EIA). The studies with sufficient information on patient characteristics and outcomes were chosen using a MEDLINE search. Results from the individual searches were combined and repeated. Studies were also found by reviewing the reference lists of the articles not included in this review. Studies focusing solely on individuals with asthma and other allergic co-morbidities (i.e. a degree of bronchial reversibility) were considered in this review. To make the paper evidence-based, the design and the quality of different studies were assessed employing the Sign criteria (evidence level [EL] and grades of recommendation [GR]). No additional statistical analyses were performed. Most of studies included paediatric patients with underlying EIA. We need to distinguish children with recurrent asthma symptoms in whom EIB is also present (patients with EIA) from asthmatic subjects whose symptoms appear only as a result of exercise (patients with EIB). Further controller treatment is indicated in patients with EIA and further reliever treatment in patients with EIB. ICSs are the first-choice controller drugs for EIA in children with persistent asthma (Sign grade of recommendation [GR]:A). In children with EIA without complete control with ICSs, SABAs (GR:A), leukotriene receptor antagonists (LTRAs) [GR:A] or LABAs (GR:A) may be added to gain control. Treatment with relievers such as SABAs (GR:A), parasympatholytics (GR:B) or, eventually, LABAs (GR:A), administered 10-15 minutes before exercise is the most preferable method of preventing EIB symptoms in children; however, not as monotherapy in children with EIA. The disadvantages and controversy relating to inhaled beta(2)-adrenoceptor agonist use lie in the development of tolerance to their effect when they are used on a regular basis, and the possibility of a resulting underuse of ICSs in patients with EIA. Researchers and guidelines recommend that if any patient requires treatment with a beta(2)-adrenoceptor agonist more than twice weekly, a low dose of ICSs should be administered. Inhaled parasympatholytics may be effective as preventive relievers in some children with EIB or EIA, especially among those with increased vagal activity. LTRAs have a well balanced efficacy-safety profile in preventing the occurrence of EIB symptoms in children. Compared with LABAs, LTRAs produce persistent attenuation of EIB and possess an additional effect with rescue SABA therapy in persistent asthmatic patients with EIA. A disadvantage of LTRAs is a non-response phenomenon. There are still insufficient data on the efficacy-safety profiles of ICS/LABA combination drugs in the treatment of EIA in children to recommend this treatment without caution. Safety profiles of inhaled SABAs, anticholinergics and montelukast in approved dosages seem sufficient enough to recommend use of these drugs in the prevention of EIB symptoms in children. Many researchers agree that treatment of EIA in children should always be individualized.

Participation in daily life of children with asthma

Asthma can have a negative effect on psychological and social well-being in childhood. Sports participation, school attendance, and quality of life are important issues for children with asthma and their parents. However, a structural evaluation of these factors is not always incorporated in the routine medical approach of children with asthma. Moreover, goals in asthma treatment, such as minimal symptoms and normal activity levels, are achieved in a minority of children. This review describes determinants that are important for the well-being of children with asthma and their parents. Besides the control of symptoms, factors such as sports participation, socializing in peer groups, school attendance, and quality of life must be considered. These issues are relevant when evaluating the management of children and adolescents with asthma. A multidisciplinary evaluation by a pediatrician, school nurse, gym teacher, and psychologist might contribute to an important decrease in the impact of asthma on daily life.

Effect of different antiasthmatic treatments on exercise-induced bronchoconstriction in children with asthma

BACKGROUND

Exercise-induced bronchoconstriction occurs in a large proportion of children with asthma, limiting everyday activities important for their physical and social development.

OBJECTIVE

The purpose of this randomized, double-blind, placebo-controlled study was to compare the ability of different patterns of antiasthmatic treatment, recommended in childhood asthma, to protect patients from exercise-induced bronchoconstriction.

METHODS

Children 6 to 18 years of age with atopic asthma were randomized to a 4-week, placebo-controlled, double-blind trial. Patients were randomly allocated to receive daily 200 microg budesonide (twice daily, 100 microg per dose) + 9 microg formoterol (twice daily, 4.5 microg per dose; n = 20); 200 microg budesonide + 5 or 10 mg montelukast (once daily at bedtime; n = 20); 5 or 10 mg montelukast (n = 20); 200 microg budesonide (n = 20); or placebo (n = 20). A standardized treadmill exercise challenge was performed before and after treatment.

