Inhaled glucocorticoids for asthma

Early use of inhaled corticosteroids in the emergency department treatment of acute asthma

BACKGROUND

Systemic corticosteroid therapy is central to the management of acute asthma The use of inhaled corticosteroids may also be beneficial in this setting.

OBJECTIVES

To determine the benefit of inhaled corticosteroids for the treatment of patients with acute asthma managed in the emergency department (ED).

SEARCH STRATEGY

Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group register. Bibliographies from included studies, known reviews, and texts also were searched. The search is considered updated to February of 2003.

SELECTION CRITERIA

Only RCTs or quasi-randomised trials were eligible for inclusion. Studies were included if patients presented with acute asthma to the ED or its equivalent, and were treated with inhaled corticosteroids or placebo, in addition to standard therapy. Two reviewers independently selected potentially relevant articles, and then independently selected articles for inclusion. Methodological quality was independently assessed by two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers if the authors were unable to verify the validity of extracted information. Missing data were obtained from the authors or calculated from other data presented in the paper.

MAIN RESULTS

Eight trials were selected for inclusion, but data were not available for one of them. In the seven usable trials, (4 adult, 3 paediatric), a total of 376 patients were studied (191 with inhaled corticosteroids, 185 without). Patients treated with inhaled corticosteroids were less likely to be admitted to hospital (OR: 0.30; 95% CI: 0.16, 0.57). This benefit was evident in the subgroup of patients not receiving concomitant systemic steroids (OR 0.21; 95% CI: 0.08, 0.53). Patients receiving concomitant systemic steroids showed a similar, but non-significant, trend towards reduced admissions compared to placebo treatment (OR 0.45; 95% CI: 0.18, 1.12). Patients receiving inhaled corticosteroids also demonstrated small, significant improvements in peak expiratory flows (PEFR WMD: 8%; 95% CI: 3, 13 %) and forced expiratory volumes (FEV1 WMD: 5%; 95% CI: 0.4, 10 %). The treatment was well tolerated, with few reported adverse side effects. A secondary analysis compared inhaled corticosteroids alone vs systemic steroids alone; in the four trials included, there was significant heterogeneity between the study results for admission rates which precluded meaningful pooling of the study results.

REVIEWER'S CONCLUSIONS

Inhaled steroids reduced admission rates in patients with acute asthma, but it is unclear if there is a benefit of inhaled corticosteroids when used in addition to systemic corticosteroids. There is insufficient evidence that inhaled corticosteroids result in clinically important changes in pulmonary function or clinical scores when used in acute asthma. Similarly, there is insufficient evidence that inhaled corticosteroids alone are as effective as systemic steroids. Further research is needed to clarify if there is a benefit of inhaled corticosteroids when used in addition to systemic steroids.

A small molecule inhibitor of redox-regulated NF-kappa B and activator protein-1 transcription blocks allergic airway inflammation in a mouse asthma model

An oxidant/antioxidant imbalance is seen in the lungs of patients with asthma. This oxidative stress in asthmatic airways may lead to activation of redox-sensitive transcription factors, NF-kappaB and AP-1. We examined the effect of the small molecule inhibitor of redox-regulated NF-kappaB and AP-1 transcription, MOL 294 on airway inflammation and airway hyperreactivity (AHR) in a mouse model of asthma. MOL 294 is a potent nonpeptide inhibitor of NF-kappaB and AP-1 based upon a beta-strand template that binds to and inhibits the cellular redox protein thioredoxin. BALB/c mice after i.p. OVA sensitization (day 0) were challenged with intranasal OVA on days 14, 25, 26, and 27. MOL 294, administered intranasal on days 25-27, blocked the airway inflammatory response to OVA assessed 24 h after the last OVA challenge on day 28. MOL 294 reduced eosinophil, IL-13, and eotaxin levels in bronchoalveolar lavage fluid and airway tissue eosinophilia and mucus hypersecretion. MOL 294 also decreased AHR in vivo to methacholine. These results support redox-regulated transcription as a therapeutic target in asthma and demonstrate that selective inhibitors can reduce allergic airway inflammation and AHR.

Improved inhalation behavior of steroid KSR-592 in vitro with Jethaler by polymorphic transformation to needle-like crystals (beta-form)

PURPOSE

The aim of the present study was to improve the dry powder inhalation behavior of steroid KSR-592 with lactose by altering the crystal shape and the particle size of the drug for use in a newly designed inhalation device, Jethaler.

METHOD

The shape of the crystals was changed by polymorphic transformation of original crystal (alpha-form) to beta-form by agitating alpha-form crystals in hexane containing 5% ethanol. The inhalation properties of the resultant crystals in vitro were evaluated with a twin impinger and cascade impactor.

RESULTS

Needle-like crystals (beta-form) with dimensions of 1.8 microm in width x 41 microm in length were obtained by the polymorphic transformation, the kinetics of which was described by the Avrami equation. The beta-form crystals loaded on lactose particles were easily separated and crushed into fine particles in the airstream produced in the Jethaler, which increased dramatically the respirable fraction (RF) deposited in the twin impinger (43.8%) and the fine particle fraction (FPF) of the cascade impactor (FPF = 39.3%) compared with their values for the original crystals (RF = 5.8%, FPF = 4.7%).

CONCLUSION

The dry powder inhalation properties of steroid KSR-592 (platelike crystal, alpha-form) were improved dramatically by changing the crystal shape to a needle-like shape by the polymorphic transformation to the beta-form.

Expression of c-fos, rather than c-jun or glucocorticoid-receptor mRNA, correlates with decreased glucocorticoid response of peripheral blood mononuclear cells in asthma

Resolution of the molecular mechanism(s) underlying glucocorticoid (GC) resistance is an important clinical problem when performing individualized GC therapy according to the GC response of peripheral cells in asthma. In order to investigate the mechanism(s) underlying the individual differences of lymphocyte GC response, we examined the relationship between lymphocyte sensitivity to GC in vitro and the expression of mRNAs for GC receptor (GR) alpha, GRbeta, c-fos and c-jun, which are reported to be implicated in the regulation of the pharmacological effects of GCs in asthma patients. Twenty-seven patients with bronchial asthma and 14 healthy subjects were included in the study. IC50s of prednisolone and methylprednisolone on blastogenesis of peripheral blood mononuclear cells (PBMCs) stimulated with concanavalin A in vitro were estimated. Transcripts for GRalpha, c-fos, c-jun and beta-actin genes in PBMCs were quantitatively determined by reverse transcription-competitive polymerase chain reaction (RT-cPCR) procedures. GRbeta mRNA expression was examined with an RT-PCR technique. A statistically significant positive correlation was observed between the IC50s for prednisolone (p <0.002) or methylprednisolone (p <0.001) and expression of c-fos mRNA in PBMCs of asthma patients (n = 27). Thus, the increased expression of c-fos mRNA correlated with the decreased responses of PBMCs to prednisolone and methylprednisolone in vitro. In contrast, the expression of GRalpha and c-jun mRNAs did not correlate with the IC50 for prednisolone and methylprednisolone in asthma patients. In addition, no statistically significant difference in IC50s of GCs between asthma patients with PBMCs exhibiting GRbeta mRNA and those without GRbeta mRNA expression was observed. The increased expression of c-fos mRNA suggests to attenuate PBMC response to GCs, which may contribute to progression of GC resistance in asthma. On the other hand, c-jun and GC receptor mRNA expression appears to have less influence on poor GC-response establishment.

