Low- and high-dose fluticasone propionate in asthma; effects during and after treatment

Inhaled corticosteroids as treatment for adolescent asthma: effects on adult anxiety-related outcomes in a murine model

RATIONALE

Allergic asthma, typically controlled with inhaled corticosteroids (ICS), is the leading chronic health condition for youth under 18 years of age. During this peri-adolescent period, significant brain maturation occurs. Prior studies indicate that both chronic inflammation and corticosteroid medications increase risk for developing an internalizing disorder like anxiety.

OBJECTIVES

To determine if chronic ICS treatments exacerbate or alleviate anxiety symptoms associated with developmental allergic asthma, we used a mouse model to isolate the influence of ICS (fluticasone propionate, FLU) vs. airway inflammation (induced with house dust mite extract, HDM).

METHODS

During development, male and female BALB/cJ mice were repeatedly exposed to HDM or saline plus one of four FLU doses (none/vehicle, low, moderate, or high). In adulthood, we assessed lung inflammation, circulating and excreted corticosteroids, anxiety-like behavior, and gene expression in stress and emotion regulation brain regions.

RESULTS

FLU treatment decreased body weight and anxiety-like behavior and increased fecal corticosterone metabolite concentrations and Crhr2 gene expression in ventral hippocampus. FLU effects were only observed in saline/non-HDM-exposed mice, and the FLU doses used did not significantly decrease HDM-induced airway inflammation. Females had greater serum and fecal corticosterone concentrations, less anxiety-like behavior, and lower Crhr1 gene expression in ventral hippocampus and prefrontal cortex than males.

CONCLUSIONS

These findings suggest that steroid medications for youth with allergic asthma may not exacerbate anxiety-related symptoms, and that they should be avoided in children/adolescents without a health condition. The results are informative to future work on the use of corticosteroid medications during childhood or adolescent development.

Performance Characteristics of Spirometry With Negative Bronchodilator Response and Methacholine Challenge Testing and Implications for Asthma Diagnosis

BACKGROUND

In patients with a history suggestive of asthma, diagnosis is usually confirmed by spirometry with bronchodilator response (BDR) or confirmatory methacholine challenge testing (MCT).

RESEARCH QUESTION

We examined the proportion of participants with negative BDR testing who had a positive MCT (and its predictors) result and characteristics of MCT, including effects of controller medication tapering and temporal variability (and predictors of MCT result change), and concordance between MCT and pulmonologist asthma diagnosis.

STUDY DESIGN AND METHODS

Adults with self-reported physician-diagnosed asthma were recruited by random-digit dialing across Canada. Subjects performed spirometry with BDR testing and returned for MCT if testing was nondiagnostic for asthma. Subjects on controllers underwent medication tapering with serial MCTs over 3 to 6 weeks. Subjects with a negative MCT (the provocative concentration of methacholine that results in a 20% drop in FEV₁ [PC₂₀] > 8 mg/mL) off medications were examined by a pulmonologist and had serial MCTs after 6 and 12 months.

RESULTS

Of 500 subjects (50.5 ± 16.6 years old, 68.0% female) with a negative BDR test for asthma, 215 (43.0%) had a positive MCT. Subjects with prebronchodilator airflow limitation were more likely to have a positive MCT (OR, 1.90; 95% CI, 1.17-3.04). MCT converted from negative to positive, with medication tapering in 18 of 94 (19.1%) participants, and spontaneously over time in 25 of 165 (15.2%) participants. Of 231 subjects with negative MCT, 28 (12.1%) subsequently received an asthma diagnosis from a pulmonologist.

INTERPRETATION

In subjects with a self-reported physician diagnosis of asthma, absence of bronchodilator reversibility had a negative predictive value of only 57% to exclude asthma. A finding of spirometric airflow limitation significantly increased chances of asthma. MCT results varied with medication taper and over time, and pulmonologists were sometimes prepared to give a clinical diagnosis of asthma despite negative MCT. Correspondingly, in patients for whom a high clinical suspicion of asthma exists, repeat testing appears to be warranted.

Efficacy and safety of AZD7594, an inhaled non-steroidal selective glucocorticoid receptor modulator, in patients with asthma: a phase 2a randomized, double blind, placebo-controlled crossover trial

Background

Inhaled corticosteroids reduce inflammation in asthma but chronic use may cause adverse effects. AZD7594, an inhaled non-steroidal selective glucocorticoid receptor modulator, has the potential of an improved risk-benefit profile. We investigated the safety and efficacy of AZD7594 in asthma.

Methods

This phase 2a multi-center, randomized, double-blind, placebo-controlled crossover study enrolled adults with asthma aged 18 to 75 years. Patients were treated with budesonide 200 μg twice daily for 2–3 3 weeks (run in part one). If controlled, as demonstrated by an asthma control questionnaire-5 score of < 1.5, patients entered a three-week run-in (part two) where they received a short acting bronchodilator alone. Thereafter, patients with a fractional exhaled nitric oxide (F_ENO) ≥25 ppb and pre-dose FEV₁ 40 to 90% predicted were randomized to one of nine treatment sequences. Each patient received placebo and two of three dose levels of AZD7594 (58, 250, 800 μg) once daily via inhalation, in 14-day treatment periods, separated by three-week washout periods. The primary endpoint was the change from baseline in morning trough FEV₁ versus placebo on day 15. Secondary endpoints included measures of airway inflammation and asthma control.

Results

Fifty-four patients were randomized and received at least 1 dose of treatment, 48 patients completed the study. Overall 52 patients received placebo, 34 received AZD7594 58 μg, 34 received AZD7594 250 μg, and 34 received AZD7594 800 μg. AZD7594 800 μg demonstrated a significant improvement in Day 15 morning trough FEV₁versus placebo (LS means difference 0.148 L 95% CI 0.035–0.261, p = 0.011), with a dose-dependent response seen in the 250 μg (0.076 L -0·036–0·188, p = 0.183) and 58 μg (0·027 L -0·086–0·140, p = 0.683). All secondary endpoints showed statistically significant improvement at the 800 μg dose. All doses demonstrated a significant reduction in F_ENO at day 15 p < 0.01. No statistically significant difference in plasma cortisol level was observed between AZD7594 and placebo at any dose. AZD7594 was considered safe and well tolerated.

Conclusions

Two-week treatment with AZD7594 demonstrated a favorable risk-benefit profile in patients with mild to moderate asthma. Further clinical studies are needed to fully characterize AZD7594.

Trial registration

ClinicalTrials.gov number NCT02479412.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1000-7) contains supplementary material, which is available to authorized users.

A Systematic Review of Patient- and Family-Level Inhaled Corticosteroid Adherence Interventions in Black/African Americans

BACKGROUND

Inhaled corticosteroid (ICS) adherence rates are suboptimal among adult black/African Americans. Comprehensive studies characterizing the effectiveness and the methodological approaches to the development of interventions to improve ICS adherence in adult black/African Americans have not been performed.

OBJECTIVES

Conduct a systematic review of patient/family-level interventions to improve ICS adherence in adult black/African Americans.

