Randomised, placebo controlled trial of effect of a leukotriene receptor antagonist, montelukast, on tapering inhaled corticosteroids in asthmatic patients

Leukotriene inhibitors and non-steroidal therapies in the treatment of asthma

Asthma is the most common chronic disease of childhood whose morbidity and mortality continues to rise [1]. Drugs used in the treatment of asthma must be targeted at reversing three principle pathophysiologic features: bronchoconstriction, mucus plugging/hypersecretion and inflammation. In the past two decades, the contribution of airway inflammation to the development and progression of asthma symptoms and airway pathology has become a critical focus. Chronic airway inflammation can lead to the progressive decline and irreversible loss of lung function and airway remodelling [2]. In recent years, therapies aimed at diminishing airway inflammation have been at the forefront of asthma management. Steroids have been extensively studied and used as primary anti-inflammatory agents in the management of the asthmatic patient with persistent symptoms of varying severity. Within the last decade, however, several additional non-steroidal classes of drugs have begun to emerge as anti-inflammatory agents for the treatment of asthma. This article will focus on these non-steroidal drugs which have been developed and investigated within the last 5 years. Particular emphasis will be placed on leukotriene receptor antagonists, but anti-IgE and anti-IL-4 therapies, as well as phosphodiesterase inhibitors will also be discussed. Of these new therapies, only two leukotriene receptor antagonists, montelukast (Singulairtrade mark, Merck) and zafirlukast (Accolatetrade mark, AstraZeneca) and the 5-lipoxygenase inhibitor, zileuton (Zyflotrade mark, Abbott Laboratories), have been recommended, approved and are currently available for use in the treatment of paediatric patients with asthma in the United States.

Changes in asthma drug therapy costs for patients receiving chronic montelukast therapy in the U.K

The aim of this study was to assess changes in the costs of asthma drug therapy before and during the use of chronic montelukast treatment in the U.K. A retrospective cohort analysis of a primary care database in the U.K. was carried out. Patients with chronic montelukast use (> or = 140 once-daily doses) were selected for analysis. Benchmarking data were obtained for matched patients with chronic inhaled corticosteroid (ICS) use and patients with chronic salmeterol therapy with concomitant ICS use. The main outcome measures were changes in utilization and monthly cost of asthma therapies costs. Asthma patients experienced significant (P<0.05) reductions in the monthly costs of ICS, short-acting beta-agonists and antibiotics following chronic montelukast therapy. Monthly concomitant drug costs were reduced by Pound Sterling 7.49 per month, which offset 27.5% of the additional cost of montelukast, yielding an increase in total drug costs of Pound Sterling 19.78 per month. Meanwhile, increased total drug costs for matched patients with chronic ICS use, and matched patients with chronic salmeterol therapy and concomitant ICS use, increased by Pound Sterling 5.37 per month and Pound Sterling 44.55 per month respectively. Additionally, patients using chronic montelukast therapy experienced a statistically significant (P<0.05) reduction in the use of short acting beta-agonists, and antibiotics, suggesting improvement in asthma control. Chronic use of montelukast therapy is associated with a reduction of concomitant drug therapy costs.

Leukotriene receptor antagonist therapy

Leukotriene receptor antagonists (LTRA) are a new class of drugs for asthma treatment, available in tablet form. Their unique mechanism of action results in a combination of both bronchodilator and anti-inflammatory effects. While their optimal place in asthma management is still under review, LTRA represent an important advance in asthma pharmacotherapy.

Fluticasone propionate/salmeterol combination provides more effective asthma control than low-dose inhaled corticosteroid plus montelukast

BACKGROUND

Asthma is a disease of chronic inflammation and bronchoconstriction. Inhaled corticosteroids (ICSs) provide important anti-inflammatory treatment but may not provide optimal control of asthma when taken alone. Two therapeutic alternatives for enhanced asthma control are to substitute the combination of fluticasone propionate (FP) and salmeterol (FP/Salm Combo) through the Diskus inhaler or to add montelukast to existing ICS therapy.

OBJECTIVE

We compared the efficacy and safety of FP/Salm Combo through the Diskus inhaler versus montelukast added to FP (FP + montelukast) in patients whose symptoms were suboptimally controlled with ICS therapy.

