Transient effect of inhaled fluticasone on airway mucosal blood flow in subjects with and without asthma

Nebulized budesonide combined with systemic corticosteroid vs systemic corticosteroid alone in acute severe asthma managed in the emergency department: a randomized controlled trial

BACKGROUND

The additive benefit of inhaled corticosteroid when used with systemic corticosteroid in acute asthma is still unclear. The objective of this study was to assess the effect of high and repeated doses of inhaled budesonide when combined with the standard treatment of adult acute asthma.

METHODS

It was a prospective double-blind randomized controlled study performed in the emergency department (ED) from May 1, 2010 to February 28, 2011 (ClinicalTrials.gov, NCT04016220). Fifty patients were included and were randomized to receive intravenous hydrocortisone hemisuccinate in association with nebulized budesonide (n = 23, budesonide group) or normal saline (n = 27, control group). Nebulization of budesonide or saline was done in combination with 5 mg of terbutaline every 20 min the first hour, then at 2 h (H2), and 3 h (H3). All patients received standard treatment. Efficacy and safety of inhaled budesonide were evaluated every 30 min for 180 min.

RESULTS

A significant increase in peak expiratory flow (PEF) was observed in both treatment groups at evaluation times. The increase in PEF persisted significantly compared to the previous measurement in both groups. There was no significant difference in the PEF between the two groups at evaluation times. There was no significant difference between the two groups in the evolution in the respiratory rate and heart rate. There was also no statistically significant difference between the two groups in the rate of hospitalization, the discharge criteria before the end of the protocol.

CONCLUSIONS

Considering its limited power, our study suggests that the association of nebulized budesonide with hydrocortisone hemisuccinate has no additional effect over the use of hydrocortisone alone in adults' acute asthma managed in the ED.

Short- and medium-term effect of inhaled corticosteroids on exhaled breath biomarkers in severe asthma

BACKGROUND

Inhaled corticosteroids (ICS) are the mainstay of therapy in asthma, but benefits vary due to disease heterogeneity. Steroid insensitivity is a particular problem in severe asthma, where patients may require systemic corticosteroids and/or biologics. Biomarkers sensitive to ICS over a short period of time could inform earlier and more personalised treatment choices.

OBJECTIVE

To investigate how exhaled breath biomarkers change over two-hours and one-week following monitored ICS dosing in severe asthma patients with evidence of uncontrolled airway inflammation.

METHOD

Patients with severe asthma and elevated FeNO (≥45ppb, indicative of active airway inflammation) were recruited. Exhaled breath biomarkers were evaluated using fractional exhaled nitric oxide (FeNO), exhaled breath temperature (EBT), particles in exhaled breath (PExA) and volatile organic compounds (VOCs). Samples were collected over 2 hrs following observed inhalation of 1000mcg fluticasone propionate, and at a second visit 1 week after taking the same dose daily via an inhaler monitoring device that recorded correct actuation and inhalation. Changes in parameters over 2 hrs were analysed by the Friedman test and 1 week by Wilcoxon's test (p-value for significance set at 0.05; for VOCs false discovery rate q of 0.1 by Benjamini-Hochberg method applied).

RESULTS

17 participants (9 male) were recruited with median (IQR) age 45 (36-59) yrs. EBT (p<0.05) and levels of six VOCs (q<0.1) fell over the 2 hrs after high dose ICS; there were no changes in FeNO or PEXA. After one week of using high dose ICS, there were falls in FeNO, EBT and two VOCs (p<0.05), but no changes in PEXA.

CONCLUSION

Reduction in exhaled breath temperature over the short and medium term after high dose ICS may reflect airway vascular changes, and this, together with the observed changes in exhaled VOCs, merits further investigation as potential markers of inhaled corticosteroid use and effectiveness.

Redundant medication use during acute exacerbation of chronic obstructive pulmonary disease in hospitalized patients

Background Few clinical studies have evaluated redundant therapy during an exacerbation of chronic obstructive pulmonary disease in hospitalized patients, but clinical practice guidelines endorse this practice. Objective The aim of this study is to measure the frequency of redundant therapy and explore its association with clinical outcomes, adverse effects, and cost among adults hospitalized with acute exacerbation of chronic obstructive pulmonary disease. Setting Six hospitals within an academic health system in the United States. Method A retrospective cohort study of adults with a principal diagnosis of acute exacerbation of chronic obstructive pulmonary disease between January 1, 2016 and March 31, 2016 was performed. Main outcome measure The primary outcome was the proportion of patients who received redundant therapy during inpatient management of acute exacerbation of chronic obstructive pulmonary disease. Results Overall, 137 patients were included and 99 (72.7%) received redundant medication therapy. Redundant therapy was not associated with significant differences in clinical outcomes such as median hospital length of stay, 30-day readmission, tachycardia, thrush, psychiatric symptoms or urinary retention in the univariate or multivariate analyses. The median medication acquisition cost per patient was nearly 11-fold higher among those receiving redundant medication therapy [$135.14 (49.21) vs 12.50 (17.02); p < 0.001]. After controlling for confounding variables using multivariate linear regression, the cost of redundant medication therapy was $50.20 higher on average (p < 0.001). Conclusion Redundant inhaled therapy for acute exacerbation of chronic obstructive pulmonary disease in the hospital setting was not associated with improved clinical outcomes or more adverse effects but did significantly increase medication cost. The findings of this study should be considered exploratory.

Optimization of Nebulized Budesonide in the Treatment of Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background

Clinical studies have suggested nebulized budesonide (NB) as an alternative to systemic corticosteroids for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, the optimal budesonide dose for AECOPD remains unclear.

Objectives

To compare the efficacy and safety of different doses of NB in the management of AECOPD.

Patients and Methods

A total of 321 AECOPD patients with moderate-to-severe exacerbation were randomly divided into three groups and treated with NB. The low dose group (L) was given 4 mg/day (n=95, 1 mg Q6h), while high-dose group 1 (H1, n=111, 2 mg Q6h) and high-dose group 2 (H2, n=115, 4 mg Q12h) were given 8 mg/day. Patients also received routine treatment including oxygen therapy, expectorant, nebulization bronchodilators, antibiotics, and fluid rehydration. The COPD assessment test (CAT), lung function, and artery blood gas were evaluated before and after 3 hrs and 5 days of treatment. In addition, hospital stay, frequency of acute exacerbations within 3 months of discharge, and adverse events during treatment were compared.

Results

H1 and H2 showed improved spirograms and CAT score faster than L. In H2, forced expiratory volume in 1 s (FEV₁%) at 3 hrs and FEV₁%, forced expiratory flow after 50% of the forced vital capacity has been exhaled (FEF_50%), mean forced expiratory flow between 25% and 75% of forced vital capacity (FEF_25-75%) and CAT score at 5 days were significantly improved compared to L. FEV₁% improved most in H2, moderately in H1, and least in L, with significant differences between groups at 5 days. No differences between groups were observed in adverse effects, hospital stay, and frequency of exacerbations within 3 months of discharge.