Regulation of equine lymphocyte beta-adrenoceptors under the influence of clenbuterol and dexamethasone

In 12 healthy horses, the effects of the beta2-agonist clenbuterol and the glucocorticoid dexamethasone on the lymphocyte beta2-adrenoceptor density and affinity (determined by (-)-[125I]-iodocyanopindolol binding) as well as its responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 micromol/l (-)-isoprenaline) were studied. Clenbuterol treatment, 2 x 0.8 microg/kg/day i.v. for 12 days, decreased significantly ICYP binding sites by approximately 30-40%; concomitantly, lymphocyte cAMP response to (-)-isoprenaline was reduced. After withdrawal of clenbuterol, beta2-adrenoceptor density and responsiveness gradually increased, reaching predrug levels after 4 days. The effects of dexamethasone on clenbuterol-induced desensitisation were further investigated. Administration of dexamethasone (1 x 0.1 mg/kg/day, i.v. for 5 days) immediately after clenbuterol withdrawal accelerated beta2-adrenoceptor recovery: only 24 h after administration dexamethasone restored the number of binding sites and cAMP response to (-)-isoprenaline to levels statistically indistinguishable from values before clenbuterol treatment. Three days after dexamethasone administration, lymphocyte beta2-adrenoceptors were further increased about 2-fold the pretreatment values, and this increase declined gradually after dexamethasone withdrawal, reaching baseline values after 4 days. Furthermore, in groups exposed simultaneously to both drugs, dexamethasone completely prevented clenbuterol-induced decrease in lymphocyte beta2-adrenergic receptor density and responsiveness. No significant change was observed in the dissociation constant for ICYP in any of the situations. We conclude that dexamethasone (glucocorticoids) can reverse and prevent Clenbuterol-induced desensitisation (down-regulation) of the lymphocyte beta2-adrenoceptors and therefore, a combined therapy with clenbuterol and dexamethasone may be potentially beneficial in horses suffering from chronic obstructive pulmonary disease (COPD).

The effectiveness of inhaled corticosteroids in the emergency department treatment of acute asthma: a meta-analysis

STUDY OBJECTIVE

Inhaled corticosteroids (ICSs) are of proven benefit in the treatment of chronic asthma; however, their role in the management of acute asthma is unclear.

METHODS

We performed a systematic review of randomized controlled trials involving children or adults treated in the emergency department for acute asthma with or without the addition of ICSs. Outcome measures included hospital admission, pulmonary function tests, and side effects.

RESULTS

Seven trials were selected for inclusion in the primary analyses. ICSs versus placebo were compared; data were not available on 1 of these trials. In the remaining 6 trials, a total of 352 patients were studied (179 ICS-treated and 173 non-ICS-treated patients). Two trials compared ICSs plus systemic corticosteroids versus placebo plus systemic corticosteroids; 4 trials compared ICSs versus placebo. Patients treated with ICSs were less likely to be admitted to the hospital (odds ratio 0.30; 95% confidence interval [CI] 0.16 to 0.57) and showed small improvements in peak expiratory flows (weighted mean difference 8%; 95% CI 3% to 13%) Overall, the treatment was well tolerated, with few reports of adverse side effects. A secondary analysis compared ICSs alone versus systemic corticosteroids alone; in the 4 included trials, significant heterogeneity between the study results for admission rates precluded meaningful pooling of admission data.

CONCLUSION

There is evidence of decreased admission rates for patients with acute asthma treated with ICSs. However, there is insufficient evidence that ICS therapy results in clinically important changes in pulmonary function when used in acute asthma, and there is insufficient evidence that ICSs alone are as effective as systemic corticosteroids.

Comparison of two budesonide powder inhalers, Easyhaler and Turbuhaler, in steroid-naïve asthmatic patients

The objective of this multicenter study was to compare the clinical efficacy, safety, and acceptability of Easyhaler and Turbuhaler for the delivery of budesonide 200 micrograms/dose twice daily in steroid-naïve asthmatic patients. Three hundred and twenty-six newly diagnosed, steroid-naïve adult patients with mild-to-moderate asthma were recruited into this randomized, double-blind, double-dummy, parallel-group study, comprising a 2-week run-in period and 8 weeks of treatment. Patients received budesonide inhalation powder 400 micrograms/day either via Easyhaler (n = 159) or via Turbuhaler (n = 167), plus salbutamol inhalation powder (100 micrograms/dose) via Easyhaler as rescue therapy. The study was completed by 292 patients: 143 in the Easyhaler group and 149 in the Turbuhaler group. The primary outcome variable, mean morning peak expiratory flow (PEF), improved significantly and almost similarly by 36.3 and 30.6 l/min, respectively, from run-in to weeks 7-8. At weeks 7-8, the mean (SE) difference in morning PEF between the two treatments was 7.1 (9.4) l/min (90% CI from -8.4 to 22.6) on per protocol analysis, which was within the defined limits for therapeutic equivalence. There were no significant differences between treatments in terms of secondary efficacy variables or adverse events. However, patients found Easyhaler more acceptable than Turbuhaler. The results show that budesonide via Easyhaler is clinically as effective as Pulmicort Turbuhaler when equal daily doses of budesonide are delivered to steroid-naïve asthmatic patients. Moreover, patients found Easyhaler more acceptable than Turbuhaler, and a majority would prefer Easyhaler if given a choice.

Transactivation assay for determination of glucocorticoid bioactivity in human serum

We have developed a mammalian cell (COS-1) bioassay, which measures glucocorticoid bioactivity (GBA) directly from a small amount of human serum. The assay is based on the expression of human glucocorticoid receptor (GR) together with a coactivator protein and reporter plasmid containing GR response elements upstream of the luciferase gene. Ten microliters of human serum, in duplicate, are added directly to the cell culture medium, and GBA is derived from reporter gene activity. The assay differentiates between biopotencies of synthetic steroids, and importantly, mifepristone (RU486) is able to block glucocorticoid-induced response. The assay is sensitive (<15.6 nM cortisol in fetal calf serum) and precise, with the within- and between-assay coefficients of variation less than 8% and 10%, respectively. We measured serum GBA (bioassay) and cortisol (RIA) levels in 34 asthmatic children (age range, 5.7-14.2 yr) at baseline and after treatment with either inhaled budesonide (800 microg/d, n = 14), fluticasone propionate (500 microg/d, n = 14), or cromones (control group, n = 6). Pretreatment serum GBA and cortisol levels correlated strongly (r = 0.90, P < 0.0001, n = 34). Two months of treatment with inhaled budesonide resulted in excess GBA in circulation, which was not attributable to endogenous cortisol (P < 0.001). In the fluticasone propionate group, the presence of serum excess GBA was at the borderline of statistical significance (P < 0.08) after 2 months of inhalation therapy, and no excess GBA was detected in the cromone group. In conclusion, our bioassay enables measurement of mammalian cell response to bioactive glucocorticoids in circulation and provides a novel means to investigate patients receiving drugs acting through the GR.

Management of children with severe asthma exacerbation in the emergency department

Although acute asthma is a very common cause of emergency department visits in children, there is as yet insufficient evidence for the establishment of a standardized treatment protocol. The aim of this review is to describe updated information on the management of asthma exacerbations in the pediatric emergency department. Oxygen is the first-line treatment of acute asthma exacerbations in the emergency department to control hypoxemia. It is accompanied by the administration of beta(2)-adrenoceptor agonists followed by corticosteroids. beta(2)-Adrenoceptor agonists have traditionally been administered by nebulization, although spacers have recently been introduced and proven, in many cases, to be as effective as nebulization. Oral prednisolone, with its reliability, simplicity, convenience and low cost, should remain the treatment of choice for the most severe asthma exacerbations, when the lung airways are extremely contracted and filled with secretions. Recently, several studies have shown that high-dose inhaled corticosteroids are at least as effective as oral corticosteroids in controlling moderate to severe asthma attacks in children and therefore should be considered an alternative treatment to oral corticosteroids in moderate to severe asthma attacks. Studies of other drugs have shown that ipratropium bromide may be given only in addition to beta(2)-adrenoceptor agonists; theophylline has no additional benefit, and magnesium sulfate has no clear advantage. Comprehensive asthma management should also include asthma education, measures to prevent asthma triggers, and training in the use of inhalers and spacers. Proper management will avoid most asthma attacks and reduce admission and readmission to emergency departments.

Anti-allergic therapies: effects on eosinophil progenitors

Marked eosinophilic infiltration is the typical inflammatory response associated with allergic inflammation. Previous research involving animal and human models has established a role for the eosinophil/basophil hematopoietic progenitor in a systemic process of allergic inflammation. In this article, we will review the evidence implicating eosinophil/basophil progenitors in this systemic response and will discuss the rationale for targeting this cell in the treatment of allergic disease. In this context, we discuss corticosteroid treatment of allergic diseases, such as asthma and its effects on hematopoietic mechanisms, the effects of therapies that inhibit the actions of cysteinyl leukotrienes, the effects of in vivo blockade of the eosinophil-active cytokine interleukin-5, and the effects of antihistamines on hematopoiesis. It is suggested that several anti-allergic therapies exert their beneficial effects on allergic inflammation by influencing eosinophil production systemically. Therefore, targeting the systemic hematopoietic response may provide additional, more beneficial, therapeutic effects.

