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

Current Approaches in the Multimodal Management of Asthma in Adolescents-From Pharmacology to Personalized Therapy

Asthma and adolescence are two sensitive points and are difficult to manage when they coexist. The first is a chronic respiratory condition, with frequent onset in early childhood (between 3 and 5 years), which can improve or worsen with age. Adolescence is the period between childhood and adulthood (12-19 years), marked by various internal and external conflicts and a limited capacity to understand and accept any aspect that is delimited by the pattern of the social circle (of the entourage) frequented by the individual. Therefore, the clinician is faced with multiple attempts regarding the management of asthma encountered during the adolescent period, starting from the individualization of the therapy to the control of compliance (which depends equally on the adverse reactions, quality of life offered and support of the close circle) and the social integration of the subject, communication probably having a more important role in the monitoring and evolution of the condition than the preference for a certain therapeutic scheme. Current statistics draw attention to the increase in morbidity and mortality among children with bronchial asthma, an aspect demonstrated by the numerous hospitalizations recorded, due either to an escalation in the severity of this pathology or to faulty management. The purpose of this article is to review the delicate aspects in terms of controlling symptoms and maintaining a high quality of life among teenagers.

Non-esophageal eosinophilic gastrointestinal diseases: a narrative review

Eosinophilic gastrointestinal disorders are a group of rare diseases characterized by the infiltration of eosinophils in the gastrointestinal wall in a greater amount than in homeostatic conditions. 'Non-esophageal eosinophilic gastrointestinal disorders' is the umbrella term for all eosinophilic gastrointestinal disorders outside of the well known eosinophilic esophagitis. This includes eosinophilic gastritis, eosinophilic enteritis and eosinophilic colitis. The clinical presentation is atypical and not very different for the three disorders. The depth of infiltration has a bigger influence on the presenting symptoms than the disease location. Although the frequency of diagnosis and research in this subject is increasing over time, non-esophageal eosinophilic disorders are rare and high quality evidence is limited to date. In this narrative review, we provide an overview of the latest insights in the pathophysiology, diagnostic approach and available treatment options. Transcriptome studies have found the pathogenesis to be T helper type 2 driven. Various laboratory findings can be used to trigger raised suspicion and investigation with endoscopy. As the endoscopic appearance of the mucosa is normal in most cases, multiple biopsies in each segment are needed to quantify the amount of eosinophils in the tissue. Eosinophilic cut-offs for diagnosis are a controversial topic and a consensus is still lacking. A recently developed tissue based diagnostic platform which measures differentially expressed genes might be available in the future to classify patients with intermediate eosinophilic tissue levels under the cut-off. For the treatment, corticosteroids are still the cornerstone of treatment but promising research suggests a role of biologicals, such as Lirentelimab (anti-siglec 8) in particular.

Developmental Pharmacogenetics of SLCO2B1 on Montelukast Pharmacokinetics in Chinese Children

Background

Montelukast, a potent oral selective leukotriene-receptor antagonist, inhibits the action of cysteinyl-leukotriene in patients with asthma. Although pharmacokinetic studies of montelukast have been reported in Caucasian adults and children, and showed large inter-individual variability on pharmacokinetics, none of these studies has been explored in Chinese children. Given the potential inter-ethnic difference, the purpose of the present study was to evaluate the effects of developmental factors and pharmacogenetics of CYP2C8 and SLCO2B1 on montelukast clearance in Chinese pediatric patients.

Methods

After the administration of montelukast, blood samples were collected from children and plasma concentrations were determined using an adapted micro high-performance liquid chromatography coupled with the fluorescence detection (HPLC-FLD) method. A previously published pharmacokinetic model was validated using the opportunistic pharmacokinetic samples, and individual patient’s clearance was calculated using the validated model. Population pharmacokinetic analysis was performed using a nonlinear mixed-effects model approach (NONMEM V 7.2.0) and variants of CYP2C8 and SLCO2B1 were genotyped.

