Effects of single-dose fluticasone on exercise-induced asthma in asthmatic children: a pilot study

Can the response to a single dose of beclomethasone dipropionate predict the outcome of long-term treatment in childhood exercise-induced bronchoconstriction?

BACKGROUND

Exercise-induced bronchoconstriction (EIB) is a frequent and highly specific symptom of childhood asthma. Inhaled corticosteroids (ICS) are the mainstay of controller therapy for EIB and asthma; however, a proportion of asthmatic children and adolescents is less responsive to ICS. We hypothesized that a single dose response to ICS could function as a predictor for individual long-term efficacy of ICS.

OBJECTIVE

To assess the predictive value of the bronchoprotective effect of a single-dose beclomethasone dipropionate (BDP) against EIB for the bronchoprotective effect of 4 weeks of treatment, using an exercise challenge test (ECT).

METHODS

Thirty-two steroid-naïve children and adolescents aged 6 to 18 years with EIB were included in this prospective cohort study. They performed an ECT at baseline, after a single-dose BDP (200µg) and after 4 weeks of BDP treatment (100 µg twice daily) to assess EIB severity.

RESULTS

The response to a single-dose BDP on exercise-induced fall in FEV1 showed a significant correlation with the response on exercise-induced fall in FEV1 after 4 weeks of BDP treatment (r = .38, p = .004). A reduction in post-exercise fall in FEV1 of more than 8% after a single-dose BDP could predict BDP efficacy against EIB after 4 weeks of treatment with a positive predictive value of 100% (CI: 86.1-100%) and a negative predictive value of 29.4% (CI: 11.7%-53.7%).

CONCLUSION

We found that the individual response to a single-dose BDP against EIB has a predictive value for the efficacy of long-term treatment with BDP. This could support clinicians in providing personalized management of EIB in childhood asthma.

An Algorithm for Strategic Continuation or Restriction of Asthma Medication Prior to Exercise Challenge Testing in Childhood Exercise Induced Bronchoconstriction

Exercise induced bronchial (EIB) constriction is a common and highly specific feature of pediatric asthma and should be diagnosed with an exercise challenge test (ECT). The impact of EIB in asthmatic children's daily lives is immense, considering the effects on both physical and psychosocial development. Monitoring childhood asthma by ECT's can provide insight into daily life disease burden and the control of asthma. Current guidelines for bronchoprovocation tests restrict both the use of reliever and maintenance asthma medication before an exercise challenge to prevent false-negative testing, as both have significant acute bronchoprotective properties. However, restricting maintenance medication before an ECT may be less appropiate to evaluate EIB symptoms in daily life when a diagnosis of asthma is well established. Rigorous of maintenance medication before an ECT according to guidelines may lead to overestimation of the real, daily life asthma burden and lead to an inappropiate step-up in therapy. The protection against EIB offered by the combined acute and chronic bronchoprotective effects of maintenance medication can be properly assessed whilst maintaining them. This may aid in achieving the goal of unrestricted participation of children in daily play and sports activities with their peers without escalation of therapy. When considering a step down in medication, a strategic wash-out of maintenance medication before an ECT aids in providing objective support of potential discontinuation of maintenance medication.

Repurposing drugs as inhaled therapies in asthma

For the first 40 years of the 20th century treatment for asthma occurred in response to an asthma attack. The treatments were given by injection or orally and included the adrenergic agonists adrenalin/epinephrine and ephedrine and a phosphodiesterase inhibitor theophylline. Epinephrine became available as an aerosol in 1930. After 1945, isoprenaline, a non-selective beta agonist, became available for oral use but it was most widely used by inhalation. Isoprenaline was short-acting with unwanted cardiac effects. More selective beta agonists, with a longer duration of action and fewer side-effects became available, including orciprenaline in 1967, salbutamol in 1969 and terbutaline in 1970. The inhaled steroid beclomethasone was available by 1972 and budesonide by 1982. Spirometry alone and in response to exercise was used to assess efficacy and duration of action of these drugs for the acute benefits of beta₂ agonists and the chronic benefits of corticosteroids. Early studies comparing oral and aerosol beta₂ agonists found equivalence in bronchodilator effect but the aerosol treatment was superior in preventing exercise-induced bronchoconstriction. Inhaled drugs are now widely used including the long-acting beta₂ agonists, salmeterol and formoterol, and the corticosteroids, fluticasone, ciclesonide, mometasone and triamcinolone, that act locally and have low systemic bio-availability. Repurposing drugs as inhaled therapies permitted direct delivery of low doses of drug to the site of action reducing the incidence of unwanted side-effects and permitting the prophylactic treatment of asthma.

