Clinical safety and tolerability of montelukast, a leukotriene receptor antagonist, in controlled clinical trials in patients aged > or = 6 years

The role of antileukotrienes in the treatment of asthma

Cysteinyl leukotrienes (Cys-LTs) are mediators released in asthma and are both direct bronchoconstrictors and proinflammatory substances that mediated several steps in the pathophysiology of chronic asthma, including inflammatory cells recruitment, vascular leakage, and possibly airway remodelling. Available evidence from clinical trials and real world experience derived from managing patients with asthma justifies a broader role for antiLTRAs in asthma management than that recommended in the National Asthma Education and Prevention Programm (NAEPP) and National Health Lung and Blood Institute (NHLBI) treatment guidelines. Leukotriene-receptor antagonist drugs (LTRAs) seem to be effective alternatives to inhaled corticosteroids (ICS) either as monotherapy or as adjunctive therapy that reduces the need for higher doses of ICS in patients with mild-to-moderate persistent asthma. LTRAs may be used as adjunctive therapy for al levels of disease severity because they are effective in combination with ICS during long-term maintenance therapy. The agents seem especially effective in preventing aspirin-induced asthma, exercise-induced asthma (EIA) and they may provide an additional advantage of reducing nasal congestion in patients with both asthma and rhinitis.

Leukotriene receptor antagonist, montelukast, can reduce the need for inhaled steroid while maintaining the clinical stability of asthmatic patients

BACKGROUND

Oral leukotriene receptor antagonists have been shown to have efficacy in chronic asthma.

OBJECTIVE

To determine whether the addition of montelukast could lead to a reduction in inhaled corticosteroid dose without a significant decrease in peak expiratory flow rate (PEFR).

METHODS

After a 4-week run-in period, 191 moderate-to-severe asthmatic patients whose asthma had been well controlled with daily inhaled corticosteroid therapy (beclometasone dipropionate 800 to 1600 micro g/day), were randomly assigned to one of two treatments - placebo (n = 98) or montelukast 10 mg once daily (n = 93) - for a 24-week, multicentre, double-blind, treatment period. At the beginning of the active treatment period, the daily dose of inhaled corticosteroid was halved in all of the patients. In addition, the inhaled corticosteroid dose was subsequently titrated every 8 weeks, based on PEFR, asthma symptoms and beta-agonist use.

RESULTS

After 8 weeks of a 50% reduction in inhaled corticosteroid use, morning PEFR increased by 5.3 +/- 32.3 L/min from baseline in patients receiving montelukast and significantly decreased by 6.9 +/- 29.0 L/min in those receiving placebo (P = 0.035). In addition, evening PEFR significantly decreased by 9.8 +/- 28.5 L/min (P = 0.003) in the placebo group, but was maintained in the montelukast group. In spite of a subsequent 50% reduction in the inhaled corticosteroid dose every 8 weeks, morning and evening PEFRs were maintained over the 24-week treatment period in the montelukast group; PEFR significantly decreased in the placebo group. There was a significant difference between the two groups with regard to morning PEFR, therapy score and asthmatic score at weeks 8, 16 and 24, as well as evening PEFR at week 8. However, the symptom scores were not significantly different between the two groups or within each group.

CONCLUSION

These data suggest that montelukast reduces the need for inhaled corticosteroids while maintaining asthma control over a 24-week period. Therefore, montelukast may be useful for long-term treatment in patients with asthma who require high doses of inhaled corticosteroids.

Montelukast: a review of its therapeutic potential in asthma in children 2 to 14 years of age