Replacement of oral corticosteroids with inhaled corticosteroids in the treatment of acute asthma following emergency department discharge: a meta-analysis

OBJECTIVES

Oral corticosteroids (CS) are standard treatment for patients discharged from the emergency department (ED) after treatment for acute asthma. Several recent, relatively small trials have investigated the replacement of CS with inhaled corticosteroids (ICS), with varied results and conclusions. This systematic review examined the effect of using ICS in place of CS on outcomes in this setting.

METHODS

Only randomized controlled trials were eligible for inclusion. Studies in which patients were treated for acute asthma in the ED or its equivalent, and on discharge compared ICS therapy to standard CS therapy, were eligible for inclusion. Trials were identified using the Cochrane Airways Review Group register, searching abstracts and bibliographies, and contacting primary authors and pharmaceutical companies. Data were extracted and methodologic quality assessed independently by two reviewers, and missing data were obtained from authors.

RESULTS

Seven trials, involving a total of 1,204 patients, compared high-dose ICS therapy vs CS therapy after ED discharge. There were no significant differences demonstrated between the treatments for relapse rates (odds ratio, 1.00; 95% confidence interval, 0.66 to 1.52) or in the secondary outcomes of beta-agonist use, symptoms, or adverse events. However, the sample size was not adequate to prove equivalence between the treatments, and severe asthmatics were excluded from these trials.

CONCLUSIONS

There is some evidence that high-dose ICS therapy alone may be as effective as CS therapy when used in mild asthmatics on ED discharge; however, there is a significant possibility of a type II error in drawing this conclusion.

Acute cardiovascular protective effects of corticosteroids are mediated by non-transcriptional activation of endothelial nitric oxide synthase

Corticosteroids have been shown to exert beneficial effects in the treatment of acute myocardial infarction, but the precise mechanisms underlying their protective effects are unknown. Here we show that high-dose corticosteroids exert cardiovascular protection through a novel mechanism involving the rapid, non-transcriptional activation of endothelial nitric oxide synthase (eNOS). Binding of corticosteroids to the glucocorticoid receptor (GR) stimulated phosphatidylinositol 3-kinase and protein kinase Akt, leading to eNOS activation and nitric oxide dependent vasorelaxation. Acute administration of pharmacological concentrations of corticosteroids in mice led to decreased vascular inflammation and reduced myocardial infarct size following ischemia and reperfusion injury. These beneficial effects of corticosteroids were abolished by GR antagonists or eNOS inhibitors in wild-type mice and were completely absent in eNOS-deficient (Nos3(-/-)) mice. The rapid activation of eNOS by the non-nuclear actions of GR, therefore, represents an important cardiovascular protective effect of acute high-dose corticosteroid therapy.

Mucoadhesive beclomethasone microspheres for powder inhalation: their pharmacokinetics and pharmacodynamics evaluation

The feasibility of prolonging drug action and/or reducing drug dosage using mucoadhesive beclomethasone dipropionate (BDP) microspheres for powder inhalation was investigated. BDP was spray-dried from ethanol solution or aqueous suspension systems dissolving a mucoadhesive polymer, hydroxypropylcellulose (HPC); this resulted in amorphous and crystalline BDP incorporation in the HPC microspheres (aBDP/HPC and cBDP/HPC; BDP-HPC ratio=1:4), respectively. These microspheres were administered as powder aerosols to healthy or antigen-induced, asthmatic guinea pigs, and BDP's retention in the lung (pharmacokinetics) and inhibitory duration with respect to eosinophil infiltration into the airways (pharmacodynamics) were compared to those for pure crystalline BDP (cBDP; 'control'). Both BDP/HPC microspheres were prepared within a respirable-size range of 2.5-2.9 microm. BDP's aqueous solubility was increased 25 times for aBDP/HPC, compared to crystalline counterpart. Pharmacokinetic profiles for three powders were dissolution-modulated. aBDP/HPC showed rapid BDP absorption from the lung (> or = 95% absorption for 180 min) with a greater metabolite (B17MP) formation, compared to cBDP, primarily due to the increased dissolution of amorphous BDP. In contrast, 86.0% of BDP remained at 180 min following cBDP/HPC administration, demonstrating the prolonged BDP's retention in the lung by virtue of poor dissolution (and/or release) and retarded mucociliary clearance. As a result, while cBDP (1.37 mg/kg) significantly inhibited eosinophil infiltration into the lungs of antigen-sensitized and -challenged guinea pigs for only 1-6 h, cBDP/HPC, despite a much lower drug dosage (0.25 mg/kg), was capable of maintaining such inhibitory effects for 24 h following administration. It appeared therefore that the prolonged lung retention of BDP by the use of the HPC microspheres (cBDP/HPC) was attributed to prolonging its pharmacological duration without requiring increased drug dosage.

p38 Mitogen-activated protein kinase-induced glucocorticoid receptor phosphorylation reduces its activity: role in steroid-insensitive asthma

BACKGROUND

Although glucocorticoids are the most effective treatment for chronic inflammatory diseases, such as asthma, some patients show a poor response. IL-2 combined with IL-4 can alter glucocorticoid receptor (GR) ligand-binding affinity and modulate glucocorticoid function.

OBJECTIVE

We sought to confirm the altered ligand-binding affinity in a distinct group of steroid-dependent asthmatic subjects and examine the mechanism by which IL-2 and IL-4 modify the ligand-binding affinity of the GR.

METHODS

We examined PBMCs from healthy subjects, subjects with mild asthma, and steroid-dependent subjects with severe asthma using dexamethasone-binding assays and Western blot analysis of GR and phosphorylated activated transcription factor 2 expression. GR phosphorylation was measured after orthophosphate labeling and immunoprecipitation and cytokine production by means of ELISA.

RESULTS

GR ligand-binding affinity was reduced in the nucleus but not in the cytoplasm of steroid-dependent asthmatic subjects compared with that seen in healthy subjects (dissociation constant, 39.8 +/- 4.6 vs. 6.79 +/- 0.8 nmol/L). This difference in ligand-binding affinity could be mimicked by IL-2 and IL-4 cotreatment and was blocked by the p38 mitogen-activated kinase (MAPK) inhibitor SB203580. Activation of p38 MAPK by IL-2 and IL-4, as shown by means of phosphorylation of activated transcription factor 2, resulted in GR phosphorylation and reduced dexamethasone repression of LPS-stimulated GM-CSF release. p38 MAPK phosphorylation of CD2(+) T cells occurred on serine residues. The ability of dexamethasone to modulate IL-10 release was also inhibited by IL-2 and IL-4 cotreatment. These effects were also inhibited by SB203580.

CONCLUSION

These data show that p38 MAPK inhibitors may have potential in reversing glucocorticoid insensitivity and reestablishing the beneficial effects of glucocorticoids in patients with severe asthma.

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.

Once-daily budesonide inhalation powder (Pulmicort Turbuhaler) is effective and safe in adults previously treated with inhaled corticosteroids

This 12-week, double-blind, placebo-controlled, multicenter study evaluated the efficacy and safety of budesonide 400 microg administered once daily via Turbuhaler in adults previously treated with at least twice-daily dosing of inhaled corticosteroids. Pulmonary function (FEV1, PEF, FVC, FEF(25-75%)), asthma symptom scores, quality of life, and breakthrough medication use were significantly (p < 0.05) different in patients receiving once-daily budesonide Turbuhaler compared to placebo, and significantly (p < 0.001) more patients receiving placebo discontinued the study. Adverse events were similar between study groups. Once-daily administration of budesonide Turbuhaler was safe and efficacious in patients previously treated with inhaled corticosteroids.