METHODS

We searched MEDLINE, EMBASE, Web of Science, and CINAHL from inception to August 2017 for English-language US studies enrolling at least 30% black/African Americans comparing patient/family-level ICS adherence interventions with any comparator. Two investigators independently selected, extracted data from, and rated risk of bias. We collected information on intervention characteristics and outcomes, and assessed whether studies were informed by behavior theory, stakeholder engagement, or both.

RESULTS

Among 1661 abstracts identified, we reviewed 230 full-text articles and identified 4 randomized controlled trials (RCTs) and 1 quasi-experimental (pre-post design) study meeting criteria. Study participants (N range, 17-333) varied in mean age (22-47 years), proportion black/African Americans studied (71%-93%), and sex (69%-82% females). RCTs evaluated problem-solving classes, self-efficacy training, technology-based motivational interviewing program, and the use of patient advocates. The RCT testing self-efficacy training was the only intervention informed by both behavior theory and stakeholder engagement. All 4 RCTs compared interventions with active control and rated as medium risk of bias. No RCTs found a statistically significant improvement in adherence.

CONCLUSIONS

Few studies assessing asthma adherence interventions focused on adult black/African-American populations. No RCTs demonstrated improved ICS adherence in participants. Future studies that are informed by behavior change theory and stakeholder engagement are needed.

Asthma Control and Sputum Eosinophils: A Longitudinal Study in Daily Practice

BACKGROUND

Longitudinal trials have suggested that asthma control may be influenced by fluctuations in eosinophilic inflammation. This association has however never been confirmed in daily practice.

OBJECTIVE

To investigate the relationship between asthma control and sputum eosinophils in clinical practice.

METHODS

A retrospective longitudinal study was conducted on 187 patients with asthma with at least 2 successful sputum inductions at our Asthma Clinic. Linear mixed models were used to assess the relationship between asthma control and individual changes in sputum eosinophils. Receiver-operating characteristic curves were constructed to define minimal important differences (MIDs) of sputum eosinophils associated with a change of at least 0.5 in Asthma Control Questionnaire (ACQ) score. Then, a validation cohort of 79 patients with asthma was recruited to reassess this relationship and the accuracy of the MID values.

RESULTS

A multivariate analysis showed that asthma control was independently associated with individual fluctuations in sputum eosinophil count (P < .001). In patients with intermittent/persistently eosinophilic asthma, we calculated a minimal important decrease of 4.3% in the percentage of sputum eosinophils (area under the curve [AUC], 0.69; P < .001) or 3.4-fold (AUC, 0.65; P = .003) for a significant improvement in asthma control and a minimal important increase of 3.5% (AUC, 0.67; P = .004) or 1.8-fold (AUC, 0.63; P = .02) for a significant worsening in asthma control. The association between asthma control and sputum eosinophils and the accuracy of the MIDs of sputum eosinophils were confirmed in the validation cohort.

CONCLUSIONS

At the individual level, asthma control was associated with fluctuations in sputum eosinophil count over time.

Revisiting early intervention in adult asthma

The term “early intervention” with inhaled corticosteroids (ICS) in asthma is used in different ways, thereby causing confusion and misinterpretation of data. We propose that the term should be reserved for start of ICS therapy in patients with a diagnosis of asthma but within a short period of time after the first symptoms, not from the date of diagnosis. Prospective clinical studies suggest a time frame of 2 years for the term “early” from the onset of symptoms to starting anti-inflammatory treatment with ICS.

The current literature supports early intervention with ICS for all patients with asthma including patients with mild disease, who often have normal or near-normal lung function. This approach reduces symptoms rapidly and allows patients to achieve early asthma control. Later introduction of ICS therapy may not reduce effectiveness in terms of lung function but delays asthma control and exposes patients to unnecessary morbidity. Results of nationwide intervention programmes support the early use of ICS, as it significantly minimises the disease burden.

Acute asthma exacerbations are usually preceded by progressing symptoms and lung function decline over a period of 1–2 weeks. Treatment with an increased dose of ICS together with a rapid- and long-acting inhaled β₂-agonist during this phase has reduced the risk of severe exacerbations.

ICS are the first-line therapy for diagnosed asthma and should be introduced early on the disease coursehttp://ow.ly/Qx1ef

Is low dose inhaled corticosteroid therapy as effective for inflammation and remodeling in asthma? A randomized, parallel group study

Background

While most of the clinical benefits of inhaled corticosteroid (ICS) therapy may occur at low doses, results of dose-ranging studies are inconsistent. Although symptom/lung function response to low and high dose ICS medication is comparable, it is uncertain whether low dose ICSs are as effective as high dose in the treatment of inflammation and remodeling.

Methods

22 mild or moderate asthmatic adult subjects (corticosteroid free for > 2 months) participated in a randomized, parallel group study to compare effects of fluticasone propionate (FP) 200 mcg/day and 1000 mcg/day. Alveolar macrophage (AM)-derived cytokines and basement membrane thickness (BMT) were measured at baseline and after 7 weeks treatment while symptoms, spirometry, exhaled nitric oxide (eNO) and airway hyperresponsiveness (AHR) to mannitol at baseline and 6 weeks.

Results

FP improved spirometry, eNO, symptoms and AHR with no difference between low and high dose FP. Both high and low dose FP reduced GM-CSF, TNF-alpha and IL-1ra, with no change in BMT and with no differences between low and high dose FP.

Conclusions

200 μg/day of FP was as effective as 1000 μg/day in improving asthma control, airway inflammation, lung function and AHR in adults in the short term. Future studies should examine potential differential effects between low and high dose combination therapy (ICS/long acting beta agonist) on inflammation and airway remodeling over longer treatment periods.

Updates on the use of inhaled corticosteroids in asthma

PURPOSE OF REVIEW

The purpose of this review is to compare and contrast the newer inhaled corticosteroid (ICS) ciclesonide with older ICSs in terms of pharmacodynamic and pharmacokinetic properties and how these affect comparative efficacy. In addition, clinical dosing strategies for ICSs including as-needed use will be explored.

RECENT FINDINGS

Ciclesonide has demonstrated similar efficacy to that of fluticasone propionate and mometasone furoate in equipotent doses with a potentially improved therapeutic index. Once-daily administration of ICSs is generally not as effective as twice-daily. Continuous administration of ICSs does not change the natural history of asthma in either children or adults. Long-term administration of medium dose ICSs does not increase the risk of cataracts or osteopenia in children and young adults. Studies of as-needed ICSs in mild persistent asthma in adults and children have demonstrated mixed results, with some showing equal efficacy to continuous therapy and others showing superiority of continuous therapy.

SUMMARY

Ciclesonide provides a newer ICS with favorable pharmacokinetics that may improve the therapeutic index, but assessment of its systemic effects such as growth await further studies. Continuous administration of ICSs in low to medium dose over many years is well tolerated. The use of as-needed ICSs in patients with mild persistent asthma is promising as a potential step-down therapy but awaits further studies.