Montelukast is a cysteinyl leukotriene receptor antagonist which is used as a preventive treatment for persistent asthma in patients > or =2 years of age. In children aged 6 to 14 years montelukast (5 mg/day) treatment resulted in a significant increase in FEV(1) (forced expiratory volume in 1 second, primary clinical outcome) during an 8-week randomized, double-blind trial. Moreover, significant improvements were observed for a range of secondary endpoints assessing symptoms, exacerbation rates, beta-agonist usage and quality of life. Concomitant administration of montelukast (5 mg/day) and inhaled budesonide (200 microg twice daily) resulted in a trend towards an increase in FEV(1) (p = 0.06, primary endpoint) and a statistically significant reduction in both as-needed beta(2)-agonist usage and the percentage of days with asthma exacerbations compared with budesonide plus placebo. No significant differences were observed in asthma-related quality of life between the two groups. During clinical trials both improvements in lung function and reductions in as-needed beta(2)-agonist usage were generally observed within 1 day after initiation of therapy in children 2 to 14 years of age with persistent asthma. Data from a randomized, nonblind trial in 6- to 11-year-old children and a 6-month extension to this trial suggest that both compliance to therapy and patient satisfaction are greater for montelukast than for either inhaled sodium cromoglycate or inhaled beclomethasone. In addition, patients and parents preferred oral montelukast over sodium cromoglycate. In 2- to 5-year-old children with persistent asthma, montelukast (4 mg/day) treatment resulted in significant improvements in a range of outcomes, such as as-needed beta(2)-agonist usage, symptom scores and percentage of days with asthma symptoms, as assessed during a randomized, double-blind trial primarily designed to assess tolerability. Data from small randomized, double-blind trials suggest that montelukast reduces exercise-induced bronchoconstriction in 6- to 14-year-old children. Montelukast is generally well tolerated. The frequency of adverse events in montelukast-treated children of all ages was comparable to that in patients receiving placebo.

CONCLUSION

Oral montelukast has shown efficacy as a preventive treatment for asthma during clinical trials in children aged 2 to 14 years. The drug offers benefits over more standard therapies such as inhaled sodium cromoglycate and nedocromil in terms of compliance and convenience. In addition, the drug offers significant benefits when added to inhaled corticosteroids (according to secondary endpoints). Montelukast offers an effective, well tolerated and convenient treatment option for children with asthma.

Montelukast for treating seasonal allergic rhinitis: a randomized, double-blind, placebo-controlled trial performed in the spring

BACKGROUND

Cysteinyl leukotrienes are important proinflammatory mediators believed to have a role in allergic rhinitis.

OBJECTIVE

This multicentre, randomized, double-blind, placebo- and active-controlled trial evaluated the effectiveness and tolerability of montelukast, a cysteinyl leukotriene receptor antagonist, for treating patients with seasonal allergic rhinitis.

METHODS

After a 3- to 5-day, single-blind placebo run-in period, 1302 male and female patients (aged 15-81 years) with active allergic rhinitis symptoms were randomly assigned to receive montelukast 10 mg (n = 348), loratadine 10 mg (n = 602), or placebo (n = 352) administered once daily at bedtime for 2 weeks during the spring allergy season.

RESULTS

Mean patient characteristics and symptom scores at baseline were similar for the three treatment groups. The primary end-point, daytime nasal symptoms score (mean of nasal congestion, rhinorrhea, nasal pruritus, and sneezing scores; 0-3 scale), improved from baseline during treatment by (least squares mean, 95% confidence interval) - 0.37 (- 0.43, - 0.31), - 0.47 (- 0.52, - 0.43), and - 0.24 (- 0.29, - 0.18) in the montelukast, loratadine, and placebo groups, respectively (P < or = 0.001 comparing each active treatment with placebo). Mean changes from baseline in all other diary-based scores, including night-time and eye symptom scores, were significantly greater for each active treatment than for placebo. The rhinoconjunctivitis quality of life overall score improved significantly with montelukast and with loratadine as compared with placebo. Montelukast and loratadine showed a safety profile comparable to that of placebo.

CONCLUSION

Montelukast is well tolerated and provides improvements in daytime and night-time symptoms, as well as quality of life parameters, for patients with seasonal allergic rhinitis.

Efficacy and tolerability of montelukast alone or in combination with loratadine in seasonal allergic rhinitis: a multicenter, randomized, double-blind, placebo-controlled trial performed in the fall

BACKGROUND

Histamine and cysteinyl leukotrienes seem to be important mediators of allergic rhinitis.

OBJECTIVE

This multicenter, randomized, double-blind, parallel-group, placebo-controlled trial evaluated the effectiveness and tolerability of montelukast, loratadine, and combination therapy with montelukast and loratadine for treating patients with fall seasonal allergic rhinitis.

METHODS

After a 1-week, single-blind, placebo run-in period, 907 male and female patients aged 15 to 82 years were randomized to 1 of 4 treatments: montelukast 10 mg (n = 155), loratadine 10 mg (n = 301), combination montelukast 10 mg and loratadine 10 mg (n = 302), or placebo (n = 149), administered once daily at bedtime for 2 weeks. The primary endpoint was the daytime nasal symptoms score (mean of congestion, rhinorrhea, pruritus, and sneezing).