Results

Fifty patients (age range: 0.7–10.0 years) with asthma were enrolled in this study. The clearance of montelukast was significantly higher in children with the SLCO2B1 c.935GA and c.935AA genotypes compared with that of children with the SLCO2B1 c.935GG genotype (0.94 ± 0.26 versus 0.77 ± 0.21, p = 0.020). The patient’s weight was also found to be significantly corrected with montelukast clearance (p <0.0001).

Conclusion

The developmental pharmacology of montelukast in Chinese children was evaluated. Weight and SLCO2B1 genotype were found to have independent significant impacts on the clearance of montelukast.

Effectiveness of montelukast administered as monotherapy or in combination with inhaled corticosteroid in pediatric patients with uncontrolled asthma: a prospective cohort study

BACKGROUND

Asthma is the most common chronic disease of childhood and a leading cause of childhood morbidity. The aim of the current study was to assess the effectiveness of montelukast administered as monotherapy or in combination with current inhaled corticosteroids (ICS) in pediatric patients with uncontrolled asthma as per the Canadian Asthma Consensus Guidelines.

METHODS

Twelve-week, multicentre, open-label, observational study. Primary effectiveness outcome was the proportion of patients achieving asthma control (Asthma Control Questionnaire (ACQ) score ≤0.75) at weeks 4 and 12.

RESULTS

A total of 328 patients with uncontrolled asthma (ACQ > 0.75) were enrolled with mean ± SD age of 6.9 ± 3.4 years. Among these, 76 (23.2%) were treated with montelukast monotherapy and 252 (76.8%) with montelukast combined with ICS. By 4 weeks of treatment 61.3% and 52.9% of the patients in the monotherapy and combination group, respectively, achieved asthma control. These proportions increased to 75.0% and 70.9%, respectively, at 12 weeks. Within the monotherapy group, clinically significant improvements in the ACQ score (mean ± SD of 1.67 ± 0.69, 0.71 ± 0.70 and 0.50 ± 0.52 at baseline, 4 and 12 weeks, respectively; p < 0.001) and the PACQLQ score (mean ± SD of 5.34 ± 1.14, 6.32 ± 0.89 and 6.51 ± 0.85 at baseline, 4 and 12 weeks, respectively; p < 0.001) were observed. In the combination group, the mean ± SD ACQ score significantly improved from 2.02 ± 0.83 at baseline to 0.90 ± 0.86 at 4 weeks and 0.64 ± 0.86 at 12 weeks (p < 0.001), while the PACQLQ score improved from 4.42 ± 1.35 at baseline to 5.76 ± 1.30 at 4 weeks and 6.21 ± 1.03 at 12 weeks (p < 0.001). After a 12-week montelukast add-on therapy, 22.6% of patients reduced their ICS dosage. Similar results were observed among preschool- and school-aged patients.

CONCLUSIONS

Montelukast as monotherapy or in combination with ICS represents an effective treatment strategy for achieving asthma control in pediatric patients and improving caregivers' quality of life.

TRIAL REGISTRATION

This study is registered at ClinicalTrial.gov: NCT00832455.

Addition of anti-leukotriene agents to inhaled corticosteroids in children with persistent asthma

BACKGROUND

In the treatment of children with mild persistent asthma, low-dose inhaled corticosteroids (ICS) are recommended as the preferred monotherapy (referred to as step 2 of therapy). In children with inadequate asthma control on low doses of ICS (step 2), asthma management guidelines recommend adding an anti-leukotriene agent to existing ICS as one of three therapeutic options to intensify therapy (step 3).

OBJECTIVES

To compare the efficacy and safety of the combination of anti-leukotriene agents and ICS to the use of the same, an increased, or a tapering dose of ICS in children and adolescents with persistent asthma who remain symptomatic despite the use of maintenance ICS. In addition, we wished to determine the characteristics of people or treatments, if any, that influenced the magnitude of response attributable to the addition of anti-leukotrienes.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register of Trials (CAGR), which were derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, AMED, and CINAHL; and the handsearching of respiratory journals and meeting abstracts, as well as the www.clinicaltrials.gov website. The search was conducted until January 2013.