METHODS

We performed a multicenter, double-blind, double-dummy, parallel-group, 12-week study in 447 patients with asthma who were symptomatic at baseline while receiving low-dose FP. Patients were treated for 12 weeks with one of the following: (1) combination of FP 100 microg plus salmeterol 50 microg twice daily through the Diskus inhaler, or (2) FP 100 microg twice daily through the Diskus inhaler plus oral montelukast 10 mg once daily.

RESULTS

FP/Salm Combo treatment provided better overall asthma control than FP + montelukast with significantly greater improvements in morning peak expiratory flow (+24.9 L/min vs +13.0 L/min, P <.001), evening peak expiratory flow (+18.9 L/min vs +9.6 L/min, P <.001), and forced expiratory volume in 1 second (+0.34 L vs +0.20 L, P <.001), as well as a change in the percentage of days with no albuterol use (+26.3% vs +19.1%, P =.032) and the shortness of breath symptom score (-0.56 vs -0.40, P =.017). The groups had comparable improvements in chest tightness, wheeze, and overall symptom scores. Asthma exacerbation rates were significantly lower (P =.031) in the FP/Salm Combo group (4 patients, 2%) than in the FP + montelukast group (13 patients, 6%). Adverse event profiles were comparable.

CONCLUSION

Symptomatic patients on low-dose ICS therapy had significantly greater improvement in asthma control when switched to the FP/Salm Combo than when montelukast was added to ICS therapy.

Feline asthma. Diagnosis and treatment

Human asthma is not a curable disease, although spontaneous resolution is common in adult asthmatics who developed asthma in childhood. We do not know if this is true or not for cats with asthma. We do know that some cats may be only mildly and intermittently symptomatic and that others may suffer life-threatening illness. An important new development in our understanding of this disease is the occurrence of airway inflammation even when patients are symptom-free. It is therefore crucial that we direct our therapeutic attention toward the underlying chronic inflammation that causes the acute clinical signs of cough, wheeze, and increased respiratory effort. Client education is also critical so that our clients develop realistic expectations of the effectiveness of these treatments for their pets. A great deal still needs to be learned regarding the pathogenesis of feline asthma and the optimal approach(es) to treating cats with this sometimes debilitating and potentially fatal respiratory syndrome. There is great hope and anticipation that ongoing research can bring new treatments for human and feline asthmatics alike.

Prevention of asthma morbidity: recent advances

Asthma prevalence has risen substantially in recent decades and is an increasing cause of disability for American children. Concern about the rise in morbidity has led to treatment guidelines and a growing body of clinical research. Recent trials continue to support the role of inhaled corticosteroids as the most effective therapy to control airway inflammation associated with persistent asthma. Growth suppression due to inhaled corticosteroids has also been well documented, although the long-term effects and relative potencies of different agents require further study. Other anti-inflammatory agents such as cromolyn and the new class of leukotriene receptor antagonists have demonstrated benefit in milder patients. Leukotriene receptor antagonists and long-acting beta2-agonists may allow for reduction of inhaled steroid doses. Control of environmental allergens and irritants is essential. New evidence suggests an increasingly important role for allergen immunotherapy.

[Role of leukotriene inhibitors in the treatment of childhood asthma]

Leukotriene inhibitors are new pharmacological agents for the treatment of mild to moderate persistent asthma and exercise-induced asthma (EIA). Studies concerning their use in children remain scarce. Available data in the treatment of persistent asthma in children suggest that they could be an alternative to long-acting beta 2-agonists when asthma control cannot be obtained with inhaled steroids alone. Their main advantages are first that they are given orally once daily; second, that they do not induce tachyphylaxis to bronchoprotection against EIA, unlike long-acting beta 2-agonists. Studies specifically conducted in children are necessary to best describe their place in pediatric asthma treatment.

Bronchoprotection with a leukotriene receptor antagonist in asthmatic preschool children