Conclusion

Compared to the conventional dose (4 mg/day), a high dose (8 mg/day) of NB improved pulmonary function and symptoms more effectively in the early treatment of AECOPD, especially when given as 4 mg twice daily.

Association Between Inhaled Corticosteroids and Tracheobronchomalacia

OBJECTIVE

The aim of this study was to assess any association between use of inhaled corticosteroids (ICS) and tracheobronchomalacia (TBM).

METHODS

This study was a retrospective analysis of patients with asthma and COPD, with and without TBM. Patients were diagnosed with TBM on the basis of CT imaging, flexible bronchoscopy, or both. Patients were deemed to be on ICS if they had been receiving treatment for at least 3 months. Simple logistic regression models were used to assess the association between TBM status and each proposed factor. A multivariable logistic regression model was used to assess the association between TBM and steroid dose.

RESULTS

A total of 463 patients with COPD (n = 153) and asthma (n = 310) were studied. In multivariate analysis, the odds of TBM were 3.5 times higher in patients on high-dose steroids compared with patients not on steroids (OR, 3.5; 95% CI, 1.4-8.5; P = .007). Age (P < .0001), presence of gastroesophageal reflux disease (P < .0001), use of long-acting muscarinic antagonists (P < .0001), and type of pulmonary disease (P = .002) were also associated with TBM. In patients using ICS, the odds of having TBM were 2.9 times greater in patients on high-dose inhaled steroids compared with those on low-dose inhaled steroids (OR, 2.9; 95% CI, 1.2-7.1; P = .02). Age (P = .003), presence of gastroesophageal reflux disease (P = .002), use of long-acting muscarinic antagonists (P = .004), type of ICS (P = .04), and number of months on ICS (P < .0001) were all associated with TBM.

CONCLUSIONS

There was a significant association between ICS use in higher doses for a longer duration of time with TBM. Prospective randomized controlled trials are needed to show causality of this observed association.

Inhaled Corticosteroids in Acute Asthma: A Systemic Review and Meta-Analysis

BACKGROUND

Asthma exacerbations are a common and important cause of attendance at emergency departments (ED) and subsequent hospital admissions. Despite previous reviews reporting that in acute settings the risk of hospital admission is reduced with the use of high doses of inhaled corticosteroids (ICS), this evidence has not changed clinical practice.

OBJECTIVE

To estimate the efficacy of ICS in the treatment of acute asthma in ED.

METHODS

Randomized controlled trials were identified using PubMed, The Cochrane Library, and EMBASE. The primary outcome was hospital admission rates. The primary comparison was between administration of ICS in addition to systemic corticosteroids (SCS) and to SCS alone. Secondary comparisons were ICS alone compared with SCS alone and ICS compared with placebo.

RESULTS

There were 25 studies involving 2733 participants. For the primary comparison, ICS in addition to SCS reduced the risk of hospital admission compared with SCS; fixed-effects odds ratio (95% confidence interval) 0.73 (0.57-0.94). Lung function was poorly reported. There was moderate evidence of an improvement in clinical scores and vital signs with ICS in addition to SCS. Relatively few studies reported adverse events.

CONCLUSION

There is moderate evidence that high doses of ICS, in addition to SCS, reduce the risk of hospital admission in ED treatment of moderate-to-severe asthma exacerbations. Further research is required to determine their optimal role in both ED and outpatient settings.

Tracheobronchopathy From Inhaled Corticosteroids

Inhaled corticosteroids (ICSs) have become the mainstay of asthma control. They are also recommended as an add-on therapy to long-acting beta agonists and anticholinergics in moderate to severe COPD with recurrent exacerbations. Ultimately this clinical practice has led to the widespread use of ICSs, which are supported by a more favorable side effect profile than that of systemic steroids.

Budesonide reduces hospital admission rates in preschool children with acute wheezing

The object of this study was to determine whether high doses of inhaled budesonide provide additional benefits to a standardized treatment regimen that includes systemic steroids and salbutamol in preschool patients presented to the emergency department (ED) with acute wheezing attacks. Methods This randomized, double-blind, placebo-controlled, parallel group trial was conducted in children, 6 months-6 years with moderate or severe acute wheezing epizode, as determined based on a pulmonary index score (PIS) of 7-13 points. We compared the addition of budesonide 3 mg versus placebo to standard acute asthma treatment, which included salbutamol and a single 1 mg/kg dose of methylprednisolone given at the beginning of therapy. The primary outcome was differences in hospitalization rates within 4 hr. Secondary outcome was difference in median PIS between treatment groups at 2 hr. Results One hundred patients were enrolled. Cumulative hospitalization rate at 120, 180, and 240 min were 0.72, 0.62, and 0.58 in placebo group; and 0.44, 0.30, and 0.24 in budesonide group. Discharged rate in budesonide group was significantly higher than the placebo group (log-rank = 12.407 ve P < 0.001). Expected mean discharged times were 200.4 (95%CI = 185.3-215.5) min in placebo group and 164.4 (95%CI = 149.4-179.4) min in budesonide group. Median (25-75%) PIS at the 120th min was significantly lower in budesonide group than the placebo group (5 [4-8] vs. 8 [5-9] respectively, P = 0.006). Conclusions The addition of budesonide nebulization may decrease the admission rate of preschool children who have moderate to severe acute wheezing epizodes. Pediatr Pulmonol. 2017;52:720-728. © 2017 Wiley Periodicals, Inc.

The use of inhaled corticosteroids in pediatric asthma: update

Despite the availability of several formulations of inhaled corticosteroids (ICS) and delivery devices for treatment of childhood asthma and despite the development of evidence-based guidelines, childhood asthma control remains suboptimal. Improving uptake of asthma management plans, both by families and practitioners, is needed. Adherence to daily ICS therapy is a key determinant of asthma control and this mandates that asthma education follow a repetitive pattern and involve literal explanation and physical demonstration of the optimal use of inhaler devices. The potential adverse effects of ICS need to be weighed against the benefit of these drugs to control persistent asthma especially that its safety profile is markedly better than oral glucocorticoids. This article reviews the key mechanisms of inhaled corticosteroid action; recommendations on dosage and therapeutic regimens; potential optimization of effectiveness by addressing inhaler technique and adherence to therapy; and updated knowledge on the real magnitude of adverse events.

The efficacy of single-high dose inhaled corticosteroid versus oral prednisone treatment on exhaled leukotriene and 8-isoprostane levels in mild to moderate asthmatic children with asthma exacerbation

BACKGROUND

The anti-inflammatory effect of high-dose inhaled corticosteroids (ICS) in children with asthma exacerbation is unknown. We aimed to investigate the efficacy of single-high dose ICS versus oral prednisone treatment followed by a course of six day high-dose ICS or oral prednisone (P) treatment on the concentrations of Cys-LTs and 8-isoprostane levels in the exhaled breath condensate (EBC) of children with asthma exacerbation.