Comparison of Inhaled Corticosteroids: What You Need to Know in Choosing a Product

Inhaled corticosteroids (ICS) are recommended by The National Asthma Education and Prevention Program's Expert Panel Report 3 for all levels of persistent asthma in the pediatric population. The recommended ICS doses are based on assessment of severity and control of asthma. The pharmacodynamics and pharmacokinetics of the current ICSs are reviewed. While comparable efficacy can be achieved with equipotent dosing, some of the newer ICSs, fluticasone propionate, mometasone furoate, and ciclesonide, have pharmacokinetic profiles that produce less risk of systemic effects. However, at high doses systemic activity increases with all ICSs. The clinicians need to weigh the benefits and risks of these different products and dosing schemes in their patients for optimal use.

The importance of airway remodelling in the natural course of asthma

INTRODUCTION

Asthma is associated with airflow limitation and increased decline in lung function. The underlying mechanism for this was probably that persisting inflammation leads to remodelling of the airways.

OBJECTIVES

To review the importance of different factors which are related to airflow limitation and lung function decline in asthma.

METHODS

Case report and literature review.

RESULTS

Asthma severity, smoking, bronchial hyperresponsiveness and eosinophil inflammation were the variables that were most convincingly related to decline in forced expiratory volume in 1 s (FEV(1)) in asthma. Treatment with inhaled corticosteroids probably decreased the rate of FEV(1) decline, although this was more uncertain because of the lack of randomised double blind studies that show such an effect. Progress in the field of the genetics of asthma may, in the near future, elucidate the role of gene-environment interaction in lung function decline in asthma.

CONCLUSION

Regular treatment with inhaled corticosteroids may partly have a beneficial effect on airway remodelling in asthma. Improved understanding of the processes leading to airway remodelling is, however, important in order to prevent a large number of asthmatics from developing irreversible airflow obstruction.

Tryptase as an inflammatory marker in allergic disease and asthma

Asthma is a chronic inflammatory disease of the airways, varying from occasional episodes of wheezing and shortness of breath, to an irreversible, life-threatening obstructive disease. While many cases are managed with relative ease, others do not respond to the traditional inhaled therapy or even to oral glucocorticosteroids. Although it cannot be cured as yet, asthma can be controlled if properly diagnosed. Usually, functional clinical parameters form the basis for estimation of the disease severity. In addition, the growing database of cytokine and mediator profiles have allowed their exploitation as molecular markers for processes underlying airway inflammation in asthma. Tryptase is a potent and versatile mediator in allergic inflammation, orchestrating both acute and chronic events by acting on a vast array of cells and tissue components. For more than a decade, tryptase has been used as a marker for allergic inflammation in asthma as well as in a variety of other airway diseases. In this review, the current advantages and disadvantages of the use of tryptase as an inflammatory marker in asthma will be discussed.

Down-titration from high-dose combination therapy in asthma: Removal of long-acting beta(2)-agonist

BACKGROUND

Asthma guidelines recommend reducing inhaled corticosteroids (ICS) to the minimum effective dose, but the timing of long-acting beta(2)-agonist (LABA) withdrawal is unclear. Recent FDA guidelines recommend LABA withdrawal once asthma is well-controlled. This 13-month double-blind study of patients taking high-dose combination therapy investigated the effect of discontinuation of LABA before ICS down-titration.

METHODS

Adults using salmeterol/fluticasone combination (SFC) 50/500 microg bd were randomized to SFC 50/500 microg bd or fluticasone propionate (FP) 500 microg bd, with subsequent ICS down-titration 8-weekly using a clinical algorithm. The primary outcome was mean daily FP dose, including ICS for exacerbations.

RESULTS

82 subjects were randomized. Asthma was well-controlled at baseline, with mean FEV(1) 84.8% predicted and Asthma Control Questionnaire (ACQ) score 0.9. There was no significant difference in mean daily FP dose (SFC: 721 microg, FP:816 microg, p = 0.3), but final dose was lower with SFC (534 microg cf. 724 microg, p = 0.005). ICS dose was reduced by >or=80% in 41% SFC and 15% FP patients. Ambulatory lung function was significantly higher with SFC, but there were no differences between groups in rescue beta(2)-agonist use, clinic spirometry, airway responsiveness, ACQ, sputum eosinophils or FeNO. Baseline airway responsiveness, and pre-reduction blood eosinophils, were significant predictors of mean daily FP dose and dose reduction failure respectively.

CONCLUSIONS

Many patients prescribed high-dose combination therapy may be over-treated. Substantial reductions in dose can be achieved with a clinical algorithm, reaching lower FP doses with SFC than FP without losing asthma control or increasing disease activity.

TRIAL REGISTRATION

This study was commenced before mandatory registration of clinical trials.

Benefits of low-dose inhaled fluticasone on airway response and inflammation in mild asthma

RATIONALE

Current guidelines suggest that asthma should be controlled with the lowest dose of maintenance medication required.

OBJECTIVES

To evaluate the effects of a low dose of inhaled corticosteroid compared to a placebo, on airway inflammation and responsiveness in patients with mild symptomatic asthma.

METHODS

In this randomized double-blind, placebo-controlled, parallel group study, we looked at the influence of inhaled fluticasone propionate 250 microg/day for 3 months followed by 100 microg/day for 9 months on airway inflammation and methacholine responsiveness in non-smoking subjects with mild allergic asthma. Subjects were evaluated at baseline and 3, 6, 9 and 12 months after treatments; a 2-week evaluation of respiratory symptoms and peak expiratory flow measurements was done before each visit.

RESULTS

Fifty-seven subjects completed the 3-month study period. Airway responsiveness, expressed as the PC20 methacholine, increased by 0.27 and 1.14 doubling concentrations, respectively, in placebo-treated (n=33) and in fluticasone-treated (n=24) asthmatic subjects (p=0.03). An additional improvement in PC20 up to 2.16 doubling concentrations was observed in the fluticasone-treated group during the 9-month lower-dose treatment (p=0.0004, end of low-dose period compared with placebo). Sputum eosinophil counts decreased after 3 months of fluticasone 250 microg/day compared with placebo (p<0.0001) and remained in the normal range during the 9-month lower-dose treatment. Respiratory symptoms and peak expiratory flows did not change significantly throughout the study in both groups.

CONCLUSION

In mild asthma, keeping a regular minimal dose of ICS after asthma control has been achieved, may lead to a further reduction in airway responsiveness and keep sputum eosinophil count within the normal range.

Fluticasone at different doses for chronic asthma in adults and children

BACKGROUND

Inhaled fluticasone propionate (FP) is a high-potency inhaled corticosteroid used in the treatment of asthma.

OBJECTIVES

1. To assess the efficacy and safety outcomes of inhaled fluticasone at different nominal daily doses in the treatment of chronic asthma.2. To test for the presence of a dose-response effect.

SEARCH STRATEGY

We searched the Cochrane Airways Group Trials Register (January 2008).

SELECTION CRITERIA

Randomised trials in children and adults comparing fluticasone at different nominal daily doses in the treatment of chronic asthma. Two reviewers independently assessed articles for inclusion and methodological quality.

DATA COLLECTION AND ANALYSIS

One review author extracted data. These were checked and verified by a second reviewer. Quantitative analyses where undertaken using Review Manager.