We hypothesized that a leukotriene receptor antagonist (LTRA) could provide bronchoprotection against the cold, dry air-induced response in asthmatic preschool children. In a randomized, double-blind, placebo-controlled crossover study, we examined the effect of the specific LTRA montelukast at 5 mg/d for 2 d on the bronchoconstriction induced by hyperventilation of cold, dry air in 13 asthmatic children 3 to 5 yr old. The bronchoconstriction was measured as the specific airway resistance (sRaw) in a whole-body plethysmograph before and 4 min after challenge with cold, dry air. The repeatability of the bronchoprotection was examined by repeating the placebo-controlled study in six of the 13 children. sRaw increased by an average of 46% (95% confidence interval [CI]: 30 to 63%) after placebo treatment and 17% (95% CI: 3 to 31%) after montelukast (p < 0.01). Eight of the children were receiving regular treatment with budesonide delivered by an inhaler with a spacer in a mean daily dose of 350 microg, but the bronchoprotection provided by montelukast was independent of concurrent steroid treatment. There was no convincing evidence of failure to respond, and the protective effect of montelukast was consistent upon repeated testing (p = 0. 02). We conclude that the LTRA montelukast provided clinically significant bronchoprotection against the effect of hyperventilation of cold dry air in asthmatic children 3 to 5 yr old. The bronchoprotection appeared to be homogeneous among the children, and seemed independent of steroid treatment. This suggests that LTRAs may be of therapeutic use in limiting clinical symptoms of asthma in young children.

Leukotriene receptor antagonists and synthesis inhibitors reverse survival in eosinophils of asthmatic individuals

Eosinophilia is a feature of airway inflammation associated with asthma. Leukotriene antagonists provide therapeutic benefit in asthma, but their potential antiinflammatory actions have not been fully explored. We have examined the role of eosinophil-derived cysteinyl leukotrienes in the maintenance of eosinophil survival, and the involvement of leukotrienes in the paracrine stimulation of eosinophil survival by mast cells and lymphocytes. We obtained eosinophils and autologous lymphocytes from peripheral blood of asthmatic subjects. Leukotriene (LT)-B(4), LTC(4) and LTD(4), granulocyte-macrophage colony-stimulating factor (GM-CSF), and fibronectin promoted eosinophil survival. LTD(4) (10(-)(6) M) was as effective as GM-CSF (5 ng/ml) and fibronectin (400 ng/ml) in promoting survival. Lymphocytes and conditioned medium from a human mast cell line (HMC-1) induced eosinophil survival. Blockade of cysteinyl leukotriene receptors with SKF 104353 (pobilukast, 3 nM), and inhibition of 5-lipoxygenase (5-LO) with BW A4C (1 microM) and of 5-LO activating protein with MK 886 (1 microM), all increased basal rates of eosinophil apoptosis and reversed GM-CSF-induced eosinophil survival. Fifty percent reversal of GM-CSF- induced survival was achieved with SKF 104353 at 0.3 nM. The potency of SKF 104353 was two orders of magnitude greater than that of the LTB(4) receptor antagonist SB 201146. Mast cell- and lymphocyte-induced eosinophil survival were completely reversed by SB 201146, SKF 104353, BW A4C, and MK 886. These findings provide evidence for the involvement of an autocrine cysteinyl leukotriene pathway that supports eosinophil survival in response to a range of survival stimuli. They also suggest that LTB(4) could act as a paracrine stimulus of eosinophil survival.

Corticosteroid-sparing options in the treatment of childhood asthma

During the last 30 years, a significant rise in wheezing illness has occurred in the child population. Despite its high prevalence there is no clear definition of the disease, which includes a heterogeneous group of syndromes ranging from transient wheezing in infancy to atopic asthma with persistence into adult life. Molecular advances and further epidemiological information from well characterised individuals and their families are likely to clarify the different subtypes of wheezing illness and inform therapeutic options. With the recognition that chronic airway inflammation is a feature of persistent disease, at least in adults, there has been a trend towards the early introduction of anti-inflammatory treatment and particularly inhaled corticosteroids (ICS). However, the natural resolution of much wheezing illness, particularly in young children and in children with viral-induced episodes, suggests that newly presenting children should remain on symptomatic therapy alone while the severity of the disease is being assessed. Although ICS have become a cornerstone of management of chronic persistent disease, their ability to protect against exacerbations in young and mildly affected children is questionable. Alongside concerns about long term use of ICS and possible systemic adverse effects, there remains a need for alternative approaches to the control of the disease in children. Extrapolation of the findings of large multicentre adult studies into childhood, particularly for doubling the doses of ICS and long-acting beta2-agonists, may be unsound. Other approaches include the early introduction of inhaled cromones, use of second generation antihistamines, low dose theophyllines and, more recently, leukotriene modifiers. As the majority of preschool children will become asymptomatic by mid-childhood, there is an urgent need to identify those in whom chronic airway inflammation is developing, as it is in this group that early introduction of ICS may be of maximum benefit. In the remainder, other approaches, including use of corticosteroid-sparing longacting P2-agonists and leukotriene modifying drugs, may be more appropriate. Safe and effective oral preparations such as leukotriene modifying drugs are likely to establish a significant role in the management of symptoms in children of all ages and with all types of asthma and wheezing illness.