METHODS

Ninety-four children with moderate-severe asthma exacerbation were evaluated with asthma scores, peak expiratory flow rate (PEF), forced expiratory volume in first second (FEV1) and exhaled Cys-LT and 8-isoprostane levels before and after treatment. EBC was collected from 52 patients before and four hours after treatment with inhaled fluticasone propionate (FP) (4000 μg) or P and after six days of treatment with FP-1000 μg/day or P. Cys-LTs and 8-isoprostane concentrations were determined using a specific immunoassay kit.

RESULTS

Both single high-dose FP (n=59) and p (n=35) treatment resulted in a significant improvement in asthma score (p<0.0001), PEF (p<0.0001), and FEV1 (p<0.0001). Cys-LT concentration in the EBC decreased significantly both after the initial treatment (p=0.001), and at the end of the six-day period in the FP group (p<0.0001). 8-Isoprostane concentration was lower only after six days of treatment with FP-1000 μg/day in the FP group (p=0.023). There was a significant decrease in exhaled Cys-LTs after four hours (p=0.012) and six days of P treatment (p=0.018) in children with asthma exacerbation.

CONCLUSIONS

High-dose ICS treatment may be useful in the treatment of children with asthma exacerbation. The effects start as early as after four hours. The suppression of Cys-LTs production contributes to the early effects. Suppression of both Cys-LTs and oxidants may favourably contribute to the effects observed later.

Interaction between corticosteroids and muscarinic antagonists in human airways

BACKGROUND

To date there is emerging clinical evidence to add long-acting anti-muscarinic agents (LAMAs) with inhaled corticosteroid (ICSs) in asthma, but the pharmacological rationale that supports the use of such a combination has not yet been explained. The aim of this study was to pharmacologically investigate the interaction between the ICS beclomethasone and the LAMA glycopyrronium on the human airway smooth muscle (ASM) tone.

METHODS

We investigated the rapid non-genomic bronchorelaxant effect of beclomethasone and glycopyrronium, administered alone and in combination, in human isolated bronchi and bronchioles. Experiments were carried out also in passively sensitized airways and the pharmacological analysis of drug interaction was performed by Bliss Independence method.

RESULTS

The acute administration of beclomethasone and glycopyrronium induced a significant relaxation of passively sensitized ASM pre-contracted with histamine, by causing submaximal/maximal inhibition of the contractile tone in both medium bronchi and bronchioles. Beclomethasone was characterized by a rapid non-genomic and epithelium independent bronchorelaxant effect. In passively sensitized airways, this effect seemed to be dependent by the activation of a Gsα--cyclic adenosine monophosphate (cAMP)--protein kinase A cascade. While no synergistic interaction was detected in non-sensitized bronchi, the beclomethasone/glycopyrronium combination synergistically enhanced the relaxation of passively sensitized medium and small bronchi. The synergistic interaction between beclomethasone and glycopyrronium was associated with an increase of cAMP concentrations.

CONCLUSIONS

Our study provides for the first time the pharmacological rationale for combining low doses of an ICS plus a LAMA.

Tracheobronchial smooth muscle atrophy and separation

We report a case series involving 4 patients with chronic obstructive pulmonary disease who were on an appropriate medical regimen including a high dose of inhaled corticosteroids (ICS). During bronchoscopy, patients were found to have an excessive dynamic collapse of the posterior wall and its separation from the ends of the adjacent cartilaginous rings. This was causing a near-total occlusion of the tracheal and bronchial lumen during exhalation, thereby presenting with an obstructive pattern on the pulmonary functions. We suspect that this was caused by the atrophy of the smooth muscles of the tracheobronchial wall. We reviewed the literature to explore the mechanisms causing atrophy of the bronchial smooth muscle, focusing on the potential role of long-term ICS use.

Acute effect of an inhaled glucocorticosteroid on albuterol-induced bronchodilation in patients with moderately severe asthma

BACKGROUND

We have previously shown that in patients with asthma a single dose of an inhaled glucocorticosteroid (ICS) acutely potentiates inhaled albuterol-induced airway vascular smooth muscle relaxation through a nongenomic action. An effect on airway smooth muscle was not seen, presumably because the patients had normal lung function. The purpose of the present study was to conduct a similar study in patients with asthma with airflow obstruction to determine if an ICS could acutely also potentiate albuterol-induced airway smooth muscle relaxation in them.

METHODS

In 15 adult patients with asthma (mean ± SE baseline FEV1, 62% ± 3%), the response to inhaled albuterol (180 μg) was assessed by determining the change in FEV1 (ΔFEV1) for airway smooth muscle and in airway blood flow (ΔQaw) for airway vascular smooth muscle measured 15 min after drug inhalation. Using a double-blind design, the patients inhaled a single dose of the ICS mometasone (400 μg) or placebo simultaneously with or 30 min before albuterol inhalation.

RESULTS

After simultaneous drug administration, mean ΔFEV1 was 0.20 ± 0.05 L (10%) after placebo and 0.32 ± 0.04 L (19%) after mometasone (P < .05); mean ΔQaw was -2% after placebo and 30% after mometasone (P < .005). When mometasone or placebo was administered 30 min before albuterol, there was a lesser and insignificant difference in ΔFEV1 between the two treatments, whereas the difference in ΔQaw remained significant.

CONCLUSIONS

This pilot study showed that in adult patients with asthma with airflow obstruction, a single standard dose of an ICS can acutely increase the FEV1 response to a standard dose of inhaled albuterol administered simultaneously. The associated potentiation of albuterol-induced vasodilation in the airway was of greater magnitude and retained when the ICS was administered 30 min before albuterol. The clinical significance of this observation will have to be established by a study involving a larger patient cohort.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01210170; URL: www.clinicaltrials.gov.

Immediate antiinflammatory effects of inhaled budesonide in patients with asthma

BACKGROUND

In patients with asthma, single doses of inhaled glucocorticosteroids (ICS) have been reported to have antiinflammatory actions that can be detected several hours after drug administration. However, the onset and duration of the effect have not been investigated. We therefore measured airway blood flow ([Formula: see text]aw) as an index of airway inflammation to determine the time course and dose dependence of the antiinflammatory action of an ICS in 20 patients with moderate asthma receiving regular ICS treatment.

METHODS

[Formula: see text]aw and spirometry were measured before and serially for 360 minutes after a single inhaled dose of 360 μg, 720 μg, and 1,440 μg budesonide or placebo as well as after four repetitive 720-μg budesonide doses given 30 minutes apart.

RESULTS

Baseline mean [Formula: see text]aw was increased and FEV1 was decreased without significant differences among the 5 treatment days. After budesonide inhalation, there was a transient, dose-dependent decrease in mean [Formula: see text]aw from 12 to 21%, with significant differences from baseline at 60 and 90 minutes for the 720-μg and 1,440-μg doses (P < 0.05). Thirty minutes after four repetitive budesonide administrations, mean [Formula: see text]aw was 28% below baseline (P < 0.05) and remained 11% below baseline after 270 minutes. There was no change in mean FEV1 after any of the treatments.

