Exercise-induced bronchoconstriction in children: montelukast attenuates the immediate-phase and late-phase responses

Can a single dose response predict the effect of montelukast on exercise-induced bronchoconstriction?

RATIONALE

Exercise-induced bronchoconstriction (EIB) can be prevented by a single dose of montelukast (MLK). The effect is variable, similar to the variable responsiveness observed after daily treatment with MLK. We hypothesized that the effect of a single MLK-dose (5 or 10 mg) on EIB could predict the clinical effectiveness of longer term once daily treatment.

METHODS

This was a prospective, open-label study. Twenty-four asthmatic adolescents (12-17 years) suboptimally controlled by low-dose inhaled corticosteroids, with ≥10% post-exercise fall in FEV1 , were included. They performed an exercise test at baseline, 20 hr after a single MLK-dose and 40-44 hr after the last dose of 4 weeks once daily treatment. The correlations between the effect of a single dose and 4 weeks treatment on area under the curve (AUC) and maximum % fall in FEV1 were calculated.

RESULTS

AUC0-20 min decreased significantly after a single MLK-dose (P = 0.001, CI: 64.9-218.2), but not after 4 weeks of treatment (P = 0.080, CI: -12.2 to 200.4). There was a moderate correlation between the effect of a single MLK-dose and 4 weeks treatment on AUC0-20 min , r = 0.49 (P = 0.011), and maximum % fall in FEV1 , r = 0.40 (P = 0.035).

CONCLUSION

The protection provided by a single MLK-dose against EIB only modestly predicts the effect of regular treatment against EIB in adolescent asthmatics on low-dose inhaled corticosteroids. If used on a daily base, MLK offered clinically significant protection against EIB in two thirds of adolescents suboptimally controlled by low-dose ICS.

Do children with stable asthma benefit from addition of montelukast to inhaled corticosteroids: randomized, placebo controlled trial

BACKGROUND

To determine the effects of montelukast added to maintenance inhaled steroids (ICS) therapy during the school year in children with stable asthma on the ICS use, frequency of exacerbations, lung function, asthma symptoms, fractional exhaled nitric oxide (FeNO) level and exercise-induced bronchoconstriction (EIB).

METHODS

Seventy six asthmatic children aged 6-14 years, allergic to house dust mites were randomized to a double-blinded trial comparing montelukast therapy to a matching placebo. We studied following end-points: the reduction in the ICS dose, the frequency of exacerbations, lung function, asthma control test score, and the change from baseline in FEV1 during a standardized exercise treadmill challenge. ICS dose was adjusted in a stepwise fashion to determine the lowest dose necessary to control asthma symptoms.

RESULTS

We showed that children with baseline value of FeNO above 31 ppb and well controlled asthma symptoms on low doses of ICS, benefit the most from additive therapy with montelukast; their cumulative ICS dose is lower than in children treated with ICS only. Also, the addition of montelukast to regular treatment in asthmatic children resulted in a significant reduction in the frequency of exacerbations and EIB protection.

CONCLUSION

It is reasonable to add montelukast to ICS therapy in asthmatic children during the school year, to lower cumulative ICS dose in children with well controlled asthma symptoms, as well as to reduce number of exacerbations, and to achieve better control of EIB.

TRIAL REGISTRATION

NCT01266772.

Clinical effectiveness and safety of montelukast in asthma. What are the conclusions from clinical trials and meta-analyses?

Asthma is a common childhood atopic disease associated with chronicity and impaired quality of life. As there is no cure for this disease, treatment relies on avoidance of triggers such as food and aeroallergens, the use of inhaled bronchodilators/corticosteroids and antiallergic or immunomodulating therapies. Inhaled corticosteroids (ICSs) and bronchodilators have been the mainstay. However, in Asia, myths and fallacies regarding Western medicine and corticosteroids are prevalent and lead to nonadherence to treatment. Also, use of traditional and proprietary herbal medicines is popular. In the past decades, a novel class of nonsteroidal immunomodulating montelukasts has become available. This article reviews the evidence for the effectiveness and clinical efficacy of these medications. A number of randomized and controlled trials have been performed over the years. The majority of studies confirm the usefulness of montelukast as monotherapy and add-on therapy to ICS in mild to moderate childhood asthma across all age groups. ICSs are generally superior to montelukasts for asthma management. However, montelukast has a place in the treatment of young children with viral-triggered wheezing diseases, exercise-induced asthma, and in children whose parents are steroid-phobic and find ICS unacceptable.

Impact of montelukast on asthma associated with rhinitis, and other triggers and co-morbidities

INTRODUCTION

Rhinitis and other specific triggers or co-morbidities (tobacco exposure, excess weight, aspirin sensitivity or heredity factors) are frequently associated with uncontrolled asthma. Asthma associated with these exacerbating factors appears to be related to an increase in leukotriene-mediated inflammation.

METHODS

We reviewed the role of montelukast, a leukotriene receptor antagonist, in the treatment of asthma associated with these factors by using the PubMed database to search the English and French biomedical literature for articles describing randomized-controlled trials, large observational studies and reviews (published up to May 2012, inclusive).

RESULTS

Montelukast, either alone or in combination with other drugs, is an effective treatment against rhinitis-associated asthma. Montelukast also offers therapeutic benefits against exercise-induced asthma or in cases of asthma linked to tobacco exposure, excess weight or aspirin hypersensitivity. Thus, for some patients, montelukast may constitute an alternative to the gold-standard treatment of inhaled corticosteroids. Polymorphisms in several genes encoding proteins of the leukotriene signaling pathway may contribute to the variability in response to montelukast.

CONCLUSIONS

In conclusion, we have shown that montelukast treatment could be of particular benefit to subgroups of patients with asthma associated with rhinitis, exercise, tobacco exposure, being overweight or aspirin hypersensitivity.