RESULTS

Exercise-induced bronchoconstriction, reflected by area under the curve for the FEV1 values from exercise over the 20-minute period and by maximum percent fall in FEV1 after exercise, was significantly diminished after 4 weeks in all active treatment groups, and compared with placebo. Exercise-induced bronchoconstriction protection improved more significantly in the budesonide + montelukast and montelukast groups compared with other therapeutic options.

CONCLUSION

These data indicate differences in effects on exercise-induced bronchoconstriction between therapeutic options recommended in childhood asthma. Control of childhood asthma with exercise-induced bronchoconstriction can be obtained by using regular controller treatment.

Beta2-agonists and exercise-induced asthma

Beta2-agonists taken immediately before exercise provide significant protection against exercise- induced asthma (EIA) in most patients. However, when they are taken daily, there are some negative aspects regarding severity, control, and recovery from EIA. First, there is a significant minority (15-20%) of asthmatics whose EIA is not prevented by beta2-agonists, even when inhaled corticosteroids are used concomitantly. Second, with daily use, there is a decline in duration of the protective effect of long-acting beta2-agonists. Third, if breakthrough EIA occurs, recovery of lung function is slower in response to a beta2-agonist, and additional doses are often required to achieve pre-exercise values. If a person who takes a beta2-agonist daily experiences problems with exercise, then the physician should consider changing the treatment regimen to achieve better control of EIA. These problems likely result from desensitization of the beta2-receptor on the mast cell, which enhances mediator release, and on the bronchial smooth muscle, which enhances the bronchoconstrictor response and delays recovery from EIA. These effects are reversed within 72 h after cessation of a beta2-agonists. The important clinical question is: Are we actually compromising the beneficial effects of beta2-agonists on the prevention and recovery from EIA by prescribing them daily? Patients with EIA need to ensure that their doses of inhaled corticosteroid or other anti-inflammatory therapy are optimized so that, if necessary, a beta2-agonist can be used intermittently as prophylactic medication with greater confidence in the outcome.

The use of inhaled formoterol in the treatment of asthma

OBJECTIVE

To discuss the clinical efficacy and safety of formoterol when used to relieve symptoms of asthma and prevent exercise-induced bronchoconstriction (EIB).

DATA SOURCES

A PubMed search was performed for articles published between 1997 and 2005 with the keywords formoterol, asthma, and long-acting beta2-adrenergic agonist, with cross-referencing to identify peer-reviewed journal articles.

STUDY SELECTION

Published articles on the clinical use of formoterol for asthma or EIB were included as well as articles detailing the pharmacologic properties of the drug. To present a thorough review of the literature, published studies based on patient number, study design, or other measures of study quality were not excluded.

RESULTS

Formoterol is the only long-acting beta2-adrenergic agonist that combines a rapid onset of action (within 3 minutes) with a long duration of effect (approximately 12 hours). Clinically, as recommended by asthma treatment guidelines, formoterol in conjunction with inhaled corticosteroids (ICSs) is a preferred treatment for moderate to severe persistent asthma. Significant clinical data support the use of formoterol in combination with ICSs for the treatment of asthma, with studies demonstrating improved pulmonary function and symptom scores and decreased need for maintenance ICSs and short-acting beta2-adrenergic agonists (SABAs) as relief medication. Recent studies also demonstrate that use of formoterol as needed as relief medication is associated with a prolonged time to exacerbation, improved pulmonary function, and decreased asthma symptoms. When used as monotherapy, formoterol provides protection against EIB. Clinical data also demonstrate that formoterol is safe and well tolerated even in high doses, with an adverse event profile similar to that of SABAs.

CONCLUSION

Overall, formoterol is safe and effective as adjunct controller therapy for moderate and severe persistent asthma and as monotherapy for EIB.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

Formoterol induces tolerance to the bronchodilating effect of Salbutamol following methacholine-provocation test in asthmatic children

OBJECTIVES

To study whether Formoterol treatment affect the bronchodilator response to salbutamol after methacholine-provocation test (MPT) in asthmatic children.

STUDY DESIGN

A prospective, double-blind, randomized, placebo-controlled study. Children aged 7-16 years with mild-persistent to moderate asthma treated with inhaled corticosteroids, were enrolled. After 2-weeks of run-in period, subjects were randomized to inhaled Formoterol 9 microg bid (n=19) or placebo (n=19) for 2 weeks. MPT with salbutamol-recovery curve was performed at the beginning and at the end of the trial period. Measurements of peak expiratory flow rate (PEFR), symptoms score, rescue bronchodilator usage and side effects were recorded daily. The primary end-points were the change in FEV1 0-10 min after salbutamol inhalation and the recovery time from 80 to 100% of pretest FEV1. Statistical analyses were performed by ANOVA with repeated measures.

