Montelukast, a leukotriene-receptor antagonist, for the treatment of mild asthma and exercise-induced bronchoconstriction

Observations on use of montelukast in pediatric eosinophilic esophagitis: insights for the future

Eosinophilic esophagitis is characterized by dense infiltration of the esophageal epithelium with eosinophils, typically accompanied by dysphagia. Effective therapies include the use of topical and systemic steroids as well as elimination diets. No previous reports have described the use of montelukast in the management of pediatric eosinophilic esophagitis. We retrospectively reviewed the charts of all patients with eosinophilic esophagitis followed in our pediatric center between 2000 and 2009. Those treated with montelukast were studied in detail. Study outcome was clinical response rate, defined by symptom (not histologic) improvement. Twenty-one patients with eosinophilic esophagitis were identified. Eight patients were maintained on montelukast (range 4-10 mg daily) after confirming the diagnosis of eosinophilic esophagitis histologically and failing to respond to a trial of proton pump inhibitor therapy. Three of eight patients had a clinical response (one had complete response and two with partial response) that could be attributed to montelukast. Four other patients responded clinically, but other therapies were concomitantly implemented. No side effects were reported with montelukast treatment with a mean follow-up duration of 32 months. Five patients had remained on montelukast therapy at the time of the final follow-up. Montelukast has minimal risk of adverse reactions compared with steroid therapy and may offer clinical relief in a small subset of children with eosinophilic esophagitis. Histologic response could not be verified in this study. Prospective studies, using higher montelukast doses, may potentially play a role and should be considered for future investigation.

Serum leptin and adiponectin levels correlate with exercise-induced bronchoconstriction in children with asthma

BACKGROUND

Exercise-induced bronchoconstriction (EIB), a form of bronchial hyperresponsiveness (BHR), is common in children with asthma or obesity. Epidemiological studies have shown that asthma and obesity are increasing in parallel, but obesity- and adipokine-related effects on inflammation and BHR have not yet been demonstrated in the human airway.

OBJECTIVE

To address the relationship between leptin and adiponectin and EIB in children with asthma.

METHODS

Eighty-five prepubertal children between the ages of 6 and 10 years were included in our study. They comprised obese with asthma (n = 19), normal weight with asthma (n = 23), obese without asthma (n = 23), and healthy (n = 20). We measured serum leptin and adiponectin levels. We also performed pulmonary function tests: baseline, postbronchodilator inhalation, methacholine inhalation, and exercise. The area under the forced expiratory volume in 1 second (FEV(1))-time curve quantified the severity of EIB over a 20-minute period after exercise (AUC(20)).

RESULTS

The obese children had significantly elevated levels of leptin and reduced levels of adiponectin. The maximum decreases in %FEV(1) and AUC(20) after exercise were positively correlated with leptin levels and negatively with serum adiponectin levels in children with asthma. The odds for having EIB were incrementally and significantly higher for children with higher levels of serum leptin.

CONCLUSIONS

Levels of the adipocyte-derived hormones leptin and adiponectin are significantly correlated with BHR induced by exercise challenge in children with asthma. Further studies are needed to elucidate whether the changes in leptin and adiponectin levels bear a causal relationship to the EIB/BHR.

Leukotriene modifiers for asthma treatment

Leukotrienes (LTs), including cysteinyl LTs (CysLTs) and LTB(4) , are potent lipid mediators that have a role in the pathophysiology of asthma. At least two receptor subtypes for CysLTs, CysLT(1) and CysLT(2) , have been identified. The activation of the CysLT(1) receptor is responsible for most of the pathophysiological effects of CysLTs in asthma, including increased airway smooth muscle activity, microvascular permeability, and airway mucus secretion. LTB(4) might have a role in severe asthma, asthma exacerbations, and the development of airway hyperresponsiveness. CysLT(1) receptor antagonists can be given orally as monotherapy in patients with mild persistent asthma, but these drugs are generally less effective than inhaled glucocorticoids. Combination of CysLT(1) receptor antagonists and inhaled glucocorticoids in patients with more severe asthma may improve asthma control and enable the dose of inhaled glucocorticoids to be reduced while maintaining similar efficacy. The identification of subgroups of asthmatic patients who respond to CysLT(1) receptor antagonists is relevant for asthma management as the response to these drugs is variable. CysLT(1) receptor antagonists have a potential anti-remodelling effect that 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 role of LT modifiers in asthma treatment.

Current recommendations for the treatment of mild asthma

Patients suffering from mild asthma are divided into intermittent or persistent classes based on frequency of symptoms and reliever medication usage. Although these terms are used as descriptors, it is important to recognize the approach of focusing on asthma control in managing asthma patients. Beta-agonists are considered first-line therapy for intermittent asthmatics. If frequent use of beta-agonists occurs more than twice a week, controller therapy should be considered. For persistent asthma, low-dose inhaled corticosteroids are recommended in addition to reliever medication. Compliance to regular therapy can pose problems for disease management, and while intermittent controller therapy regimens have been shown to be effective, it is imperative to stress the value of regular therapy especially if an exacerbation occurs. It is also important when such an approach is adopted that there is regular re-evaluations of asthma control. This is because regular anti-inflammatory therapy may become necessary if symptoms become more persistent. Other therapies are seldom needed. Antileukotrienes can be considered an option for mild asthma; however, studies have shown that they are not as effective as inhaled corticosteroids. Aside from therapy, patient education, which includes a written action plan, should be a component of the patient's strategy for disease management.