Clinical pharmacokinetics of inhaled budesonide

The corticosteroid budesonide is a 1:1 racemic mixture of 2 epimers, (22R)- and (22S)-, and is available in 3 different inhaled formulations for the management of asthma: a pressurised metered dose inhaler (pMDI), a dry powder inhaler (DPI) and a solution for nebulised therapy. Inhaled corticosteroids such as budesonide reach the systemic circulation either by direct absorption through the lungs (a route that is much more important than previously recognised) or via gastrointestinal absorption of drug that is inadvertently swallowed. Although the pharmacokinetics of budesonide have been extensively investigated following oral and intravenous administration, relatively few studies have defined the systemic disposition of budesonide after inhalation. Drug deposition in the lungs depends on the inhaler device: 15% of the metered dose of budesonide reached the lung with a pMDI compared with 32% with a breath-actuated DPI. In patients with asthma (n = 38) receiving different doses of budesonide by DPI (Turbuhaler), the pharmacokinetic parameters peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) were dose-dependent after both single dose and repeat dose (3 weeks) administration: time to Cmax (tmax) was short (0.28 to 0.40 hours) and the elimination half-life approximately 3 hours. Both AUC and Cmax were linearly related to budesonide dose. In a small group of healthy male volunteers (n = 9), the pharmacokinetics of budesonide 1,600 microg twice daily via pMDI were assessed on the fifth day of administration. Mean model-independent parameters for (22R)-budesonide were as follows: Cmax 1.8 microg/L, tmax 0.46 hours, elimination half-life 2.3 hours and oral clearance 163 L/h, and there were no enantiomer-specific differences in drug disposition. Budesonide undergoes fatty acid conjugation within the lung, but very limited pharmacokinetic data are available to define the pulmonary absorption characteristics. There is evidence from a population analysis that the pulmonary absorption of budesonide is prolonged and shows wide interindividual variation. Further pharmacokinetic studies are required to define the time-course of budesonide absorption through the lung in specific patient groups, and to investigate the effect of new inhaler devices (especially chlorofluorocarbon-free pMDIs) on the pharmacokinetic profile and systemic drug exposure.

Update in pulmonary medicine

Chronic inflammation in many pulmonary diseases, such as sarcoidosis and IPF, lead to end-stage lung disease and fibrosis. In other diseases, such as chronic thromboembolic disease and emphysema, long-term complications can result in pulmonary hypertension and cor pulmonale. Therapeutic options for end-stage lung disease are quite limited. One possible solution is lung transplantation. Although fraught with potential serious complications, including infection, rejection, and death, lung transplantation may offer overall improvement in mortality rates and quality of life.

Molecular mechanisms of decreased steroid responsiveness induced by latent adenoviral infection in allergic lung inflammation

BACKGROUND

We recently reported that allergic lung inflammation in guinea pigs became steroid resistant in the presence of latent adenoviral infection.

OBJECTIVE

We sought to investigate the molecular mechanisms that underlie steroid resistance in adenoviral infection.

METHODS

Guinea pigs with a latent adenoviral infection were sensitized and challenged with ovalbumin (OVA) and given daily injections of budesonide (20 mg/kg administered intraperitoneally). Sham-infected animals received either saline challenge without budesonide injection or OVA challenge with or without budesonide. The inflammatory response in the lung was measured by means of quantitative histology. Eotaxin, monocyte chemoattractant protein 1 (MCP-1), and RANTES expression in the lung were analyzed by means of Northern blotting, and the binding activity of activator protein 1 (AP-1) and nuclear factor kappaB in nuclear extracts from the lung was analyzed with electrophoretic mobility shift assays.

RESULTS

OVA challenge increased eosinophil infiltration and eotaxin and MCP-1 mRNA expression in the lungs, and glucocorticoids reduced these increases in the sham-infected, but not the adenovirus-infected, animals. Changes in binding activity of AP-1, but not nuclear factor kappaB, paralleled changes in eotaxin and MCP-1 mRNA.

CONCLUSION

We conclude that latent adenoviral infection inhibits the anti-inflammatory effects of glucocorticoids on allergen-induced eotaxin and MCP-1 expression through AP-1, leading to steroid-resistant allergic lung inflammation.

Efficacy of inhaled budesonide and oral theophylline in asthmatic subjects

The aim of present study was to evaluate clinical, functional, and anti-inflammatory effects of inhaled budesonide and oral theophylline treatments in patients with mild to moderate asthma. The study included 38 patients. After a 10-day run-in period, the patients were randomly assigned into two groups. Group 1 received inhaled budesonide (Pulmicort Turbuhaler) 800 microg/day for 4 weeks. Group 2 received oral theophylline (Talotren tablets, 200 mg twice daily) for 4 weeks. Inhaled budesonide therapy was accompanied by a significant decrease in serum interleukin (IL)-5 levels (p < 0.0005) and blood, sputum, and nasal eosinophil counts (p < 0.005). It produced a significant reduction in daytime (p < 0.01) and nighttime (p < 0.005) symptom scores and an increase in morning (p < 0.005) and evening (p < 0.05) peak expiratory flow (PEF) and forced expiratory volume in I sec (FEV1) values (p < 0.01). Theophylline therapy was associated with a significant decrease in blood (p < 0.02) and nasal (p < 0.01) eosinophil counts and serum IL-5 levels (p < 0.01). It resulted in significant improvements in daytime and nighttime symptom scores (p < 0.05), and morning PEF and FEV1 values (p < 0.05). These changes were more significant in group I than in group 2. There was no statistically significant difference between the two groups with respect to post-treatment values. Our results confirm the role of inhaled corticosteroids in the treatment of asthma and are consistent with the recommendation that theophylline exerts an anti-inflammatory effect. Further studies should be conducted to determine long-term benefits of theophylline.

Asthma stability after oral prednisone: a clinical model for comparing inhaled steroid potency

Clinical studies comparing the potency of inhaled corticosteroids require steep dose-response slopes (b) and minimal response variability (s), as statistical power is inversely related to the s/b ratio. To evaluate a new study model, we performed a randomized, crossover study of 12 adult asthmatics who required 800 to 2,000 microg of inhaled corticosteroids daily, and calculated s/b for 21 raw clinical outcomes and 36 mathematically derived variables based on these raw outcomes. Each of two 21-d treatment periods was preceded by 4 to 7 d of oral prednisone to maximize asthma control and minimize carry-over of previous inhaled treatment. Treatments were 100 and 800 micron/d of an HFA-134a beclomethasone dipropionate formulation. Assessments included daily home spirometry, histamine challenge, inhaled albuterol use, and asthma symptom scores. Efficacy variables with the greatest power (lowest s/b values) were A.M.FEF25-75, A.M.FEV1, and A.M.PEF, (s/b = 0.46, 0.48, and 0.59). Carry-over between treatment periods was not significant. Crossover study sample size calculations using these ratios yielded samples of 23, 25, and 37 patients, respectively. Otherwise identical parallel studies would require sample sizes of 657, 1,438, and 2,261 patients. These results support the use of a crossover asthma stability model after a short course of oral prednisone as a clinical study model for comparing topical potency of inhaled corticosteroids.

Quantification of the effect of inhaled budesonide on airway inflammation in intermittent asthma by bronchitis index

The bronchitis index (BI) is a scoring system for the visual quantification of airway inflammation by flexible bronchoscopy. A prospective study was carried out to determine whether patients with intermittent asthma present a considerable visible airway inflammation. Ten steroid-naive patients with intermittent asthma taking only inhaled beta2-agonists were enrolled and received budesonide (800 microg/day) over a period of 4 weeks. The airway inflammation was assessed by flexible electronic videobronchoscopy before and after the steroid treatment phase and quantified using the BI. Despite normal pulmonary function, all patients with intermittent asthma showed a marked visible airway inflammation that was reversed by a 4-week treatment with the inhaled steroid budesonide. The present study demonstrates that the BI may be useful as a clinical research tool for the assessment and quantification of airway inflammation in asthma. Furthermore, our results support the widely recognized theory that airway inflammation is present even in patients with mild asthma, and emphasize the necessity of an early therapy with inhaled steroids.