Epithelial regulation of eicosanoid production in asthma

Alterations in the airway epithelium have been associated with the development of asthma in elite athletes and in subjects that are susceptible to exercise-induced bronchoconstriction (EIB). The syndrome of EIB refers to acute airflow obstruction that is triggered by a period of physical exertion. Asthmatics who are susceptible to EIB have increased levels of cysteinyl leukotrienes (CysLTs, i.e., LTs C₄, D₄, and E₄) in induced sputum and exhaled breath condensate, and greater shedding of epithelial cells into the airway lumen. Exercise challenge in individuals susceptible to this disorder initiates a sustained increase in CysLTs in the airways, and secreted mucin release and smooth muscle constriction, which may be mediated in part through activation of sensory nerves. We have identified a secreted phospholipase A₂ (sPLA₂) with increased levels in the airways of patients with EIB called sPLA₂ group X(sPLA₂-X).We have found that sPLA₂-X is strongly expressed in the airway epithelium in asthma. Further,we discovered that transglutaminase 2 (TGM2) is expressed at increased levels in asthma and serves asa regulator of sPLA₂-X. Finally, we demonstrated that sPLA₂-X acts on target cells such as eosinophils to initiate cellular eicosanoid synthesis. Collectively, these studies identify a novel mechanism linking the airway epithelium to the production of inflammatory eicosanoids by leukocytes.

Role of cells and mediators in exercise-induced bronchoconstriction

A susceptible group of subjects with asthma develops airflow obstruction in response to the transfer of water out of the airways during exercise. The transfer of water or the challenge with a hypertonic solution serves as a strong stimulus to the airway epithelium. Susceptible subjects have epithelial shedding into the airway lumen, and airway inflammation that leads to the overproduction of leukotrienes and other eicosanoids following exercise challenge. The sensory nerves of the airways may serve as a critical link that mediates the effect of eicosanoids, leading to bronchoconstriction and mucus production in response to exercise challenge.

Ratio of leukotriene e(4) to exhaled nitric oxide and the therapeutic response in children with exercise-induced bronchoconstriction

Purpose

This study assessed the association between the ratio of leukotriene E₄ (LTE₄) to fractional exhaled nitric oxide (FE_NO) in the response of children with exercise-induced bronchoconstriction (EIB) enrolled in a therapeutic trial with montelukast or inhaled corticosteroid (fluticasone propionate [FP]).

Methods

Children aged 6 to 18 years with EIB were randomized in a 4-week, placebo-controlled, double-blinded trial with montelukast or FP. Before and after treatment, treadmill exercise challenges were performed. The LTE₄ levels in the induced sputum and urine and the FE_NO levels were measured in subjects before and 30 minutes after the exercise challenges. The same tests were conducted after treatment.

Results

A total of 24 patients completed the study: 12 in the montelukast group and 12 in FP group. Both study groups displayed a similar postexercise maximum decrease in forced expiratory volume in one second (FEV1) before treatment as well as after treatment. However, there were significant differences in the magnitude of change between the two (Δ; -18.38±14.53% vs. -4.67±8.12% for the montelukast and FP groups, respectively; P=0.021). The Δ logarithmic sputum baseline and postexercise LTE₄/FE_NO ratio were significantly lower in the montelukast group than in the FP group (baseline; -0.09±0.21 vs. -0.024±0.03, P=0.045; postexercise, -0.61±0.33 vs. -0.11±0.28, P=0.023).

Conclusions

These data indicate that the efficacy of montelukast for preventing a maximum decrease in FEV1 after exercise is significantly higher than that of FP, and the high LTE₄/FE_NO ratio is associated with a greater response to montelukast than to FP for EIB therapy. These results suggest that LTE₄ may play an important role in EIB.

Role of leukotriene receptor antagonists in the management of pediatric asthma: an update

At present, the main indications for leukotriene receptor antagonists (LTRA) in pediatric asthma are as add-on therapy to inhaled corticosteroids (ICS) and as initial controller therapy in children with mild asthma, especially those who cannot or will not use ICS. LTRA are also useful for patients who have concomitant rhinitis, and patients with viral-induced wheeze and exercise-induced asthma. It should be noted that the benefits of LTRA therapy have been demonstrated in children as young as 6 months of age and recent clinical trials have further proven the benefits of LTRA in acute asthma exacerbations. However, considering the important pro-inflammatory effects that leukotrienes (LT) have in experimental models of asthma, it may seem surprising that LTRA treatment outcomes are not better and that in some clinical trials only a minority of patients could be classified as full responders. This could be explained by potential additional LT receptors that are not affected by LTRA. Such receptors could represent new therapeutic targets in asthma. Furthermore, progress in differentiating between asthma phenotypes that result from different pathogenic mechanisms, some of which may involve LT to a lesser degree, should lead to an improved, personalized use of LTRA for treating asthma.

Time-effect of montelukast on protection against exercise-induced bronchoconstriction

INTRODUCTION

Montelukast has been proven to assure a protective effect against exercise-induced bronchoconstriction.

AIM

To verify exactly when montelukast begins protection in asthmatic children by evaluating different time intervals between dosing and challenge.

METHODS

In a double blind, placebo-controlled, three day doses, crossover study, patients were randomized to receive in sequence treatment with either a placebo or montelukast and assigned to one of seven groups that were tested 1, 2, 3, 4, 5, 6 and 8 h after drug administration, respectively. For each group, the exercise challenge was always performed at the same hour on the first and third days of treatment.

RESULTS

Sixty-nine asthmatic children took part in the study. On day 3, the mean FEV(1) % fall from baseline was 25.54 (95% CI = 21.63/29.46) and 14.89 (95% CI = 11.85/17.92) for the placebo and active drug (p < 0.05), respectively. On day 1, the mean fall of FEV(1) was 28.20 (95% CI = 24.46/31.94) and 19.01 (95% CI = 15.71/22.31) for the placebo and montelukast (p < 0.05), respectively. Clinical protection was achieved in 21 (30%) and 33 (48%) subjects by montelukast on the first and third days, respectively.

CONCLUSIONS

Montelukast assured protection against exercise-induced bronchoconstriction from the first through the eighth hour from the first day of treatment. However, individual susceptibility to protection was evident since some individuals were not protected at any time. We conclude that in clinical use individual responses to the drug should be carefully evaluated in the follow-up management.