Treatment options for the management of exercise-induced asthma and bronchoconstriction

Treatment for exercise-induced bronchospasm and exercise-induced asthma includes both pharmacologic and nonpharmacologic options. Pharmacologic agents that have been proven to be effective for treating these conditions include short- and long-acting β2-adrenoceptor agonists, mast cell-stabilizing agents, anticholinergics, leukotriene receptor antagonists, and inhaled corticosteroids (ICS). When selecting the most appropriate medication, factors to consider include the effectiveness of each, the duration of action, frequency of administration, potential side effects, and tolerance level. Long-acting β2-adrenoceptor agonists should not be used without ICS. Nonpharmacologic treatments include physical conditioning, incorporating a warm-up before and a cool-down period after exercise, performing nasal breathing, avoiding cold weather or environmental allergens, using a face mask or other aid to warm and humidify inhaled air, and modifying dietary intake. The data to support nonpharmacologic treatments are limited; however, they are routinely recommended because of the low risk associated with their use. This article highlights the advantages and limitations of each treatment option.

Randomized controlled trial of fish oil and montelukast and their combination on airway inflammation and hyperpnea-induced bronchoconstriction

Background

Both fish oil and montelukast have been shown to reduce the severity of exercise-induced bronchoconstriction (EIB). The purpose of this study was to compare the effects of fish oil and montelukast, alone and in combination, on airway inflammation and bronchoconstriction induced by eucapnic voluntary hyperpnea (EVH) in asthmatics.

Methods

In this model of EIB, twenty asthmatic subjects with documented hyperpnea-induced bronchoconstriction (HIB) entered a randomized double-blind trial. All subjects entered on their usual diet (pre-treatment, n = 20) and then were randomly assigned to receive either one active 10 mg montelukast tablet and 10 placebo fish oil capsules (n = 10) or one placebo montelukast tablet and 10 active fish oil capsules totaling 3.2 g EPA and 2.0 g DHA (n = 10) taken daily for 3-wk. Thereafter, all subjects (combination treatment; n = 20) underwent another 3-wk treatment period consisting of a 10 mg active montelukast tablet or 10 active fish oil capsules taken daily.

Results

While HIB was significantly inhibited (p<0.05) by montelukast, fish oil and combination treatment compared to pre-treatment, there was no significant difference (p>0.017) between treatment groups; percent fall in forced expiratory volume in 1-sec was −18.4±2.1%, −9.3±2.8%, −11.6±2.8% and −10.8±1.7% on usual diet (pre-treatment), fish oil, montelukast and combination treatment respectively. All three treatments were associated with a significant reduction (p<0.05) in F_ENO, exhaled breathe condensate pH and cysteinyl-leukotrienes, while the fish oil and combination treatment significantly reduced (p<0.05) urinary 9α, 11β-prostaglandin F₂ after EVH compared to the usual diet; however, there was no significant difference (p>0.017) in these biomarkers between treatments.

Conclusion

While fish oil and montelukast are both effective in attenuating airway inflammation and HIB, combining fish oil with montelukast did not confer a greater protective effect than either intervention alone. Fish oil supplementation should be considered as an alternative treatment for EIB.

Trial Registration

ClinicalTrials.gov NCT00676468

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.

[Exercise-induced bronchoconstriction in non-asthmatic athletes]

INTRODUCTION

A new clinical entity, exercise-induced bronchoconstriction (EIB), has been recently defined which describes bronchoconstriction occurring in association with exercise in susceptible non-asthmatic persons.

STATE OF ART

There is considerable evidence that the pathogenesis of this condition is related to airway injury, due to prolonged hyperventilation and aggressive environmental factors. If the objective diagnostic tests are identical for the diagnosis of exercise induced asthma and EIB, the diagnoses are established differently, according to the high sensitivity of provocation by exercise "in the field" or the eucapnic voluntary hyperventilation provocation test.

PERSPECTIVES

Current pharmacological treatment is based upon the inhalation of ß2-agonists prior to exercise, but to be granted permission to use them, athletes are required to provide documentation of objective evidence of EIB. Therefore, the diagnostic pathway in athletes is essential and respiratory physicians need to know the specific features of this new clinical entity.

CONCLUSIONS

EIB distinct from the presence of asthma is prevalent in elite athletes and its determinants should be well known by their health care providers to assure an optimal management of this peculiar disease, in respect to drug doping regulations.

Effect of montelukast or salmeterol added to inhaled fluticasone on exercise-induced bronchoconstriction in children

OBJECTIVES

To evaluate the effect of montelukast, 5 mg, or inhaled salmeterol, 50 microg, added to inhaled fluticasone in reducing the maximum percentage decrease in forced expiratory volume in 1 second (FEV1) after a standardized exercise challenge and response to rescue bronchodilation with albuterol in children aged 6 to 14 years with persistent asthma and exercise-induced bronchoconstriction (EIB).

METHODS

Randomized, double-blind, double-dummy, multicenter, 2-period, 4-week, crossover study conducted between December 22, 2005 and November 14, 2008 at 30 centers in Europe, Asia, Mexico, and South America. Patients with asthma receiving inhaled corticosteroids demonstrated an FEV1 of 70% or higher of the predicted value and EIB (defined as a decrease in FEV1 > or = 15% compared with preexercise baseline FEV1 on 2 occasions before randomization). Standardized exercise challenges were performed at baseline (prerandomization) and at the end of each active treatment period.