SELECTION CRITERIA

We considered for inclusion randomised controlled trials (RCTs) conducted in children and adolescents, aged one to 18 years, with asthma, who remained symptomatic despite the use of a stable maintenance dose of ICS and in whom anti-leukotrienes were added to the ICS if they were compared to the same, an increased, or a tapering dose of ICS for at least four weeks.

DATA COLLECTION AND ANALYSIS

We used standard methods expected by The Cochrane Collaboration.

MAIN RESULTS

Five paediatric (parallel group or cross-over) trials met the inclusion criteria. We considered two (40%) trials to be at a low risk of bias. Four published trials, representing 559 children (aged ≥ six years) and adolescents with mild to moderate asthma, contributed data to the review. No trial enrolled preschoolers. All trials used montelukast as the anti-leukotriene agent administered for between four and 16 weeks. Three trials evaluated the combination of anti-leukotrienes and ICS compared to the same dose of ICS alone (step 3 versus step 2). No statistically significant group difference was observed in the only trial reporting participants with exacerbations requiring oral corticosteroids over four weeks (N = 268 participants; risk ratio (RR) 0.80, 95% confidence interval (CI) 0.34 to 1.91). There was also no statistically significant difference in percentage change in FEV₁ (forced expiratory volume in 1 second) with mean difference (MD) 1.3 (95% CI -0.09 to 2.69) in this trial, but a significant group difference was observed in the morning (AM) and evening (PM) peak expiratory flow rates (PEFR): N = 218 participants; MD 9.70 L/min (95% CI 1.27 to 18.13) and MD 10.70 (95% CI 2.41 to 18.99), respectively. One trial compared the combination of anti-leukotrienes and ICS to a higher-dose of ICS (step 3 versus step 3). No significant group difference was observed in this trial for participants with exacerbations requiring rescue oral corticosteroids over 16 weeks (N = 182 participants; RR 0.82, 95% CI 0.54 to 1.25), nor was there any significant difference in exacerbations requiring hospitalisation. There was no statistically significant group difference in withdrawals overall or because of any cause with either protocol. No trial explored the impact of adding anti-leukotrienes as a means to taper the dose of ICS.

AUTHORS' CONCLUSIONS

The addition of anti-leukotrienes to ICS is not associated with a statistically significant reduction in the need for rescue oral corticosteroids or hospital admission compared to the same or an increased dose of ICS in children and adolescents with mild to moderate asthma. Although anti-leukotrienes have been licensed for use in children for over 10 years, the paucity of paediatric trials, the absence of data on preschoolers, and the variability in the reporting of relevant clinical outcomes considerably limit firm conclusions. At present, there is no firm evidence to support the efficacy and safety of anti-leukotrienes as add-on therapy to ICS as a step-3 option in the therapeutic arsenal for children with uncontrolled asthma symptoms on low-dose ICS.

Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults

BACKGROUND

Daily inhaled corticosteroids (ICS) are the recommended mainstay of treatment in children and adults with persistent asthma. However, often, ICS are used intermittently by patients or recommended by physicians to be used only at the onset of exacerbations.

OBJECTIVES

The aim of this review was to compare the efficacy and safety of intermittent versus daily ICS in the management of children and adults with persistent asthma and preschool-aged children suspected of persistent asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov web site up to October 2012.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intermittent ICS versus daily ICS in children and adults with persistent asthma. No co-interventions were permitted other than rescue relievers and oral corticosteroids used during exacerbations.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data. The primary efficacy outcome was the number of patients with one or more exacerbations requiring oral corticosteroids and the primary safety outcome was the number of patients with serious adverse health events. Secondary outcomes included exacerbations, lung function tests, asthma control, adverse effects, withdrawal rates and inflammatory markers. Equivalence was assumed if the risk ratio (RR) estimate and its 95% confidence interval (CI) were between 0.9 and 1.1. Quality of the evidence was assessed using GRADE.