CONCLUSIONS

In subjects with moderate asthma who use ICS regularly, inhaled budesonide caused a transient dose-dependent vasoconstriction in the airway, thereby reversing one manifestation of airway inflammation. These results suggest that a pure controller medication can have immediate beneficial effects not paralleled by changes in airflow. Clinical trial registered with www.clinicaltrials.gov (NCT 01219738).

Asthma is not only an airway disease, but also a vascular disease

Multiple studies have identified an expansion and morphological dysregulation of the bronchial vascular network in the airways of asthmatics. Increased number, size and density of blood vessels, as well as vascular leakage and plasma engorgement, have been reported in the airways of patients with all grades of asthma from mild to fatal. This neovascularisation is an increasingly commonly reported feature of airway remodelling; however, the pathophysiological impact of the increased vasculature in the bronchial wall and its significance to pulmonary function in asthma are unrecognised at this time. Multiple factors capable of influencing the development and persistence of the vascular network exist within asthmatic airway tissue. These include structural components of the altered extracellular matrix (ECM), imbalance of proteases and their endogenous inhibitors, release of active matrikines and the dysregulated levels of both soluble and matrix sequestered growth factors. This review will explore the features of the asthmatic airway which influence the development and persistence of the increased vascular network, as well as the effect of enhanced tissue perfusion on chronic inflammation and airway dynamics. The response of cells of the airways to the altered vascular profile and the subsequent influence on the features of airway remodelling will also be highlighted. We will explore the failure of current asthma therapeutics in "normalising" this vascular remodelling. Finally, we will summarize the outcomes of recent clinical trials which provide hope that anti-angiogenic therapies may be a potent asthma-resolving class of drugs and provide a new approach to asthma management in the future.

Effects of inhaled corticosteroids on voice production in healthy adults

The isolated effects of inhaled corticosteroids (ICS) on voice production were examined in 30 healthy adults with no known pre-existing airway disease. All participants followed a daily ICS treatment regime of 500 μg in the morning and evening over a 6-day period. Sustained vowels and connected speech samples were audio recorded before, during, and after the ICS regime. Each participant's audio recorded samples were acoustically analysed. Results revealed that ICS has a short-term detrimental effect on various acoustic properties of voice. These effects were more evident in connected speech compared to isolated vowel productions. All acoustic parameters returned to normalcy after discontinuing the ICS. The study provides insight as to the influence of ICS on healthy voice production.

Skin-blanching is associated with FEV(1), allergy, age and gender in asthma families

BACKGROUND

Inhaled glucocorticosteroids reduce airway inflammation in asthma patients, thereby improving lung function and reducing airway hyperresponsiveness and symptoms. The response to glucocorticosteroids can be measured with the glucocorticosteroid skin-blanching test. We investigated if asthmatics have a lower skin-blanching response to glucocorticosteroids than non-asthmatic subjects and if asthmatics with airway obstruction have lower skin-blanching response than those without obstruction. Finally, we assessed which clinical and inflammatory parameters influence the variability in skin-blanching response.

METHODS

We evaluated the skin-blanching response to topical budesonide in a large group of 315 well-characterized asthmatics and their relatives (asthma n = 114, healthy n = 140, other = 61).

RESULTS

The skin-blanching scores of the asthma probands and their healthy spouses were not significantly different. The skin-blanching score of patients with FEV(1) < 80% predicted was lower than of patients without obstruction. Lower skin-blanching score was significantly associated with lower FEV(1) %predicted, higher age, female gender, absence of allergy and summer season, but not with use of inhaled or oral glucocorticosteroids or packyears smoking.

CONCLUSIONS

Asthmatics do not have lower skin-blanching response to glucocorticosteroids than healthy subjects. Furthermore, lower skin-blanching response to glucocorticosteroids is associated with lower FEV(1), female gender, higher age and the absence of allergy.

Comparative evaluation of nasal blood flow and airflow in the decongestant response to oxymetazoline

BACKGROUND

Nasal blood flow (NBF) plays a crucial role in many physiological and pathological processes but its regulation and relation to other rhinological outcomes is poorly understood.

OBJECTIVES

We measured nasal airway patency, nasal blood flow, and subjective and objective measures of decongestion and assessed their reproducibility and responsiveness.

METHODS

19 healthy adults attended twice. A dose-response curve was constructed using doubling doses of oxymetazoline of 25 μg, 50 μg, 100 μg, and 200 μg at 20 minute intervals. Peak nasal inspiratory flow (PNIF) and nasal airway resistance (NAR) were measured at baseline and after each successive dose, NBF using laser Doppler flowmetry at baseline, 50 μg and 200 μg and a decongestion visual analogue scale after the final dose.

RESULTS

After the final dose of oxymetazoline, NBF decreased by a mean (95% CI, P value) of 139.6 (108.3-170.8, P < .001) units and 99.4 (68.1-130.7, P < .001) units, PNIF increased by 48.9 (22.0-75.8, P < .001) L.min-1 and 38.9 (12.0-65.8, P = .003) L.min-1, and NAR decreased by 0.1 (0.02-0.15, P < .001) Pa/s/cm(3) and 0.09 (0.02-0.15, P = .002) Pa.s.cm-3 at the first and second visits respectively. The area under the curve of decongestion was not significantly different between visits for each variable. The standardized response means for the decongestant response were as follows: NBF, 1.41; PNIF, 1.03; and NAR, 0.97.

CONCLUSIONS

Nasal blood flow using laser Doppler flowmetry is a sensitive and reproducible outcome to decongestion with oxymetazoline, similar to nasal patency and symptoms.

CLINICAL TRIALS REGISTRATION

www.clinicaltrials.gov (NCT 00487032).

Role of Inhaled Steroids in Vascular Airway Remodelling in Asthma and COPD

In chronic obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), changes in bronchial microvasculature are present in response to inflammatory stimuli. Vascular changes may significantly contribute to airway wall remodelling. Angiogenesis and vascular leakage are prevalent in asthma, while vasodilation and vascular leakage dominate in COPD. An endothelial dysfunction may be present both in asthma and in COPD. Vascular changes may occur simultaneously with the thickening of the airway wall and the narrowing of the bronchial lumen. Consequently, pharmacological control of bronchial vascular remodelling may be crucial for symptom control in asthma and COPD. In asthmatic airways, inhaled steroids can downregulate vascular remodelling by acting on proangiogenic factors. Additionally, studies on combination therapy with long-acting β2-agonists and inhaled steroids have provided evidence of a possible synergistic action on components of vascular remodelling in asthma. In COPD, there is less experimental evidence on the effect of inhaled steroids on airway microvascular changes. Importantly, vascular endothelial growth factor (VEGF), the most specific growth factor for vascular endothelium, is crucially involved in the pathophysiology of airway vascular remodelling, both in asthma and COPD. The inhibition of VEGF and its receptor may be useful in the treatment of the vascular changes in the airway wall.