RESULTS

Of 154 patients randomized, 145 completed the study. Montelukast, compared with salmeterol, significantly reduced the mean maximum percentage decrease in FEV1 (10.6% vs 13.8%; P = .009), mean area under the curve for the first 20 minutes after exercise (116.0% x min vs 168.8% x min; P = .006), and median time to recovery (6.0 vs 11.1 minutes; P = .04). Response to albuterol rescue after exercise challenge was significantly greater (P < .001) with montelukast. Montelukast and salmeterol were generally well tolerated.

CONCLUSIONS

Attenuation and response of EIB to albuterol rescue after exercise challenge were significantly better with montelukast than with salmeterol after 4 weeks of treatment.

Novel anti-inflammatory treatments for asthma

Inhaled corticosteroids do not suppress inflammation or control symptoms in all asthmatics. In particular, corticosteroid insensitivity exists in many patients and may potentially be reversible. There is a need to develop new anti-inflammatory therapies for this disease. This article critically reviews clinical trial data of novel anti-inflammatory drugs in asthma, encompassing specific anti-eosinophil therapies, including antisense chemokine receptor antagonists, anti-cytokine monoclonal antibodies and small-molecule approaches. We provide an insight into the possible future of asthma therapy by identifying drugs with the most promising therapeutic profile.

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 wheeze: Fraction of exhaled nitric oxide-directed management

BACKGROUND AND OBJECTIVE

Exercise-induced wheeze (EIW) is common. Several treatment options exist. Patients with low fraction of exhaled nitric oxide (F(E)NO) are unlikely to be steroid-responsive and might benefit from non-steroidal therapies. We assessed: the efficacy of cromoglycate, formoterol and montelukast in patients with EIW and low F(E)NO (<35 ppb) in a randomized cross-over trial, and the efficacy of inhaled corticosteroid in a high F(E)NO (>35 ppb) group.

METHODS

Patients had EIW and airway hyperresponsiveness (AHR) to mannitol and/or exercise. Those with low F(E)NO (n = 19) received cromoglycate (20 mg inh. bd + before challenge tests), formoterol (12 microg inh. bd + before challenge tests) and montelukast (10 mg p.o. od), each for 2 weeks. Those with high F(E)NO (n = 20) took inhaled fluticasone (500 microg) daily for 4 weeks. Primary end-points were: 50% reduction in maximum FEV(1) %fall (clinical protection) and decrease in AHR to mannitol.

RESULTS

In patients with low F(E)NO, cromoglycate, formoterol and montelukast significantly decreased AHR to mannitol in 63%, 61% and 47% of patients, respectively. In this group, the magnitude of exercise-induced bronchoconstriction (EIB) was significantly reduced with montelukast and formoterol; between-treatment differences were not significant. Of 6/19 with low F(E)NO and EIB, protection occurred in 67% (cromoglycate), 83% (formoterol) and 50% (montelukast), respectively. In the high F(E)NO group, AHR to mannitol and EIB decreased significantly with fluticasone (P < 0.001, P = 0.005, respectively), and protection occurred in 7/8 (88%) with EIB.

CONCLUSIONS

In patients with EIW and low F(E)NO, the number of 'responders' to cromoglycate, formoterol and montelukast was similar. In a high F(E)NO population the response to inhaled corticosteroid was highly significant and comparable to previous studies.

Ergogenic effects of inhaled beta2-agonists in non-asthmatic athletes

The potential ergogenic effects of asthma medication in athletes have been controversially discussed for decades. The prevalence of asthma is higher in elite athletes than in the general population. The highest risk for developing asthmatic symptoms is found in endurance athletes and swimmers. In addition, asthma seems to be more common in winter-sport athletes. Asthmatic athletes commonly use inhaled beta2-agonists to prevent and treat asthmatic symptoms. However, beta2-agonists are prohibited according to the "Prohibited List of the World Anti-Doping Agency" (WADA). Until the end of 2009 an exception was only allowed for the substances formoterol, salbutamol, salmeterol, and terbutaline by inhalation, as long as a so-called therapeutic use exemption has been applied for and was granted by the relevant anti-doping authorities. From 2010 salbutamol and salmeterol are allowed by inhalation requiring a so called declaration of use.

Section 2. Exercise-Induced Bronchospasm: Albuterol versus Montelukast: Highlights of the Asthma Summit 2009: Beyond the Guidelines

Exercise-induced bronchospasm (EIB) involves airway obstruction with an onset shortly after exercising. It can occur in individuals without a diagnosis of asthma, but is most common in asthmatic patients (and in this scenario may be referred to as exercise-induced asthma, EIA), correlating with the patient's degree of airway hyperreactivity. While albuterol is the most commonly used rescue and prophylactic medication for EIB, the leukotriene antagonist, monetlukast, may be an appropriate choice for some patients. Clinical data have shown that once-daily treatment with montelukast (5 or 10 mg tablet) can offer protection against EIB within 3 days for some patients. Such an approach might be preferred for patients who have difficulty with inhaled medications and for children who cannot access their inhalers during the school day. Montelukast also may be an option to reduce side effects associated with albuterol for individuals who exercise regularly.

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.