MAIN RESULTS

Six trials (including one trial testing two relevant protocols) met the inclusion criteria for a total of seven group comparisons. The four paediatric trials (two involving preschool children and two school-aged children) and two adult parallel-group trials, lasting 12 to 52 weeks, were of high methodological quality. A total of 1211 patients with confirmed, or suspected, persistent asthma contributed to the meta-analyses. There was no statistically significant group difference in the risk of patients experiencing one or more exacerbations requiring oral corticosteroids (1204 patients; RR 1.07; 95% CI 0.87 to 1.32; the large confidence interval translates into a risk of exacerbations in the intermittent ICS group varying between 17% and 25%, assuming a 19% risk with daily ICS). Age, severity of airway obstruction, step-up protocol used during exacerbations and trial duration did not significantly influence the primary efficacy outcome. No group difference was observed in the risk of patients with serious adverse health events (1055 patients; RR 0.82; 95% CI 0.33 to 2.03). Compared to the daily ICS group, the intermittent ICS group displayed a smaller improvement in change from baseline peak expiratory flow rate (PEFR) by 2.56% (95% CI -4.49% to -0.63%), fewer symptom-free days (standardised mean difference (SMD) -0.15 (95% CI -0.28 to -0.03), fewer asthma control days -9% (95% CI -14% to -4%), more use of rescue β2-agonists by 0.12 puffs/day (95% CI 0 to 0.23) and a greater increase from baseline in exhaled nitric oxide of 16.80 parts per billion (95% CI 11.95 to 21.64). There was no significant group difference in forced expiratory volume in one second (FEV1), quality of life, airway hyper-reactivity, adverse effects, hospitalisations, emergency department visits or withdrawals. In paediatric trials, intermittent ICS (budesonide and beclomethasone) were associated with greater growth by 0.41 cm change from baseline (532 children; 95% CI 0.13 to 0.69) compared to daily treatment.

AUTHORS' CONCLUSIONS

In children and adults with persistent asthma and in preschool children suspected of persistent asthma, there was low quality evidence that intermittent and daily ICS strategies were similarly effective in the use of rescue oral corticosteroids and the rate of severe adverse health events. The strength of the evidence means that we cannot currently assume equivalence between the two options.. Daily ICS was superior to intermittent ICS in several indicators of lung function, airway inflammation, asthma control and reliever use. Both treatments appeared safe, but a modest growth suppression was associated with daily, compared to intermittent, inhaled budesonide and beclomethasone. Clinicians should carefully weigh the potential benefits and harm of each treatment option, taking into account the unknown long-term (> one year) impact of intermittent therapy on lung growth and lung function decline.

Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults

BACKGROUND

Daily inhaled corticosteroids (ICS) are the recommended mainstay of treatment in children and adults with persistent asthma. Yet often, ICS are used intermittently by patients or recommended by physicians to be used only at the onset of exacerbations.

OBJECTIVES

The aim of this review was to compare the efficacy and safety of intermittent versus daily ICS in the management of children and adults with persistent asthma and preschool-aged children suspected of persistent asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov website up to December 2011.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intermittent ICS versus daily ICS in children and adults with persistent asthma. No co-interventions were permitted other than rescue relievers and oral corticosteroids used during exacerbations.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data. The primary efficacy outcome was the number of patients with one or more exacerbations requiring oral corticosteroids and the primary safety outcome was the number of patients with serious adverse health events. Secondary outcomes included exacerbations, lung function tests, asthma control, adverse effects, withdrawal rates and inflammatory markers. Equivalence was assumed if the risk ratio (RR) estimate and its 95% confidence interval (CI) were between 0.9 and 1.1.