MAIN RESULTS

Fifty-one published and unpublished trials (representing 55 group comparisons, 10,797 participants) met the inclusion criteria. In asthmatics with mild to moderate disease who were not on oral steroids, FP did not exhibit a dose-response effect in the lower dose comparisons in FEV1 (50mcg, 100mcg, 200mcg and 4-500mcg daily). There were no statisitically significant differences between 4-500mcg and 800-1000mcg, and between 50-100 and 800-1000mcg of FP. When 200mcg was compared with 800-1000mcg daily FEV1 favoured the four/five fold increase. For PEF, a dose response was present with FP when low and moderate, and low and high doses of FP were compared. There was no evidence of a dose-response effect on symptoms or rescue beta-2 agonist use. The likelihood of hoarseness and oral candidiasis was significantly greater for the higher doses (800 to 1000 microg/day). People with oral steroid-dependent asthma treated with FP (2000 microg/day) were significantly more likely to reduce oral prednisolone than those on 1000 to 1500 microg/day (Peto odds Ratio 2.8, 95% CI 1.3 to 6.3). The highest dose also allowed a significant reduction in daily oral prednisolone dose compared to 1000 to 1500 microg/day (WMD 2.0 mg/day, 95% CI 0.1 to 4.0 mg/day).

AUTHORS' CONCLUSIONS

We have not found evidence of a pronounced dose response in FEV1 with increasing doses of fluticasone. The number of studies contributing to our primary outcomes was low. At dose ratios of 1:2, there are statistically significant differences in favour of the higher dose in morning peak flow across the low dose range. The clinical impact of these differences is open to interpretation. Patients with moderate disease achieve similar levels of asthma control on medium doses of fluticasone (400 to 500 microg/day) as they do on high doses (800 to 1000 microg/day). More work in severe asthma would help to confirm that doses of FP above 500 microg/day confer greater benefit in this subgroup than doses of around 200 microg/day. In oral corticosteroid-dependent asthmatics, reductions in prednisolone requirement may be gained with FP 2000 microg/day.

Effect of disease duration on dose-response of inhaled budesonide in asthma

BACKGROUND

Inhaled corticosteroids (ICS) represent first-line treatment in persistent asthma with clinical studies showing benefits of initiating therapy early. Whether treatment should be started with a high or low dose remains controversial. We investigated the importance of disease duration on the response to the starting dose of the ICS, budesonide, in asthma patients not previously treated with ICS.

METHODS

Forty patients with newly detected asthma (symptoms for <12 months) and 41 patients with established asthma (mean duration 5.2 years, range 2-11) were randomized (double-blind, parallel-group) to treatment with budesonide Turbuhaler 100 or 400microg twice daily or placebo for 12 weeks.

RESULTS

For morning peak expiratory flow (mPEF), all four budesonide treatments resulted in statistically significant improvements from baseline and, after 12 weeks, the changes in all four groups were statistically significantly greater than placebo. In patients receiving early treatment, no significant differences were seen between budesonide doses. In patients with established symptoms, 800 mg/day [corrected] improved mPEF significantly more than 200 mg/day [corrected] The 200 mg/day [corrected] dose in the early treatment group improved mPEF significantly more than in the delayed treatment group. Changes in forced expiratory volume in 1s (FEV(1)), the concentration of inhaled histamine causing a 20% drop in FEV(1), and use of as-needed medication behaved in very similar ways to mPEF. Asthma symptoms were reduced in all budesonide groups without a difference between doses.

CONCLUSION

In patients with newly detected asthma treated early the initial ICS dose is not important. In contrast, in patients with symptoms for a longer duration a high starting dose improves airway function and hyperresponsiveness significantly better than a low dose.

Omeprazole reduces the response to capsaicin but not to methacholine in asthmatic patients with proximal reflux

OBJECTIVE

To study the relationships between airway responsiveness to methacholine and capsaicin, proximal or distal reflux and the effects of short-term acid inhibition.

MATERIAL AND METHODS

Twenty-nine asthmatics, not taking steroids regularly, underwent respiratory symptom measurements, 24-h dual-probe pH monitoring, and challenges with methacholine and capsaicin. Challenges and symptom measurements were repeated after 12 days' omeprazole treatment (20 mg b.i.d.). The results (median and range) were expressed as PD20 methacholine (mg) and PD5 capsaicin (dose causing five coughs, nmol).

RESULTS

Seventeen patients presented pathological reflux in the distal esophagus, and 17 in the proximal esophagus. At baseline no correlation was found between PD20 or PD5 and reflux. Treatment with omeprazole did not change bronchial responsiveness to methacholine (basal: 0.16 mg, 0.02-1.27; omeprazole: 0.15 mg, 0.02-1.60); omeprazole decreased the tussive response to capsaicin (basal: 0.08 nmol, 0.08-2.46; omeprazole: 0.61 nmol, 0.08-9.84, p<0.001) only in patients with pathological reflux. The decrease was positively correlated with proximal acid exposure (r2=0.70, p<0.001). Omeprazole reduced asthma symptoms in patients with proximal reflux, cough in those with proximal or distal reflux.

CONCLUSIONS

In asthmatics, inhibition of gastric acid secretion does not influence bronchial hyperresponsiveness but decreases tussive sensitivity and this effect is related to proximal reflux.

Once-daily administration of fluticasone propionate does not worsen controlled airway hyperresponsiveness in patients with asthma

BACKGROUND

Inhaled steroids are currently the most important drugs for asthma patients, but compliance tends to be low. Compliance could be improved by reducing the number of daily administrations.

OBJECTIVES

In the present study, we compared once- and twice-daily administration of fluticasone propionate (FP) to determine the differences in efficacy.

METHODS

Subjects were 40 patients diagnosed with bronchial asthma with stable symptoms and pulmonary functions who were on twice-daily FP administration of 100 microg. There were 14 men and 26 women ranging from 29 to 72 years of age. After a 4-week observation period, subjects were randomized into two administration groups by the envelope method and followed for 8 weeks: group A, once-daily administration (200 microg of FP at night), and group B, twice-daily administration (100 microg of FP in the morning and at night). Clinical symptoms, pulmonary functions and airway responsiveness were compared between these two groups.

RESULTS

No significant deterioration in clinical symptoms, pulmonary functions and airway responsiveness were observed in group A compared with group B.

CONCLUSIONS

These results demonstrate that once-daily FP administration is as effective as twice-daily administration, and that it may improve the compliance for inhaled steroids.

Eosinophilic bronchitis in asthma: a model for establishing dose-response and relative potency of inhaled corticosteroids

BACKGROUND

Newer generations and formulations of inhaled corticosteroids have necessitated the development of a clinically relevant model to compare their clinical potency.

OBJECTIVE

We evaluated whether sputum eosinophil counts could demonstrate a dose-response to inhaled corticosteroids, and compared the response with other inflammatory markers.

METHODS

Fourteen steroid-naive patients with asthma with an initial sputum eosinophilia of > or = 2.5% entered a 6-week sequential, placebo-controlled, patient-blinded, cumulative dose-response study. After 7 days of placebo, they received incremental doses of fluticasone propionate (FP), 50, 100, 200, and 400 microg/d, each for 7 days. Measurements were made of sputum and blood eosinophils, exhaled nitric oxide, spirometry, airway responsiveness to methacholine (methacholine PC20), and symptom scores before and after each dose.