Exercise-induced bronchoconstriction update-2016

The first practice parameter on exercise-induced bronchoconstriction (EIB) was published in 2010. This updated practice parameter was prepared 5 years later. In the ensuing years, there has been increased understanding of the pathogenesis of EIB and improved diagnosis of this disorder by using objective testing. At the time of this publication, observations included the following: dry powder mannitol for inhalation as a bronchial provocation test is FDA approved however not currently available in the United States; if baseline pulmonary function test results are normal to near normal (before and after bronchodilator) in a person with suspected EIB, then further testing should be performed by using standardized exercise challenge or eucapnic voluntary hyperpnea (EVH); and the efficacy of nonpharmaceutical interventions (omega-3 fatty acids) has been challenged. The workgroup preparing this practice parameter updated contemporary practice guidelines based on a current systematic literature review. The group obtained supplementary literature and consensus expert opinions when the published literature was insufficient. A search of the medical literature on PubMed was conducted, and search terms included pathogenesis, diagnosis, differential diagnosis, and therapy (both pharmaceutical and nonpharmaceutical) of exercise-induced bronchoconstriction or exercise-induced asthma (which is no longer a preferred term); asthma; and exercise and asthma. References assessed as relevant to the topic were evaluated to search for additional relevant references. Published clinical studies were appraised by category of evidence and used to document the strength of the recommendation. The parameter was then evaluated by Joint Task Force reviewers and then by reviewers assigned by the parent organizations, as well as the general membership. Based on this process, the parameter can be characterized as an evidence- and consensus-based document.

Air quality and temperature effects on exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) is exaggerated constriction of the airways usually soon after cessation of exercise. This is most often a response to airway dehydration in the presence of airway inflammation in a person with a responsive bronchial smooth muscle. Severity is related to water content of inspired air and level of ventilation achieved and sustained. Repetitive hyperpnea of dry air during training is associated with airway inflammatory changes and remodeling. A response during exercise that is related to pollution or allergen is considered EIB. Ozone and particulate matter are the most widespread pollutants of concern for the exercising population; chronic exposure can lead to new-onset asthma and EIB. Freshly generated emissions particulate matter less than 100 nm is most harmful. Evidence for acute and long-term effects from exercise while inhaling high levels of ozone and/or particulate matter exists. Much evidence supports a relationship between development of airway disorders and exercise in the chlorinated pool. Swimmers typically do not respond in the pool; however, a large percentage responds to a dry air exercise challenge. Studies support oxidative stress mediated pathology for pollutants and a more severe acute response occurs in the asthmatic. Winter sport athletes and swimmers have a higher prevalence of EIB, asthma and airway remodeling than other athletes and the general population. Because of fossil fuel powered ice resurfacers in ice rinks, ice rink athletes have shown high rates of EIB and asthma. For the athlete training in the urban environment, training during low traffic hours and in low traffic areas is suggested.

Protective effect of a low single dose inhaled steroid against exercise induced bronchoconstriction

OBJECTIVE

Daily use of inhaled corticosteroids (ICS) reduces exercise induced bronchoconstriction (EIB) in asthmatic children. A high single dose of ICS also provided acute protection against EIB. Objective of this study is to investigate whether a low single dose of ICS offers protection against EIB in asthmatic children.

METHODS

31 Mild asthmatic children not currently treated with inhaled corticosteroids, 5-16 years, with EIB (fall in FEV0.5/1 ≥ 13%) were included in a prospective intervention study. They performed two ECT's within 2 weeks. Four hours before the second test children inhaled 200 μg beclomethasone-dipropionate (BDP) with a breath-actuated inhaler (BAI).

RESULTS

The median fall in FEV0.5/1 after 200 μg BDP was significantly reduced from 30.9% at baseline to 16.0% (P < 0.001). Twenty children (64.5%) showed a good response to 200 μg BDP (≥ 50% decrease in fall of FEV0.5/1), while 8 children showed a moderate response (25-50%), and three children showed no response at all (< 25%).

CONCLUSION

A low single dose ICS offers acute protection against EIB in the majority of asthmatic children not currently treated with inhaled corticosteroids.

The effect of body posture during medication inhalation on exercise induced bronchoconstriction in asthmatic children

RATIONALE

Inhaling medication in a standard body posture leads to impaction of particles in the sharp angle of the upper airway. Stretching the upper airway by extending the neck in a forward leaning body posture may improve pulmonary deposition. A single dose of inhaled corticosteroids (ICS) offers acute, but moderate protection against exercise induced bronchoconstriction (EIB). This study investigated whether inhaling a single dose of ICS in a forward leaning posture improves this protection against EIB.

METHODS

32 Asthmatic children, 5-16 years, with EIB (Median fall in FEV1 or FEV0.5 30.9%) performed two exercise challenge tests (ECT's) with spirometry in a single blinded cross-over trial design. Children inhaled a single dose of 200 μg beclomethasone dipropionate (BDP) 4 h before the ECT, once in the standard posture and once with the neck extended in a forward leaning posture. Spirometry was also performed before the inhalation of the single dose of BDP.

RESULTS

Inhalation of BDP in both body postures provided similar protection against EIB (fall in FEV1 or FEV0.1 in standard posture 16.7%; in forward leaning posture 15.1%, p = 0.83). Inhaling ICS in a forward leaning posture significantly delayed EIB compared to inhaling in the standard posture (respectively 2.5 min ± 1.0 min vs. 1.6 min ± 0.8 min; difference 0.9 min (95CI 0.25; 1.44 min); p = 0.01).

CONCLUSION

Inhalation of a single dose BDP in both the forward leaning posture and the standard posture provided effective and similar protection against EIB in asthmatic children, but the forward leaning posture resulted in a delay of EIB.

REGISTER

NTR3432 (www.trialregister.nl).