Leukotriene modifiers in the treatment of asthma in children

Asthma is one of the most common respiratory disorders in clinical practice, affecting up to 13% of people worldwide. Inflammation is the most important component of asthma and inhaled corticosteroids (ICS) are recommended as the first line controller treatment for patients of all ages. Treatment with corticosteroids is often unable to fully control asthma symptoms and progression. Recently, leukotrienes have come to the forefront of research as they have been found play a pivotal role in the airway inflammatory process, and specific drugs have been developed to target them. Cysteiny leukotriene antagonists (LTRAs) have recently emerged as important therapeutic options that show a large potential clinical utility. Three specific LTRAs are licensed for clinical use: montelukast, zafirlukast and pranlukast, although montelukast is the only drug approved in the paediatric age range. It is well tolerated (although adverse effects such as headaches, abdominal pain, rashes, angioedema, pulmonary eosinophilia and arthralgia have been reported) and shows many positive effects in asthmatic patients. Current Global Initiative for Asthma guidelines recommend LTRAs as: (1) a second choice treatment to ICS for patients with mild persistent asthma, (2) an add-on therapy to reduce the dose of ICS in patients with moderate or severe asthma, due to the different and complementary mechanisms of action of these agents. LTRAs may be particularly appropriate choices in a number of clinical situations, including the following: patients with concomitant rhinitis; patients with viral-induced wheeze; patients with exercise-induced bronchoconstriction (EIB) and, in children aged 2-5 years, to reduce the frequency of asthma exacerbations.

The Saudi Initiative for Asthma

The Saudi Initiative for Asthma (SINA) provides up-to-date guidelines for healthcare workers managing patients with asthma. SINA was developed by a panel of Saudi experts with respectable academic backgrounds and long-standing experience in the field. SINA is founded on the latest available evidence, local literature, and knowledge of the current setting in Saudi Arabia. Emphasis is placed on understanding the epidemiology, pathophysiology, medications, and clinical presentation. SINA elaborates on the development of patient-doctor partnership, self-management, and control of precipitating factors. Approaches to asthma treatment in SINA are based on disease control by the utilization of Asthma Control Test for the initiation and adjustment of asthma treatment. This guideline is established for the treatment of asthma in both children and adults, with special attention to children 5 years and younger. It is expected that the implementation of these guidelines for treating asthma will lead to better asthma control and decrease patient utilization of the health care system.

Montelukast: Pharmacology, Safety, Tolerability and Efficacy

Allergic rhinitis and asthma are common disorders effecting large percentages of the population of Western countries. There are multiple treatment options available for allergic rhinitis and asthma and stepwise approaches to therapy have been recommended. Montelukast is a cysteinyl leukotriene receptor antagonist that has been found to be effective both in the treatment of allergic rhinitis and asthma. This paper will describe the pharmacology, safety, efficacy and tolerability of montelukast. It will examine the comparative efficacy of montelukast to other medications for the treatment of allergic rhinitis and asthma, as well as discuss the recent studies of combination therapy.

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.

Efficacy of leukotriene receptor antagonists and synthesis inhibitors in asthma

Cysteinyl leukotrienes are important mediators of asthmatic responses. They are the most potent bronchoconstrictors known; their release is triggered by exposure to inhaled allergens after exercise and after aspirin ingestion by subjects with aspirin-sensitive asthma. The cysteinyl leukotrienes promote inflammatory cell migration into the airways, as well as bone marrow eosinophilopoiesis after allergen inhalation. Leukotriene inhibitors are effective at attenuating asthmatic responses to all of these stimuli and are also effective at treating persistent asthma. These drugs are a viable alternative to low-dose inhaled corticosteroid (ICS) treatment but should be reserved for patients who cannot or will not use ICSs, often because of concerns about potential side effects of ICS treatment, which limits their use, particularly in children. Leukotriene receptor antagonists are also alternatives to long-acting inhaled beta(2)-agonists as add-on therapy to ICSs, but their efficacy together with ICSs is less than that of ICS/long-acting inhaled beta(2)-agonist combinations. Leukotriene receptor antagonists have an excellent safety profile.

Montelukast in guidelines and beyond

In all asthma guidelines, preventive anti-inflammatory treatment is essential in all patients with persistent asthma. Inhaled corticosteroids are the mainstay of treatment in the control of asthma, but other treatments may be used as a monotherapy in patients with mild asthma or as an add-on treatment in those with moderate-to-severe asthma. Leukotriene modifiers are the only validated preventive treatment for all age groups. This review discusses the place of montelukast, a leukotriene receptor antagonist, using guidelines and consensus reports on asthma and rhinitis: the US National Asthma Education and Prevention Program (NAEPP); the British Guideline on the Management of Asthma; the Global Initiative on Asthma (GINA); and Allergic Rhinitis and its Impact on Asthma (ARIA). This review includes new studies that have not yet been considered in guidelines.

Complementary therapy in asthma: inhaled corticosteroids and what?

PURPOSE OF REVIEW

For optimal asthma control, complementary strategies are advocated to cover several aspects of the disease. This mini-review highlights different complementary strategies with special focus on the combined use of inhaled corticosteroids (ICSs) and long-acting beta2 agonists and as an alternative, the combination of ICSs and antileukotrienes.

RECENT FINDINGS

New data show that combinations of ICSs/long-acting beta2 agonists or ICSs with antileukotrienes improve disease stability with concomitant control of the underlying airway inflammation. Moreover, there is some evidence that combination therapy may prevent some aspects of airway remodelling. The use of a fixed combination of both a reliever and a controller medication may have certain advantages compared with a fixed dose regime with as-needed separate reliever therapy. Alternatively, in some asthma phenotypes, such as combined allergic rhinitis and asthma syndrome, the combination of ICSs with antileukotrienes offers a complementary anti-inflammatory treatment in combination with controller effects on both airway compartments.