RESULTS

Sputum eosinophils and exhaled nitric oxide were extremely sensitive to the effects of FP, and exhibited significant dose-dependent reductions of 99.4% and 99.8 parts per billion, respectively, where each variable was expressed per 100 microg/d FP. This compared with a 0.5 doubling dose increase of airway responsiveness to methacholine and a 0.3 decrease in symptom scores. Airway responsiveness to methacholine was the only variable that increased throughout the study.

CONCLUSION

These results suggest that the model of eosinophilic bronchitis could be used to compare the effect of cumulative doses of an inhaled corticosteroid delivered by different types of delivery systems or preparations using a relatively small number of patients.

CLINICAL IMPLICATIONS

Future clinical studies based on this model will allow clinicians to make informed decisions regarding the relative potencies of different inhaled corticosteroids.

Cost-effectiveness of inhaled steroids in asthma: impact of effect on bone mineral density

BACKGROUND

The effects of inhaled corticosteroid (ICS) preparations on bone health have been debated. Multiple analyses have been published examining the question, with mixed results.

OBJECTIVES

We examined how assumptions about the effect of ICS on bone mineral density (BMD) influence the cost-effectiveness of ICS in asthma.

METHODS

We developed a mathematical simulation model to estimate clinical outcomes and costs for a cohort with mild/moderate asthma. The analysis conformed to reference case recommendations of the US Panel on Cost-Effectiveness in Health and Medicine. Sensitivity analysis evaluated the stability of our results to uncertainty in treatment duration, age at treatment, and ICS dose.

RESULTS

Assuming a dose of 200 microg twice per day of ICS, a literature-based average effect of ICS on BMD and a 10-year time horizon, we observed a minimal increase in the costs attributed to hip fracture and incremental cost effectiveness ratio of $26,000 per quality-adjusted life-year and $14.00 per symptom-free day gained. Over an extended the time horizon (lifetime), the incremental cost effectiveness ratio increased to $42,000/quality-adjusted life-year. Only under a scenario of high-dose ICS, a lifetime horizon, and a large effect of ICS on BMD did the potential impact of ICS on BMD dramatically affect the economic attractiveness of therapy.

CONCLUSION

To minimize any potential impact, use of the lowest effective dose of ICS and measures to target and intervene in high-risk individuals are warranted. However, ICS therapy in mild/moderate asthma compares favorably with commonly accepted interventions over a wide range of assumptions regarding this treatment and its effects on BMD.

Biomarkers predicting response to corticosteroid therapy in asthma

International guidelines on the management of asthma support the early introduction of corticosteroids to control symptoms and to improve lung function by reducing airway inflammation. However, not all individuals respond to corticosteroids to the same extent and it would be an advantage to be able to predict the response to corticosteroid treatment. Several biomarkers have been assessed following treatment with corticosteroids including measures of lung function, peripheral blood and sputum indices of inflammation, exhaled gases and breath condensates. The most widely examined measures in predicting a response to corticosteroids are airway hyperresponsiveness, exhaled nitric oxide (eNO) and induced sputum. Of these, sputum eosinophilia has been demonstrated to be the best predictor of a short-term response to corticosteroids. More importantly, directing treatment at normalizing the sputum eosinophil count can substantially reduce severe exacerbations. The widespread utilization of sputum induction is hampered because the procedure is relatively labor intensive. The measurement of eNO is simpler, but incorporating the assessment of NO in an asthma management strategy has not led to a reduction in exacerbation rates. The challenge now is to either simplify the measurement of a sputum eosinophilia or to identify another inflammatory marker with a similar efficacy as the sputum eosinophil count in predicting both the short- and long-term responses to corticosteroids.

Inhaled fluticasone at different doses for chronic asthma in adults and children

BACKGROUND

Inhaled fluticasone propionate (FP) is a high-potency inhaled corticosteroid used in the treatment of asthma.

OBJECTIVES

1. To assess the efficacy and safety outcomes of inhaled fluticasone at different nominal daily doses in the treatment of chronic asthma. 2. To test for the presence of a dose-response effect.

SEARCH STRATEGY

We searched the Cochrane Airways Group Trials Register (January 2005) and reference lists of articles. We contacted trialists and pharmaceutical companies for additional studies and searched abstracts of major respiratory society meetings (1997 to 2004).

SELECTION CRITERIA

Randomised trials in children and adults comparing fluticasone at different nominal daily doses in the treatment of chronic asthma. Two reviewers independently assessed articles for inclusion and methodological quality.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data. These were checked and verified by a second reviewer. Quantitative analyses where undertaken using RevMan (Analyses 1.0.2).

MAIN RESULTS

Forty-three studies (45 data sets with 8913 participants) met the inclusion criteria. Methodological quality was high. In asthmatics with mild to moderate disease who were not on oral steroids a dose-response effect was present with FP for change in morning peak expiratory flow (PEF). For low doses (100 versus 200 microg/day) the weighted mean difference (WMD) was 6.29 litres/min, 95% confidence interval (CI) 2.28 to 10.29. Comparing medium (400 to 500 microg/day) to low dose (200 microg/day) FP the WMD was 6.46 litres/min (95% CI 3.02 to 9.89); this effect was more pronounced in one trial with more severely asthmatic children. For FP 100 versus 400 to 500 microg/day the WMD was 8 litres/min (95% CI 1 to 15) and at high versus low doses (800 to 1000 versus 50 to 100 microg/d) the WMD was 22 litres/min (95% CI 15 to 29). When high and medium doses were compared there was no significant difference in the change in morning PEF: at 400 to 500 versus 800 to 1000 microg/day the WMD was 0.16 litres/min (95% CI 6.95 to 6.63). There was no dose-response effect on symptoms or rescue beta-2 agonist use. The likelihood of hoarseness and oral candidiasis was significantly greater for the higher doses (800 to 1000 microg/day). People with oral steroid-dependent asthma treated with FP (2000 microg/day) were significantly more likely to reduce oral prednisolone than those on 1000 to 1500 microg/day (Peto odds Ratio 2.8, 95% CI 1.3 to 6.3). The highest dose also allowed a significant reduction in daily oral prednisolone dose compared to 1000 to 1500 microg/day (WMD 2.0 mg/day, 95% CI 0.1 to 4.0 mg/day).

AUTHORS' CONCLUSIONS

Effects of fluticasone are dose dependent but relatively small. At dose ratios of 1:2, there are significant differences in favour of the higher dose in morning peak flow across the low dose range. The clinical impact of these differences is open to interpretation. Patients with moderate disease achieve similar levels of asthma control on medium doses of fluticasone (400 to 500 microg/day) as they do on high doses (800 to 1000 microg/day). More work in severe asthma would help to confirm that doses of FP above 500 microg/day confer greater benefit in this subgroup than doses of around 200 microg/day. In oral corticosteroid-dependent asthmatics, reductions in prednisolone requirement may be gained with FP 2000 microg/day.

Characterization of within-subject responses to fluticasone and montelukast in childhood asthma

BACKGROUND

Responses to inhaled corticosteroids (ICSs) and leukotriene receptor antagonists (LTRAs) vary among asthmatic patients.