Serum dehydroepiandrosterone sulfate concentration as an indicator of adrenocortical suppression in asthmatic children treated with inhaled steroids

ACTH regulates adrenal androgen production, which may thus be reduced during glucocorticosteroid therapy. Dehydroepiandrosterone sulfate is the most abundant androgen secreted by the adrenals. We wished to evaluate whether serum levels of dehydroepiandrosterone sulfate can be used as an indicator of adrenal suppression during inhaled steroid treatment in children. Sixty school-aged children with newly diagnosed asthma were randomly divided into budesonide (n = 30) and fluticasone propionate (n = 30) groups. Fifteen cromone-treated children served as a control group. The budesonide dose was 800 microg/d during the first 2 months and 400 microg/d thereafter. The respective fluticasone propionate doses were 500 and 200 microg/d. Serum dehydroepiandrosterone sulfate concentrations were measured before and after 2 and 4 months of treatment. In the budesonide group, serum dehydroepiandrosterone sulfate decreased from the baseline by a mean of 21% (95% confidence interval, 13-29%; P < 0.001) after 2 months of high dose treatment and by 16% (95% confidence interval, 8-25%; P < 0.001) after 4 months of treatment. In the fluticasone propionate group, the respective figures were 10% (95% confidence interval, 4-16%; P < 0.01) and 6% (95% confidence interval, 16% decrease-3% increase; P = NS). A low dose ACTH test indicated adrenocortical suppression at 4 months in 14 (23%) steroid-treated children. In these children, dehydroepiandrosterone sulfate decreased by a mean of 21% (95% confidence interval, 14-28%), whereas in those 46 steroid-treated children with normal ACTH test results, dehydroepiandrosterone sulfate decreased by 8% (95% confidence interval, 0-16%; P < 0.05 between these groups). In the control group, dehydroepiandrosterone sulfate levels tended to increase (by a mean of 26%), reflecting the normal physiological change at this age. In conclusion, inhaled steroid treatment suppresses dehydroepiandrosterone sulfate production in a dose-dependent manner. Monitoring of serum dehydroepiandrosterone sulfate concentrations can be used as a practical method to follow adrenocortical function and to detect its suppression during inhaled steroid treatment in children.

Suppression of granulocyte-macrophage colony-stimulating factor expression by glucocorticoids involves inhibition of enhancer function by the glucocorticoid receptor binding to composite NF-AT/activator protein-1 elements

Increased expression of a number of cytokines including GM-CSF is associated with chronic inflammatory conditions such as bronchial asthma. Glucocorticoid therapy results in suppression of cytokine levels by a mechanism(s) not yet fully understood. We have examined regulation of GM-CSF expression by the synthetic glucocorticoid dexamethasone in human T cells. Transient transfection assays with reporter constructs revealed that dexamethasone inhibited the function of the GM-CSF enhancer, but had no effect on regulation of GM-CSF expression occurring through the proximal promoter. Activation of the GM-CSF enhancer involves cooperative interaction between the transcription factors NF-AT and AP-1. We demonstrate here that glucocorticoid-mediated inhibition of enhancer function involves glucocorticoid receptor (GR) binding to the NF-AT/AP-1 sites. These elements, which do not constitute recognizable glucocorticoid response elements, support binding of the GR, primarily as a dimer. This binding correlates with the ability of dexamethasone to inhibit enhancer activity of the NF-AT/AP-1 elements, suggesting a competition between NF-AT/AP-1 proteins and GR.

The dental patient with asthma. An update and oral health considerations

OVERVIEW

Asthma is a serious global health problem that has steadily increased in prevalence during the past two decades. New classification and treatment guidelines have been published, and dental providers need to be aware of these changes.

LITERATURE REVIEWED

The authors searched textbooks and MEDLINE, looking for the most updated medical information on asthma, as well as for previous publications on treatment of asthmatic patients in a dental setting.

RESULTS

More than 9,000 articles on asthma were published in English between 1997 and 2000. From 1960 until 2000, approximately 40 articles specifically addressed asthma and dental care. The authors reviewed more than 300 articles from the medical literature and all articles after 1980 that directly focused on oral health issues for importance and relevance.

CONCLUSIONS

Recent information regarding the etiology, pathogenesis and treatment of asthma had not been adequately addressed in the dental literature. Dental care of asthmatic patients may necessitate considerations beyond what has previously been published in the dental literature.

CLINICAL IMPLICATIONS

In the treatment of asthma, as with treatment of most medical conditions, oral health care providers play a role that is important in terms of both the patient's overall health and the systemic condition's effect on oral health. This article provides dentists with a timely update on asthma and the relationship between asthma and oral health, and it offers suggestions for safe and appropriate dental care.

History and future perspectives of treating asthma as a systemic and small airways disease

Asthma is an inflammatory disorder in which the small airways of the lung play an important role. There is also evidence for the systemic nature of asthma. No current method adequately measures small airways function alone. Therefore, a combination of functional and clinical parameters should be used to ensure that patients with asthma are adequately treated with due consideration of the small airways. Previously therapeutic strategies have focused on bronchodilation and attenuation of airway inflammation. While early oral therapies had the advantage of reaching the small airways and treating the systemic aspect of asthma, they were associated with serious side-effects. Inhaled therapies were therefore developed to limit these effects. However, inhaled therapies have the disadvantage of limited penetration into the peripheral airways and an inability to treat the systemic component of asthma. They are also associated with local and systemic side-effects. The future for asthma treatment is likely to be a systemically administered medication with few side-effects targeting disease-specific mediators. The leukotriene receptor antagonists and anti-IgE monoclonal antibodies are examples of such therapies and the emergence of other new strategies is awaited.

Inhaled corticosteroids and the risk of mortality and readmission in elderly patients with chronic obstructive pulmonary disease

There is considerable controversy concerning the utility of inhaled corticosteroids for the long-term treatment of patients with COPD. Recent studies have suggested that although inhaled corticosteroids do not alter the rate of decline in lung function, they may reduce airway hyperresponsiveness, decrease the frequency of exacerbations, and slow the rate of decline in the patients' health status. The relationship between inhaled corticosteroids and subsequent risk of hospitalization or mortality remains unknown. We therefore conducted a population-based cohort study using administrative databases in Ontario, Canada (n = 22,620) to determine the association between inhaled corticosteroid therapy and the combined risk of repeat hospitalization and all-cause mortality in elderly patients with COPD. Patients who received inhaled corticosteroid therapy postdischarge (within 90 d) had 24% fewer repeat hospitalizations for COPD (95% confidence interval [CI], 22 to 35%) and were 29% less likely to experience mortality (95% CI, 22 to 35%) during 1 yr of follow-up after adjustment for various confounding factors. This cohort study has suggested that inhaled corticosteroid therapy is associated with reduced COPD-related morbidity and mortality in elderly patients. Although not definitive, because of the observational nature of these findings, these data provide a compelling rationale for a large randomized trial to determine the effect of inhaled corticosteroids on COPD-related morbidity and mortality.

p65-activated histone acetyltransferase activity is repressed by glucocorticoids: mifepristone fails to recruit HDAC2 to the p65-HAT complex

Glucocorticoids acting through their specific receptor can either enhance or repress gene transcription. Dexamethasone represses interleukin-1beta-stimulated histone acetylation and granulocyte-macrophage colony-stimulating factor expression through a combination of direct inhibition of p65-associated histone acetyltransferase (HAT) activity and by recruiting histone deacetylase 2 (HDAC2) to the p65-HAT complex. Here we show that mifepristone, a glucocorticoid receptor partial agonist, has no ability to induce gene expression but represses interleukin-1beta-stimulated histone acetylation and granulocyte-macrophage colony-stimulating factor release by 50% maximally. Mifepristone was able to inhibit p65-associated HAT activity to the same extent as dexamethasone but failed to inhibit the natural promoter to an equal extent due to an inability to recruit HDAC2 to the p65-associated HAT complex. These data suggest that the maximal repressive actions of glucocorticoids require recruitment of HDAC2 to a p65-HAT complex. These data also suggest that pharmacological manipulation of specific histone acetylation status is a potentially useful approach for the treatment of inflammatory diseases.

Glucocorticoids induce basophil apoptosis

BACKGROUND

Induction of apoptosis represents an important mechanism by which glucocorticoids (GCCs) exert their anti-inflammatory properties. The effects of GCCs on apoptosis have been determined in various immune cells and found to vary among different cell types. On the other hand, the effects of GCCs on apoptosis of basophils, active participants in allergic inflammation, have remained obscure.

OBJECTIVE

The objective of this study was to investigate the effects of GCCs on basophil apoptosis.

METHODS

Basophils were highly purified (purity, >97%) by Percoll density gradient centrifugation followed by negative selection. Cell status was determined by their ability to bind annexin V and exclude propidium iodide. DNA fragmentation was determined by flow cytometry.

RESULTS

Dexamethasone (DEX) significantly accelerated the decrease in live cells and increased the number of apoptotic cells in a time-dependent fashion. Light microscopy as well as DNA fragmentation assay confirmed the induction of apoptosis by DEX. A half-maximal effect was observed in a DEX concentration range from 10(-9) to 10(-8) mol/L. Sex steroids did not induce basophil apoptosis at all. DEX also induced basophil apoptosis in the presence of low doses of IL-3.