Pharmacotherapy for exercise-induced asthma: allowing normal levels of activity and sport

Exercise-induced bronchoconstriction (EIB) is experienced by the majority of an estimated 300 million individuals who have asthma, a condition that affects all ages and is increasing globally. Respiratory water loss with dehydration of the airways causing mediator release and airway narrowing is considered the cause of EIB, the severity of which will be increased if the inhaled air is cold or polluted. Adequate control of asthma is essential to minimize or prevent EIB and permit normal levels of physical activity and sport. This is important because exercise is a necessary component of daily living, assists in obtaining and maintaining a healthy body and has been demonstrated to benefit asthmatics. Inhaled glucocorticosteroids and inhaled β(2)-adrenoceptor agonists (IβA) are the pharmacological agents of choice to manage asthma and minimize EIB, assisted when necessary, by other drugs including leukotriene receptor antagonists and chromones. Tolerance from daily use of IβA is of concern and more flexible drug therapy needs to be considered. Optimal use of inhalers to deliver drugs effectively requires closer attention. Pharmacogenetics may hold the key to future drug therapy.

Effects of a single dose inhaled corticosteroid on the dynamics of airway obstruction after exercise

RATIONALE

Exercise-induced bronchoconstriction (EIB) is defined as a transient narrowing of the airways induced by exercise. Repetitive measurements of spirometric parameters, such as FEV(1) and expiratory flows, and forced oscillation technique (FOT) measurements can be used to analyze the dynamics of EIB. A single high dose of fluticasone propionate (FP) protects against EIB. The aim of the study was to analyze the effect of FP on the dynamics of exercise-induced airway narrowing as measured with FOT and spirometry.

METHODS

Twelve children performed an exercise challenge on 2 separate days, 4 hr after inhalation of 1 mg FP (pressurized metered dose inhaler) or a placebo. Before and after the exercise flow-volume loops as well as the FOT (frequency range: 4-32 Hz) were measured.

RESULTS

The FEV(1) , and FEF(50) fell significantly after exercise within groups; the peak fall in FEV(1) after FP was significantly smaller than after placebo (respectively, 19.3 ± 14.6% and 29.2 ± 14.8%, P = 0.03, 95% CI: 0.9-18.8%). The fall in FEV(1) and FEF(50) peaked 3 min after exercise and showed a subsequent partial recovery. The fall in the FEV(1) /FVC ratio showed a later peak fall (12 min after exercise). The resistance increased while the reactance decreased significantly after exercise. FP significantly decreased the maximal increase in Rrs(6) when compared to the placebo (respectively 176.5 ± 59.1% and 201.0 ± 63.8%, P = 0.05, 95% CI: 0.5-48.7%). The maximal decrease in Xrs(6) was not significantly affected by FP (P = 0.06).

CONCLUSION

Repetitive spirometric and FOT measurements after exercise show a rapid narrowing and steady recovery of the patency of the conducting airways, and indicate a delayed and prolonged recovery of the smaller airways. A single high dose of inhaled FP seems to employ its effect mainly in the conducting airways.

Evaluation of fluticasone propionate and fluticasone propionate/salmeterol combination on exercise in pediatric and adolescent patients with asthma

OBJECTIVE

This study was designed to demonstrate that four weeks of fluticasone propionate (FP) 100 micrograms (mcg) combined with salmeterol 50 mcg twice daily (BID) via DISKUS(®) resulted in protection against bronchospasm induced by activity, as measured by standardized exercise challenge testing in pediatric and adolescent subjects who required regular use of inhaled corticosteroids for the treatment of persistent asthma.

METHODS

Prior to study entry, all patients reported regular use of inhaled corticosteroids (ICS). During screening all patients demonstrated ≥20% fall in FEV(1) following exercise.

RESULTS

A total of 231 subjects aged 4 to 17 were randomized to the two study treatments: 113 to the FP/salmeterol combination group (FSC) and 118 to receive FP 100 mcg BID. Of the subjects randomized, 106 (94%) subjects in the FSC 100/50 group and 108 (92%) subjects in the FP 100 group completed the study. At the end of treatment (Week 4), both FSC and FP protected against a fall in FEV(1) following exercise in patients who at baseline experienced ≥20% fall in FEV(1) following exercise. A mean decrease in FEV(1) of 9.9% was observed in the FSC 100/50 group as compared with a mean decrease of 11.1% in the FP 100 group; there was no statistical difference between treatments.

CONCLUSION

Both FSC 100/50 and FP 100 provided protection against an exercised-induced fall in FEV(1); but statistically significant differences we not noted. Both treatments were well-tolerated over four weeks and FSC 100/50 had an adverse event profile comparable to that observed with FP 100.

Baseline predictors of placebo response in exercise-induced bronchoconstriction (EIB): pooled regression analysis >from three studies of montelukast in EIB

BACKGROUND

Exercise-induced bronchoconstriction (EIB) can be variable in its presentation and severity. Evaluating patterns of placebo response and patient-related factors driving placebo response could facilitate more efficient clinical trials for EIB.

METHODS

Data were pooled from three randomized, double-blind, crossover trials evaluating single-dose montelukast 10 mg or placebo in patients (N = 160) 15-45 years of age with EIB, defined as maximum % fall in forced expiratory volume in one second (FEV₁) ≥20% after two screening exercise challenges. Serial exercise challenges were performed at 2, 8.5-12, and 24 h postdose. The authors evaluated the distribution and variability of placebo response. They also evaluated possible drivers of response, analyzing all baseline patient demographic and prerandomization screening visit pulmonary function data as single covariates in a simple univariate regression model for maximum % fall in FEV₁ while on placebo at 2 h postdose. All covariates with p values <.1 were entered into both stepwise forward and backward regression procedures to select the "best" model.