Acute effects of salmeterol and fluticasone propionate alone and in combination on airway blood flow in patients with asthma

BACKGROUND

The airway contains airway smooth muscle and airway vascular smooth muscle. The acute effects of inhaled long-acting β(2)-adrenergic agonists (LABAs) alone, or in combination with an inhaled glucocorticoid (ICS), on airway smooth muscle tone in asthma are known; however, to the best of our knowledge, their effect on airway vascular smooth muscle tone has not been investigated previously. The objective of this study was to investigate the immediate effects of a LABA and an ICS alone and in combination on airway blood flow (Qaw) as an index of airway vascular smooth muscle tone in patients with stable asthma.

METHODS

Fourteen subjects with moderate asthma inhaled single doses of salmeterol (50 μg), fluticasone propionate (250 μg), salmeterol/fluticasone propionate (50/250 μg), or placebo; Qaw was measured before and serially for 240 min after drug administration.

RESULTS

Mean Qaw increased after salmeterol and salmeterol/fluticasone propionate, with peaks at 60 min of 34% and 40%, respectively, and returned to baseline by 240 min after inhalation. Fluticasone propionate alone caused a transient decrease in mean Qaw. The maximal changes in Qaw, which occurred at different times, were 60% for salmeterol, 67% for salmeterol/fluticasone propionate, and -19% for fluticasone propionate (P < .05 vs placebo for all).

CONCLUSIONS

The LABA salmeterol has an acute vasodilator action on the airway of subjects with stable asthma. The addition of fluticasone propionate, which by itself causes vasoconstriction, does not attenuate the salmeterol-induced vasodilation, suggesting that fluticasone propionate potentiates the vasodilator effect of salmeterol. The vasodilation could be of clinical benefit by promoting the vascular clearance of inflammatory mediators including spasmogens from the airway.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01231230; URL: www.clinicaltrials.gov.

Genomic and non-genomic actions of glucocorticoids in asthma

Glucocorticoids are the mainstay of asthma therapy. They are primarily used to suppress airway inflammation, which is the central pathological change in asthmatic patients’ airways. This is achieved by many different mechanisms. The classical mechanism is by suppression of the genetic transcription of many inflammatory cytokines that are key in asthma pathophysiology (transrepression). On the other hand, the transcription of certain inhibitory cytokines is activated by glucocorticoids (transactivation), a mechanism that also mediates many of the adverse effects of glucocorticoids. The onset of action through these mechanisms is often delayed (4-24 hours). Other mechanisms mediated through non-genomic pathways are increasingly appreciated. These are delivered in part by binding of glucocorticoids to nonclassical membrane-bound glucocorticoid receptors or by potentiating the α1-adrenergic action on the bronchial arterial smooth muscles, in addition to other mechanisms. These effects are characterized by their rapid onset and short duration of action. Understanding these different mechanisms will help in the development of new and better drugs to treat this common disease and to develop new improved strategies in our approach to its management. Here, the genomic and non-genomic mechanisms of actions of glucocorticoids in asthma are briefly reviewed, with special emphasis on the current updates of the non-genomic mechanisms.

Pharmacologic approaches to life-threatening asthma

Following a peak in asthma mortality in the late 1980s and early 1990s, we have been fortunate to see a substantial decrease in asthma deaths in recent years. Although most asthma deaths occur outside the hospital, near-fatal events are commonplace, with anywhere from 2-20% of patients with acute asthma admitted to intensive care, and 2-4% intubated for respiratory failure. Standard therapies for acute severe and near-fatal asthma include administration of systemic corticosteroids, and frequent or continuous inhaled beta agonists. Controversy remains regarding the optimal therapy of those who fail to respond to these initial treatments, those who remain at risk of acute respiratory failure, and patients requiring mechanical ventilation. There remain significant gaps in our knowledge regarding relative benefits of intravenous versus oral corticosteroids, intermittent versus continuous beta agonists, and the role of various adjunctive treatments including intravenous magnesium, systemic beta agonists, aminophylline, and helium-oxygen mixtures. Using models and radiolabeled aerosols, there is a greater understanding regarding effective administration of inhaled beta-agonists in ventilated patients. There is limited available evidence for treatment of near-fatal asthma, a fact reflected by the significant variability in asthma critical care practice. Much of the data guiding treatment in this setting has been generalized from studies of acute asthma in the ED and from general populations of hospitalized patients with acute asthma. This review will focus on pharmacologic approaches to life-threatening asthma by reviewing current guideline recommendations, reviewing the scientific basis of the guidelines, and highlighting gaps in our knowledge in treatment of refractory acute or near-fatal asthma.

Airway endothelial dysfunction in asthma and chronic obstructive pulmonary disease: a challenge for future research

Endothelial dysfunction in the extrapulmonary circulation has been linked to cardiovascular disease. Recent investigations have revealed that in the airway circulation, cigarette smoking, chronic obstructive pulmonary disease (COPD), and asthma are also accompanied by endothelial dysfunction. Inhaled glucocorticosteroids can partially or fully restore normal endothelium-dependent vasodilation in these conditions, thereby identifying the airway endothelium as a novel therapeutic target in the treatment of airway disease. The role of the defective endothelium-dependent vasodilation in the pathophysiology in asthma and COPD is still subject to speculation. However, there appears to be an association between COPD and extrapulmonary vascular dysfunction, and the possibility exists that the use of inhaled glucocorticosteroids has a beneficial effect on cardiovascular disease in COPD as suggested by database studies showing that inhaled glucocorticosteroids reduce the incidence of nonfatal and fatal cardiovascular events in COPD.

Inhaled corticosteroids as rescue medication in acute severe asthma

Systemic corticosteroids (CS) should be considered as first-line treatment for acute asthma exacerbations, especially severe exacerbations. They may sometimes require a few hours or more to achieve their maximum effect. This time delay observed between administration of CS and improvement in lung function or hospital admissions is consistent with the belief that these effects of CS, involving the modification of gene expression, occur with a time lag of hours or days (genomic effect). On the other hand, CS also have effects initiated by specific interactions with membrane-bound or cytoplasmic receptors for CS, or nonspecific interactions with the cell membrane, with a much more rapid response (seconds or minutes; nongenomic effect). This review analyzes the clinical evidence regarding the use of inhaled CS in acute asthma patients, according to the characteristics of the nongenomic effect, and presents a proposal for the use of inhaled CS as a rescue medication in the emergency-department setting.

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.