CONCLUSION

GCCs exert potent apoptogenic effects on basophils. GCC-mediated apoptogenic effects on basophils might have implications with respect to the mechanism of action of this class of drugs in allergic disorders.

The anti-inflammatory effects of leukotriene-modifying drugs and their use in asthma

Asthma is a chronic inflammatory disease of the airways. Anti-inflammatory drug therapy, primarily using corticosteroids, is now considered the first-line treatment in the management of all grades of asthma severity. Although corticosteroids are believed to be the most potent anti-inflammatory agents available, they do not suppress all inflammatory mediators involved in the asthmatic response. Leukotrienes, which are lipid mediators generated from the metabolism of arachidonic acid, play an important role in the pathogenesis of asthma. They produce bronchospasm, increase bronchial hyperresponsiveness, mucus production, and mucosal edema, and enhance airway smooth muscle cell proliferation and eosinophil recruitment into the airways, and their synthesis or release is unaffected by corticosteroid administration. The use of leukotriene synthesis inhibitors or leukotriene receptor antagonists as anti-inflammatory therapies in asthma has therefore been investigated. Beneficial effects of leukotriene-modifying drugs have been demonstrated in the management of all grades of asthma severity, and there is evidence that certain patient groups (such as those with exercise-induced asthma or aspirin-induced asthma) may be particularly suitable for such therapy.

Ambulatory use of inhaled beta(2)-agonists for the treatment of asthma in Quebec : a population-based utilization review

STUDY OBJECTIVES

To assess whether the utilization of inhaled short-acting beta(2)-agonists (ISAB) and inhaled long-acting beta(2)-agonists (ILAB) for the treatment of asthma was appropriate according to the 1996 Canadian Asthma Consensus Conference recommendations.

DESIGN

Population-based retrospective drug utilization review using pharmacists' billing data of the Prescription Drug Insurance Plan administered by the Quebec health insurance board. However, the database used did not contain complete patient clinical information to accurately assess severity of asthma.

SETTING

Province of Quebec, Canada.

PATIENTS

Persons who received at least one outpatient prescription of ISAB (age range, 5 to 45 years) or ILAB (age range, 12 to 45 years) for the treatment of asthma between August 1997 and April 1998.

MEASUREMENTS

Percentages of patients whose use was appropriate according to three criteria regarding the average daily dose of ISAB (criterion 1), the renewal interval of ILAB (criterion 2), and the concomitant daily use of corticosteroids for the expected length of utilization of ILAB (criterion 3).

RESULTS

Overall proportions of appropriate use according to criterion 1 were as follows: 75% (without inhaled corticosteroids [ICS]) and 84% and 43% (with one or more than one prescription of ICS, respectively). Appropriateness was slightly higher for female patients, younger patients (5 to 18 years old), and those treated by pediatricians. However, appropriateness was only 9% among patients who received at least two prescriptions of ISAB during the study period. The proportion of appropriate use was 19% according to criterion 2 and 15% according to criterion 3; there were few differences by gender or by age, but the appropriateness according to criterion 2 was somewhat higher for patients of respirologists.

CONCLUSION

Compared to the 1996 Canadian asthma consensus conference recommendations, ISAB are overused, ICS are underused, and ILAB are often used improperly. Close collaboration between health professionals and patients is essential to improve the pharmacotherapy of asthma.

Proinflammatory cytokines regulate human glucocorticoid receptor gene expression and lead to the accumulation of the dominant negative beta isoform: a mechanism for the generation of glucocorticoid resistance

Inflammatory responses in many cell types are coordinately regulated by the opposing actions of NF-kappaB and the glucocorticoid receptor (GR). The human glucocorticoid receptor (hGR) gene encodes two protein isoforms: a cytoplasmic alpha form (GRalpha), which binds hormone, translocates to the nucleus, and regulates gene transcription, and a nuclear localized beta isoform (GRbeta), which does not bind known ligands and attenuates GRalpha action. We report here the identification of a tumor necrosis factor (TNF)-responsive NF-kappaB DNA binding site 5' to the hGR promoter that leads to a 1.5-fold increase in GRalpha mRNA and a 2.0-fold increase in GRbeta mRNA in HeLaS3 cells, which endogenously express both GR isoforms. However, TNF-alpha treatment disproportionately increased the steady-state levels of the GRbeta protein isoform over GRalpha, making GRbeta the predominant endogenous receptor isoform. Similar results were observed following treatment of human CEMC7 lymphoid cells with TNF-alpha or IL-1. The increase in GRbeta protein expression correlated with the development of glucocorticoid resistance.

Molecular mechanisms of corticosteroid actions

Glucocorticoids are the most effective therapeutic agents used for the treatment of chronic inflammatory diseases of the lung. They act by interacting with, and thereby activating, a specific cytoplasmic receptor (GR) which then migrates to the cell nucleus and inhibits inflammatory gene transcription. Inflammatory gene transcription is enhanced by activation of several intracellular signalling pathways which activate transcription factor such as NF-kappaB and AP-1. These transcription factors bind to DNA and induce local unwinding of the DNA structure allowing increased gene transcription. Glucocorticoids interfere with the ability of NF-kappaB and AP-1 to induce transcription by increasing the compaction of unwound chromosomal DNA in a process that involves deacetylation of histone proteins. A small number of asthmatic patients are resistant to the beneficial effects of glucocorticoids. This defect does not appear to be due to a reduced expression of GR but may be associated with a failure of GR to translocate into the nucleus and/or a reduced ability to inhibit AP-1 actions.

Onset of bronchodilation of budesonide/formoterol vs. salmeterol/fluticasone in single inhalers

Combinations of inhaled glucocorticoids and long-acting beta2-agonists in the same inhaler device have become available in recent years. In this double-blind, randomized, placebo-controlled and crossover study we have evaluated the onset of action of budesonide and formoterol in a single inhaler (Symbicort Turbuhaler) and that of the fixed combination of salmeterol and fluticasone (Seretide Diskus). Thirty patients with a mean FEV1 of 2.54 l (range: 1.48-4.28) and a mean inclusion reversibility in FEV1 of 19.1% were included. Single doses of budesonide/formoterol 160/4.5 microg and 2x (160/4.5) microg, salmeterol/fluticasone 50/250 microg, or placebo were given. Serial measurements of FEV1 were performed over 3 h. The combination of one or two inhalations of budesonide/formoterol showed a faster onset of action than salmeterol/fluticasone, both evaluated as mean FEV1 at 3 min (2.74, 2.75 and 2.56 l respectively P<0.001 for both doses of budesonide/formoterol), or as average FEV1 from 0 to 15 min (2.80, 2.83 and 2.67 l respectively P<0.001 for both doses of budesonide/formoterol). For placebo, mean FEV1 at 3 min was 2.46 l, and the average FEV1 at 0-15 min was 2.50 l. Furthermore, budesonide/formoterol at both doses resulted in higher FEV1 than salmeterol/fluticasone at 3 h. We conclude that the combination of budesonide/formoterol has a faster onset of action than salmeterol/fluticasone.

The relationship between systemic exposure to fluticasone propionate and cortisol reduction in healthy male volunteers

OBJECTIVE

The aim of this analysis was to assess the pharmacokinetic/pharmacodynamic relationship between systemic exposure to fluticasone propionate (FP) and reductions in the plasma cortisol level and urinary cortisol excretion.

METHODS

A total of 122 healthy male volunteers participating in 7 different studies received either oral (5 to 40 mg), inhaled (500 to 2000 microg) or intravenous (250 to 1000 g) single morning doses of FP or placebo. Data on systemic exposure to FP, expressed in terms of the area under the FP concentration-time curve up to 24 hours (AUC(24h,FP)) for the 3 different routes of administration were pooled, together with corresponding data on the 24-hour plasma cortisol level or urinary cortisol excretion. The data were used to develop a pharmacokinetic/pharmacodynamic model, from which parameter estimates and 95% confidence intervals (CI) for the estimates could be derived.

RESULTS

The intercept in the absence of drug (E0) was -0.5% (95% CI: -0.6, -0.3%) and the maximum drug-induced reduction in mean plasma cortisol levels (Emax) was 72% (95% CI: 64, 79%). The systemic exposure to FP that resulted in half the maximum possible reduction in plasma cortisol levels (AUC50) was 3.2 microg/L x h (95% CI: 2.8, 3.7 microg/L x h); this equates approximately to the plasma FP concentration obtained after administration of a 1000 microg inhaled dose. A similar relationship was seen between AUC50 and urinary cortisol excretion, although the variability in AUC50 for urinary cortisol was much greater than for plasma cortisol.