RESULTS

There was a decrease in the bronchodilator response to salbutamol and an improved PEFR in the Formoterol group. There was no difference in all other parameters.

CONCLUSION

Formoterol decreases the bronchodilator response to salbutamol following MPT. Whether this phenomenon has clinical implication during acute asthma needs further studies.

Past, present and future--beta2-adrenoceptor agonists in asthma management

The beta-adrenoceptor agonists (beta-agonists) have been used to relieve bronchoconstriction for at least 5000 years. beta-agonists are based on adrenaline and early forms, such as isoprenaline, Lacked bronchial selectivity and had unpleasant side effects. Modern beta-agonists are more selective for the beta2-adrenoceptors (beta2-receptors) located in bronchial smooth muscle and have less cardiotoxicity. Traditional beta2-adrenoceptor agonists (beta2-agonists), such as salbutamol, terbutaline and fenoterol, were characterised by a rapid onset but relatively short duration of action. While valuable as reliever medication, their short duration gave inadequate night-time relief and limited protection from exercise-induced bronchoconstriction. beta2-agonists with longer durations of action, formoterol and salmeterol, were subsequently discovered or developed. When combined with inhaled corticosteroids they improved lung function, and reduced symptoms and exacerbations more than an increased dose of corticosteroids. However, tolerance to the bronchprotective effects of long-acting beta2-agonists and cross-tolerance to the bronchodilator effects of short-acting beta2-agonists is apparent despite use of inhaled corticosteroids. The role of beta2-receptor polymorphisms in the development of tolerance has yet to be fully determined. Formoterol is unique in having both a long-lasting bronchodilator effect (> 12 h) and a fast onset of action (1-3min from inhalation), making it effective both as maintenance and reliever medication. The recent change in classification from short- and long-acting beta2-agonists to rapid-acting and/or long-acting agents reflects the ongoing evolution of beta2-agonist therapy.

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.

Single-dose agents in the prevention of exercise-induced asthma: a descriptive review

Exercise-induced asthma (EIA) refers to the transient narrowing of the airways that occurs after vigorous exercise in 50-60% of patients with asthma. The need to condition the air inspired during exercise causes water to be lost from the airway surface, and this is thought to cause the release of inflammatory mediators (histamine, leukotrienes, and prostaglandins) from mast cells. EIA is associated with airway inflammation and its severity is markedly reduced following treatment with inhaled corticosteroids. Drugs that inhibit the release of mediators and drugs that inhibit their contractile effects are the most successful in inhibiting EIA. Single doses of short-acting beta(2)-adrenoceptor agonists, given as aerosols immediately before exercise, are very effective in the majority of patients with asthma, providing about 80% protection for up to 2 hours. Long-acting beta(2)-adrenoceptor agonists (LABAs) given in single doses can be effective for up to 12 hours when used intermittently, but tolerance to the protective effect occurs if they are taken daily. Drugs such as cromolyn sodium (sodium cromoglicate) and nedocromil given as aerosols are less effective than beta(2)-adrenoceptor agonists (beta(2)-agonists), providing 50-60% protection for only 1-2 hours, but they have some advantages. They do not induce tolerance, the aerosol dosage can be easily titrated for the individual, and the protective effect is immediate. Because they cause no significant adverse effects, multiple doses can be used in a day. Leukotriene receptor antagonists, such as montelukast and zafirlukast, are also used for the prevention of EIA and provide 50-60% protection for up to 24 hours when given as tablets. Tolerance to the protective effect does not develop with regular use. If breakthrough EIA occurs, a beta(2)-agonist can be used effectively for rescue medication. For those patients with more persistent symptoms, the use of a LABA in combination with an inhaled corticosteroid has raised a number of issues with respect to the choice of prophylactic treatment for EIA. The most important issue is the development of tolerance to the protective effect of a LABA such that extra treatment may be needed in the middle of a treatment period. Recommending extra doses of a beta(2)-agonist to control EIA is not advisable on the basis that multiple doses can enhance the severity of EIA, delay spontaneous recovery from bronchoconstriction, and enhance responses to other contractile stimuli. It is time to take into account the advantages and disadvantages of the different drugs available to prevent EIA and to recognize that there are some myths related to their use in EIA.

Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline

OBJECTIVES

To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children.