Pharmacotherapy of patients with mild persistent asthma: strategies and unresolved issues

In studies comparing regular versus on-demand treatment for patients with mild persistent asthma, on-demand treatment seems to have a similar efficacy on clinical and functional outcomes, but it does not suppress chronic airway inflammation or airway hyper-responsiveness (AHR) associated with asthma. Data on the efficacy of a continuous treatment with inhaled corticosteroids (ICS) in preventing the progression of asthma are conflicting. There is the possibility that patients without a regular treatment with ICS may develop a more severe asthma associated with airway structural changes (remodeling) and a progressive loss of lung function. However, the possible clinical and functional consequences of persistent, not controlled, airway inflammation in patients with asthma have to be established. Assessment of asthma control should include inflammatory outcomes, such as fraction of exhaled nitric oxide and sputum eosinophil counts. Until the relationships between symptoms, lung function tests, AHR, airway inflammation, exacerbations, and airway remodeling are clarified, regular treatment seems to be generally more appropriate than on-demand treatment to warrant a greater control of asthma. Select subgroups of patients with mild asthma who are well controlled by regular treatment might adopt the on-demand treatment plan as an intermediate step toward the suspension of controller medication. The increasing evidence for heterogeneity of asthma, the growing emphasis on asthma subphenotypes, including molecular phenotypes identified by omics technologies, and their possible implications for different asthma severity and progression and therapeutic response, are changing the paradigm of treating patients with asthma only based on classification of their disease severity to a pharmacological strategy more focused on the individual asthmatic patient. Pharmacological treatment of asthma is going toward a personalized approach.

Exercise increases exhaled breath condensate cysteinyl leukotriene concentration in asthmatic patients

BACKGROUND

Although the importance of cysteinyl leukotrienes (Cys-LTs) in exercise-induced bronchoconstriction (EIB) is supported by various sources of evidence, how the concentration of these mediators change during the development of EIB has not been investigated.

OBJECTIVES

Our goal was to determine the effect of exercise on the concentration of airway Cys-LT in asthmatic patients by measuring Cys-LT in exhaled breath condensate (EBC).

METHODS

Seventeen atopic asthmatic patients with a previous history of EIB and six healthy volunteers were studied. Before and two times within 10 minutes after exercise challenge, FEV₁ was measured and EBC was collected for Cys-LT measurement. Exhaled nitric oxide level, a marker of airway inflammation, was also determined at baseline.

RESULTS

Baseline Cys-LT level was higher in the asthmatic group versus healthy subjects (168 pg/mL /112-223/ vs. 77 pg/mL /36-119/, p = .03). EBC Cys-LT concentration increased in all asthmatic patients post-exercise (n = 17, p = .03), with the increase significantly greater in patients developing exercise-induced bronchospasm (n = 7, p = .03), whereas no change was observed in healthy controls (p = .59). The exercise-induced fall in FEV(1) in asthmatics was related to the increase in EBC Cys-LT concentration (r = -0.40, p = .03).

CONCLUSIONS

Our study shows that Cys-LT concentration of EBC is elevated minutes after physical exercise in asthmatic patients and strongly supports the concept that the release of this mediator is involved in the development of EIB.

Asthma control in adolescents: role of leukotriene inhibitors

Asthma is a chronic inflammatory disease of the airways and is a big burden worldwide. It affects both children and adults, but it is insufficiently studied in adolescents, although this age group has important peculiarities and is challenging to treat, due to, but not exclusively because of, lack of adherence to treatment instructions. Evidence-based guidelines for the treatment of asthma targeting specifically adolescents are lacking, due to the fact that most studies are conducted either on children or in adults. Exercise-induced asthma occurs commonly in adolescents, leading to impaired physical activity. This review describes current treatment options for asthma in adolescents, focusing on leukotriene receptor antagonists, both as a monotherapy and as an add-on therapy for optimal asthma control.

Montelukast in the treatment of asthma and beyond

Asthma is a chronic inflammatory disease affecting over 300 million people worldwide. The common association with allergic rhinitis and the presence of proinflammatory cells and mediators in the circulation of patients qualify asthma as a systemic disease. This characteristic and the fact that the gold-standard therapy for persistent asthma, inhaled corticosteroids, cannot suppress all components of airway inflammation and fail to adequately penetrate into the small airways, warrant the quest for effective systemic anti-asthma therapies. This review describes the most important controlled studies of montelukast, a once-daily leukotriene receptor antagonist, in asthma and allergic rhinitis in both adults and children. Montelukast is a systemically active drug with a targeted, dual mechanism of action, acting both as a bronchodilator and anti-inflammatory. In patients of all ages, montelukast has shown a favorable safety profile and was well-tolerated. Both as monotherapy or in combination with inhaled corticosteroids, montelukast produced clinically relevant improvements in asthma-related parameters, including symptoms, lung function parameters, quality of life and the number of asthma exacerbations. Furthermore, bronchoprotective effects have been reported both against specific and nonspecific bronchoactive stimuli. Similarly, in patients with allergic rhinitis, montelukast produced substantial improvements in symptoms and quality of life. Long-term studies aimed to determine its effects on airway remodeling are still lacking.

Montelukast in the treatment of asthma as a systemic disease

Asthma affects 300 million people worldwide. The common association of asthma with allergic rhinitis and the presence of proinflammatory mediators in the circulation of patients provide strong evidence for the need to treat asthma as a systemic disease. The leukotriene receptor antagonist montelukast is a disease-specific oral medication that has dual effects on airway smooth muscle cells and inflammatory processes. This review describes recent randomized, controlled studies of montelukast in asthma and allergic rhinitis in adults and children as young as 3 months old. Montelukast treatment consistently produced significant reductions in asthma exacerbations. While many patients may benefit from montelukast as monotheray, combination treatment for chronic asthma with inhaled corticosteroids is advocated as being rational. Significant improvements in symptoms and quality of life were observed in allergic rhinitis patients. Montelukast is well tolerated in patients of all ages. Long-term studies are underway to determine its effects on airway remodeling.