RESULTS

Mean symptom scores at baseline were similar for the four treatment groups. For each of the three active treatments, the difference was significant for the mean change from baseline compared with placebo (P < or = 0.001). However, the effect of montelukast/loratadine compared with loratadine alone, the primary comparison, was not significantly different. Differences for each therapy alone compared with placebo were also significant for most secondary endpoints, including nighttime symptom scores, eye symptoms scores, and rhinitis-specific quality of life. Differences for montelukast/loratadine compared with each therapy alone generally showed numerical superiority, and a few endpoints showed differences that were statistically significant. All active treatments showed a safety profile generally similar to placebo.

CONCLUSIONS

Montelukast alone or in combination with loratadine is well tolerated and provides clinical and quality-of-life benefits for patients with seasonal allergic rhinitis.

Use of oral montelukast in the treatment of asthma

Montelukast, a new leukotriene modifier, has several benefits in the treatment of asthma in adults and children including improved relief of asthma symptoms, rapid onset, a safety profile comparable with placebo, and oral, once-daily dosing means excellent adherence.

Where do leukotriene modifiers fit in asthma management?

Effective asthma treatment requires long-term inflammation control. Patient adherence to corticosteroid treatment regimens remains problematic. Leukotriene modifiers, a newer drug class, add to the pharmacologic approaches to asthma management. Here, we review the role of leukotrienes in asthma pathogenesis and appropriate uses for leukotriene modifiers in asthma management.

Therapeutic significance of distal airway inflammation in asthma

Inflammation in asthma is not merely confined to the large central airways but also extends to the small peripheral airways. Distal lung inflammation can be observed even in patients with asthma with mild disease and normal spirometric readings. Subjects with asymptomatic asthma can exhibit significant increases in peripheral airway resistance, likely the result of distal lung inflammation. As determined from measurements of eosinophilic and other cellular infiltrates, the inflammatory response in the distal lung can exceed that in the large airways. Nocturnal asthma, a natural model of cyclic asthma worsening, is associated with an increase in nighttime distal lung inflammation, as evidenced by the accumulation of alveolar tissue eosinophils. Distal lung disease appears to increase the risk of recurrent asthma exacerbation, whereas disease-related anatomic changes in the small airways of the distal lung are prominent in fatal asthma. The clinical significance of distal lung disease makes this region an important therapeutic target. Chlorofluorocarbon (CFC)-based preparations of inhaled corticosteroids used to treat airway inflammation produce aerosols of relatively large particle size (approximately 4 microm); such aerosols have poor access to the distal lung. New formulations of inhaled corticosteroids that use hydrofluoroalkane (HFA) propellants can have smaller particle sizes (approximately 1 microm). Extrafine HFA aerosols have better access to the distal lung, with less oropharyngeal deposition. Imaging studies suggest that anti-inflammatory medication delivered as an extrafine aerosol produces beneficial changes in distal lung function. In one study, an HFA formulation of an inhaled corticosteroid reduced air trapping to a greater degree than a CFC formulation of the same corticosteroid. By extending the delivery of anti-inflammatory medication to the distal lung, the new HFA-based corticosteroids have the potential to treat asthma more effectively and at reduced steroid doses.

Antileukotrienes in clinical development for asthma

Asthma is a serious world health problem characterised by a chronic inflammatory disorder of the airways. Asthma attacks, or exacerbations, are episodic but airway inflammation is chronically present. Thus, this disorder requires long-term management. The goals of asthma management include prevention steps for long-term control, action steps to stop attacks, recognising deteriorating asthma, how to treat deteriorating asthma, how and when to seek medical attention and education. In order to achieve the best therapeutic choice, a stepwise approach should be adopted. In recent years, much progress regarding the characterisation of leukotrienes (LTs) has been achieved. These substances are important products of action of the 5-lipoxygenase (5-LO) enzyme on arachidonic acid (AA) and it has been established that the leukotrienes are key mediators of both allergy and inflammation. Consequently, the important role of the cysteinyl-leukotrienes (Cys-LTs) in the pathophysiology of bronchial asthma has been suggested. Pharmacological support for the role of Cys-LTs in asthma has been observed using inhibitors of 5-LO and specific LT receptor antagonists. In the clinical setting, the LT receptor, which plays the most important role, is the Cys-LT1 receptor. The antagonists of this receptor have proven an effective therapy in chronic asthmatics, agonist antigens and exercise-induced bronchoconstriction and in aspirin-intolerant asthmatics. These drugs provide a new approach in asthmatic therapy and therefore may facilitate the compliance of daily therapy.