MAIN RESULTS

Six trials (including one trial testing two relevant protocols) met the inclusion criteria for a total of seven group comparisons. The four paediatric trials (two involving preschool children and two school-aged children) and two adult parallel-group trials, lasting 12 to 52 weeks, were of high methodological quality. A total of 1211 patients with confirmed, or suspected, persistent asthma contributed to the meta-analyses. There was no statistically significant group difference in the risk of patients experiencing one or more exacerbations requiring oral corticosteroids (1204 patients; RR 1.07; 95% CI 0.87 to 1.32). The patients' age, severity of airway obstruction, step-up protocol used during exacerbations and trial duration did not significantly influence the primary efficacy outcome. No group difference was observed in the risk of patients with serious adverse health events (1055 patients; RR 0.82; 95% CI 0.33 to 2.03). Compared to the daily ICS group, the intermittent ICS group displayed a smaller improvement in change from baseline peak expiratory flow rate (PEFR) by 2.56% (95% CI -4.49% to -0.63%), fewer symptom-free days (standardised mean difference (SMD) -0.15 (95% CI -0.28 to -0.03), fewer asthma control days -9% (95% CI -14% to -4%), more use of rescue β(2)-agonists by 0.12 puffs/day (95% CI 0 to 0.23) and a greater increase from baseline in exhaled nitric oxide of 16.80 parts per billion (95% CI 11.95 to 21.64). There was no significant group difference in forced expiratory volume in one second (FEV(1)), quality of life, airway hyper-reactivity, adverse effects, hospitalisations, emergency department visits or withdrawals. In paediatric trials, intermittent ICS (budesonide and beclomethasone) were associated with greater growth by 0.41 cm change from baseline (532 children; 95% CI 0.13 to 0.69) compared to daily treatment.

AUTHORS' CONCLUSIONS

In children and adults with persistent asthma and in preschool children suspected of persistent asthma, intermittent and daily ICS strategies did not significantly differ in the use of rescue oral corticosteroids and the rate of severe adverse health events, neither did they reach equivalence. Daily ICS was superior to intermittent ICS in several indicators of lung function, airway inflammation, asthma control and reliever use. Both treatments appeared safe, but a modest growth suppression was associated with daily, compared to intermittent, inhaled budesonide and beclomethasone. The clinician should carefully weigh the potential benefits and harm of each treatment option, taking into account the unknown long-term (> one year) impact of intermittent therapy on lung growth and lung function decline.

Montelukast versus inhaled corticosteroids in the management of pediatric mild persistent asthma

International guidelines recommend the use of inhaled corticosteroids (ICSs) as the preferred therapy, with leukotriene receptor antagonists (LTRAs) as an alternative, for the management of persistent asthma in children. Montelukast (MLK) is the first LTRA approved by the Food and Drug Administration for the use in young asthmatic children.Therefore, we performed an analysis of studies that compared the efficacy of MLK versus ICSs. We considered eligible for the inclusion randomized, controlled trials on pediatric populations with Jadad score > 3, with at least 4 weeks of treatment with MLK compared with ICS.Although it is important to recognize that ICSs use is currently the recommended first-line treatment for asthmatic children, MLK can have consistent benefits in controlling asthmatic symptoms and may be an alternative in children unable to use ICSs or suffering from poor growth. On the contrary, low pulmonary function and/or high allergic inflammatory markers require the corticosteroid use.

Montelukast in the treatment of duodenal eosinophilia in children with dyspepsia: effect on eosinophil density and activation in relation to pharmacokinetics

Background

We have previously demonstrated the clinical efficacy of montelukast in a randomized double-blind controlled cross-over trial in patients with dyspepsia in association with duodenal eosinophilia. The mechanism of this clinical response is unknown but could involve a decrease in eosinophil density or activation.

Methods

Twenty-four dyspeptic patients 8–17 years of age underwent initial blood sampling and endoscopy with biopsy. Eighteen of these patients had elevated duodenal eosinophil density and underwent repeat blood sampling and endoscopy following 21 days of therapy with montelukast (10 mg/day). The following were determined: global clinical response on a 5-point Lickert-type scale, eosinophil density utilizing H & E staining, eosinophil activation determined by degranulation indices on electron microscopy, and serum cytokine concentrations. On day 21, pharmacokinetics and duodenal mucosal drug concentrations were determined.