OBJECTIVE

We sought to determine whether responses to ICSs and LTRAs are concordant for individuals or whether asthmatic patients who do not respond to one medication respond to the other.

METHODS

Children 6 to 17 years of age with mild-to-moderate persistent asthma were randomized to one of 2 crossover sequences, including 8 weeks of an ICS, fluticasone propionate (100 microg twice daily), and 8 weeks of an LTRA, montelukast (5-10 mg nightly depending on age), in a multicenter, double-masked, 18-week trial. Response was assessed on the basis of improvement in FEV 1 and assessed for relationships to baseline asthma phenotype-associated biomarkers.

RESULTS

Defining response as improvement in FEV 1 of 7.5% or greater, 17% of 126 participants responded to both medications, 23% responded to fluticasone alone, 5% responded to montelukast alone, and 55% responded to neither medication. Compared with those who responded to neither medication, favorable response to fluticasone alone was associated with higher levels of exhaled nitric oxide, total eosinophil counts, levels of serum IgE, and levels of serum eosinophil cationic protein and lower levels of methacholine PC(20) and pulmonary function; favorable response to montelukast alone was associated with younger age and shorter disease duration. Greater differential response to fluticasone over montelukast was associated with higher bronchodilator use, bronchodilator response, exhaled nitric oxide levels, and eosinophil cationic protein levels and lower methacholine PC(20) and pulmonary function values.

CONCLUSIONS

Response to fluticasone and montelukast vary considerably. Children with low pulmonary function or high levels of markers associated with allergic inflammation should receive ICS therapy. Other children could receive either ICSs or LTRAs.

Step-down compared to fixed-dose treatment with inhaled fluticasone propionate in asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are an effective treatment of asthma even when administered at a low dose. Once asthma is controlled, current guidelines recommend that the dose of ICS be reduced to the lowest possible and effective dose. Although the most appropriate strategy for the stepping down has not yet been defined, quantification of sputum eosinophils and bronchial hyperresponsiveness (BHR) are indeed measures of asthma control.

OBJECTIVE

To compare the efficacy of step-down and fixed-dose strategies in the control of BHR to methacholine and eosinophilic inflammation patients with mild-to-moderate asthma.

METHODS

We performed a double-blind, randomized study to compare inhaled fluticasone propionate (FP), 1,000 microg/d, then reduced to 200 microg/d (group 1; n = 18) to a fixed dose of FP, 200 microg/d (group 2; n = 17) administered for 6 weeks and then 8 weeks in reducing the provocative dose of methacholine causing a 20% fall in FEV1 (PD20) and sputum eosinophils in 35 patients. The duration of the efficacy was also followed subsequently after 8 weeks of placebo treatment.

RESULTS

PD20 remarkably increased with both treatment strategies, but differences between groups were not significant. Sputum eosinophils (median values, percentage) at baseline and after each treatment period were not different (group 1, 16.4 to 1.0 to 2.7%; group 2, 16.7 to 2.8 to 2.8%, respectively). The percentages of patients in whom sputum eosinophilia was normalized (< or = 3%) were as follows: group 1, 69% and 60%; group 2, 50% and 57%. After placebo treatment, sputum eosinophils were still "normalized" in approximately one third of patients.

CONCLUSION

Step-down and fixed-dose strategies with FP improved PD20 and sputum eosinophilia to a similar degree. The effect on sputum eosinophils persisted longer than that on methacholine.

The dose-response relationship of inhaled corticosteroids in asthma

Inhaled corticosteroids are the only class of asthma medication that can reduce symptoms, improve lung function, reduce the frequency of severe exacerbations, including hospital and ICU admissions, and decrease the risk of mortality. The therapeutic dose range for all clinical outcome measures in adults is 100 to 1000 mg/d of beclomethasone dipropionate or budesonide, or 50 to 500 mg/d of fluticasone propionate. Doses in excess of this range are not recommended for routine use because they are likely to increase the risk of systemic side-effects without further major improvement in efficacy. The recommendations are qualified by the recognition that there is considerable individual variability in the response to inhaled corticosteroids in asthma, which would suggest that some patients might obtain greater benefit at higher doses, just as some might obtain maximum benefit at lower doses.

Brain-derived neurotrophic factor in platelets and airflow limitation in asthma

Brain-derived neurotrophic factor (BDNF), a key mediator of neuronal plasticity, contributes to airway obstruction and hyperresponsiveness in a model of allergic asthma. BDNF is stored in human platelets and circulates in human plasma, but the significance of BDNF in this compartment is poorly understood. We investigated the relationship between platelet and plasma BDNF levels and pulmonary function in a cohort of 26 adult patients with recently diagnosed allergic asthma. BDNF levels in serum, platelets, and plasma were significantly increased in participants with asthma, as compared with 26 age- and sex-matched control subjects. In steroid-naive patients, but not in patients using inhaled corticosteroids, enhanced platelet BDNF levels correlated with parameters of airway obstruction and airway hyperresponsiveness to histamine. Experiments with activated peripheral blood mononuclear cells revealed that corticosteroids such as fluticasone effectively suppress BDNF secretion. In conclusion, we demonstrate that enhanced platelet BDNF is associated with airflow limitation and airway hyperresponsiveness in asthma. In addition, we provide evidence that corticosteroids suppress BDNF production by activated immune cells.

Clinical usefulness of inflammatory markers in asthma

Asthma is a significant and increasing health problem. Airway inflammation and hyperresponsiveness are key pathophysiological mechanisms underlying asthma. Currently, effective treatments target these two processes and can lead to clinically important improvements in disease control. At present, decisions to initiate or modify therapy are based on symptoms and measures of airway caliber, with no direct assessment of airway inflammation or hyperresponsiveness. It is now possible to measure airway inflammation using noninvasive markers such as exhaled gases, induced sputum and serum measurements. Exhaled nitric oxide (eNO) and induced sputum eosinophils show the greatest promise as clinically useful markers of airway inflammation in asthma. Induced sputum can now be applied to the diagnosis of airway diseases, based on its ability to detect eosinophilic bronchitis in cough, and to differentiate between eosinophilic and non-eosinophilic asthma. The place of induced sputum and eNO in the ongoing monitoring of patients with asthma are now being investigated in controlled trials.

High dose versus low dose inhaled corticosteroid as initial starting dose for asthma in adults and children

BACKGROUND

Inhaled corticosteroids (ICS) form the basis of maintenance therapy in asthma and their efficacy is well established. However, the optimal starting dose of ICS is not clearly established. Recent reviews demonstrate a relatively flat efficacy curve for ICS and increasing side effects with increasing ICS doses. High doses are frequently prescribed and there are now reports of significant side effects occurring with high dose ICS use. These issues demonstrate the need to establish the optimal starting dose of ICS in asthma.

OBJECTIVES

To establish the optimal starting dose of ICS by evaluating the efficacy of initial high dose ICS with low dose ICS in subjects with asthma, not currently on ICS.

SEARCH STRATEGY

We searched the Cochrane Airways Group trials register and reference lists of articles. Date of last search: January 2003

SELECTION CRITERIA

Randomised controlled trials of two different doses of the same ICS in adults and children with asthma with no concomitant ICS or OCS.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted independently by two reviewers. Study authors were contacted for confirmation. Trials were analysed according to the following ICS dose comparisons: step down vs constant dose ICS (n=7); high vs moderate (n=11); high vs low (n=9); moderate vs low (n=11); fold change in dose (all studies).