CONCLUSION

A pharmacokinetic/pharmacodynamic model has been established which relates systemic exposure to FP (after a single morning dose) to the percentage reduction in urinary or plasma cortisol. The relationship is independent of both dose and route of administration.

Bioavailability of orally administered micronised fluticasone propionate

OBJECTIVE

The aim of this study was to determine the absolute oral bioavailability of fluticasone propionate (FP) in healthy volunteers.

METHODS

A 3-period incomplete block crossover design was used. On separate occasions, 21 male volunteers received a single 250 microg intravenous dose of FP (n = 21) and twice daily oral doses of either micronised FP 0.1 mg (n = 9), 1 mg (n = 12), 10 mg (n = 11) or placebo (n = 9) for 4 days.

RESULTS

FP was not measurable in the plasma after twice daily oral administration of a 0.1 mg dose. FP concentrations just above the limit of quantification could be measured in only 5 volunteers, and only at some time points, after administration of FP 1 mg twice daily. At a dose of 10 mg twice daily the absolute oral bioavailability of the drug was <1% when a liquid chromatography-mass spectrometry assay was used to assess plasma concentrations. Only oral doses of FP 10 mg twice daily, 10 times greater than the recommended maximum inhaled dose, produced any detectable change in urinary cortisol excretion.

CONCLUSION

The results of this study confirm that oral absorption of FP into the systemic circulation is negligible. The swallowed portion of an inhaled dose of FP is unlikely to increase the systemic exposure to the drug, thus decreasing the likelihood of adverse systemic effects.

Underuse of inhaled steroid therapy in elderly patients with asthma

STUDY OBJECTIVES

Despite their proven efficacy, inhaled steroids may be underused in the elderly asthmatic population. The objectives of this study were to determine if inhaled steroids are underused in the elderly asthmatic population, who are at a high risk for rehospitalization and mortality, and to identify certain risk factors that predict lower use of inhaled steroids in this group of patients.

DESIGN

Population-based, retrospective, cohort study using linked data from hospital discharge and outpatient drug databases.

PARTICIPANTS

All people > or = 65 years old in Ontario, Canada, who survived an acute exacerbation of asthma between April 1992 and March 1997.

MEASUREMENTS AND RESULTS

Of the 6,254 patients, 2,495 patients (40%) did not receive inhaled steroid therapy within 90 days of discharge from their initial hospitalization for asthma. Patients > 80 years old were at a greater risk of not receiving inhaled steroid therapy, compared to those 65 to 70 years of age (adjusted odds ratio [OR], 1.23; 95% confidence interval [CI], 1.05 to 1.47). Patients with a Charlson comorbidity index of > or = 3 were also at an increased risk of not receiving inhaled steroid therapy, compared to those having no comorbidities (adjusted OR, 3.45; 95% CI, 1.56 to 7.69). Moreover, receipt of care from a primary-care physician was independently associated with an elevated risk of not receiving inhaled steroid therapy, compared to receipt of care from respirologists/allergists (adjusted OR, 1.35; 95% CI, 1.10 to 1.61).

INTERPRETATION

Forty percent of Ontario patients > or = 65 years old who experienced a recent acute exacerbation of asthma did not receive inhaled steroid therapy near discharge from their initial hospitalization for asthma. Nonreceipt of inhaled steroid therapy was particularly prominent in the older patients with multiple comorbidities. Moreover, those who received care from primary-care physicians were also less likely to receive inhaled steroid therapy, compared to those who received care from specialists.

Use of inhaled corticosteroids and risk of fractures

Treatment with systemic corticosteroids is known to increase the risk of fractures but little is known of the fracture risks associated with inhaled corticosteroids. A retrospective cohort study was conducted using a large UK primary care database (the General Practice Research Database [GPRD]). Inhaled corticosteroid users aged 18 years or older were compared with matched control patients and to a group of noncorticosteroid bronchodilator users. Patients with concomitant use of systemic corticosteroids were excluded. The study comprised 170,818 inhaled corticosteroid users, 108,786 bronchodilator users, and 170,818 control patients. The average age was 45.1 years in the inhaled corticosteroid, 49.3 years in the bronchodilator, and 45.2 years in the control groups. In the inhaled corticosteroid cohort, 54.5% were female. The relative rates (RRs) of nonvertebral, hip, and vertebral fractures during inhaled corticosteroid treatment compared with control were 1.15 (95% CI, 1.10-1.20), 1.22 (95% CI, 1.04-1.43), and 1.51 (95% CI, 1.22-1.85), respectively. No differences were found between the inhaled corticosteroid and bronchodilator groups (nonvertebral fracture RR = 1.00; 95% CI, 0.94-1.06). The rates of nonvertebral fractures among users of budesonide (RR = 0.95; 95% CI, 0.85-1.07) and fluticasone propionate (RR = 1.03; 95% CI, 0.71-1.49) were similar to the rate determined for users of beclomethasone dipropionate. We conclude that users of inhaled corticosteroids have an increased risk of fracture, particularly at the hip and spine. However, this excess risk may be related more to the underlying respiratory disease than to inhaled corticosteroid.

Clinical considerations in the use of inhaled corticosteroids for asthma

Inhaled corticosteroids are the most potent and effective therapy for treating asthma. They exert their pharmacologic action through activation of the glucocorticoid receptor, which helps regulate gene transcription. Corticosteroids also directly inhibit several inflammatory mediators involved in the pathophysiology of asthma. In randomized, controlled clinical trials, inhaled corticosteroids, as monotherapy, are superior to other therapies in improving lung function and clinical outcomes in patients with asthma. However, the use of inhaled corticosteroids is limited by concerns of dose-related adverse effects, including growth suppression and decreased bone density. Combination regimens with these agents and other long-term therapies are beneficial in maintaining asthma control while minimizing dose-related toxicities. Several inhaled corticosteroid products are available in the United States. They differ in potency; however, clinical efficacy is similar when equipotent doses are administered. A variety of factors influence product selection and patient response, including the therapeutic ratio, pharmacokinetic properties, and the inhalation delivery device. In addition, adherence to therapy and the patient's skill in administering the inhaled drug contribute to the therapeutic outcome.

New immunosuppressive drugs: an update

An increasing number of immunosuppressive drugs became available for clinical use over the past few decades. These include substances with recently recognized immunosuppressive properties, which needed careful evaluation in various trials before they could be approved for use in different diseases. The effectiveness of other agents was already established, but knowledge about their modes of action or the mechanisms that lead to side effects was acquired much later. This understanding also contributed to the development of new drugs that display synergistic effects or lack certain adverse effects. The greater choice afforded by such research endeavours allows us to select the best therapeutic strategy for an individual patient; however, this requires a comprehensive knowledge of the available options. The present review provides an update of current knowledge of the most important substances (including calcineurin and target of rapamycin inhibitors, regulators of gene expression, and inhibitors of purine and pyrimidine synthesis) and surveys some of the novel agents that are expected to play an important role in the future.

Glucocorticoids inhibit lipopolysaccharide-induced up-regulation of arginase in rat alveolar macrophages

1. As arginase by limiting nitric oxide (NO) synthesis may play a role in airway hyperresponsiveness and glucocorticoids are known to induce the expression of arginase I in hepatic cells, glucocorticoid effects on arginase in alveolar macrophages (AM Phi) were studied. 2. Rat AM Phi were cultured in absence or presence of test substances. Thereafter, nitrite accumulation, arginase activity, and the expression pattern of inducible NO synthase, arginase I and II mRNA (RT - PCR) and proteins (immunoblotting) were determined. 3. Lipopolyssacharides (LPS, 20 h) caused an about 2 fold increase in arginase activity, whereas interferon-gamma (IFN-gamma), like LPS a strong inducer of NO synthesis, had no effect. 4. Dexamethasone decreased arginase activity by about 25% and prevented the LPS-induced increase. Mifepristone (RU-486) as partial glucocorticoid receptor agonist inhibited LPS-induced increase by 45% and antagonized the inhibitory effect of dexamethasone. 5. Two different inhibitors of the NF-kappa B-pathway also prevented LPS-induced increase in arginase activity. 6. Rat AM Phi expressed mRNA and protein of arginase I and II, but arginase I expression was stronger. Arginase I mRNA and protein was not affected by IFN-gamma, but increased by LPS and this effect was prevented by dexamethasone. Both, LPS and IFN-gamma enhanced the levels of arginase II mRNA and protein, effects also inhibited by dexamethasone. As IFN-gamma did not affect total arginase activity, arginase II may represent only a minor fraction of total arginase activity. 7. In rat AM Phi glucocorticoids inhibit LPS-induced up-regulation of arginase activity, an effect which may contribute to the beneficial effects of glucocorticoids in the treatment of inflammatory airway diseases.