Role of Leukotrienes and Leukotriene Modifiers in Asthma

Leukotrienes (LTs), including cysteinyl LTs (CysLTs) and LTB₄, are potent lipid mediators that are pivotal in the pathophysiology of asthma phenotypes. At least two receptor subtypes for CysLTs - CysLT1 and CysLT₂ - have been identified. Most of the pathophysiological effects of CysLTs in asthma, including increased airway smooth muscle activity, microvascular permeability and airway mucus secretion, are mediated by the activation of the CysLT1 receptor. LTB₄ may have a role in the development of airway hyperresponsiveness, severe asthma and asthma exacerbations. Although generally less effective than inhaled glucocorticoids, CysLT₁ receptor antagonists can be given orally as monotherapy in patients with persistent mild asthma. In patients with more severe asthma, CysLT₁ receptor antagonists can be combined with inhaled glucocorticoids. This therapeutic strategy improves asthma control and enables the dose of inhaled glucocorticoids to be reduced, while maintaining similar efficacy. The identification of subgroups of patients with asthma who respond to CysLT₁ receptor antagonists is relevant for asthma management, as the response to these drugs is variable. The potential anti-remodeling effect of CysLT₁ receptor antagonists might be important for preventing or reversing airway structural changes in patients with asthma. This review discusses the role of LTs in asthma and the therapeutic implications of the pharmacological modulation of the LT pathway for asthma.

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.

Exercise-induced asthma: critical analysis of the protective role of montelukast

Exercise-induced asthma/exercise-induced bronchospasm (EIA/EIB) is a prevalent and clinically important disease affecting young children through older adulthood. These terms are often used interchangeably and the differences are not clearly defined in the literature. The pathogenesis of EIA/EIB may be different in those with persistent asthma compared to those with exercise-induced symptoms only. The natural history of EIA is unclear and may be different for elite athletes. Leukotriene biology has helped the understanding of EIB. The type and intensity of exercise are important factors for EIB. Exercise participation is necessary for proper development and control of EIA is recommended. Symptoms of EIB should be confirmed by proper testing. Biologic markers may also be helpful in diagnosis. Not all exercise symptoms are from EIB. Many medication and nonpharmacologic treatments are available. Asthma education is an important component of managing EIA. Many medications have been tested and the comparisons are complicated. Montelukast is a US Food and Drug Administration-approved asthma and EIB controller and has a number of potential advantages to other asthma medications including short onset of action, ease of use, and lack of tolerance. Not all patients improve with montelukast and rescue medication should be available.

Role of leukotrienes in exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) refers to acute airflow obstruction that is triggered by a period of physical exertion. EIB occurs mainly in individuals with other features of asthma but is especially prominent in a subset of asthmatics with pronounced indirect airway hyperresponsiveness. Leukotrienes (LTs) play a critical role in the pathophysiology of EIB. Asthmatics who are susceptible to EIB have increased levels of cysteinyl LTs (cysLTs [ie, LTs C4, D4, and E4]) in induced sputum and exhaled breath condensate. Exercise challenge in individuals susceptible to this disorder initiates the sustained increase in cysLTs in the airways and an increase in the ratio of cysLTs to prostaglandin E(2). The effects of cysLTs leading to secreted mucin release and smooth muscle constriction may be mediated in part through activation of sensory nerves. Therapies that block cysLT production or the cysLT(1) receptor effectively reduce the severity of EIB.

Asthma in childhood

Management decisions for pediatric asthma (in patients younger than 12 years of age) based on extrapolation from available evidence in adolescents and adults (age 12 years and older) is common but rarely appropriate. This article addresses the disparity in response between the two age groups, presents the available pediatric evidence, and highlights the important areas in which further research is required. Evidence-based recommendations for acute and interval management of pediatric asthma are provided.

Exercise-induced bronchoconstriction: The effects of montelukast, a leukotriene receptor antagonist

Exercise-induced bronchoconstriction (EIB) is very common in both patients with asthma and those who are otherwise thought to be normal. The intensity of exercise as well as the type of exercise is important in producing symptoms. This may make some types of exercise such as swimming more suitable and extended running more difficult for patients with this condition. A better understanding of EIB will allow the physician to direct the patient towards a type of exercise and medications that can result in a more active lifestyle without the same concern for resulting symptoms. This is especially important for schoolchildren who are usually enrolled in physical education classes and elite athletes who may desire to participate in competitive sports. Fortunately several medications (short- and long-acting beta(2)-agonists, cromolyn, nedocromil, inhaled corticosteroids, and more recently leukotriene modifiers) have been shown to be effective in preventing or attenuating the effects of exercise in many patients. In addition, inhaled beta(2)-agonists have been shown to quickly reverse the airway obstruction that develops in patients and continue to be the reliever medications of choice. Inhaled corticosteroids are increasingly being recommended as regular therapy now that the role of inflammation and airway injury has been identified in EIB. With the discovery that there is a release of mediators such as histamine and leukotrienes from cells in the airway following exercise with resulting airway obstruction in susceptible individuals, interest has turned to attenuating their effects with mediator antagonists especially those that block the effects of leukotrienes. Studies with an oral leukotriene antagonist, montelukast, have shown beneficial effects in adults and children aged as young as 6 years with EIB. These effects can be demonstrated as soon as two hours and as long as 24 hours after administration without a demonstrated loss of a protective effect after months of treatment. The studies leading up to and resulting in an approval of montelukast for EIB for patients aged 15 years and older are reviewed in this paper.