MAIN RESULTS

31 papers reporting the results of 26 trials were included in the review. For studies that compared a step down approach to a constant moderate/low ICS dose, there were no significant differences in lung function, symptoms, rescue medications or asthma control between the two treatment approaches. Significant but clinically small improvements in percent predicted FEV(1) ( WMD 5.32, 95% CI 0.65 to 9.99) and non significant improvements in the change in morning PEF were found for high dose ICS compared to moderate dose ICS. There were no significant differences in efficacy between high and low dose ICS. For moderate dose ICS, compared to low dose ICS, there were significant improvements in the change in morning PEF l/min from baseline (WMD 11.14, 95% CI 1.34 to 20.93) and nocturnal symptoms (SMD -0.29, 95% CI -0.53 to -0.06 ). Commencing ICS at double or quadruple a base moderate or low dose had no greater effect than commencing with the base dose. Several studies reported greater improvement in airway hyperresponsiveness for high dose ICS.

REVIEWERS' CONCLUSIONS

For patients with asthma who require ICS, commencing with a moderate dose ICS is equivalent to commencing with a high dose ICS and down-titrating. The small significant benefits of commencing with a high ICS dose are not of sufficient clinical benefit to warrant its use when compared to moderate or low dose ICS. Initial moderate ICS dose appears to be more effective than initial low ICS dose. High dose ICS may be more effective than moderate or low dose ICS for airway hyperresponsiveness. There is no benefit in doubling or quadrupling ICS in subjects with stable asthma.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

Sustained reduction in bronchial hyperresponsiveness with inhaled fluticasone propionate within three days in mild asthma: time course after onset and cessation of treatment

BACKGROUND

Bronchial hyperresponsiveness (BHR) is characteristic of asthmatic airways, is induced by airway inflammation, and is reduced by inhaled corticosteroids (ICS). The time course for the onset and cessation of the effect of ICS on BHR is unclear. The effect of inhaled fluticasone propionate (FP) on BHR in patients with mild persistent asthma was assessed using time intervals of hours, days and weeks.

METHODS

Twenty six asthmatic patients aged 21-59 years were selected for this randomised, double blind, parallel group study. The effect of 250 micro g inhaled FP (MDI) administered twice daily was compared with that of placebo on BHR assessed using a dosimetric histamine challenge method. The dose of histamine inducing a decrease in forced expiratory volume in 1 second (FEV(1)) by 15% (PD(15)FEV(1)) was measured before and 6, 12, 24 and 72 hours, and 2, 4 and 6 weeks after starting treatment, and 48 hours, 1 week and 2 weeks after cessation of treatment. Doubling doses of changes in PD(15)FEV(1) were calculated and area under the curve (AUC) statistics were used to summarise the information from individual response curves.

RESULTS

The increase in PD(15)FEV(1) from baseline was greater in the FP group than in the placebo group; the difference achieved significance within 72 hours and remained significant until the end of treatment. In the FP group PD(15)FEV(1) was 1.85-2.07 doubling doses above baseline between 72 hours and 6 weeks after starting treatment. BHR increased significantly within 2 weeks after cessation of FP treatment.

CONCLUSIONS

A sustained reduction in BHR to histamine in patients with mild asthma was achieved within 3 days of starting treatment with FP at a daily dose of 500 micro g. The effect tapered within 2 weeks of cessation of treatment.

Stepping down inhaled corticosteroids in asthma: randomised controlled trial

OBJECTIVES

To determine whether the dose of inhaled corticosteroids can be stepped down in patients with chronic stable asthma while maintaining control.

DESIGN

One year, randomised controlled, double blind, parallel group trial.

SETTING

General practices throughout western and central Scotland.

PARTICIPANTS

259 adult patients with asthma receiving regular treatment with inhaled corticosteroids at high dose (mean dose 1430 microg beclomethasone dipropionate).

INTERVENTIONS

Participants were allocated to receive either no alteration to their dose of inhaled corticosteroid (control) or a 50% reduction in their dose if they met criteria for stable asthma (stepdown).

MAIN OUTCOME MEASURES

Comparison of asthma exacerbation rates, asthma related visits to general practice and hospital, health status measures, and corticosteroid dosage between the two groups.

RESULTS

The proportions of subjects with asthma exacerbations were not significantly different (stepdown 31%, control 26%, P=0.354). Similarly, the numbers of visits to general practice or hospital and the disease specific and generic measures of health status over the one year period were not significantly different. On average the stepdown group received 348 microg (95% confidence interval 202 microg to 494 microg) of beclomethasone dipropionate less per day than the controls (a difference of 25%), with no difference in the annual dose of oral corticosteroids between the two treatment regimens.

CONCLUSIONS

By adopting a stepdown approach to the use of inhaled steroids at high doses in asthma a reduction in the dose can be achieved without compromising asthma control.

Fifty microg b.i.d. of inhaled fluticasone propionate (FP) are effective in stable asthmatics previously treated with a higher dose of FP

Twenty-seven subjects with moderate asthma at the time of diagnosis, well controlled under regular fluticasone propionate (FP) (250 microg b.i.d.) for 6 months at least, were randomized to receive in double-blind fashion: FP 125 microg b.i.d. (Group 1) or FP 50 microg b.i.d. (Group 2) or placebo (Group 3) for 3 months or until symptom recurrence. Daily symptom score and peak expiratory flow were monitored. At the beginning and at the end of the study subjects underwent methacholine challenge and sputum induction. Recurrence of symptoms occurred shortly after randomization in all subjects receiving placebo. None from Group 1 or 2 experienced symptom recurrence during the study. No significant difference in clinical and functional data, and in sputum eosinophil percentages was observed between the beginning and the end of the study in both Groups 1 and 2. Subjects from Group 3 showed a significant increase of sputum eosinophils (P<0.05) and a significant decrease in provocative dose of methacholine (P<0.05) when asthma symptoms recurred. Therefore, very low doses of FP (50 microg b.i.d.) are effective in maintaining for 3 months a good control of the disease in asthmatics already stable under high-dose fluticasone, considering both clinical and functional outcomes and markers of airway inflammation.

Inhaled corticosteroids for asthma: common clinical quandaries

This narrative review provides evidence-based explanations to some of the common clinical concerns regarding inhaled corticosteroids. Inhaled corticosteroids are the treatment of choice for a newly diagnosed asthmatic patient. Better results are obtained when treatment is initiated as soon as the diagnosis is made. Asthma control can be achieved and maintained in most patients with a low or moderate dose of inhaled corticosteroid administered in two daily doses. Longer duration of treatment provides more sustained benefits than treatment that is intermittent and for short periods of time. The clinical benefits can be observed within 24 hours of commencing treatment and may be more pronounced in patients with an eosinophilic bronchitis. Inhaled corticosteroids provide additional benefit when used in conjunction with prednisone in acute severe asthma. Low doses do not have clinically deleterious side effects on the bones, growth, eye, or hypothalamo-pituitary-adrenal-axis. However, they do not normalize lung function and prevent structural changes in the airway wall in all asthmatic patients.