RESULTS

Placebo response was variable, and showed a significant non-normal distribution (p < .001). Significant predictors of a greater response to placebo included: higher screening FEV₁ % predicted (p <.001), smaller maximum % fall in FEV₁ in screening (p < .001), shorter time to recovery in screening (p = .007), more asthma-related health care visits in the previous year (p = .004), older age (p = .001), less frequent asthma awakenings in the previous month (p = .003), and less frequent asthma symptoms in the past year (p = .011).

CONCLUSION

Predictors of a larger placebo response were generally markers of less severe asthma and/or EIB. This may be related to EIB variability, spontaneous improvement, or the extent of placebo response relative to the outcomes in less severe patients.

Indirect challenge tests: Airway hyperresponsiveness in asthma: its measurement and clinical significance

Indirect challenges cause the release of endogenous mediators that cause the airway smooth muscle to contract and the airways to narrow. Airway sensitivity to indirect challenges is reduced or even totally inhibited by treatment with inhaled corticosteroids (ICS), so a positive response to an indirect stimulus is believed to reflect active airway inflammation. The indirect challenges commonly used in pulmonary function laboratories include exercise, eucapnic voluntary hyperpnea, hypertonic (4.5%) saline, and mannitol. Exercise was the first test to be standardized and was used to identify exercise-induced bronchoconstriction (EIB). The inhibition of EIB in young children by sodium cromoglycate led to the concept that mast cells were important very early in the onset of asthma. All of these indirect challenges are associated with the release of mast cell mediators (eg, prostaglandins, leukotrienes, and histamine). The hypertonic saline and mannitol challenges arose from the concept that EIB was caused by an increased osmolarity of the airway surface with release of mediators. These osmotic aerosols simplified testing with indirect challenges in the laboratory, improving the potential to identify currently active asthma. Although hyperresponsiveness to indirect challenges is frequently associated with a sputum eosinophilia, it is not a prerequisite because the mast cell is the most important source of mediators. The mechanism for ICS reducing hyperresponsiveness to indirect challenges likely involves both mast cells and eosinophils. Indirect challenges are appropriate to inform further on both the pathogenesis of asthma and the role of antiinflammatory agents in its treatment.

Monitoring asthma therapy using indirect bronchial provocation tests

OBJECTIVES

Bronchial provocation tests that assess airway hyperresponsiveness (AHR) are known to be useful in assisting the diagnosis of asthma and in monitoring inhaled corticosteroid therapy. We reviewed the use of bronchial provocation tests that use stimuli that act indirectly for monitoring the benefits of inhaled corticosteroids.

DATA SOURCE

Published clinical trials investigating the effect of inhaled corticosteroids on bronchial hyperresponsiveness in persons with asthma were used for this review.

STUDY SELECTION

Studies using indirect stimuli to provoke airway narrowing such as exercise, eucapnic voluntary hyperventilation, cold air hyperventilation, hypertonic saline, mannitol, or adenosine monophosphate (AMP) to assess the effect of inhaled corticosteroids were selected.

RESULTS

Stimuli acting indirectly result in the release of a variety of bronchoconstricting mediators such as leukotrienes, prostaglandins, and histamine, from cells such as mast cells and eosinophils. A positive response to indirect stimuli is suggestive of active inflammation and AHR that is consistent with a diagnosis of asthma. Persons with a positive response to indirect stimuli benefit from daily treatment with inhaled corticosteroids. Symptoms and lung function are not useful to predict the long-term success of inhaled corticosteroid dose as they usually resolve rapidly, and well before inflammation and AHR has resolved. Following treatment, AHR to indirect stimuli is attenuated. Further, during long-term treatment, asthmatics can become as non-responsive as non-asthmatic healthy persons, suggesting that asthma is not active.

CONCLUSIONS

Non-responsiveness to indirect bronchial provocation tests following inhaled corticosteroids occurs weeks to months following the resolution of symptoms and lung function. Non-responsiveness to indirect stimuli may provide a goal for adequate therapy with inhaled corticosteroids.

Acute additive effect of montelukast and beclomethasone on AMP induced bronchoconstriction

Bronchial hyperresponsiveness to 5-adenosine mono-phosphate (AMP) is a marker of airway inflammation. Inhaled corticosteroids and antileukotrienes are used as anti-inflammatory drugs for the treatment of asthma. To find out if these two drugs exert their protection in an additive fashion, we compared the effects of acute treatment with inhaled beclomethasone (BDP) and montelukast (ML), alone or in combination, on methacholine and AMP induced bronchoconstriction. 15 asthmatic patients undertook methacholine and AMP challenges at baseline and after receiving ML or BDP, alone or in combination, in a randomized, double-blind, double-dummy placebo-controlled, crossover design. BDP pretreatment significantly increased the AMP PC(20) value (68.34+/-15.9mg/mL) as compared to placebo (22.87+/-5.7mg/mL). Combined treatment, BDP plus ML, afforded a further significant increase of AMP PC(20) (154.57+/-55.0mg/mL) as compared to each single treatment. The significant protection exerted by combined treatment as compared to each single active treatment was also demonstrated by the change of AMP PC(20) doubling dose as compared to placebo and each single active treatment. Our findings suggest that these two agents exert their acute additive protection against AMP induced bronchoconstriction acting on distinct inflammatory pathways and their combined use might provide greater protection against inflammatory response elicited by AMP than either drug alone.