Use of prescription drugs in athletes

Although athletes are young and generally healthy, they use a variety of non-doping classified medicines to treat injuries, cure illnesses and obtain a competitive edge. Athletes and sports medicine physicians try to optimize the treatment of symptoms related to extreme training during an elite athlete's active career. According to several studies, the use of antiasthmatic medication is more frequent among elite athletes than in the general population. The type of training and the kind of sport influence the prevalence of asthma. Asthma is most common among those competing in endurance events, such as cycling, swimming, cross-country skiing and long-distance running. Recent studies show that athletes use also NSAIDs and oral antibacterials more commonly than age-matched controls, especially athletes competing in speed and power sports. Inappropriately high doses and concomitant use of several different NSAIDs has been observed. All medicines have adverse effects that may have deleterious effects on elite athletes' performance. Thus, any unnecessary medication use should be minimized in elite athletes. Inhaled beta(2)-agonists may cause tachycardia and muscle tremor, which are especially harmful in events requiring accuracy and a steady hand. In experimental animal models of acute injury, especially selective cyclo-oxygenase-2 inhibitors have been shown to be detrimental to tissue-level repair. They have been shown to impair mechanical strength return following acute injury to bone, ligament and tendon. This may have clinical implications for future injury susceptibility. However, it should be noted that the current animal studies have limited translation to the clinical setting. Adverse effects related to the CNS and gastrointestinal adverse reactions are commonly reported in connection with NSAID use also in elite athletes. In addition to the potential for adverse effects, recent studies have shown that NSAID use may negatively regulate muscle growth by inhibiting protein synthesis. Physicians and pharmacists taking care of athletes' medication need to be aware of the medicines that an athlete is taking and how those medicines interact with performance, exercise, environment and other medicines. Sport associations should repeatedly monitor not only the use of banned substances, but also the trends of use of legal medicines in athletes. Not only physicians and pharmacists, but also athletes and coaches should be better educated with respect to potential benefits and risks, and how each agent may affect an athlete's performance. The attitudes and beliefs leading to ample use of legal medicines in athletes is an interesting area of future research.

Inhaled corticosteroids or montelukast as the preferred primary long-term treatment for pediatric asthma?

According to current guidelines, inhaled corticosteroids (ICS) are the preferred primary long-term treatment for asthmatic children of all age groups, but leukotriene receptor antagonists can be considered to be an alternative treatment for mild persistent asthma. In this article, all randomized double-blind efficacy studies comparing the long-term (>4-week) treatment using a leukotriene receptor antagonist with an inhaled corticosteroid in asthmatic children were critically reviewed. In school-aged children, five reports with an adequate study design were available. All of these studies compared montelukast with inhaled fluticasone. The meta-analysis of the two main outcome measures, forced expiratory volume in 1 s (weighted mean difference, 4.6% predicted, 95% confidence interval: 3.5-5.5) and asthma control days (respectively, 5.6%, 4.3-6.9) demonstrated the superiority of fluticasone over montelukast. Many other clinical and pulmonary outcomes also consistently showed that low-dose inhaled fluticasone was more effective than montelukast in the long-term management of mild to moderate persistent asthma. A more favorable response to fluticasone over montelukast was associated with more severe disease or markers of allergic inflammation. About a quarter of patients benefited more from montelukast than fluticasone. In children under school age, no comparative studies were available. However, long-term montelukast treatment was found to be effective in placebo-controlled studies in asthmatic children aged >2 years. These findings support the present international recommendations for ICS as the preferred first-line controller therapy for mild to moderate persistent childhood asthma. If montelukast is selected as a monotherapy and asthma is not adequately controlled within 4-6 weeks, the treatment should be discontinued and the preferred medication initiated.

Pretreatment with albuterol versus montelukast for exercise-induced bronchospasm in children

STUDY OBJECTIVES

To compare pretreatment with albuterol versus montelukast added to the current asthma regimen for protection against exercise-induced bronchospasm in children with mild-to-moderate asthma, and to determine whether cysteinyl leukotriene (Cys-LT) concentrations measured in the exhaled breath condensate correlated with response to montelukast.

DESIGN

Prospective, randomized, double-blind, double-dummy, crossover study.

SETTING

Asthma clinic at a university-affiliated medical center.

PATIENTS

Eleven children aged 7-17 years with physician-diagnosed mild-to-moderate asthma for at least 6 months and with self-reported exercise-induced bronchospasm (defined as > or = 15% decrease in forced expiratory volume in 1 sec [FEV(1)] at screening and baseline visit).

INTERVENTION

Patients were randomly assigned to receive 3-7 days of oral montelukast 5-10 mg/day or 2 puffs of an albuterol metered-dose inhaler just before an exercise challenge and then were crossed over to the alternate therapy for the last visit.

MEASUREMENTS AND MAIN RESULTS

Serial spirometry was performed before and at 0, 5, 10, 15, 30, 45, and 60 minutes after the exercise challenge at each visit. Measurement of exhaled breath condensate was performed at the screening visit and study visits 1 and 2. The primary outcome was the maximum change in FEV(1) after exercise. Secondary outcomes were the area under the curve for FEV(1) (expressed as percentage decrease from baseline) during the first 60 minutes (AUC(0-60)) after exercise and the proportion of patients in whom exercise-induced bronchospasm was prevented (defined as < 15% decrease in FEV(1) after exercise challenge). The mean +/- SD maximum decrease in FEV(1) was 27.5 +/- 7.9% at baseline. Patients receiving montelukast had an 18.3 +/- 13.7% decrease in FEV(1) compared with 0.7 +/- 1.6% in patients receiving albuterol (p=0.002, paired t test). Exercise-induced bronchospasm was prevented in 100% of the patients receiving albuterol compared with 55% receiving montelukast (p<0.05, McNemar's test). The AUC(0-60) was significantly smaller with albuterol compared with montelukast (p<0.001, Wilcoxon signed rank test). No correlations were found between Cys-LT concentration and the severity of exercise-induced bronchospasm or the response to montelukast.

CONCLUSION

Pretreatment with albuterol is more effective than montelukast for prevention of exercise-induced bronchospasm in children with asthma.

Treatment of exercise-induced asthma, respiratory and allergic disorders in sports and the relationship to doping: Part II of the report from the Joint Task Force of European Respiratory Society (ERS) and European Academy of Allergy and Clinical Immunology (EAACI) in cooperation with GA(2)LEN

AIM

The aims of part II is to review the current recommended treatment of exercise-induced asthma (EIA), respiratory and allergic disorders in sports, to review the evidence on possible improvement of performance in sports by asthma drugs and to make recommendations for their treatment.