Effects of varying doses of fluticasone propionate on the physiology and bronchial wall immunopathology in mild-to-moderate asthma

OBJECTIVES

Inhaled corticosteroids (ICS) are typically associated with a flat dose-response curve when traditional efficacy values are examined (eg, FEV(1)). The aim of the present study was to investigate if a dose-response relationship exists for lung function and inflammatory cell numbers in bronchial biopsy specimens.

METHODS

Bronchial biopsy specimens were obtained from 36 patients randomized to receive 100 micro g, 500 microg, or 2,000 microg/d of fluticasone propionate (FP). Lung physiology and bronchial biopsies were performed at baseline and after 2 weeks of treatment.

RESULTS

Improvement in lung function and suppression of airway inflammation were optimal at a dose of 500 microg/d of FP. Significant changes from baseline following treatment were documented in FEV(1) (p = 0.02), forced expiratory flow (p = 0.002), FEV(1)/FVC (p = 0.007), provocative concentration of histamine causing a 20% fall in FEV(1) (PC(20)) [p = 0.02], T-cell numbers (p = 0.0005), activated eosinophils (p = 0.01), and numbers of macrophages (p = 0.01) in the group treated with 500 microg/d of FP. Comparison between groups administered different doses of FP failed to demonstrate a dose-response relationship for change from baseline in PC(20) (p = 0.43), any of the lung function parameters, T-cell numbers (p = 0.64), activated T cells (p = 0.46), eosinophils (p = 0.53), activated eosinophils (p = 0.48), or macrophage numbers (p = 0.68).

CONCLUSION

The apparent lack of a dose-response for ICS treatment in patients with asthma further validates the preferential use of add-on therapy over increasing the dose of ICS.

Alterations in airway inflammation and lung function during corticosteroid therapy for atopic asthma

INTRODUCTION

Although corticosteroid therapy for asthma improves lung function and reduces airway inflammation, the relation between these two events is unclear. This article investigates associations between changes in bronchial inflammation and lung function during high-dose inhaled corticosteroid therapy for asthma.

METHODS

Nine subjects with atopic asthma received high-dose inhaled fluticasone propionate (FP), 2,000 microg/d for 8 weeks. Fiberoptic bronchoscopy with endobronchial biopsies, spirometry, and histamine provocation challenge were performed on each subject at baseline, after 2 weeks, and again after 8 weeks of therapy. Spearman rank correlation coefficients between changes in parameters of bronchial inflammation and lung function were computed.

RESULTS

As expected, significant down-regulation of airway inflammation and improvements in lung function were observed after both short-term and long-term therapy with high-dose inhaled FP. During corticosteroid therapy, changes in lymphocyte and macrophage numbers in bronchial biopsy specimens were closely correlated. Changes in EG1+ eosinophils were associated with changes in EG2+ eosinophils after 8 weeks of therapy. Although changes in airway inflammation and changes in lung function were not closely associated after 2 weeks of therapy, changes in eosinophils (EG1) in bronchial biopsy specimens correlated with changes in bronchodilator response (r = 0.77, p = 0.016) after 8 weeks of therapy.

CONCLUSION

In patients with atopic asthma, changes in bronchial eosinophils and lung function during steroid therapy are closely related but do not occur simultaneously.

Influence of cigarette smoking on inhaled corticosteroid treatment in mild asthma

BACKGROUND

Although inhaled corticosteroids have an established role in the treatment of asthma, studies have tended to concentrate on non-smokers and little is known about the possible effect of cigarette smoking on the efficacy of treatment with inhaled steroids in asthma. A study was undertaken to investigate the effect of active cigarette smoking on responses to treatment with inhaled corticosteroids in patients with mild asthma.

METHODS

The effect of treatment with inhaled fluticasone propionate (1000 microg daily) or placebo for 3 weeks was studied in a double blind, prospective, randomised, placebo controlled study of 38 steroid naïve adult asthmatic patients (21 non-smokers). Efficacy was assessed using morning and evening peak expiratory flow (PEF) readings, spirometric parameters, bronchial hyperreactivity, and sputum eosinophil counts. Comparison was made between responses to treatment in non-smoking and smoking asthmatic patients.

RESULTS

There was a significantly greater increase in mean morning PEF in non-smokers than in smokers following inhaled fluticasone (27 l/min v -5 l/min). Non-smokers had a statistically significant increase in mean morning PEF (27 l/min), mean forced expiratory volume in 1 second (0.17 l), and geometric mean PC20 (2.6 doubling doses), and a significant decrease in the proportion of sputum eosinophils (-1.75%) after fluticasone compared with placebo. No significant changes were observed in the smoking asthmatic patients for any of these parameters.

CONCLUSIONS

Active cigarette smoking impairs the efficacy of short term inhaled corticosteroid treatment in mild asthma. This finding has important implications for the management of patients with mild asthma who smoke.

One-year treatment with different dosing schedules of fluticasone propionate in childhood asthma. Effects on hyperresponsiveness, lung function, and height

Dose-dependent effects of inhaled corticosteroids have been described. Although it has been advised to start treatment with inhaled corticosteroids with a high dose tapering off subsequently (stepdown approach), no clinical studies have assessed this strategy. We compared two different dosage schedules of inhaled fluticasone propionate (FP) in chronic persistent childhood asthma with respect to efficacy (airways hyperresponsiveness [PD(20)], lung function, exhaled nitric oxide [eNO]) and safety (height). During this double-blind study, children with asthma (aged 6-10 yr) were randomized to receive either FP 200 microg/d (constant dose approach) or to start with 1000 microg/d with two monthly reductions to 500, 200, and 100 microg/d (stepdown approach). PD(20) improved in both approaches during treatment with FP, with a significantly better PD(20) after 2 mo of 1000 microg/d followed by 500 microg/d in the stepdown approach versus 200 microg/d in the constant dose approach. No significant differences in PD(20) or other efficacy parameters were found after 1 yr. Changes in standing height were similar in both treatment approaches. This study showed no superior clinical effect of a stepdown approach compared with a constant dose strategy of FP for 1 yr in children with chronic persistent asthma.

The use of sputum cell counts to evaluate asthma medications

Total and differential cell counts from hypertonic-induced, dithiothreitol-dispersed sputum provide reproducible measurements of airway inflammatory cell counts, which are responsive to treatment with anti-inflammatory drugs. They have helped to understand the kinetics of inflammatory cell changes in asthma after the reduction of corticosteroids and the subsequent re-introduction of treatment. They have identified that the presence of sputum eosinophilia in asthma, chronic cough and chronic airflow limitation is a predictor of steroid-responsiveness and of lack of 'asthma control'. They can be used to study the dose-response effect of inhaled corticosteroids and may be useful to establish the relative potency of different corticosteroid formulations and delivery devices. Sputum cell counts are also useful to study the potential anti-inflammatory effects of drugs like theophylline, long-acting beta-adrenoceptor agonists, leukotriene antagonists and newer drugs in development. They may be helpful to select add-on therapy to corticosteroids in 'difficult-to-control' asthma.