SUMMARY

This review compares different strategies of complementary therapy in asthma with special focus on how to achieve the best clinical control also aimed at controlling the underlying airway inflammation. We have chosen to focus on two major topics: the use of ICSs and long-acting beta2 agonists in two different strategies, that is, a symptom-driven versus a fixed symptom-preventive approach; and the use of ICSs with a long-acting beta2 agonist versus ICSs and a leukotriene receptor antagonist. What regime should be chosen is highly dependent on the individual phenotype and defined treatment goal.

Evaluating combination therapies for asthma: pros, cons, and comparative benefits

Combination therapies with inhaled corticosteroids (ICS) and either long-acting beta2 agonists (LABA) or leukotriene receptor antagonists (LTRA) are commonly used to help patients maintain control of their asthma. LABA and LTRA have different mechanisms of action and both provide complementary benefits when combined with ICS. This paper compares the two regimens based on recent clinical trial data, evaluates their efficacy on various clinical and quality of life outcomes, and discusses the importance of therapy choice in people with specific asthma phenotypes. The potential of new dosing strategies, including adjustable maintenance therapy and single-inhaler maintenance and reliever therapy is also reviewed. Given the variety of outcomes, phenotypes, and treatment strategies that must be considered, the importance of individualized management is emphasized.

[Guidelines on asthma in extreme environmental conditions]

Asthma is a highly prevalent chronic disease which, if not properly controlled, can limit the patient's activities and lifestyle. In recent decades, owing to the diffusion of educational materials, the application of clinical guidelines and, most importantly, the availability of effective pharmacological treatment, most patients with asthma are now able to lead normal lives. Significant social changes have also taken place during the same period, including more widespread pursuit of sporting activities and tourism. As a result of these changes, individuals with asthma can now participate in certain activities that were inconceivable for these patients only a few years ago, including winter sports, underwater activities, air flight, and travel to remote places with unusual environmental conditions (deserts, high mountain environments, and tropical regions). In spite of the publication of several studies on this subject, our understanding of the effects of these situations on patients with asthma is still limited. The Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) has decided to publish these recommendations based on the available evidence and expert opinion in order to provide information on this topic to both doctors and patients and to avert potentially dangerous situations that could endanger the lives of these patients.

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.

Association of IL-13 polymorphisms with leukotriene receptor antagonist drug responsiveness in Korean children with exercise-induced bronchoconstriction

BACKGROUND

IL-13 is a pivotal cytokine in allergic inflammation and bronchial hyperresponsiveness, and is known to influence leukotriene levels.

OBJECTIVE

We investigated whether IL-13 polymorphisms may be associated with clinical phenotypes and drug responsiveness to the leukotriene receptor antagonist (LTRA) in Korean asthmatic children with exercise-induced bronchoconstriction (EIB).

METHODS

We enrolled 242 normal controls and 374 patients with asthma. Of the asthmatic patients, 100 performed exercise challenge tests before and after receiving montelukast (5 mg/day) for 8 weeks and included 80 subjects in drug responsiveness analysis. We assessed IL-13 polymorphisms (-1512A/C, -1112C/T, +2044G/A) through PCR-restriction fragment length polymorphism analysis.

RESULTS

Significantly higher total IgE levels and maximum percent fall in forced expiratory volume in 1 s (FEV1) (%) after exercise challenge test were found in asthmatic patients carrying one or two copies of the IL-13 +2044A versus those homozygous for +2044G (P=0.011 and 0.040, respectively). We further noted a correlation of total IgE with maximum percent fall in FEV1 (%) in asthmatic patients, as well as a reverse correlation with improvement of maximum percent fall in FEV1 (%) after exercise challenge tests. Finally, we observed a significant association between responsiveness to montelukast and IL-13 -1112C/T polymorphism and the haplotype of IL-13 polymorphisms.

CONCLUSION

The IL-13 +2044G/A polymorphism may be associated with atopy and EIB severity in Korean children with EIB, and thus could potentially be considered as a disease-modifying gene. Moreover, the IL-13 -1112C/T polymorphism and the haplotype of IL-13 polymorphisms seem to be associated with LTRA drug responsiveness, and thus might prove useful as a target for modulation of LTRA drug responsiveness.

Exercise-induced bronchospasm in children

This review will encompass definition, history, epidemiology, pathogenesis, diagnosis, and management of exercise -induced bronchospasm in the pediatric individual with and without known asthma. Exercise induced asthma is the conventional term for transient airway narrowing in a known asthma in association with strenuous exercise usually lasting 5-10 minutes with a decline in pulmonary function by at least 10%. Exercise induced asthma will be referred to as exercise induced bronchospasm in an asthmatic. Exercise-induced bronchospasm (EIB ) is the same phenomenon in an individual without known asthma. EIB can be seen in healthy individuals including children as well as defense recruits and competitive or elite athletes. The diagnosis with objective exercise challenge methods in conjunction with history is delineated. Management is characterized with pharmacotherapy and non pharmacotherapeutic measures for underlying asthma as well as exercise induced bronchospasm and inhalant allergy. Children can successfully participate in all sports if asthma is properly managed.

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.