Acute effects of beclomethasone on hyperpnea-induced bronchoconstriction

PURPOSE

The aim of this study was to assess whether a single high dose of beclomethasone dipropionate (BDP) could blunt mast cell activation and bronchoconstriction after eucapnic voluntary hyperpnea (EVH).

METHODS

In this model of exercise-induced bronchoconstriction (EIB), seven athletes with EIB and eight untrained subjects with mild asthma performed two EVH tests 5.5 h apart on the same day; the first challenge after inhalation of a placebo aerosol and the second 4 h after inhalation of BDP (1500 microg). Prechallenge and postchallenge pulmonary function and urinary excretion of the mast cell mediator 9alpha, 11beta-prostaglandin (PG) F2 were followed, as well as urinary excretion of the bronchoconstrictor leukotriene (LT) E4.

RESULTS

The EVH-induced bronchoconstriction was inhibited by BDP in both groups (P < 0.001): in athletes, mean +/- SEM percent fall in forced expiratory volume in 1 s was 22% +/- 4% after placebo versus 13% +/- 3% after BDP; in subjects with asthma, 23% +/- 4% after placebo versus 14 +/- 3% after BDP. This inhibition of airway response was associated with a significant reduction in the urinary excretion of 9alpha,11beta-PGF2 (P = 0.039) and LTE4 (P = 0.003) in both groups. Significant correlations were found between the percent fall in forced expiratory volume in 1 s and the increase in urinary excretion of both mediators 9alpha,11beta-PGF2 (r = 0.544, P = 0.002) and LTE4 (r = 0.380, P = 0.038) after EVH.

CONCLUSIONS

We conclude that a single dose of BDP has an acute protective effect on the bronchial response to hyperpnea in both untrained subjects with asthma and athletes with EIB. This effect was associated with decreased excretion of urinary mediators, suggesting that BDP blunted the mast cell activation.

Effects of mometasone furoate administered via a dry powder inhaler once daily in the evening on nocturnal lung function and sleep parameters in patients with moderate persistent asthma: a randomized, double-blind, placebo-controlled pilot study

BACKGROUND AND OBJECTIVE

Nocturnal symptoms are common in asthma patients and have the potential for considerable clinical effects due to a lack of sleep and persistent daytime symptoms of somnolence and activity impairment. The primary objective of this investigation was to determine the effect of a 14-day course of once-daily evening administration of mometasone furoate 400 microg administered via a dry powder inhaler (MF-DPI 400 microg qd pm) on the overnight decline in pulmonary function observed in patients with nocturnal asthma.

METHODS

Eligible enrollees were between the ages of 18 and 60 years and had established mild to moderate asthma, with an improvement in forced expiratory volume in 1 second (FEV(1)) of >15% after administration of inhaled salbutamol (albuterol) 200 microg. All enrolled patients had a history of nocturnal asthma. Enrollees were randomized to receive MF-DPI 400 microg qd pm or placebo administered between 6 pm and 8 pm for 14 days. The primary outcome evaluated in the study was reduction in nocturnal decline in evening (8 pm) to morning (6 am) FEV(1) values. Secondary outcomes included reduction in nocturnal decline in evening to morning peak expiratory flow rate (PEFR), polysomnographic indices of sleep, and psychometric indices (Nocturnal Rhinoconjunctivitis Quality of Life Questionnaire [NRQLQ], 36-item Short Form of the Medical Outcomes Survey [SF-36], and Asthma Quality of Life Questionnaire [AQLQ]).

RESULTS

A total of 20 patients were randomized and completed all phases of the study. No significant differences were observed between treatment groups in the primary outcome of nocturnal decline in FEV(1) from pretreatment to end of treatment. Likewise, there was no significant difference between treatment groups in polysomnographic indices of sleep or quality-of-life assessments. However, there was a trend toward improvement in the activity scale of the AQLQ assessment in the MF-DPI 400 microg qd pm treatment group.

CONCLUSION

No significant treatment effect on nocturnal pulmonary function, sleep indices or quality of life was observed with 14-day administration of MF-DPI 400 microg qd pm. These findings are limited by the small sample size and the short treatment period evaluated. Future studies are warranted to study the effects of MF-DPI therapy in patients with nocturnal asthma.

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.

Inhaled corticosteroids compared to placebo for prevention of exercise induced bronchoconstriction

BACKGROUND

The pathogenesis of exercise induced bronchoconstriction is likely multifactorial and is not completely understood. Inflammation plays an important role in the pathogenesis of exercise induced bronchoconstriction in asthmatic subjects but the evidence seems less strong in non-asthmatic subjects. The management of exercise induced bronchoconstriction focuses on prevention, through both pharmacologic and non-pharmacologic interventions.

OBJECTIVES

The objectives of this review were to evaluate the use of inhaled corticosteroids in the treatment of exercise induced bronchoconstriction in a systematic way. Specifically, the review was designed to: determine whether inhaled corticosteroids (compared to placebo) has an attenuating effect on exercise induced bronchoconstriction in adult and pediatric asthmatic patients; estimate the magnitude of the attenuating effect.

SEARCH STRATEGY

We searched the Cochrane Airways Review Group Specialised Register of trials, the Cochrane Central Register of Controlled Trials, review articles, textbooks and reference list of articles.