Results

Eighty-three percent of the patients had a positive clinical response to montelukast with regard to relief of pain with 50% having a complete or nearly complete clinical response. The response was unrelated to systemic drug exposure or to mucosal drug concentration. Other than a mild decrease in eosinophil density in the second portion of the duodenum, there were no significant changes in eosinophil density, eosinophil activation, or serum cytokine concentrations following treatment with montelukast. Pre-treatment TNF-α concentration was negatively correlated with clinical response.

Conclusion

The short-term clinical response to montelukast does not appear to result from changes in eosinophil density or activation. Whether the effect is mediated through specific mediators or non-inflammatory cells such as enteric nerves remains to be determined.

Trial Registration

ClinicalTrials.gov; NCT00148603

Absorption of montelukast is transporter mediated: a common variant of OATP2B1 is associated with reduced plasma concentrations and poor response

OBJECTIVES

To (i) determine whether montelukast undergoes carrier-mediated uptake; (ii) classify the carrier protein(s) responsible for uptake; (iii) identify specific transporters that mediate transport of montelukast; and (iv) evaluate whether variation in the gene encoding the transport protein(s) influences the pharmacokinetics and pharmacodynamics of montelukast.

METHODS

In-vitro permeability studies of montelukast are carried out using Caco-2 cell culture, a standard model of human intestinal drug transport. In-vivo plasma concentrations of montelukast in an asthmatic population are determined by high-performance liquid chromatography, and genotyping of transport proteins is by LightTyper analysis.

RESULTS

Permeability of montelukast has an activation energy of 13.7+/-0.7 kcal/mol, consistent with carrier-mediated transport. Permeability is saturable at high concentrations of montelukast and follows Michaelis-Menten kinetics. Permeability is subject to competition by sulfobromophthalein, estrone-3-sulfate, pravastatin, taurocholic acid, and cholic acid (P<0.05, percentage of control: 72+/-7-86+/-7) and is inhibited by 5-10% citrus juice (P<0.05, maximal inhibition percentage of control: 31+/-2). An MDCKII cell line expressing OATP2B1 (coded for by the SLCO2B1 gene) displays significantly increased permeability of montelukast (P<0.05, percentage of control: 140+/-20). A nonsynonymous polymorphism in SLCO2B1, rs12422149; SLCO2B1 {NM_007256.2}:c.935G>A, associates with significantly reduced plasma concentration in patients measured on the morning after an evening dose (P<0.025, square root mean transformed plasma concentration+/-SE; c.[935G>A]+[935G]=3+/-1, c.[935G]+[935G]=7.0+/-0.9) and differential response as assessed by change in baseline Asthma Symptom Utility Index scores after 1 month of therapy (delta mean Asthma Symptom Utility Index; c.[935G>A]+[935G]=0.02+/-0.01, P=1.0; c.[935G]+[935G]=1.0+/-0.3, P<0.0001).

CONCLUSION

Altogether, these observations suggest that the genetics of SLCO2B1 may be an important variable in determining the pharmacokinetics and the pharmacodynamics of montelukast.

Pharmacokinetics and safety of montelukast in children aged 3 to 6 months

The single-dose population estimate of the area under the concentration-time curve (AUC(pop)) from time zero to infinity (AUC(0-infinity)), maximum plasma concentration (C(max)), and time to C(max) (t(max)) of montelukast 4-mg oral granules were investigated in infants aged 3 to 6 months. Montelukast concentrations were quantitated after a single 4-mg dose of montelukast oral granules. Pharmacokinetic parameters were determined using a population-based approach with a nonlinear mixed-effect, 1-compartment model with first-order absorption and elimination. Ninety-five percent confidence intervals for the AUC(pop) ratio (3 to 6 months/6 to 24 months) were determined. Safety and tolerability were assessed. Montelukast 4-mg oral granules in children 3 to 6 months of age yielded systemic exposure (AUC(pop) = 3644.3 +/- 481.5 ng x h/mL) similar to that observed in children aged 6 to 24 months (3226.6 +/- 250.0 ng x h/mL). Systemic exposure after a 4-mg dose of montelukast as oral granules is similar in children aged 3 to 6 months and 6 to 24 months.