Clinical evidence with montelukast in the management of chronic childhood asthma

OBJECTIVE

The aim of this article is to review data on the efficacy and safety of montelukast in the treatment of children with asthma.

METHODOLOGY

Available published literature, including published abstracts, is reviewed.

RESULTS

In patients aged 6 to 14 years with asthma (n = 27), montelukast 5mg demonstrated a significant decrease in exercise-induced bronchoconstriction 20 to 24 hours postdose after 2 days of treatment. For children with chronic asthma, only one study of the regular use of a leukotriene receptor antagonist has been published. The efficacy and safety of montelukast in children aged 6 to 14 years with asthma (n = 336) were studied during an 8-week, double-blind, placebocontrolled trial. There was a significantly greater improvement in forced expiratory volume in 1 second (FEV1) from baseline for the montelukast group (8.23%) compared with the placebo group (3.58%). There was a significant decrease in the use of a 3-agonist for symptom relief, as well as in the percentage of days and percentage of patients with asthma exacerbations. An asthma specific quality-of-life (QOL) questionnaire revealed a significant overall improvement in QOL and a significant improvement in the QOL domains for symptoms, activity and emotions in montelukast recipients. There was no significant difference between montelukast and placebo recipients in the frequency of adverse events, with the exception of allergic rhinitis, which was more prevalent in the placebo group. An open label follow-up of patients from the above study was undertaken. The effect of montelukast on FEV1 was consistent for up to 1.4 years, with the increase in FEV1 being not significantly different from that in a small control group treated with inhaled beclomethasone dipropionate. QOL remained significantly improved during the open treatment period.

CONCLUSIONS

Montelukast appears effective and safe for the treatment of children with asthma.

Leukotriene-receptor antagonists. Role in asthma management

OBJECTIVE

To examine the role of leukotriene-receptor antagonists (LTRAs) in management of asthma.

QUALITY OF EVIDENCE

Most data were derived from randomized, double-blind, controlled trials.

MAIN MESSAGE

Leukotrienes appear to have an important role in the pathophysiology of asthma, including airway inflammation. Leukotriene-receptor antagonists are effective in improving asthma control end points, such as allergen, ASA, and exercise challenge, in clinical models of asthma. In chronic asthma, LTRA administration reduces asthma symptoms and rescue beta 2-agonist use, changes that are paralleled by improvements in lung function. Both zafirlukast and montelukast decrease circulating levels of eosinophils and could have other useful anti-inflammatory properties. Administration of LTRAs allows doses of inhaled corticosteroids to be reduced. Currently available LTRAs are free of serious side effects and are available as oral formulations.

CONCLUSIONS

Leukotriene-receptor antagonists belong to a new class of asthma medication. While inhaled corticosteroids remain first-line therapy for managing chronic asthma, LTRAs should be considered for patients with ASA-sensitive asthma; as adjunct therapy when low to moderate doses of inhaled steroid alone provide incomplete control; or as adjunct therapy to allow reduction in doses of inhaled corticosteroids.