METHODS

Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxis) 4.5 microg (F4.5) or terbutaline (Bricanyl) 500 microg (T500) were inhaled cumulatively via a dry powder inhaler (Turbuhaler) over 1 h (three patients) or 2.5 h (17 patients) and compared to a day of no treatment, in a randomised, double-blind (active treatments only), crossover trial. Blood pressure (BP), ECG, plasma potassium, glucose, lactate, and adverse events were monitored up to 10 h to assess tolerability and relative systemic dose potency.

RESULTS

Formoterol and terbutaline had significant beta2-adrenergic effects on most outcomes. Apart from the effect on systolic BP, QRS duration and PR interval, the systemic effects were significantly more pronounced with terbutaline than with formoterol. Thus, mean minimum plasma potassium, was suppressed from 3.56 (95% confidence interval, CI: 3.48-3.65) mmol l(-1) on the day of no treatment to 2.98 (CI: 2.90-3.08) after 10 x F4.5 and 2.70 (CI: 2.61-2.78) mmol l(-1) after 10 x T500, and maximum Q-Tc (heart rate corrected Q-T interval [Bazett's formula]) was prolonged from 429 (CI: 422-435) ms on the day of no treatment, to 455 (CI: 448-462) ms after 10 x F4.5 and 470 (CI: 463-476) ms after 10 x T500. Estimates of relative dose potency indicated that F4.5 microg had the same systemic activity as the clinically less effective dose of 250 microg terbutaline. The duration of systemic effects differed marginally between treatments. Spontaneously reported adverse events (most frequently tremor) were fewer with formoterol (78% of the children) than with terbutaline (95%). A serious adverse event occurred after inhalation of 45 microg formoterol over the 1 h dosing time, that prompted the extension of dosing time to 2.5 h.

CONCLUSIONS

Multiple inhalations over 2.5 h of formoterol (4.5 microg) via Turbuhaler) are at least as safe as and associated with less systemic effects than multiple inhalations of the clinically equipotent dose of terbutaline (500 microg) in children with asthma.

Long-acting beta 2-adrenoceptor agonists and exercise-induced asthma: lessons to guide us in the future

The safety and efficacy of long-acting beta(2)-adrenoceptor agonists (LABAs) taken intermittently for the prevention of exercise-induced asthma (EIA) in children is well established. However, the safety and efficacy of LABAs taken twice daily, either alone or in combination with inhaled corticosteroids, for the prevention of EIA is not as clear because of issues of tolerance (defined as being less responsive to the influence of LABAs). There have been many observations on short-acting beta(2)-adrenoceptor agonists (SABAs) and EIA that should have alerted us to the potential for tolerance and desensitization to occur with LABAs. For example, we expected that the use of LABAs for EIA would overcome the problem of the short duration of protection of SABAs, and to some extent they have. The protective period of a LABA is two to three times longer in duration than that of a SABA. However, when a LABA is taken daily it is apparent that the duration of its protective effect is reduced and there is a risk of EIA occurring well within the 12-hour administration schedules. Furthermore, daily use of LABAs attenuates the bronchodilator effect of SABAs, an effect that is greater the more severe the bronchoconstriction. This 'tolerance' increases both the time and the amount of therapy that is needed to recover from bronchoconstriction, and thus, could potentially impact on the success of rescue therapy should severe EIA occur. The daily use of LABAs also increases the sensitivity of the bronchial smooth muscle to contractile agents. This increase in sensitivity is almost equivalent to the extent to which inhaled corticosteroids reduce sensitivity to the same contractile agents. The increased sensitivity to contractile agents may occur either by a reduction in the inhibitory effect of beta(2)-adrenoceptor agonists on release of mediators from mast cells or by a direct effect on the bronchial smooth muscle. These unwanted effects of LABAs are not necessarily reduced by concomitant treatment with inhaled corticosteroids. As the number of children being treated with LABAs increases, it is predicted that problems with breakthrough EIA will also increase. We need to know the percentage of children taking a LABA daily who are requiring either extra doses of a beta(2)-adrenoceptor agonist to prevent (or reverse) EIA or other provocative stimuli. If this percentage is significant then we may need to reconsider the position of LABAs in the treatment of children with asthma who regularly perform strenuous physical activity.