Emerging anti-inflammatory agents for allergic rhinitis

Allergic rhinitis (AR) is a high-prevalence disease, affecting 10-15% of the general population. AR is sustained by an IgE-mediated reaction, and by a complex inflammatory network of cells, mediators and cytokines that becomes chronic when exposure to allergen persists. A T helper 2 (TH2)-biased immune response is the basis for the allergic inflammation. The current therapeutic strategy is mainly based on drugs (antihistamines, nasal corticosteroids, cromones, decongestants) and allergen immunotherapy. Drugs are overall effective in controlling symptoms, but do not modify the immune background that leads to allergic inflammation, and safety concerns may be present especially for prolonged treatments. Immunotherapy can modify the allergic response, but there is still space for improvement. Nowadays, several approaches are under investigation to optimise the management of AR. On one hand, new drugs and antimediators are being developed; on the other hand, attempts are made to selectively block relevant signal pathways of allergic reaction. Finally, one of the major goals is to modify the TH2-biased immune response by improving the characteristics and modes of action of allergen immunotherapy.

Pharmacokinetics of montelukast in asthmatic patients 6 to 24 months old

Montelukast is a cysteinyl leukotriene receptor antagonist approved for the treatment of asthma for those ages 1 year old to adult. The purpose of this study was to evaluate the pharmacokinetic comparability of a 4-mg dose of montelukast oral granules in patients > or = 6 to < 24 months old to the 10-mg approved dose in adults. This was an open-label study in 32 patients. Population pharmacokinetic parameters included estimates of AUC(pop), C(max), and t(max). Results were compared with estimates from adults (10-mg film-coated tablet [FCT]). Dose selection criteria were for the 95% confidence interval (CI) for the AUC(pop) estimate ratio (pediatric/adult 10 mg FCT) to be within comparability bounds of (0.5, 2.00). The AUC(pop) ratio and the 95% CI for children compared with adults were within the predefined comparability bounds. Observed plasma concentrations were also similar. Based on systemic exposure of montelukast, a 4-mg dose of montelukast appears appropriate for children as young as 6 months of age.

Management of exercise-induced bronchospasm in children: the role of leukotriene antagonists

This review assesses the evidence on the efficacy of leukotriene antagonists in the management of exercise-induced bronchospasm (EIB) in children. Only two randomized, double-blind, placebo-controlled, crossover studies have examined the effect of leukotriene antagonists in EIB in a pediatric setting. All other studies, including those comparing leukotriene antagonists with other agents such as beta(2)-adrenoceptor agonists (beta(2)-agonists) and inhaled corticosteroids, primarily involve adult patients. In children, not receiving other asthma medication, leukotriene antagonists can offer statistically significant protection from EIB compared with placebo. However, protection is not complete, as a significant proportion of children will continue to experience a >15% reduction in FEV(1). None of the studies involved children treated concurrently with other asthma medications; therefore, comments on additive therapy cannot be made. Despite evidence from only a few studies, leukotriene antagonists are seen to be well tolerated, efficacious, and of benefit to some children. In addition, current management for EIB with short-acting beta(2)-agonists is less than ideal. It is therefore concluded that in children with EIB, leukotriene antagonists are indicated on a trial basis with individualized therapy and follow-up to evaluate treatment response.

Clinical efficacy and pharmacokinetics of montelukast in dyspeptic children with duodenal eosinophilia

BACKGROUND

Montelukast, a competitive cysteinyl leucotriene-1 receptor antagonist, reduces airway eosinophilia in asthmatics. We evaluated the effect of this drug in children with eosinophilic duodenitis, defined histologically as duodenal mucosa with peak eosinophil count of more than 10 eosinophils/hpf.

METHODS

Forty children and adolescents (6-18 yr) with dyspepsia and duodenal eosinophilia were enrolled in a double blind, randomized, placebo-controlled, cross-over study of monteleukast therapy. Subjects were randomized to receive either 10 mg montelukast or an identical placebo once daily and were evaluated on day 14 for symptomatic and biochemical responses. Subjects were also randomized to one of two blood sampling schemes to evaluate montelukast pharmacokinetics.