METHODS

The literature cited with respect to the treatment of exercise induced asthma in athletes (and in asthma patients) is mainly based upon the systematic review given by Larsson et al. (Larsson K, Carlsen KH, Bonini S. Anti-asthmatic drugs: treatment of athletes and exercise-induced bronchoconstriction. In: Carlsen KH, Delgado L, Del Giacco S, editors. Diagnosis, prevention and treatment of exercise-related asthma, respiratory and allergic disorders in sports. Sheffield, UK: European Respiratory Journals Ltd, 2005:73-88) during the work of the Task Force. To assess the evidence of the literature regarding use of beta(2)-agonists related to athletic performance, the Task Force searched Medline for relevant papers up to November 2006 using the present search words: asthma, bronchial responsiveness, exercise-induced bronchoconstriction, athletes, sports, performance and beta(2)-agonists. Evidence level and grades of recommendation were assessed according to Sign criteria.

RESULTS

Treatment recommendations for EIA and bronchial hyper-responsiveness in athletes are set forth with special reference to controller and reliever medications. Evidence for lack of improvement of exercise performance by inhaled beta(2)-agonists in healthy athletes serves as a basis for permitting their use. There is a lack of evidence of treatment effects of asthma drugs on EIA and bronchial hyper-responsiveness in athletes whereas extensive documentation exists in treatment of EIA in patients with asthma. The documentation on lack of improvement on performance by common asthma drugs as inhaled beta(2)-agonists with relationship to sports in healthy individuals is of high evidence, level (1+).

CONCLUSIONS

Exercise induced asthma should be treated in athletes along same principles as in ordinary asthma patients with relevance to controller and reliever treatment after careful diagnosis. There is very high level of evidence for the lack of improvement in athletic performance by inhaled beta2-agonists.

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.

Update on montelukast and its role in the treatment of asthma, allergic rhinitis and exercise-induced bronchoconstriction

Montelukast sodium (Singulair, Merck and Co., Inc., Whitehouse Station, NJ) is a selective and orally-active leukotriene receptor antagonist with demonstrated effectiveness for treating allergic asthma and allergic rhinitis in adults and children as young as 12 months of age for allergic asthma and 6 months of age for allergic rhinitis. It was recently approved in the US for prevention of exercise-induced bronchoconstriction in patients who are > or = 15 years of age. This paper updates a prior review of the data on the clinical efficacy of montelukast published in this journal.

Mast cells and eicosanoid mediators: a system of reciprocal paracrine and autocrine regulation

When activated by specific antigen, complement, or other transmembrane stimuli, mast cells (MCs) generate three eicosanoids: prostaglandin (PG)D(2), leukotriene (LT)B(4), and LTC(4), the parent molecule of the cysteinyl leukotrienes (cysLTs). These diverse lipid mediators, which are generated from a single cell membrane-associated precursor, arachidonic acid, can initiate, amplify, or dampen inflammatory responses and influence the magnitude, duration, and nature of subsequent immune responses. PGD(2) and cysLTs, which were originally recognized for their bronchoconstricting and vasoactive properties, also serve diverse and pivotal functions in effector cell trafficking, antigen presentation, leukocyte activation, matrix deposition, and fibrosis. LTB(4) is a powerful chemoattractant for neutrophils and certain lymphocyte subsets. Thus, MCs can contribute to each of these processes through eicosanoid generation. Additionally, MCs express G-protein-coupled receptors specific for cysLTs, LTB(4), and another eicosanoid, PGE(2). Each of these receptors can regulate MC functions in vivo by autocrine and paracrine mechanisms. This review focuses on the biologic functions for MC-associated eicosanoids, the regulation of their production, and the mechanisms by which eicosanoids may regulate MC function in host defense and disease.

Montelukast in pediatric asthma management

Leukotriene modifiers (receptor antagonist and biosynthesis inhibitor) represent the first mediator specific therapeutic option for asthma. Montelukast, a leukotriene receptor antagonist is the only such agent approved for use in pediatric patients. Montelukast modifies action of leukotrienes, which are the most potent bronchoconstrictors, by blocking Cysteinyl leukotriene receptors. Systemic drug like mountelukast can reach lower airways and improves the peripheral functions which play a crucial role in the evolution of asthma. Review of existing literature showed that montelukast compared to placebo has proven clinical efficacy in better control of day time asthma symptoms, percentage of symptom free days, need for rescue drugs and improvement in FEV 1. Studies also demonstrated improvement in airway inflammation as indicated by reduction in fractional exhaled nitric oxide, a marker of inflammation. Studies comparing low dose inhaled corticosteroids (ICS) with montelukast are limited in children and conclude that it is not superior to ICS. For moderate to severe persistent asthma, montelukast has been compared with long acting beta agonists (LABA) as an add-on therapy to ICS, montelukast was less efficacious and less cost-effective. It has beneficial effects in exercise induced asthma and aspirin-sensitive asthma. Montelukast has onset of action within one hour. Patient satisfaction and compliance was better with montelukast than inhaled anti-inflammatory agents due to oral, once a day administration. The recommended doses of montelukast in asthma are- children 1-5 years: 4 mg chewable tablet, children 6-14 years: 5mg chewable tablet,

ADULTS

10mg tablet; administered once daily. The drug is well tolerated. Based on the presently available data montelukast may be an alternative treatment for mild persistent asthma as monotherapy where ICS cannot be administered. It is also an alternative to LABA as an add-on therapy to ICS for moderate to severe persistent asthma. The other indications for use of montelukast include: allergic rhinitis, exercise induced bronchoconstriction and aspirin-induced asthma.

Montelukast administered in the morning or evening to prevent exercise-induced bronchoconstriction in children

Montelukast is recommended to be taken in the evening. The effectiveness of this drug to prevent exercise-induced bronchoconstriction (EIB) in children was already evaluated. However, there is no information to determine if this effectiveness could vary depending on dosage time. Children (n = 24) with a documented history of EIB performed an exercise challenge test before starting montelukast treatment. Twelve children were randomly allocated to receive the drug in the morning for 2 weeks, and another 12 to receive it in the evening. After this treatment period and after a week of washout, the children were crossed over. An exercise test was repeated after the first and second periods of treatment. Values obtained after morning or evening dosage were compared with pretreatment values for the whole group of children. There was a significant effect of montelukast for protecting against EIB, measured both as percent of maximum fall in forced expired volume in 1 sec (FEV1) (18.9 +/- 9.7, morning, 18.7 +/- 11.3, evening, vs. 27.5 +/- 9.8, pretreatment; P < 0.05) or as area under the curve (156.4 +/- 102.0, morning, 145.4 +/- 130.6, evening, vs. 294.3 +/- 156.5, pretreatment; P < 0.005). There were no statistical differences between taking the drug in the morning or evening. In conclusion, montelukast, taken for 2 weeks, is equally effective in exercise-induced bronchoconstriction when dosing either in the morning or in the evening.