Budesonide and formoterol in a single inhaler controls asthma in adolescents

Despite the availability of effective treatments and national guidelines, morbidity from asthma remains high among adolescents. Adolescents need to be considered as a distinct group of individuals with different requirements to those of children and adults. In particular, their non-adherence to prescribed treatment regimens is of concern and is a significant factor contributing to the high rate of morbidity in adolescents. Studies in children aged 4 to 17 years suggest that the combination of an inhaled corticosteroid (ICS) and a long-acting beta2-agonist effectively controls asthma symptoms in patients who remain symptomatic on ICS alone. In order to improve adherence to therapy, the use of combined therapy with an ICS and a long-acting beta2-agonist in a single inhaler should be considered and the dosing frequency should be adjusted according to the severity of asthma symptoms. This should empower patients with a greater degree of self-management and may be important in helping adolescents feel responsible for the management of their asthma. Results from a recent subanalysis demonstrate that the combination of budesonide and formoterol administered twice daily via a single inhaler (Symbicort Turbuhaler) rapidly gains and maintains control of asthma in adolescents whose asthma is not controlled on ICS alone. It is anticipated that this will lead to improved adherence to therapy in this difficult-to-treat population.

Efficacy and safety of formoterol Turbuhaler when added to inhaled corticosteroid treatment in children with asthma

This double-blind, placebo-controlled, randomized, parallel-group, multicenter study was conducted in 302 children aged 6-11 years with asthma not optimally treated with inhaled corticosteroids alone. Patients continued with their existing dose of inhaled corticosteroids and in addition received placebo, formoterol 4.5 microg or formoterol 9 microg b.i.d., for 12 weeks (all delivered via Turbuhaler). Terbutaline was available as reliever medication. The primary efficacy variable was change from baseline in morning peak expiratory flow (PEF); secondary efficacy variables included forced expiratory volume in 1 sec (FEV(1)), serial PEF measured over 12 hr, evening PEF, asthma symptom score, and quality of life. Compared with placebo, formoterol 4.5 microg and 9 microg improved morning PEF by 8 l/min (P = 0.035) and 11 l/min (P = 0.0045), respectively. Evening PEF and FEV(1) were also significantly increased compared with placebo, with no statistically significant difference between formoterol doses. Lung-function improvements compared with placebo were greater in the middle of the day. Twelve-hour average serial PEF after 3 months increased by 24 l/min (95% CI, 9, 39 l/min) in the formoterol 9-microg group, and by 14 l/min (95% CI, 0, 29 l/min) in the formoterol 4.5-microg group. The incidence of severe exacerbations in both formoterol groups was numerically lower than in the placebo group, indicating that formoterol may have the potential to improve exacerbation control in children. Both formoterol doses were well-tolerated, and tolerance to the drug's bronchodilator effect was not observed. Formoterol provided sustained improvements in lung function and was well-tolerated in children with asthma suboptimally treated with inhaled corticosteroids alone.

Budesonide/formoterol for the treatment of asthma

Budesonide/formoterol (Symbicort), AstraZeneca plc) is a novel treatment for asthma, combining an inhaled corticosteroid - budesonide, and a long-acting beta(2)-agonist - formoterol, in a single inhaler, the Turbuhaler. Randomised, clinical studies in patients with asthma have demonstrated that budesonide/formoterol is more effective than the inhaled corticosteroids, budesonide and fluticasone alone, and at least as effective as both monocomponents in separate inhalers. Results from clinical studies suggest a synergistic effect when both drugs are administered via one inhaler, although the mechanisms for this are not fully understood. Budesonide/formoterol has a rapid onset of effect, apparent within 1 min of treatment, which is largely because of the properties of formoterol. Once- and twice-daily dosing with budesonide/formoterol are effective treatment options for patients with mild or moderate asthma. Studies have also shown that the beneficial safety profiles and dose relationships of both budesonide and formoterol allow dose adjustments of budesonide/formoterol in response to variations in the patient's asthma. Findings from the budesonide/formoterol adjustable maintenance dosing programme, comparing fixed and adjustable, symptom-guided dosing regimens, demonstrate that patients achieve equally good asthma control with adjustable dosing (from one inhalation twice-daily to more than four inhalations twice-daily), but at a significantly lower overall drug load. Adverse events, mainly expected inhaled corticosteroid and long-acting beta(2)agonist class effects, have been few in number and mild in nature. In addition, there is growing evidence that budesonide/formoterol is also effective in patients with chronic obstructive pulmonary disease. The future for treatment with budesonide/formoterol may include as-needed administration in addition to maintenance therapy.