SELECTION CRITERIA

Randomised trials in adults or children comparing inhaled corticosteroids with placebo to prevent bronchoconstriction in patients with exercise induced bronchoconstriction.

DATA COLLECTION AND ANALYSIS

Trial quality assessment and data extraction were conducted independently by two reviewers.

MAIN RESULTS

The results from six randomised controlled trials involving 123 participants were analyzed (two trials involving adults and four involving children). Combining results from the two parallel studies with at least 4 weeks duration of inhaled corticosteroids, the use of inhaled corticosteroids significantly attenuated the percent fall index in forced expiratory volume in 1 second (WMD = 14.07%; 95% CI: 11.62% to 16.52%). The result from one crossover study with duration of inhaled corticosteroids of 4 weeks revealed significant attenuation of percent fall in forced expiratory volume in 1 second ( WMD = 6.90%; 95% CI: 1.40% to 12.40%) and the percent fall in peak expiratory flow ( WMD =11.50%; 95% CI: 6.31% to 16.69%). The small amount of data from placebo-controlled trials using a single treatment do not currently allow conclusions to be drawn.

AUTHORS' CONCLUSIONS

Inhaled corticosteroids used for 4 weeks or more before exercise testing significantly attenuated exercise-induced bronchoconstriction. The relative benefits of inhaled corticosteroids compared to other forms of exercise induced bronchoconstriction treatment (sodium cromoglycate, nedocromil sodium, salbutamol, and other anti-inflammatory agents) remains unclear.

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.

Differences in the evaluation and management of exercise-induced bronchospasm between family physicians and pulmonologists

Previous studies have demonstrated that specialists and generalists differ in the evaluation and management of asthma especially in terms of use of objective testing. We speculated that there also may be differences in the diagnosis and management of exercise-induced respiratory complaints. An Internet survey was sent to samples of pulmonologists and family physicians. Our data suggests that pulmonologists are much more likely to order bronchoprovocation testing than family physicians, and family physicians are more likely to start any empiric therapy than perform bronchoprovocation testing when exercise-induced bronchospasm is suspected. These differences may lead to inaccurate or missed diagnoses and unnecessary morbidity.

Effect of ciclesonide dose and duration of therapy on exercise-induced bronchoconstriction in patients with asthma

BACKGROUND

Inhaled corticosteroid therapy improves exercise symptoms in asthmatic subjects.

OBJECTIVE

We sought to evaluate exercise-induced bronchoconstriction (EIB) as a method of determining the dose and time responses of inhaled corticosteroid therapy.

METHODS

In this double-blind, randomized, cross-over study with 2 parallel arms, 4 doses of inhaled ciclesonide (40 microg and 160 microg or 80 microg and 320 microg) were compared over 3 weeks of treatment. Twenty-six asthmatic subjects (age range, 14-27 years) with baseline FEV1 values of greater than 70% of predicted value were enrolled. The primary outcome was the maximum percentage decrease in FEV1 after standardized exercise challenge.

RESULTS

After 1 week of therapy, the mean +/- SEM reduction in maximum decrease in FEV1 in the ciclesonide 40-microg/80-microg dose group was 9% +/- 2.6% (95% CI, 3.9% to 14%), with no additional reduction thereafter. In the ciclesonide 160-microg/320-microg dose group, there was an 8.7% +/- 2.5% (95% CI, 3.7% to 13.7%) reduction in maximum decrease in FEV1 after week 1, which continued in a linear fashion during subsequent weeks of treatment. No difference was found between the 2 treatment arms in the temporal response of EIB to ciclesonide treatment. The maximum percentage attenuation in EIB achieved was 51.1% +/- 7.9%, which was achieved by using the 320-microg dose after 3 weeks of treatment.

CONCLUSIONS

A significant improvement in EIB was demonstrated for all doses of ciclesonide. Use of 160 microg/320 microg of ciclesonide resulted in a continuing improvement in FEV1 with time, and no plateau was seen in protective effect during 3 weeks of treatment.

CLINICAL IMPLICATIONS

Attenuation in exercise-induced decrease can be seen as early as after 1 week of therapy with inhaled ciclesonide at doses greater than 40 microg. However, maximal attenuation in exercise response continues to increase at doses greater than or equal to 200 microg, even after 3 weeks of therapy.

Role of leukotriene receptor antagonists in the treatment of exercise-induced bronchoconstriction: a review

Asthma is a very common disorder that still causes significant morbidity and mortality. A high percentage of individuals with asthma also experience exercise-induced bronchoconstriction (EIB). This article reviews the current literature and updates the reader on the safety, efficacy, and clinical applications of leukotriene modifiers in the treatment of EIB.

Protection by budesonide and fluticasone on allergen-induced airway responses after discontinuation of therapy

BACKGROUND

Treatment with inhaled steroids is an effective method of reducing bronchoconstriction and airway inflammation after allergen challenge. However, the duration of the protective effects of inhaled steroids after discontinuation of therapy has not been established.

OBJECTIVE

We sought to evaluate the protective effect of 1 week of inhaled steroid therapy against inhaled allergen challenge 12 hours after discontinuation of therapy.

METHODS

In this randomized, double-blind, placebo-controlled crossover trial, 26 asthmatic subjects (>18 years old) not using inhaled steroids were administered 200 microg of budesonide twice daily, 200 microg of fluticasone twice daily, or placebo twice daily for 1 week. Twelve hours after discontinuation of therapy, subjects were administered an inhaled allergen challenge. Each treatment period was separated by a 3-week washout period.