RESULTS

Using a post treatment global pain assessment, a positive clinical response was observed in 62.1% of patients receiving montelukast compared with 32.4% on placebo (p < 0.02). Pain assessment score deteriorated in 45% of montelukast responders (5/11) after cross-over to placebo and improved in 62% (8/13) of placebo non-responders on cross-over to montelukast. In patients with peak duodenal eosinophil counts between 20-29/hpf (n=19), a positive pain assessment response was observed in 84% of patients receiving montelukast compared to 42% receiving placebo (p < 0.01). Response rate did not differ by age, gender or histologic findings at baseline. Pharmacokinetic analysis yielded parameter estimates for absorption rate constant (Ka), apparent volume of distribution (Vd/F) and elimination rate constant (Kel) of 0.42 h, 0.19 L/kg and 0.26 h, respectively. The relative extent of systemic drug exposure was comparable to that observed in previous pediatric investigations with similar weight-adjusted montelukast doses. Neither dose nor calculated drug exposure were associated with the level of post treatment pain assessment or the change in biochemical markers.

CONCLUSIONS

These data suggest a beneficial role for montelukast in the treatment of pediatric patients with dyspepsia associated with duodenal eosinophilia.

Pulmonary mucus: Pediatric perspective

Airway mucus hypersecretion is a clinical feature of a number of childhood diseases, including asthma and bronchitis-associated conditions. However, compared with adults, there is relatively scarce information concerning mucus pathophysiology in respiratory diseases in children. The available evidence indicates many similarities between adult and childhood respiratory hypersecretory conditions, including goblet-cell hyperplasia and submucosal gland hypertrophy, and airway mucus plugging in asthma. Consequently, it is likely that treatments that are effective in adults would be effective in children. Numerous therapeutic targets are linked to the pathophysiology of airway mucus hypersecretion in experimental models and adults with respiratory disease. Whether or not these same targets are relevant in children is for the most part unclear. These targets include the inflammatory cells mediating the inflammatory response that generates the hypersecretory phenotype, and highly specific cellular elements such as epidermal growth factor receptor tyrosine kinase and calcium-activated chloride (CACL) channels. Identification of these factors is linked with the development of different classes of pharmacotherapeutic molecules directed at these targets. Compounds with a broader spectrum of anti-inflammatory activity are likely to be more effective than compounds with restricted activity. However, certain highly specific targets, such as human CACL1 channels, appear to be strongly associated with the development of an airway hypersecretory phenotype. Data from current clinical trials in adults with blockers of these specific targets are awaited with great interest. The hope is that, if effective, pediatric trials with these compounds could be initiated with a view to alleviation of the clinical impact of airway mucus hypersecretion in children. A significant challenge to the therapeutic progression of these new compounds is effective delivery to the airways in children, with the research effort into development of new compounds matched by advances in inhaler design.

Dispensing error leading to alendronate ingestion

OBJECTIVE

To report a case of medication dispensing error by administration of similarly packaged drugs.

CASE SUMMARY

A 6-year-old East Indian boy with asthma was mistakenly given alendronate, a bisphosphonate, for 3 months instead of montelukast, a leukotriene-receptor antagonist. Symptoms of esophageal irritation developed and disappeared on discontinuation of alendronate.

DISCUSSION

Alendronate and montelukast have very similar packaging and are available in dosages that also can be similar for some patients. Alendronate caused symptoms of irritative gastritis in this child before the error was identified. This case report emphasizes one of the possible sources of medication dispensing errors: a mistaken identification due to similar packaging (confirmation bias). Manufacturers can help to prevent medication errors in many ways; in this case, more distinct packaging would have decreased the risk of error. A standard bar-coding scheme among manufacturers could lead to an important improvement in the safety of medication dispensation. Practitioners are also encouraged to report such errors to the United States Pharmacopoeia Medication Errors Reporting Program.

CONCLUSIONS

With increased awareness of medication errors, healthcare practitioners, manufacturers, and patients should take precautionary steps to prevent dispensing errors and their consequences.