The bronchial circulation--worth a closer look: a review of the relationship between the bronchial vasculature and airway inflammation

Until recently, the bronchial circulation has been relatively ignored in the research and clinical arenas, perhaps because of its small volume and seeming dispensability relative to the pulmonary circulation. Although the bronchial circulation only receives around 1% of the cardiac output in health, it serves functions that are critical to maintaining airway and lung function. The bronchial circulation also plays an important role in many lung and airway diseases; through its ability to increase in size, the bronchial circulation is able to provide lung parenchymal perfusion when the pulmonary circulation is compromised, and more recently the role of the bronchial circulation in the pathogenesis of inflammatory airway disease has been explored. Due to the anatomic variability and small volume of the bronchial circulation, much of the research to date has necessitated the use of animal models and invasive procedures. More recently, non-invasive techniques for measuring bronchial blood flow in the mucosal microvascular network have been developed and offer a new avenue for the study of this circulation in humans. In conjunction with molecular research, measurement of airway blood flow (Q(aw)) may help elucidate the role of the bronchial circulation in inflammatory airway disease and become a useful tool for monitoring therapy.

Increased vascular permeability precedes cellular inflammation as asthma control deteriorates

BACKGROUND

Airway microcirculation is abnormal in asthma but the role of vascular changes in asthma deteriorations remains poorly defined. We prospectively assessed the vascular changes accompanying worsening of asthma control by using an inhaled corticosteroid (ICS) dose-reduction model.

OBJECTIVES

To evaluate airway vascularity, vascular permeability and expression of vascular endothelial growth factor (VEGF) in early asthma deterioration induced by ICS back-titration.

METHODS

Twenty mild-to-moderate persistent symptomatic asthmatics on low-to-moderate ICS were recruited and treated with 4 weeks of high-dose fluticasone propionate (1000 microg/day) to achieve symptom control. This was followed by dose reduction to half of the pre-study doses for 4-8 weeks until the symptoms began to return. Endobronchial biopsy and bronchoalveolar lavage (BAL) samples were obtained after both treatment periods.

RESULTS

Vascularity as measured by the number and size of blood vessels, as well as VEGF expression did not change following ICS reduction. Even on high-dose ICS, perivascular albumin staining and BAL microalbumin levels in asthmatic subjects, as markers of permeability, were elevated when compared with normal subjects and both further increased significantly after ICS reduction. There was a significant association between changes in vascular leakiness and clinical deterioration. Increases in airway albumin correlated with previously reported increases in airway wall infiltration with T lymphocytes.

CONCLUSIONS

Our results suggest that airway vascular leakage is a major pathophysiologic feature of early asthma deterioration, occurring before recrudescence of cellular inflammation.

Airway vascular reactivity and vascularisation in human chronic airway disease

Altered bronchial vascular reactivity and remodelling including angiogenesis are documented features of asthma and other chronic inflammatory airway diseases. Expansion of the bronchial vasculature under these conditions involves both functional (vasodilation, hyperperfusion, increased microvascular permeability, oedema formation, and inflammatory cell recruitment) and structural changes (tissue and vascular remodelling) in the airways. These changes in airway vascular reactivity and vascularisation have significant pathophysiological consequences, which are manifest in the clinical symptoms of airway disease. Airway vascular reactivity is regulated by a wide variety of neurotransmitters and inflammatory mediators. Similarly, multiple growth factors are implicated in airway angiogenesis, with vascular endothelial growth factor amongst the most important. Increasing attention is focused on the complex interplay between angiogenic growth factors, airway smooth muscle and the various collagen-derived fragments that exhibit anti-angiogenic properties. The balance of these dynamic influences in airway neovascularisation processes and their therapeutic implications is just beginning to be elucidated. In this review article, we provide an account of recent developments in the areas of vascular reactivity and airway angiogenesis in chronic airway diseases.

Differentiating chronic obstructive pulmonary disease from asthma

PURPOSE

Chronic obstructive pulmonary disease (COPD) and asthma are chronic diseases that are increasing worldwide in incidence, prevalence, and burden. The purpose of this article is to provide nurse practitioners (NPs) with the information necessary to make a differential diagnosis and to understand the different treatment approaches to these two diseases.

DATA SOURCES

Peer-reviewed journal articles, book chapters, and evidence-based Internet sources.

CONCLUSIONS

NPs who are familiar with the pathophysiology that differentiates COPD from asthma can make an appropriate diagnosis and initiate effective pharmacologic and nonpharmacologic interventions, which may lead to a reduced incidence of exacerbations.

IMPLICATIONS FOR PRACTICE

A misdiagnosis of COPD or asthma leads to inadequate management of patients and to escalating healthcare costs. An early and accurate diagnosis can help to ensure optimal and cost-effective management of patient care.

Comparison of single 2000-microg dose treatment vs. sequential repeated-dose 500-microg treatments with nebulized budesonide in acute asthma exacerbations

BACKGROUND

High repeated doses of inhaled corticosteroids (ICSs) are recognized as having a more rapid improvement of outcomes than a single dose of ICS in severe acute asthma. However, to our knowledge, there has been no direct comparison of the early effects of single or repeated administration of the same total dosage of ICS in children with moderate to severe exacerbations of asthma.

OBJECTIVE

To compare the efficacy of a single dose of 2000 microg of nebulized budesonide with 4 repeated doses of 500 microg of nebulized budesonide in 40 children with an acute asthma exacerbation.

METHODS

Randomized, double-blind, parallel study that compared the efficacy of 2000 microg of nebulized budesonide, administered in a single dose, with repeated doses (4 doses of 500 microg each) during the first 90 minutes in 40 children (mean [SD] age, 10.7 [2.4] years) with an acute asthma exacerbation that required treatment with an oral corticosteroid. Forced expiratory volume in 1 second, asthma attack score, and oxygen saturation were evaluated at 20, 40, 60, 90, 120, 180, and 240 minutes after initial treatment. Oral corticosteroids were given to all patients at 90 minutes.

RESULTS

There were no significant differences in forced expiratory volume in 1 second (P = .54) at any times between the groups. Also, asthma scores and oxygen saturation were not different in either group within 90 minutes (P = .51 and P = .64, respectively) and thereafter (P = .35 and P = .87, respectively).

CONCLUSION

The use of a single dose of nebulized budesonide is as effective as repeated administration of the same total dosage during the first 90 minutes before giving oral corticosteroids in children with moderate to severe exacerbations of asthma.

Rapid non-genomic effects of glucocorticoids on oxidative stress in a guinea pig model of asthma

BACKGROUND AND OBJECTIVE

Glucocorticoids (GC) may exert therapeutic effects in asthma by a rapid non-genomic mechanism. The lungs of asthmatic patients are exposed to oxidative stress, which is believed to be critical in the pathogenesis of asthma. The aim of this study was to investigate whether GC exert a rapid non-genomic effect on oxidative stress in asthmatic guinea pigs.

METHODS

The guinea pig asthma model was used to assess inhibitory effects of budesonide (BUD) on oxidative stress. BAL fluid (BALF), trolox equivalent antioxidant capacity and lung manganese superoxide dismutase (MnSOD) activity were measured by spectrophotometry. Superoxide anion production was measured by cytochrome c reduction assay.