Activity-induced asthma

Exercise is the most common trigger of persistent childhood asthma. The history for EIA can be complicated by the lack of perception of significant airway obstruction during exercise. One must carefully identify those children with EIA from the group of children who report low level of activity because of lack of interest or because they are out of shape. Baseline spirometry of children with persistent asthma is frequently normal. Spirometry is important to identify those children with EIA who underrecognize their disease, but normal results should not be used as evidence of absence of disease. Formal exercise testing should be considered when the diagnosis is unclear or if there seems to be a lack of bronchoprotection with inhaled albuterol. The goal of treatment of EIA should be the attainment of a normal activity level for children and adolescents. Identification of the limits imposed by EIA and establishment of goals of therapy with the child and family should be the initial action. Inactivity or reduced exertion, in the presence of this diagnosis. should not be accepted. Therapy for EIA starts with control of the underlying persistent asthma. Inhaled corticosteroids are the most effective initial treatment of both EIA and persistent asthma in children and adolescents. Exercise-induced asthma is a common aspect of a prevalent disease that warrants proper diagnosis and treatment. With appropriate therapy, children with EIA should be able to participate in sports and maintain normal activity. They should strive to compete in the same playing field as their peers and have the same goals as those children and athletes who do not have exercise-induced asthma.

Formoterol delivered by Turbuhaler: in pediatric asthma

Formoterol is an inhaled long-acting beta(2)-adrenoceptor agonist, with a rapid onset of action and a bronchodilator effect that lasts for at least 12 hours. As add-on therapy to anti-inflammatory medication (e.g. corticosteroids), formoterol 4.5 and 9 microg twice daily delivered by Turbuhaler for 3 months significantly improved lung function (change from baseline in forced expiratory volume in 1 second and/or peak expiratory flow) compared with placebo in randomised, double-blind trials in pediatric patients (aged 6-17 years). In addition, formoterol 9 microg twice daily for 12 weeks reduced the use of rescue medication compared with salmeterol 50 microg twice daily in a nonblind trial in pediatric patients (aged 7-16 years). Single-dose formoterol 4.5 or 9 microg delivered by Turbuhaler provided significant prophylaxis against exercise-induced bronchoconstriction compared with placebo, and demonstrated a longer duration of effect than terbutaline, in a randomized, double-blind, crossover trial in pediatric patients (aged 8-17 years). Formoterol delivered by Turbuhaler was well tolerated in pediatric patients, with respiratory infection being the most commonly reported adverse event.

Budesonide/formoterol in a single inhaler versus inhaled corticosteroids alone in the treatment of asthma

The aim of this study was to evaluate the efficacy (expressed as effect on lung function) and tolerability of Symbicort (budesonide/formoterol in a single inhaler) in children with asthma. This was a double-blind, double-dummy, randomized, parallel-group, multicenter trial. After a 2-4-week run-in period, 286 asthmatic children (177 boys, 109 girls; mean age, 11 years; mean forced expiratory volume in 1 sec (FEV(1)), 75% predicted normal), previously treated with inhaled corticosteroids (average dose 548 microg/day), were randomized to 12 weeks' treatment with either budesonide/formoterol 80/4.5 microg, two inhalations twice daily (n = 148), or an equivalent dose of budesonide 100 microg, two inhalations twice daily (n = 138). Efficacy variables included morning and evening peak expiratory flow (PEF), spirometery, asthma symptoms, and use of rescue medication (beta(2)-agonists). Serial FEV(1) assessments were carried out on a subgroup of children (budesonide/formoterol, n = 41; budesonide, n = 40) at randomization and at week 12. Relative to baseline, morning PEF (primary variable) increased to a significantly greater extent with budesonide/formoterol than with budesonide alone (7.22% predicted normal vs 3.45% predicted normal; P < 0.001). Evening PEF also increased significantly with budesonide/formoterol (6.13% predicted normal vs. 2.73% predicted normal; P < 0.001), as did mean FEV(1) and serial FEV(1) measured over 12 hr (both P < 0.05). Similar improvements in asthma symptoms and rescue medication use were observed in both groups. The two treatment groups were similar in terms of their adverse-event profile and rates of discontinuation. Budesonide/formoterol in a single inhaler provided rapid improvements in PEF and FEV(1) compared to inhaled budesonide alone. These improvements were sustained throughout the study period. Budesonide/formoterol was well-tolerated in children with moderate persistent asthma.