Nasal obstruction, the airway, and the athlete

Rhinitis is a common condition that affects a significant proportion of the general population, as well as a high proportion of athletes. Nasal congestion is a predominate symptom of the late-phase reaction in allergic rhinitis and can have far-reaching effects that extend through the airway and beyond the nose. Rhinitis is often found in conjunction with asthma and is a risk factor for asthma. Nasal obstruction, which does not permit conditioning of inspired air by the nasal turbinates, may contribute to asthma symptoms and the development of asthma. These adverse conditions may be especially troublesome for the high-performance athlete who has increased nasal airflow turbulence and who competes under extreme conditions that may worsen rhinitis and asthma. Under the theory of the unified airway, an immune response induced in the nose may extend into the lungs via cytokines and other inflammatory mediators. Nasal congestion can significantly contribute to sleep dysfunction, leading to daytime fatigue and decreased performance. Treatment of allergic rhinitis can improve sleep and foster productivity. Control of rhinitis and nasal congestion, which is obtained by various therapies, may reverse lower airway tendency to bronchoconstriction.

Advances in the management of pediatric asthma: a review of recent FDA drug approvals and label updates

Children have the highest prevalence of asthma of any age group. In the United States during 2001, there were 12.6 million physician and hospital outpatient visits for asthma treatment, of which almost 5 million involved children 18 years and younger. Therapeutic advances in pediatric asthma could improve patient outcomes and potentially reduce the burden on health care systems. Efforts to obtain efficacy and safety data in pediatric populations and develop pediatric formulations of asthma treatments have been encouraged by the FDA and clinicians. This article reviews the newest additions to asthma therapies approved for use in children, including an inhaled corticosteroid, some long-acting beta2-agonists, some leukotriene-receptor blockers, and a single-isomer, short-acting beta2-agonist.

Effects of montelukast on airway narrowing from eucapnic voluntary hyperventilation and cold air exercise

BACKGROUND

Exercise induced bronchoconstriction (EIB) is common in elite athletes. Eucapnic voluntary hyperventilation (EVH) is a laboratory test recommended for the identification of EIB in athletes, secondary to a field exercise challenge. Montelukast attenuates EIB, but its protective effect against airway narrowing from EVH has not been investigated.

OBJECTIVE

To examine the effectiveness of montelukast after exercise and after EVH.

METHODS

A randomised, placebo controlled, double blind, crossover study was performed with 11 physically active EIB positive subjects (eight men, three women; mean (SD) age 22.8 (6.8) years). Six hours before each of the following challenges 10 mg montelukast or placebo was ingested: (a) a six minute, cold air (-3 degrees C) maximal effort work accumulation cycle ergometer exercise; (b) EVH, breathing 5% CO(2) compressed air at 85% maximal voluntary ventilation for six minutes. Spirometry was performed before and 5, 10, and 15 minutes after the challenge. At least 48 hours was observed between challenges.

RESULTS

No differences in forced expiratory volume in one second (FEV(1)) were found after the two challenges. Exercise and EVH resulted in falls in FEV(1) of 22.4 (18.0) and 25.6 (16.8) respectively. Falls in FEV(1) after montelukast were less than after placebo (10.6 (10.6) and 14.3 (11.3) after exercise and EVH respectively; p<0.05). Montelukast provided protection against bronchoconstriction (59% and 53%; p<0.05) for eight exercising subjects and 10 EVH subjects; no protection was afforded for three exercising and one EVH challenged subject.

CONCLUSIONS

Both exercise and EVH were potent stimuli of airway narrowing. A single dose of montelukast provided reasonable protection in attenuating bronchoconstriction from either exercise or EVH. The similar protection by montelukast suggests that EVH is a suitable laboratory surrogate for EIB evaluation.

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.

Exhaled breath condensate cysteinyl leukotrienes are increased in children with exercise-induced bronchoconstriction

BACKGROUND

It is recognized that airway inflammation has a central role in the pathogenesis of asthma, but how it relates to exercise-induced bronchoconstriction (EIB) is not completely understood.

OBJECTIVE

The aim of our study was to investigate the relationship between EIB and baseline concentrations of cysteinyl leukotrienes (Cys-LTs) and other inflammatory markers in exhaled breath condensate (EBC).

METHODS

EBC was collected, and the fraction of exhaled nitric oxide (FE NO ) was measured in a group of 19 asthmatic children, after which they performed a treadmill exercise test. Fourteen healthy children were enrolled as control subjects.

RESULTS

The asthmatic children were divided into the EIB group (decrease in FEV 1 , > or =12%) and the non-EIB group. The EBC was analyzed for the presence of Cys-LTs, leukotriene B 4 , and ammonia. Asthmatic patients with EIB (mean FEV 1 decrease, 23% +/- 3%) had higher Cys-LT concentrations than either asthmatic patients without EIB or control subjects (42.2 pg/mL [median] vs 11.7 pg/mL and 5.8 pg/mL; P < .05 and P < .001, respectively). Ammonia concentrations were lower in both the EIB and non-EIB groups than in control subjects (253.2 microM and 334.6 microM vs 798.4 microM; P < .01 and P < .05, respectively). No difference in EBC leukotriene B 4 levels was found among the 3 groups. Both asthmatic groups had higher FE NO levels than control subjects ( P < .001). EBC Cys-LT ( P < .01; r = 0.7) and FE NO ( P < .05; r = 0.5) values both correlated significantly with the postexercise FEV 1 decrease.