Eosinophilic esophagitis: a case report. Effective treatment with systemic corticosteroids for the relapse of the disease

We report on a case of eosinophilic esophagitis in a 33-year-old Japanese woman who visited our hospital with dysphagia and esophageal food impaction in April 2006. She had had the same symptoms in May 2005, and, by endoscopic and histologic examination, she was diagnosed with eosinophilic esophagitis. Biopsy specimens from multiple locations in the esophageal mucosa had shown remarkable infiltration of eosinophils, more than 20 eosinophils per high-power field in squamous mucosa, and she had been treated with Th2 cytokine antagonist and proton pump inhibitor at the time. Her symptoms had not improved, but she had received no further medical treatment. In 2006, upper gastrointestinal endoscopy showed edematous whitish esophageal mucosa, multiple ulcerations with whitish exudates on their surfaces, and white plaques. Biopsy specimens showed the same change as before, and corticosteroid (prednisolone 20 mg/day) was administered orally. After 2 weeks of corticosteroid therapy, her symptom had effectively improved. Endoscopy after 15 weeks of the therapy revealed remarkable improvement, and biopsy specimens from esophageal mucosa revealed the disappearance of the eosinophil infiltrates. We report on a case of eosinophilic esophagitis effectively treated with systemic corticosteroids. Eosinophilic esophagitis has, as yet, no standardized treatment. However, wider recognition of its features on endoscopy may reveal more cases, thereby increasing our understanding of this disease, and will provide new therapeutic possibilities.

Effects of exercise training and montelukast in children with mild asthma

PURPOSE

Data from the general population suggest that habitual exercise decreases bronchial responsiveness, but the possible role of exercise in asthmatics is undefined. The leukotriene receptor antagonist montelukast decreases bronchial responsiveness and exercise-induced symptoms in asthmatic children. This randomized study in children with mild asthma evaluated the combined effects of aerobic training for 12 wk and montelukast or placebo on bronchial responsiveness (BHR) to methacholine, exercise-induced bronchoconstriction (EIB), inflammatory markers in exhaled breath condensate (EBC), and asthma exacerbations.

METHODS

Fifty children (mean age +/- SD: 10.2 +/- 2.4 yr) with mild stable asthma were randomly assigned to placebo (N = 25) or montelukast (N = 25). Before and after training, we assessed BHR and EIB and markers of airway inflammation-that is, exhaled nitric oxide (eNO), pH, and cysteinyl-leukotriene concentration-in EBC.

RESULTS

Training increased maximal workload and peak minute ventilation. After training, the methacholine dose causing a 20% fall in FEV1 (PD20) increased in both groups. A decreased slope of FEV1 decline at increasing methacholine dose was found only in montelukast-treated children. EIB prevalence halved after training in both groups (EIB + children, placebo group: 10 pretraining, 4 posttraining; EIB + children, montelukast group: 8 pretraining, 5 posttraining; P < 0.05 by chi on all children). Resting eNO was unaffected, whereas the pH of EBC decreased after training in both groups. Cysteinyl-leukotriene concentrations were low in most children at both times. During training, montelukast-treated children showed fewer asthma exacerbations compared with the same period of the previous year.

CONCLUSIONS

In children with mild stable asthma, exercise training decreased bronchial responsiveness to methacholine. Montelukast also decreased bronchial reactivity (FEV1 slope) and protected against exacerbations, suggesting a beneficial synergistic action of these two interventions in mild 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.

Bronchoprovocation testing in asthma

Bronchial hyperresponsiveness (BHR) is an important feature of asthma and is useful in diagnosis, monitoring, and prognostication. It probably represents inherent elements of the disease process such as genetic predisposition, airway inflammation, and airway remodeling. Airway inflammation likely accounts for the variable component of BHR, whereas the persistent component of BHR correlates significantly with structural changes in the airway, such as basement membrane thickness and epithelial damage. It might be this component that is resistant or refractory to the effects of available interventions. A few trials of immunomodulatory therapy have shown considerable improvements in markers of airway inflammation, without significantly modifying airway reactivity. Interventions to impact the more permanent feature of BHR are needed.

The impact of a medical food containing gammalinolenic and eicosapentaenoic acids on asthma management and the quality of life of adult asthma patients

BACKGROUND

Leukotriene synthesis inhibitors and receptor antagonists are efficacious for the treatment of asthma. Diets containing the fatty acids gammalinolenic acid (GLA) and eicosapentaenoic acid (EPA) decrease leukotriene synthesis; however, their impact on asthma management and quality of life (QOL) has not been evaluated in asthmatic subjects.

OBJECTIVE

To evaluate asthma management and the QOL of asthmatic adult subjects consuming a medical food emulsion containing GLA and EPA.

RESEARCH DESIGN AND METHODS

Trial 1 was a randomized, prospective, double-blind, placebo-controlled, parallel group trial in atopic subjects with mild-to-moderate asthma (n = 35 evaluable) consuming a low dose (0.75 g GLA + 0.5 g EPA), high dose (1.13 g GLA + 0.75 g EPA) or placebo emulsion daily. Subjects were questioned about their asthma management using a non-validated questionnaire after 2 and 4 weeks. Blood leukotrienes were measured at baseline and after 4 weeks. Trial 2 was an open-label study (n = 65 evaluable) where subjects consumed the low-dose medical food emulsion, EFF1009, daily. QOL and asthma management were measured using the validated Mini Asthma Quality of Life (MiniAQLQ) and the Asthma Control (ACQ) questionnaires, respectively, administered at baseline and after 4 weeks.

RESULTS

In Trial 1, leukotriene biosynthesis decreased (p < 0.05). Self-reported asthma status and bronchodilator use improved in subjects consuming low- and high-dose emulsion between week 2 and week 4 (p < 0.01), but not compared to placebo (p > 0.1). In Trial 2, mean +/- standard error total MiniAQLQ and ACQ scores improved by 1.5 +/- 0.2 and 1.0 +/- 0.1, respectively (p < 0.001). Subdomain scores from MiniAQLQ improved and rescue bronchodilator use decreased (p < 0.001).