RESULTS

When compared with placebo (26% +/- 14%), there was a slight but significant protection against the allergen-induced early response after fluticasone treatment (19% +/- 10%, P = .001) but not after budesonide treatment (23% +/- 13%, P = .08). However, when the area under the curve for the early airway response was examined, there was no difference between the 2 drugs in the amount of protection ( P = .62). Partial protection was demonstrated against the late-response allergen-induced sputum eosinophilia with both treatments ( P = .001). By contrast, no protection was observed against allergen-induced airway hyperresponsiveness for either treatment.

CONCLUSIONS

The protective effects of inhaled steroids against allergen-induced early responses, airway eosinophilia, and allergen-induced airway hyperresponsiveness are partially or completely lost as early as 12 hours after discontinuation of therapy.

Single-dose agents in the prevention of exercise-induced asthma: a descriptive review

Exercise-induced asthma (EIA) refers to the transient narrowing of the airways that occurs after vigorous exercise in 50-60% of patients with asthma. The need to condition the air inspired during exercise causes water to be lost from the airway surface, and this is thought to cause the release of inflammatory mediators (histamine, leukotrienes, and prostaglandins) from mast cells. EIA is associated with airway inflammation and its severity is markedly reduced following treatment with inhaled corticosteroids. Drugs that inhibit the release of mediators and drugs that inhibit their contractile effects are the most successful in inhibiting EIA. Single doses of short-acting beta(2)-adrenoceptor agonists, given as aerosols immediately before exercise, are very effective in the majority of patients with asthma, providing about 80% protection for up to 2 hours. Long-acting beta(2)-adrenoceptor agonists (LABAs) given in single doses can be effective for up to 12 hours when used intermittently, but tolerance to the protective effect occurs if they are taken daily. Drugs such as cromolyn sodium (sodium cromoglicate) and nedocromil given as aerosols are less effective than beta(2)-adrenoceptor agonists (beta(2)-agonists), providing 50-60% protection for only 1-2 hours, but they have some advantages. They do not induce tolerance, the aerosol dosage can be easily titrated for the individual, and the protective effect is immediate. Because they cause no significant adverse effects, multiple doses can be used in a day. Leukotriene receptor antagonists, such as montelukast and zafirlukast, are also used for the prevention of EIA and provide 50-60% protection for up to 24 hours when given as tablets. Tolerance to the protective effect does not develop with regular use. If breakthrough EIA occurs, a beta(2)-agonist can be used effectively for rescue medication. For those patients with more persistent symptoms, the use of a LABA in combination with an inhaled corticosteroid has raised a number of issues with respect to the choice of prophylactic treatment for EIA. The most important issue is the development of tolerance to the protective effect of a LABA such that extra treatment may be needed in the middle of a treatment period. Recommending extra doses of a beta(2)-agonist to control EIA is not advisable on the basis that multiple doses can enhance the severity of EIA, delay spontaneous recovery from bronchoconstriction, and enhance responses to other contractile stimuli. It is time to take into account the advantages and disadvantages of the different drugs available to prevent EIA and to recognize that there are some myths related to their use in EIA.

Long-acting beta 2-adrenoceptor agonists and exercise-induced asthma: lessons to guide us in the future

The safety and efficacy of long-acting beta(2)-adrenoceptor agonists (LABAs) taken intermittently for the prevention of exercise-induced asthma (EIA) in children is well established. However, the safety and efficacy of LABAs taken twice daily, either alone or in combination with inhaled corticosteroids, for the prevention of EIA is not as clear because of issues of tolerance (defined as being less responsive to the influence of LABAs). There have been many observations on short-acting beta(2)-adrenoceptor agonists (SABAs) and EIA that should have alerted us to the potential for tolerance and desensitization to occur with LABAs. For example, we expected that the use of LABAs for EIA would overcome the problem of the short duration of protection of SABAs, and to some extent they have. The protective period of a LABA is two to three times longer in duration than that of a SABA. However, when a LABA is taken daily it is apparent that the duration of its protective effect is reduced and there is a risk of EIA occurring well within the 12-hour administration schedules. Furthermore, daily use of LABAs attenuates the bronchodilator effect of SABAs, an effect that is greater the more severe the bronchoconstriction. This 'tolerance' increases both the time and the amount of therapy that is needed to recover from bronchoconstriction, and thus, could potentially impact on the success of rescue therapy should severe EIA occur. The daily use of LABAs also increases the sensitivity of the bronchial smooth muscle to contractile agents. This increase in sensitivity is almost equivalent to the extent to which inhaled corticosteroids reduce sensitivity to the same contractile agents. The increased sensitivity to contractile agents may occur either by a reduction in the inhibitory effect of beta(2)-adrenoceptor agonists on release of mediators from mast cells or by a direct effect on the bronchial smooth muscle. These unwanted effects of LABAs are not necessarily reduced by concomitant treatment with inhaled corticosteroids. As the number of children being treated with LABAs increases, it is predicted that problems with breakthrough EIA will also increase. We need to know the percentage of children taking a LABA daily who are requiring either extra doses of a beta(2)-adrenoceptor agonist to prevent (or reverse) EIA or other provocative stimuli. If this percentage is significant then we may need to reconsider the position of LABAs in the treatment of children with asthma who regularly perform strenuous physical activity.