CONCLUSION

this study shows that EBC Cys-LT values are higher in asthmatic children with EIB and correlate with the decrease in FEV 1 after exercise. These findings suggest that the pathways of both Cys-LT and nitric oxide are involved in the pathogenesis of EIB.

Prolonged effect of montelukast in asthmatic children with exercise-induced bronchoconstriction

Accumulating evidence shows that cysteinyl leukotrienes are the most important mediators in exercise-induced bronchoconstriction (EIB). In contrast to several studies in adults, there are few long-term studies of leukotriene receptor antagonists (LTRAs) in children with EIB. The aim of this study was to assess the prolonged clinical and bronchoprotective effects of montelukast in asthmatic children with EIB. We randomly assigned 64 asthmatic children with EIB. Forty subjects received montelukast (5 mg/day), and 24 subjects received placebo once daily for 8 weeks. Exercise challenge was performed before and after 8 weeks of treatment. Of the 40 patients in the montelukast group, 28 patients crossed over after 8 weeks. The response was measured as asthma symptom score, maximum percent fall in forced expiratory volume in 1 sec (FEV(1)) from pre-exercise baseline, and time to recovery of FEV(1) to within 10% of pre-exercise baseline (time to recovery). Following 8 weeks of treatment with montelukast, the montelukast group compared with placebo showed significant improvements in all endpoints, including asthma symptom score, maximum percent fall in FEV(1) after exercise, and time to recovery. In the cross-over group, even 8 weeks after stopping montelukast treatment, all endpoints were significantly and persistently improved. These results indicate that montelukast provides clinical protection from airway hyperresponsiveness in asthmatic children with EIB, and suggest that LTRAs may be useful for the long-term management of asthmatic children with EIB.

Cysteinyl leukotrienes and their receptors: cellular distribution and function in immune and inflammatory responses

The cysteinyl leukotrienes (cys-LTs) are a family of potent bioactive lipids that act through two structurally divergent G protein-coupled receptors, termed the CysLT(1) and CysLT(2) receptors. The cloning and characterization of these two receptors has not only reconciled findings of previous pharmacologic profiling studies of contractile tissues, but also has uncovered their expression on a wide array of circulating and tissue-dwelling leukocytes. With the development of receptor-selective reagents, as well as mice lacking critical biosynthetic enzymes, transporter proteins, and the CysLT(1) receptor, diverse functions of cys-LTs and their receptors in immune and inflammatory responses have been identified. We review cys-LT biosynthesis; the molecular biology and distribution of the CysLT(1) and CysLT(2) receptors; the functions of cys-LTs and their receptors in the recruitment and activation of effector leukocytes and induction of adaptive immunity; and the development of fibrosis and airway remodeling in animal models of lung injury and allergic inflammation.

Montelukast Has No Ergogenic Effect on Cycle Ergometry in Cold Temperature

PURPOSE

To examine the effects of a single 10-mg dose of ML on physical performance in EIB- and EIB+ athletes.

METHODS

Twenty-four male college ice hockey players performed two 6-min maximal work accumulation bouts on an electronically braked cycle ergometer in subfreezing conditions (-2.5 +/- 0.4 degrees C) 6-8 h after either ML or placebo (PL) to obtain total work accumulated (kJ); subjects were evaluated for EIB after each exercise trial.

RESULTS

Eight (33%) subjects were identified as EIB+ (23.5 +/- 13.35% fall in FEV1); 16 were EIB- (1.8 +/- 3.03% fall in FEV1). ML provided an approximately 50% protection against postexercise fall in FEV1. No significant differences in kJ were found between PL and ML trials for pooled subjects (95.3 +/- 13.69 and 94.8 +/- 13.27 kJ, respectively), EIB- subjects (99.6 +/- 13.26 and 99.0 +/- 11.81 kJ, respectively), or EIB+ subjects (86.8 +/- 10.67 and 86.5 +/- 12.72 kJ, respectively). Total work accumulated for EIB- subjects was significantly greater than for EIB+ subjects for both PL and ML (P < 0.05).

CONCLUSION

A single 10-mg dose of ML had no ergogenic effect for EIB- and EIB+ subjects performing short-duration high-intensity exercise in subfreezing temperature, supporting the use of ML as EIB prophylaxis during international sport competition.

Current concepts in asthma treatment in children

PURPOSE OF REVIEW

The purpose of this review is to present current literature related to the management of childhood asthma.

RECENT FINDINGS

Persistent asthma is now considered an inflammatory airways disease. Inhaled corticosteroids are recognized as the preferred long-term control medication. New classes of medications have been introduced during the last 5 years, including leukotriene modifiers, long-acting beta-adrenergic agonists, combination inhaled corticosteroids with long-acting beta-adrenergic agonists, and anti-IgE. Research is also being directed to understand the early onset of asthma.

SUMMARY

Management of childhood asthma is now being directed to early recognition and early intervention. Recent updates in the asthma guidelines prompt clinicians to consider intervention with antiinflammatory therapy, preferably inhaled corticosteroids, in children who have frequent asthma exacerbations and a risk profile for persistent asthma. In children with persistent asthma, inhaled corticosteroids are recognized as the preferred antiinflammatory therapy. Health care systems that have adapted this approach have recognized the benefits of reduced hospitalizations and urgent care visits. Continued research is needed to identify asthma at a very early stage so that interventions can be directed to interrupting the development of this disease.

Advances in adult and pediatric asthma

This review summarizes the highlights in the study of adult and pediatric asthma from October 2002 through October 2003. It is easiest to categorize this year's advances into physiologic, epidemiologic, therapeutic, and primarily pediatric developments. In physiology the identification of the ADAM33 gene as an asthma susceptibility gene has led to a new hypothesis concerning the pathogenesis of asthma. Understanding the integration of the upper and lower airways is likely to have important implications for patient management. Epidemiologic studies continue to show that asthma is a significant and costly disease, with medications comprising the most significant direct costs. Early intervention and improved management can significantly reduce the burden of illness. Research presented indicates there is an opportunity for allergist-immunologists to improve diagnostic and therapeutic approaches to asthma management. Our community has a strong commitment to health care quality, education, and delivery. The Journal will reflect this commitment with a new section devoted to these issues.