CONCLUSION

The inclusion of the medical food EFF1009 in asthma management regimens can improve patient quality of life and decrease reliance on rescue medication.

Antileukotrienes as adjunctive therapy in acute asthma

The leukotriene receptor antagonists (LTRAs) are a comparatively new class of asthma drugs that exhibit both bronchodilator and anti-inflammatory properties. There is a substantial body of evidence for their benefit in the management of chronic asthma in both adults and children, and particularly in specific types of asthma such as exercise-induced and aspirin-sensitive asthma. Despite best practice using current treatment guidelines for the management of acute asthma, a significant proportion of patients require continued treatment and are unable to be discharged from the emergency department; many require a short course of oral corticosteroids. The relatively rapid onset of action of LTRAs after oral administration and their additive effect to beta(2)-adrenoceptor agonists led to the hypothesis that they might be of benefit in acute asthma. This review examines the available evidence for the effect of LTRAs in acute asthma. Although the evidence is limited, it suggests that treatment with LTRAs provides additional bronchodilator effect to nebulised and inhaled beta(2)-adrenoceptor agonists. Short-term therapy with LTRAs results in fewer treatment failures and readmissions for patients with acute asthma, and less need for additional therapies such as nebulisers and corticosteroids.

Angiopoietin-2 as a contributing factor of exercise-induced bronchoconstriction in asthmatic patients receiving inhaled corticosteroid therapy

BACKGROUND

Airway microcirculation has the potential to contribute to the pathogenesis of exercise-induced bronchoconstriction (EIB) in asthma. Recently, angiopoietin-1 has been found to stabilize microvessels and make them leak resistant, whereas angiopoietin-2 is an antagonist of angiopoietin-1 and enhances microvascular permeability.

OBJECTIVE

We sought to examine the roles of angiopoietin-2 in EIB in asthmatic patients with inhaled corticosteroid therapy.

METHODS

Levels of angiopoietin-1 and angiopoietin-2 in induced sputum were examined in 32 asthmatic patients who were receiving inhaled corticosteroid therapy for more than 6 months at the entry of this study and 14 healthy control subjects. All asthmatic patients performed an exercise test.

RESULTS

The degree of eosinophilic airway inflammation did not differ significantly between asthmatic patients and healthy control subjects. Angiopoietin-1 levels were also similar in the 2 groups (asthmatic patients: median, 6.0 ng/mL [range, 2.0-10.7 ng/mL]; healthy control subjects: median, 4.2 ng/mL [range, 1.5-10.7 ng/mL]). In contrast, angiopoietin-2 levels were significantly higher in asthmatic patients than in healthy control subjects (asthmatic patients: median, 0.74 ng/mL [range, 0.3-1.2 ng/mL]; healthy control subjects: median, 0.26 ng/mL [range, 0.05-0.47 ng/mL]; P < .001). There was no significant correlation between angiopoietin-1 levels and the severity of EIB in asthmatic patients. However, angiopoietin-2 levels were significantly correlated with the severity of EIB and airway microvascular permeability index.

CONCLUSION

Angiopoietin-2 levels were increased in the airways of asthmatic patients with inhaled corticosteroid therapy, and its levels were associated with the severity of EIB.

Responsiveness to montelukast is associated with bronchial hyperresponsiveness and total immunoglobulin E but not polymorphisms in the leukotriene C4 synthase and cysteinyl leukotriene receptor 1 genes in Korean children with exercise-induced asthma (EIA)

BACKGROUND

As previous studies have shown that cysteinyl leukotrienes are important mediators in exercise-induced bronchoconstriction (EIB), and leukotriene receptor antagonists (LTRAs) such as montelukast have been shown to improve post-exercise bronchoconstrictor responses, we herein investigated whether clinical responsiveness to montelukast was associated with polymorphisms in the genes encoding leukotriene C4 synthase (LTC4S) and cysteinyl leukotriene receptor 1 (CysLTR1) and/or clinical parameters in Korean asthmatic children with EIB.

METHODS

The study population consisted of 100 asthmatic children with EIB. The individuals studied were given exercise challenge tests before and after receiving montelukast (5 mg/day) for 8 weeks. Responders were defined as children showing>10% post-treatment improvement in forced expiratory volume in 1 s (FEV1). The LTC4S A(-444)C and CysLTR1 T(+927)C polymorphisms were genotyped by PCR-restriction fragment length polymorphism analysis.

RESULTS

Of 100 enrolled children, 68 were classified as responders and 32 were classified as non-responders. No significant association was observed between montelukast responsiveness and LTC4S or CysLTR1 genotype, either alone or in combination. In contrast, montelukast-induced improvement in FEV(1) after exercise was correlated with higher pre-treatment PC20 (methacholine) values (r=0.210, P=0.036) and lower total IgE levels (r=-0.216, P=0.031).

CONCLUSIONS

The LTC4S A(-444)C and CysLTR1 T(+927)C genotypes do not appear to be useful for predicting clinical responsiveness to montelukast, whereas bronchial hyperresponsiveness and total IgE appear to predict the degree of montelukast responsiveness in Korean asthmatic children with EIB.

Single-Dose Montelukast or Salmeterol as Protection Against Exercise-Induced Bronchoconstriction

BACKGROUND AND OBJECTIVE

It has been previously established that montelukast provides protection against exercise-induced bronchoconstriction (EIB) after a single dose. The present objective was to assess the onset and duration of this protective action in a trial that included both positive and negative controls.