Exercise-Induced Asthma: An Update

Exercise-induced asthma (E.I.A) affects 12–16% of the general population and most of the patients affected by extrinsic or intrinsic asthma. Surprisingly, also a high percentage of professional and Olympic athletes are affected, showing that E.I.A. does not impair physical activity, whereas endurance sports bear a higher risk than the others. The mast cell role, late asthmatic responses, diagnosis, therapy, theories and data about immunological parameters in sports are taken into consideration in this review.

Rapid effect of inhaled steroids on nocturnal worsening of asthma

BACKGROUND

Inhaled steroids are the most commonly used anti-inflammatory agents for asthma and are increasingly recognised as having a more rapid onset of action than was previously thought. We have investigated the effect of a single dose of inhaled steroid on nocturnal worsening of asthma.

METHODS

Ten patients with steroid naive moderate asthma and nocturnal asthma participated in a randomised, double blind, placebo controlled, crossover trial. Participants spent three nights in the laboratory, one week apart. On each night they underwent spirometric testing at 16.00 hours and received one of the three treatments (placebo, beclomethasone 1000 micro g, or fluticasone 1000 micro g) delivered by metered dose inhaler. Spirometric tests were repeated at 04.00 hours the following morning.

RESULTS

Following placebo administration the mean (SE) overnight fall in FEV(1) was 0.65 (0.27) l compared with -0.02 (0.13) l following fluticasone (p=0.019) and 0.23 (0.12) l following beclomethasone (p=0.048 v placebo).

CONCLUSION

A single dose of inhaled steroid (within the therapeutic range) reduced the fall in FEV(1) in patients with nocturnal asthma when administered at 16.00 hours. Nocturnal worsening of asthma is a useful model for testing inhaled steroid activity in a single night study.

Activity-induced asthma

Exercise is the most common trigger of persistent childhood asthma. The history for EIA can be complicated by the lack of perception of significant airway obstruction during exercise. One must carefully identify those children with EIA from the group of children who report low level of activity because of lack of interest or because they are out of shape. Baseline spirometry of children with persistent asthma is frequently normal. Spirometry is important to identify those children with EIA who underrecognize their disease, but normal results should not be used as evidence of absence of disease. Formal exercise testing should be considered when the diagnosis is unclear or if there seems to be a lack of bronchoprotection with inhaled albuterol. The goal of treatment of EIA should be the attainment of a normal activity level for children and adolescents. Identification of the limits imposed by EIA and establishment of goals of therapy with the child and family should be the initial action. Inactivity or reduced exertion, in the presence of this diagnosis. should not be accepted. Therapy for EIA starts with control of the underlying persistent asthma. Inhaled corticosteroids are the most effective initial treatment of both EIA and persistent asthma in children and adolescents. Exercise-induced asthma is a common aspect of a prevalent disease that warrants proper diagnosis and treatment. With appropriate therapy, children with EIA should be able to participate in sports and maintain normal activity. They should strive to compete in the same playing field as their peers and have the same goals as those children and athletes who do not have exercise-induced asthma.

Exercise-induced asthma: diagnosis and management

OBJECTIVE

To review the diagnosis and management of exercise-induced asthma (EIA).

DATA SOURCES

Computer-assisted literature searches on MEDLINE for articles, abstracts, and other relevant data on exercise-induced asthma

STUDY SELECTION

Published articles, abstracts, and conference proceedings were selected.

RESULTS

EIA is seen in 40 to 90% of asthmatic patients. Exercise can be the sole trigger or be one of multiple triggers of asthma exacerbations. A good history and physical examination can diagnose most cases of EIA. Spirometry can confirm the diagnosis. Exercise testing may be necessary in certain cases. Prevention through both pharmacologic and nonpharmacologic measures is the key to EIA management. Inhaled beta-agonists remain the medications of choice for EIA prophylaxis. Inhaled cromolyn and antileukotrienes are alternatives. Good long-term control of asthma with anti-inflammatory medications such as inhaled steroids will also decrease the incidence of EIA.

CONCLUSIONS

Early diagnosis and proper preventive and maintenance therapy can reduce episodes of EIA and enable patients to continue to engage in sports and lead an active life.

Acute asthma: under attack

The burden of asthma (death, disability, and an increasing prevalence) makes it a major public health problem worldwide. In an effort to decrease this burden, investigators are studying many aspects of this disease. The role of race, ethnicity, infections, and pollutants as triggers, as well as the risk factors are now being defined. Research into methods to decrease acute exacerbations and improve emergency and in-hospital management, using standardized protocols and incentives for follow-up care, has yielded valuable information but has met with limited success. Adherence to the national guidelines has been poor and to some extent can be attributed to the lack of a practical method of measuring the degree of lung inflammation and cumbersome treatment protocols. Exhaled nitric oxide is a noninvasive marker of inflammation and may provide a rational method to titrate corticosteroid and leukotriene receptor antagonist therapy. The best route and dosing regimen for corticosteroid administration (oral vs intramuscular vs nebulized) are the subject of several studies, with no clear-cut winner. The burden of asthma in developing countries with limited financial resources has also triggered a search for simpler, cheaper, and practical methods for beta-agonist delivery using indigenous spacers. Recent research in asthma has unveiled our incomplete knowledge of the disease but has also provided a sense of where efforts should be expended. Research into the genetics and pharmacogenetics of asthma and into the societal factors limiting the delivery of optimal care is likely to yield useful and practical information.