RESULTS

Oxidative stress occurred within minutes following antigen challenge and BUD reduced the severity of oxidative stress in asthmatic guinea pigs within 15 min. BUD significantly decreased BALF trolox equivalent antioxidant capacity and lung MnSOD activity, as compared with those of vehicle-treated asthmatic guinea pigs (P < 0.05). Additionally, BUD rapidly inhibited in vitro superoxide anion production by BALF cells and bronchi harvested from sensitized animals. These rapid effects were not blocked by the GC receptor antagonist RU486 and/or the protein synthesis inhibitor cycloheximide.

CONCLUSIONS

BUD reduced oxidative stress in a guinea pig model of asthma by a rapid non-genomic mechanism. These data suggest new mechanisms whereby GC treatments may benefit asthma.

Tiotropium and salmeterol/fluticasone combination do not cause oxygen desaturation in COPD

It has been documented that tiotropium is less likely to induce oxygen desaturation in stable COPD patients compared to long-acting beta2-agonists (LABAs) and combined administration of a LABA and an inhaled corticosteroid (ICS) reduces the potential for acute effects of LABA on blood-gas tensions. In this study, we have compared the acute effects of tiotropium 18 microg and salmeterol/fluticasone combination (SFC) 50/250 microg on arterial blood gases in 20 patients with stable COPD. Each subject was studied on 2 days, separated from one another by at least 4 days. Blood specimens were taken just before the inhalation and at 15, 30, 60, 180 and 360 min after inhalation of each treatment, and spirometry was performed at the same time points. As expected, both treatments significantly improved FEV1 (greatest changes were 0.20 L, 95% CI: 0.13-0.27 at 360 min after tiotropium; and 0.13 L, 95% CI: 0.06-0.19 at 180 min after SFC). The greatest mean changes from baseline in PaO2 were -1.7 (95% CI: -4.0 to 0.6)mmHg, p=0.134, after tiotropium; -0.8 (95% CI: -2.2 to 0.6)mmHg, after SFC. Both changes were observed after 15 min. Both drugs caused a small decrease in PaCO2 (greater changes: -1.9 (95% CI -3.2 to -0.6)mmHg, p=0.005 at 60 min after tiotropium; and -2.4 (95% CI: -3.5 to -1.3) mmHg, p=0.0002 at 180 min after SFC). These results indicate that both tiotropium and SFC are able to induce a significant long-last bronchodilation without affecting arterial blood gases. Moreover, they confirm that the impact of tiotropium on PaO2 is small and without clinical significance and the addition of a LABA to an ICS can reduce the potentially dangerous acute effect of the LABA on blood gases.

Pathophysiology and progression of nasal septal perforation

OBJECTIVE

To review the prevalence, causes, and treatments of nasal septal perforation (NSP).

DATA SOURCES

A literature search was conducted in MEDLINE to identify peer-reviewed articles related to NSP using the keywords nasal septal perforation and septal perforation for articles published between January 1, 1969, and December 31, 2006, and references cited therein.

STUDY SELECTION

Articles were selected based on their direct applicability to the subject matter.

RESULTS

Causes of NSPs include piercings, exposure to industrial chemicals, illicit drug use, intranasal steroid use, surgical trauma, bilateral cautery, and possibly improper use of nasal applicators. Prevalence is poorly reported. Mechanisms of substance-induced NSP formation are not understood. Progression from epistaxis to ulceration to NSP could not be substantiated by the literature.

CONCLUSION

Depending on the patient, NSP may be viewed as desirable (nose rings), problematic (whistling, congestion), or inconsequential. Understanding the pathogenesis of NSP is important for the practicing physician required to make decisions about whether to recommend surgical correction or medical treatment. Although the etiology of NSP is overwhelmingly iatrogenic, there is an association with a number of medical diseases in addition to use of illicit drugs and/or prescription nasal sprays.

Rapid corticosteroid effect on beta(2)-adrenergic airway and airway vascular reactivity in patients with mild asthma

BACKGROUND

Long-term glucocorticoid therapy has been suggested to improve airway and airway vascular smooth muscle responsiveness to inhaled beta(2)-agonists in patients with asthma.

OBJECTIVE

We sought to assess whether a single dose of an inhaled glucocorticoid acutely potentiates beta(2)-adrenergic airway and airway vascular smooth muscle reactivity in asthma.

METHODS

In 10 asthmatic and 10 healthy subjects, airway blood flow and FEV(1) were measured before and 30 minutes after fluticasone or placebo inhalation and 15 minutes after the subsequent inhalation of racemic albuterol (0.6 mg or 1.25 mg) or (R)-albuterol (0.3 mg or 0.6 mg).

RESULTS

In healthy subjects all albuterol formulations increased airway blood flow equally after placebo or fluticasone pretreatment. In asthmatic subjects airway blood flow response was blunted after placebo and acutely restored after fluticasone pretreatment. Fluticasone pretreatment did not increase FEV(1) responses to any albuterol formulation, except 0.6 mg racemic albuterol.

CONCLUSION

A single dose of an inhaled glucocorticoid restores beta(2)-adrenergic airway vasodilator responses in patients with mild asthma. The mechanism of this rapid glucocorticoid effect remains to be clarified.

The effect of corticosteroids on the disposal of long-acting beta2-agonists by airway smooth muscle cells

BACKGROUND

Organic cation transporters (OCTs) have an important role in tissue distribution and elimination of cationic drugs. Carrier-mediated disposal of cationic bronchodilators in the airway tissue, however, is incompletely understood.

OBJECTIVES

We sought to assess the uptake of long-acting beta(2)-agonist bronchodilators by bronchial and vascular smooth muscle cells.

METHODS

Human airway cells and tissues obtained from organ donors were evaluated for cationic drug transporter expression by means of quantitative RT-PCR and immunofluorescence. For in vitro functional studies, tritiated formoterol and tritiated salmeterol uptake by bronchial and vascular smooth muscle cells was measured.

RESULTS

Quantitative RT-PCR analysis revealed high mRNA levels for the corticosteroid-sensitive OCT3 in bronchial and vascular smooth muscle cells. Immunofluorescence staining of airway sections confirmed OCT3 expression in these cells. In bronchial smooth muscle cells, uptake of the cationic formoterol was inhibited with OCT inhibitors. Corticosteroids also inhibited formoterol uptake through a rapid (within 15 minutes) nongenomic action, with the following rank order for inhibitory potency: corticosterone > budesonide > fluticasone. The corticosteroid-induced inhibition was significantly higher in vascular than bronchial smooth muscle cells. In comparison with formoterol, uptake of the noncharged lipophilic salmeterol was approximately 10-fold higher and insensitive to all OCT inhibitors and corticosteroids.

CONCLUSIONS

Our findings suggest that corticosteroids, through OCT3 inhibition, rapidly interfere with the disposal of cationic drugs by smooth muscle cells in the airway.

CLINICAL IMPLICATIONS

This novel immediate interaction between corticosteroids and cationic beta(2)-agonist bronchodilators supports the use of such combinations in the pharmacotherapy of asthma.