Montelukast: a review of its therapeutic potential in persistent asthma

Montelukast is a cysteinyl leukotriene receptor antagonist used to treat persistent asthma in patients aged > or = 6 years. The drug has a rapid onset of action. Improvements in lung function and reductions in as-needed beta2-agonist usage are apparent within 1 day of initiating montelukast treatment in adults and adolescents (aged > or = 15 years treated with 10 mg/day) or children (aged 6 to 14 years treated with 5 mg/day) with persistent asthma as shown in clinical trials. In two 12-week, multicentre, randomised, double-blind studies in adults and adolescents aged > or = 15 years with persistent asthma [forced expiratory volume in 1 second (FEV1) = 50 to 85% predicted] there was significantly (p < 0.05) greater improvement in FEV1, symptom scores, peak expiratory flow (PEF), as-needed beta2-agonist use, peripheral eosinophil counts and health-related quality of life (QOL) in patients treated with montelukast 10 mg/day than in recipients of placebo. Improvements were significantly greater in patients treated with inhaled beclomethasone 400 microg/day than in recipients of montelukast 10 mg/day in 1 of these studies. Nonetheless, 42% of montelukast recipients experienced > or = 11% improvement in FEV1, the median improvement in this parameter in beclomethasone-treated patients. In an 8-week multicentre, randomised, double-blind, study in children aged 6 to 14 years with persistent asthma (FEV1 50 to 85% predicted), montelukast 5 mg/day produced significantly greater improvements in FEV1, clinic PEF, as-needed beta2-agonist use, peripheral eosinophil counts, asthma exacerbations and QOL scores than placebo. The combination of montelukast 10 mg/day plus inhaled beclomethasone 200 microg twice daily provided significantly better asthma control than inhaled beclomethasone 200 microg twice daily in adults with poorly controlled asthma (mean FEV1 = 72% predicted) despite 4 weeks treatment with inhaled beclomethasone. Patients receiving the combination experienced significant improvements in FEV1 and morning PEF, significant reductions in daytime symptom scores, as-needed beta2 agonist usage and night-time awakenings with asthma, and had significantly lower peripheral blood eosinophil counts after 16 weeks in this multicentre, randomised, double-blind, placebo-controlled study. Among adults (FEV1 > or = 70%) treated with montelukast 10 mg/day for 12 weeks, inhaled corticosteroid dosages were titrated downward by 47% (vs 30% in placebo recipients), 40% of patients were tapered off of inhaled corticosteroids (vs 29%), and significantly fewer patients (16 vs 30%) experienced failed corticosteroid rescues in a multicentre, randomised, double-blind study. During clinical studies, the frequency of adverse events in montelukast-treated adults, adolescents and children was similar to that in placebo recipients. In conclusion, montelukast is well tolerated and effective in adults and children aged > or = 6 years with persistent asthma including those with exercise-induced bronchoconstriction and/or aspirin sensitivity. Furthermore, montelukast has glucocorticoid sparing properties. Hence, montelukast, as monotherapy in patients with mild persistent asthma, or as an adjunct to inhaled corticosteroids is useful across a broad spectrum of patients with persistent asthma.

Montelukast added to inhaled beclomethasone in treatment of asthma. Montelukast/Beclomethasone Additivity Group

The primary objective of this study was to determine whether montelukast, an oral leukotriene receptor antagonist, provides additional clinical benefit to the effect of inhaled corticosteroids. A total of 642 patients with chronic asthma (FEV(1) 50 to 85% of predicted value and at least a predefined level of asthma symptoms) incompletely controlled with inhaled beclomethasone, 200 microg twice daily using a spacer device, during the 4-wk run-in period were randomly allocated, in a double-blind, double-dummy manner to one of four treatment groups: (1) montelukast 10 mg plus continuing inhaled beclomethasone; (2) placebo tablet plus continuing inhaled beclomethasone; (3) montelukast 10 mg and inhaled placebo (after blind beclomethasone removal); and (4) placebo tablet and inhaled placebo (after blind beclomethasone removal). The primary endpoints were FEV(1) and daytime asthma symptoms score. Montelukast provided significant (p < 0.05) clinical benefit in addition to inhaled beclomethasone by improving FEV(1), daytime asthma symptom scores, and nocturnal awakenings. Blind removal of beclomethasone in the presence of placebo tablets caused worsening of asthma control, demonstrating that patients received clinical benefit from inhaled corticosteroids. Blind removal of beclomethasone in the presence of montelukast resulted in less asthma control but not to the level of the placebo group. All treatments were well tolerated; clinical and laboratory adverse experiences were generally similar to placebo treatment in this study. In conclusion, montelukast provided additional asthma control to patients benefitting from, but incompletely controlled on, inhaled beclomethasone.

Use of leukotriene antagonists in childhood asthma

Leukotrienes have been shown to cause bronchoconstriction, increased mucus production, and airway inflammation, three critical features in asthma. Antileukotriene drugs were developed to inhibit the effects of these lipid mediators. This class of drugs represents the first new approach to asthma therapy in 25 years. The leukotriene receptor antagonists, montelukast, zafirlukast, and pranlukast, and the 5-lipoxygenase inhibitor, zileuton, are unique in their ability to target specific components of asthmatic inflammation. Although the role of these drugs continues to evolve, the antileukotrienes have demonstrated efficacy against exercise and allergen-induced bronchoconstriction and additive benefit for use in patients with symptomatic, moderate asthma on maintenance-inhaled corticosteroids. Further, they may be considered for primary use in patients with mild, persistent asthma, especially those who are steroid-phobic or who have compliance issues.