Exercise-induced bronchoconstriction

Exercise-induced asthma, or more appropriately, exercise-induced bronchoconstriction (EIB), occurs in 80 to 90% of individuals with asthma and in approximately 11% of the general population without asthma. EIB is characterised by post-exercise airways obstruction resulting in reductions in forced expiratory volume in 1 second (FEV(1)) of greater than 10% compared with pre-exercise values. The mechanism of EIB remains elusive, although both cooling and drying of airways play prominent roles. Cold, dry inhaled air during exercise or voluntary hyperventilation is the most potent stimulus for EIB. Inflammatory mediators play central roles in causing the post-exercise airways obstruction. Diagnosis of EIB requires the use of an exercise test. The exercise can be a field or laboratory based test, but should be of relatively high intensity (80 to 90% of maximal heart rate) and duration (at least 5 to 8 minutes). Pre- and post-exercise pulmonary function should be compared, and post exercise pulmonary function determined over 20 to 30 minutes for characterisation of EIB. A pre- to post-exercise drop in FEV(1) of greater than 10% is abnormal. Approaches to treatment of EIB include both nonpharmacological and pharmacological strategies. A light exercise warm up prior to moderate to heavy exercise reduces the severity of EIB. More recently, studies have supported a role for dietary salt as a modifier of the severity of EIB, suggesting that salt restrictive diets should reduce symptoms of EIB. Short acting, inhaled beta(2)-agonists constitute the most used prophylactic treatment for EIB. However, antileukotriene agents are emerging as effective, well tolerated, long-term treatments for EIB.

Formoterol Turbuhaler 4.5 microg (delivered dose) has a rapid onset and 12-h duration of bronchodilation

Clinical trials show that formoterol (Oxis) Turbuhaler 4.5 microg delivered dose (6 microg metered dose) has a rapid onset of bronchodilation similar to that of salbutamol and a 12-h duration of action. Maximum increase in FEV(1) and duration of bronchodilation are dose-dependent, the 4.5 microg dose being the lowest dose tested giving both effects. Clinical studies investigating onset of bronchodilation show a significant increase in specific airway conductance occurring within 1 min after inhalation of formoterol Turbuhaler 4.5 microg. When measured from 3-20 min after inhalation, formoterol Turbuhaler 4.5 microg showed similar increases in FEV(1) to salbutamol administered via pMDI. No difference in onset of bronchodilation was observed between the formoterol Turbuhaler 4.5 and 9 microg doses.Single-dose studies and studies of 1-12 weeks' duration show that formoterol Turbuhaler 4.5 microg produces a significant and clinically important mean bronchodilating effect for > or =12 h after inhalation. In the cited studies no significant differences in duration of bronchodilation were observed between the formoterol Turbuhaler 4.5 and 9 microg doses.

CONCLUSION

clinical data show that formoterol Turbuhaler 4.5 microg is an effective dose in patients with asthma, with a rapid onset of bronchodilation and a duration of at least 12 h.

Formoterol delivered via a dry powder inhaler (Aerolizer): results from long-term clinical trials in children

Over 500 children with asthma, aged 5-12 years, have been treated with formoterol fumarate (Foradil) delivered via the Aerolizer dry powder inhaler in clinical trials, with treatment periods of up to 15 months. In pivotal double-blind trials, two dose levels, 12 and 24 microg taken twice daily, provided significant benefit in terms of lung function measurements and symptom control (a lower dose of 6 microg twice daily appeared insufficient with this formulation). The higher, 24 microg dose appeared to provide an additional margin of benefit in a subgroup of children with more unstable/severe disease when the results from long-term follow-up (12-15 months) were analysed. Formoterol was shown to have a good safety profile when taken as regular maintenance treatment and when used as rescue medication by patients already receiving formoterol as regular maintenance treatment. In this flexible regimen, with formoterol used for rescue and maintenance, the overall daily intake of formoterol was low, with 96.1% of all treatment days (n = 2452) covered by a total daily dose (regular + rescue) of 48 microg (four doses) or less. There was no increase in the average daily intake of rescue formoterol over time. The clinical efficacy associated with this regimen was maintained over time and, in the case of morning peak expiratory flow rate, steadily improved over time. The Foradil Aerolizer inhalation system is simple to use and has a low resistance to inspiratory airflow that maximises the patient's control over dosing, while minimising the risk of under- and overdosing. These features may be especially valuable in a young patient population.

Is there a need for another inhalative beta(2)-agonist besides formoterol in patients with asthma?