Acute severe asthma

Acute severe asthma remains a major economic and health burden. The natural history of acute decompensations is one of resolution and only about 0.4% of patients succumb overall. Mortality in medical intensive care units is higher but is less than 3% of hospital admissions. "Near-fatal" episodes may be more frequent, but precise figures are lacking. However, about 30% of medical intensive care unit admissions require intubation and mechanical ventilation with mortality of 8%. Morbidity and mortality increase with socioeconomic deprivation and ethnicity. Seventy to 80% of patients in emergency departments clear within 2 hours with standardized care. The relapse rate varies between 7 and 15%, depending on how aggressively the patient is treated. The airway obstruction in the 20-30% of people resistant to adrenergic agonists in the emergency department slowly reverses over 36-48 hours but requires intense treatment to do so. Current therapeutic options for this group consist of ipratropium and corticosteroids in combination with beta2 selective drugs. Even so, such regimens are not optimal and better approaches are needed. The long-term prognosis after a near-fatal episode is poor and mortality may approach 10%.

[Inhaled corticosteroids in the treatment of asthma exacerbations: essential concepts]

The use of systemic corticosteroids reduces hospitalizations in patients suffering an asthma attack and improves lung function within 6 to 12 hours of administration. However, despite the considerable body of positive evidence published in the last decade, doubts remain in regard to the effectiveness of inhaled corticosteroids. Analysis of this evidence has been cursory; crucial data on the mechanism of action of corticosteroids have been overlooked and there has been a failure to distinguish between antiinflammatory effects and so-called nongenomic effects. This review considers the biological basis for the effects of inhaled corticosteroids and analyzes the best data available on the use and therapeutic implications of inhaled corticosteroids for the treatment of asthma exacerbations.

Rapid effects of inhaled corticosteroids in acute asthma: an evidence-based evaluation

BACKGROUND

Current reviews on the use of inhaled corticosteroids (ICS) for acute asthma underestimated their early (minutes) clinical impact and produced conclusions of questionable validity.

OBJECTIVE

The analysis of the best evidence available on the early (1 to 4 h) clinical impact of ICS for patients with acute asthma in the emergency department (ED) setting.

METHODS

Published (from 1966 to 2006) randomized controlled trials were retrieved using different databases (MEDLINE, EMBASE, Cochrane Controlled Trials Register), bibliographic reviews of primary research, review articles, and citations from texts. Primary outcome measures were admission and ED discharge rates.

RESULTS

Seventeen studies met criteria for inclusion in the review (470 adults and 663 children and adolescents). After 2 to 4 h of protocol, a greater reduction in admission rate was observed with trials that used multiple doses of ICS (odds ratio [OR], 0.30; 95% confidence interval [CI], 0.16 to 0.55), especially when they were compared with placebo. Patients treated with ICS also displayed a faster clinical improvement compared with placebo or systemic corticosteroids (SCS), increasing the probability of an early ED discharge (OR, 4.70; 95% CI, 2.97 to 7.42; p = 0.0001). The advantage of the use of ICS was also demonstrated in spirometric and clinical measures as early as 60 min. These benefits were obtained only when patients received multiple doses of ICS along with beta-agonists compared with placebo or SCS.

CONCLUSIONS

Data suggests that ICS present early beneficial effects (1 to 2 h) when they were used in multiple doses administered in time intervals < or = 30 min over 90 to 120 min. The nongenomic effect is a possible candidate by covering the link between molecular pathways and the clinical effects of corticosteroids.

Rapid selective priming of FcalphaR on eosinophils by corticosteroids

Preactivation or priming of eosinophils by (proinflammatory) cytokines is important in the pathogenesis of allergic diseases. Several priming-dependent eosinophil responses, such as migration and adhesion, are reduced by treatment with corticosteroids. Many inhibitory effects of corticosteroids are mediated by the glucocorticoid receptor via genomic mechanisms, which are evident only after prolonged interaction (>30 min). However, also faster actions of corticosteroids have been identified, which occur in a rapid, nongenomic manner. In this study, fast effects of corticosteroids were investigated on the function of eosinophil opsonin receptors. Short term corticosteroid treatment of eosinophils for maximal 30 min with dexamethasone (Dex) did not influence eosinophil cell surface CD11b/CD18 expression, adhesion, and/or chemokinesis. In marked contrast, incubation with Dex resulted in a rapid increase in binding of IgA-coated beads to human eosinophils, showing that Dex can up-regulate the activation of FcalphaR (CD89). This priming response by Dex was dose dependent and optimal between 10(-8) and 10(-6) M and was mediated via the glucocorticoid receptor as its selective antagonist RU38486 (10(-6) M) blocked the priming effect. In contrast to FcalphaR, eosinophil FcgammaRII (CD32) was not affected by Dex. Further characterization of the Dex-induced inside-out regulation of FcalphaR revealed p38 MAPK as the central mediator. Dex dose dependently enhanced p38 MAPK phosphorylation and activation in situ as measured by phosphorylation of its downstream target mitogen-activated protein kinase-activated protein kinase 2. The dose responses of the Dex-induced activation of these kinases were similar as seen for the priming of FcalphaR. This work demonstrates that corticosteroids selectively activate the FcalphaR on eosinophils by activation of p38 MAPK.

Epithelial organic cation transporters ensure pH-dependent drug absorption in the airway

Most inhaled beta(2)-adrenergic agonist and anticholinergic bronchodilators have low lipid solubility because of their transient or permanent positive net charge at physiologic pH. Airway absorption of these cationic drugs is incompletely understood. We examined carrier-mediated mechanisms of cationic drug uptake by human airway epithelia. Airway tissues and epithelial cells, obtained from lung donors without preexisting lung disease, were evaluated for organic cation transporter expression by quantitative RT-PCR and immunofluorescence. For in vitro functional studies on primary airway epithelial cells, uptake of the cationic fluorophore 4-[4-(dimethylamino)-styryl]-N-methylpyridinium (ASP+) was characterized. Quantitative RT-PCR analysis demonstrated high mRNA levels for two polyspecific organic cation/carnitine transporters, OCTN1 and OCTN2, in human airway epithelia. Immunofluorescence of human airway sections confirmed OCTN1/2 protein expression, with a predominant localization to the apical portion of epithelial cells. Primary airway epithelial cells showed a carrier-mediated, temperature-sensitive and saturable uptake of ASP(+). Seventy-five to eighty percent of ASP(+) uptake was inhibited by L-carnitine, an OCTN2-carried zwitterion. The uptake was pH dependent, with approximately 3-fold lower rates at acidic (pH 5.7) than at alkaline (pH 8.2) extracellular pH. Albuterol and formoterol inhibited ASP(+) uptake, suggesting that all these molecules are carried by the same transport mechanism. These findings demonstrate the existence and functional role of a pH-dependent organic cation uptake machinery, namely OCTN1 and OCTN2, in human airway epithelia. We suggest that epithelial OCTN1/2 are involved in the delivery of inhaled cationic bronchodilators to the airway tissue.