METHODS

A randomized, active-controlled and placebo-controlled, double-blind, double-dummy, three-way crossover study was conducted in 47 patients (age range, 15 to 44 years) in whom there was a 20 to 40% fall in FEV(1) following exercise (DeltaFEV(1)). In randomized sequence, patients received oral montelukast (10 mg), placebo, or inhaled salmeterol (50 microg) as a positive control. Dosing was followed by exercise challenges at 2, 8.5, and 24 h. The primary end point was maximum DeltaFEV(1) at 2 h postdose. Secondary end points included maximum DeltaFEV(1) at the two later time points, and other measures (including recovery time and need for beta-agonist rescue) at all time points.

RESULTS

The maximum DeltaFEV(1) magnitudes at 2, 8.5, and 24 h were significantly smaller after montelukast administration than after placebo administration (least squares mean [+/- SE], 13.2 +/- 1.2%, 11.7 +/- 1.2%, and 10.0 +/- 1.1% vs 21.8 +/- 1.2%, 16.8 +/- 1.3%, and 14.0 +/- 1.1%, respectively; p <or= 0.001, < 0.01, and < 0.05). All secondary end point results supported the primary end point. Montelukast and salmeterol had similar efficacy at 2 and 8.5 h, but only montelukast was effective at 24 h.

CONCLUSION

Montelukast provided significant protection against EIB having an onset within 2 h following a single oral dose and lasting for at least 24 h.

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.

Etiology of exercise-induced asthma: physical stress-induced transcription

Exercise-induced asthma (EIA) occurs with a high prevalence in both asthmatic and nonasthmatic individuals. Although understanding of the functional genomics (proteomics) in sports medicine remains limited, this review focuses on immunologic changes as reflected in transcriptional regulation in respect to EIA. Studies demonstrated that leukotrienes play a significant role in EIA. Exercise increases the distribution of leukotrienes and influences the leukotriene transcription pathway; it could be shown that the genes ALOX5 and ALOX5AP encoding for 5-lipooxygenase (5-LO) and 5-lipoxygenase-activating protein (FLAP) as well as activators for 5-LO, p38 -mitogen-activated protein kinase (MAPK), and others, are enhanced after exercise in healthy subjects. Possibly EIA is triggered via leukotriene release if a predisposition or other conditions (eg, epithelial injury and repair) are present. Furthermore, exercise influences transcription factors such as nuclear factor-kappa B (NF-jB), activator protein-1 (AP1), cytokines, and chemokines and promotes cellular responses linked to EIA, which are possibly able to modify further the incidence or the severity of EIA.

Protection against exercise-induced bronchoconstriction two hours after a single oral dose of montelukast

The objective of this double-blind cross-over study was to evaluate montelukast for the prevention of exercise-induced bronchoconstriction (EIB). Sixty-two patients with EIB (post-exercise decrease in forced expiratory volume in 1 second (FEV(1)) > or = 20% at pre-randomization) were randomized to montelukast 10 mg or placebo, followed by exercise-challenge 2, 12, and 24 hours postdose. The primary endpoint was the maximum percent-fall in FEV(1) (from pre-exercise FEV(1)) during 60 minutes after exercise-challenge at 2 hours postdose. This endpoint was improved after montelukast (mean +/- SD = 11.7% +/- 10.8) versus placebo (17.5% +/- 13.8) (p < or = 0.001); numerically greater improvements were seen at 12 hours and 24 hours. A quicker time to recovery after challenge (p < or = 0.001) and a smaller area under the curve for percent-fall in FEV(1) during 60 minutes after challenge (p < or = 0.01) were seen with montelukast at 2 hours. At this timepoint, more patients taking montelukast (45/54) than taking placebo (37/54) were protected against EIB (p = 0.039). We concluded that montelukast provided significant protection against EIB at 2 hours after a single dose.

Safety of sputum induction with hypertonic saline solution in exercise-induced bronchoconstriction

BACKGROUND

The safety of sputum induction (SI) is well described in stable asthma, but the safety of SI in exercise-induced bronchoconstriction (EIB) has not been established.

OBJECTIVES

Our goals were to examine the relationship between the severity of EIB and bronchoconstriction during SI, and to determine if SI conducted after exercise challenge increases the risk of excess bronchoconstriction during SI.

METHODS

SI was conducted in 32 patients with mild-to-moderate asthma (baseline FEV(1), 86 +/- 9% of predicted [mean +/- SD]) with EIB (15 to 63% reduction in FEV(1) following exercise challenge) following pretreatment with albuterol using 3% saline solution and repeated on a separate day 30-min after exercise challenge.

RESULTS

There was a reduction in peak expiratory flow rate (PEFR) during SI without exercise (mean maximum reduction vs baseline, 4.0% at 10 min; 95% confidence interval [CI], 1.0 to 7.1; p = 0.02) and during SI 30 min following exercise (mean maximum reduction vs baseline, 5.2% at 8 min; 95% CI, 1.0 to 7.5; p < or = 0.01); however, there was no difference between the PEFR reductions during SI without or following exercise challenge. The best predictor of reduction in PEFR during SI was the preprocedure FEV(1), while the severity of EIB was not associated with bronchoconstriction during SI.

CONCLUSIONS

We conclude that SI can be performed safely following exercise challenge in asthmatics with EIB, and that the severity of EIB prior to SI is not a major determinant of bronchoconstriction during SI.