Formoterol can substitute the rapid- and short-acting beta(2)-agonists as well as the slow- and long-acting salmeterol. Therefore formoterol in a fixed combination with an inhalant steroid reduces the aerosol devices necessary for asthma control to only one, to be used for regular "controller" and, as needed, "rescue therapy". The side effect profile of formoterol is comparable to the short-acting beta(2)-agonists which makes the combination with a topically active glucocorticoid applicable in patients of any asthma severity as long as they are able to perform an inspiratory vital capacity maneuver

Formoterol used as needed--clinical effectiveness

A number of studies have already demonstrated the clinical effectiveness of formoterol when used as maintenance therapy in patients requiring both a beta2-agonist with a long duration of action and a regular inhaled corticosteroid. However, formoterol has a unique mechanism of action that gives it both fast- and long-acting properties. Hence the question arises as to whether formoterol can also be used as first-line reliever medication in addition to maintenance therapy. Compared with terbutaline, formoterol used as needed in steroid-treated mild to moderate asthma has superior efficacy, not only significantly improving peak flow, but also the exacerbation rate. In moderate to severe asthma, formoterol used as needed has demonstrated efficacy comparable with salbutamol and terbutaline in improving symptoms and lung function. Single doses of formoterol have also been shown to result in protection against exercise-induced bronchoconstriction for periods up to 12 h. Furthermore, bronchoprotection was maintained following repeated dosing, although further research is needed to confirm the duration of protection achieved with frequent and regular use. Initial research also suggests that formoterol is as effective and well tolerated as terbutaline in the treatment of acute asthma attacks. The evidence presented supports the use of formoterol on an as-needed basis for effective asthma control.

Formoterol--where does it fit in the current guidelines?

Drugs available to treat asthma have improved considerably over the past three decades and understanding of the disease process is continually improving. However, the incidence of asthma is increasing and the cause(s) of this increase are not yet identified. Asthma is often underdiagnosed and undertreated. Poor compliance with medication is also an important consideration in how effective management strategies can be. The aim of current asthma treatment, according to the Global Initiative for Asthma (GINA), is to control the disease. However, two surveys, one in Europe and the other in the U.S.A. indicate that the objectives of treatment guidelines are not being met. Patients were shown to experience high rates of exacerbations and require many doses of reliever medication. There was also a large difference between patient and physician perceptions of treatment--this needs to be countered by improved education for both the general public and healthcare professionals. Formoterol, which is the only beta2-agonist to possess both fast- and long-acting properties, may help to improve patient compliance by allowing a single inhaler to be used for both maintenance and as-needed therapy. However, although formoterol is already widely used as maintenance therapy current treatment guidelines do not include the use of formoterol as first-line reliever medication. Evidence is increasing to support as-needed use and a large, randomized effect veness study in 18,000 patients across the world is ongoing to assess the safety and efficacy of formoterol as needed in a real-life setting. The results from the Real-Life Effectiveness of Oxis Turbuhaler (RELIEF) study should help to establish the position of formoterol as an effective first line reliever medication and ultimately lead to the inclusion of formoterol as needed in treatment guidelines.

Protection against cold air and exercise-induced bronchoconstriction while on regular treatment with Oxis

This study aimed to compare the duration of protection against exercise-induced bronchoconstriction (EIB) after inhalation of formoterol (Oxis) Turbuhaler with that of terbutaline Turbuhaler and placebo Turbuhaler in asthmatic patients treated regularly with formoterol Turbuhaler 9 microg b.i.d. and inhaled steroids. The study. performed at three centres (Göteborg and Lund, Sweden, and Trondheim, Norway), consisted of an open-label part with formoterol Turbuhaler 9 microg b.i.d. and a randomized, double-blind, cross-over part with a single dose (on top of the regular treatment) of either formoterol Turbuhaler 9 microg, terbutaline Turbuhaler 0.5 mg or placebo Turbuhaler. The patients attended the clinic six times: twice for screening visits, three times for randomized treatment and once for a follow-up visit. Patients received regular b.i.d. treatment with formoterol 9 microg for a mean period of 16 days. Formoterol gave a post-exercise fall of 12, 10, 15 and 17% in forced expiratory volume in 1 sec (FEV1) 15 min, 4, 8 and 12 h after inhalation. The differences compared with placebo (falls of 26, 22, 23 and 22%) and terbutaline (falls of 17, 18, 22 and 22%) were all statistically significant (P<0.05 for all comparisons). Patients on regular treatment with formoterol Turbuhaler 9 microg b.i.d. have a significant protection against EIB up to 12 h after inhalation of formoterol 9 microg. The protection was also significantly better than that of terbutaline Turbuhaler 0.5 mg.