Asthma in pregnancy

Although about 1% of pregnant women have asthma, it is often underrecognized and suboptimally treated. The course of asthma during pregnancy varies; it improves, remains stable, or worsens in similar proportions of women. The risk of an asthma exacerbation is high immediately postpartum, but the severity of asthma usually returns to the preconception level after delivery and often follows a similar course during subsequent pregnancies. Changes in beta(2)-adrenoceptor responsiveness and changes in airway inflammation induced by high levels of circulating progesterone have been proposed as possible explanations for the effects of pregnancy on asthma. Good control of asthma is essential for maternal and fetal well-being. Acute asthmatic attacks can result in dangerously low fetal oxygenation. Chronically poor control is associated with pregnancy-induced hypertension, preeclampsia, and uterine hemorrhage, as well as greater rates of cesarian section, preterm delivery, intrauterine growth retardation, low birth weight, and congenital malformation. Women with well-controlled asthma during pregnancy, however, have outcomes as good as those in their nonasthmatic counterparts. Inhaled therapies remain the cornerstone of treatment; most appear to be safe in pregnancy.

Therapeutic ratio of inhaled corticosteroids in adult asthma. A dose-range comparison between fluticasone propionate and budesonide, measuring their effect on bronchial hyperresponsiveness and adrenal cortex function

Inhaled corticosteroids have become the mainstay treatment of bronchial asthma. However, simultaneous evaluations of efficacy and side effects are few. This study aimed to compare the relative effect of fluticasone propionate (FP) and budesonide (BUD) on bronchial responsiveness and endogenous cortisol secretion in adults with asthma. The study was double-blind and included 66 adults with asthma, who were randomized to FP (n = 33) or BUD (n = 33). Prestudy, all participants were clinically stable, using inhaled corticosteroids and hyperresponsive to methacholine. Eligible patients were randomized to three consecutive 2-wk periods with either FP 250 microg twice daily, FP 500 microg twice daily, and FP 1,000 microg twice daily, or BUD 400 microg twice daily, BUD 800 microg twice daily, and BUD 1,600 microg twice daily, delivered by Diskhaler and Turbuhaler, respectively. Before randomization and at the end of each treatment, bronchial methacholine PD(20), 24-h urinary cortisol excretion (24-h UC), plasma cortisol, serum osteocalcin, and blood eosinophils were determined. The relative PD(20) potency between FP and BUD was 2.51 (95% CI, 1.05-5.99; p < 0. 05), while the relative 24-h UC potency was 0.60 (95% CI, 0.44-0.83; p < 0.01). The differential therapeutic ratio (FP/BUD) based on PD(20) potency and 24-h UC was 4.18 (95% CI, 1.16-15.03; p < 0.05). The difference in systemic potency was also seen for plasma cortisol, serum osteocalcin, and blood eosinophils. Therapeutic ratio over a wide dose range, determined by impact on bronchial responsiveness and endogenous corticosteroid production, seems to favor FP.

Glucocorticoids preferentially upregulate functional CXCR4 expression in eosinophils

BACKGROUND

Chemokines play an important role in accumulation of eosinophils at allergic inflammatory sites. Systemic administration of glucocorticoids (GCCs) attenuates tissue eosinophilia. In vivo chemokine actions are regulated at levels of both ligand production and receptor expression. The inhibitory effects of GCCs on the production of eosinophil-active chemokines, such as eotaxin, have been well established. However, no data exist regarding the effects of GCCs on expression of chemokine receptors in eosinophils per se.

OBJECTIVE

The objective of this study was to investigate the regulation of chemokine receptor expression in eosinophils by GCCs.

METHODS

Chemokine receptor expression was analyzed by using flow cytometry and reverse transcriptase PCR. Intracellular Ca(2+) influx and chemotaxis were also analyzed.

RESULTS

Eosinophil CCR3 expression was slightly downregulated by 24-hour treatment with dexamethasone (DEX). On the other hand, DEX-treated eosinophils showed markedly increased CXCR4 expression ( approximately 6 fold) in a time- and dose-dependent fashion. In contrast to eosinophils, CXCR4 expression in neutrophils was only marginally affected by DEX. In DEX-treated eosinophils, stromal cell-derived factor 1alpha, a natural ligand for CXCR4, induced a higher level of Ca(2+) influx and chemotaxis compared with untreated cells.

CONCLUSION

GCCs upregulate the expression of CXCR4 in eosinophils but not in neutrophils. Because stromal cell-derived factor 1alpha may play a role in baseline trafficking of eosinophils into extravascular tissues rather than recruiting them directly to inflammatory sites, upregulation of CXCR4 by GCCs may mediate the antiallergic property of these drugs by sequestering eosinophils from the circulation to extravascular tissues.

Randomized trial of inhaled flunisolide versus placebo among asthmatic patients discharged from the emergency department

STUDY OBJECTIVE

Inhaled corticosteroids (ICs) improve airflow and decrease symptoms in patients with chronic asthma. We examined whether high-dose inhaled flunisolide would have similar benefits after an emergency department visit for acute asthma.

METHODS

Over a 16-month period at one inner-city ED, we documented 551 eligible patients (acute asthma; age 18 to 50 years; no ICs in past week; no oral corticosteroids in past month; and peak expiratory flow rate [PEFR] <70% of predicted value after first beta-agonist treatment); 104 patients agreed to participate. At ED discharge, all patients were given prednisone 40 mg/d for 5 days and inhaled beta-agonists as needed and were randomly assigned to receive high-dose inhaled flunisolide 2 mg/d (n=51) or placebo (n=53). Patients were telephoned daily and asked to return for PEFR measurement at 3, 7, 12, 21, and 24 days.

RESULTS

Despite precautions, 28% (16 receiving flunisolide and 13 receiving placebo) of patients were completely lost to follow-up, 2 patients had only one follow-up (day 3), 2 patients receiving flunisolide withdrew because of medication-related bronchospasm, and 4 patients in each group experienced relapse. Among the 63 remaining patients, we found no difference between flunisolide and placebo at day 24 follow-up in percent predicted PEFR (87% versus 83% on day 24, P =.36; difference 4%, 95% confidence interval [CI] -5% to 13%). Nocturnal wheezing and nocturnal albuterol inhaler use was higher among patients receiving flunisolide than those receiving placebo on day 24 (48% versus 18% for nocturnal wheezing, P =.01; mean difference 30%, 95% CI 11% to 49%; 3.8 versus 1.4 nocturnal albuterol puffs, P =.03; mean difference 2.4 puffs, (95% CI 0.2 to 4). Levels of dyspnea, cough, and overall well-being were similar between the flunisolide and placebo groups.

CONCLUSION

Addition of high-dose inhaled flunisolide to standard therapy does not benefit inner-city patients with acute asthma in the first 24 days after ED discharge. Airway inflammation during acute asthma may require higher doses or more potent anti-inflammatory agents.

Latent adenoviral infection modifies the steroid response in allergic lung inflammation

BACKGROUND

Steroid-resistant asthma develops after adenoviral bronchiolitis.

OBJECTIVE

We sought to determine the effect of steroids on allergic lung inflammation in the presence of latent adenoviral infection.

METHODS

Guinea pigs with latent adenoviral (n = 12) or sham (n = 12) infections were sensitized and challenged with ovalbumin (OA) or sham sensitized and challenged with saline solution. The effect of steroids (20 mg/kg administered intraperitoneally) on OA-induced lung inflammation was examined by using quantitative histology as the outcome measure.

RESULTS

Latent adenoviral infection increased CD8(+) cells in the airway wall and CD8(+) cells, macrophages, B cells, and CD4(+) cells in the lung parenchyma. Ovalbumin challenge, on the other hand, increased eosinophils, macrophages, B cells, and CD4(+) cells in both the airway wall and lung parenchyma independent of the effect of latent adenoviral infection. In the sham-infected groups steroid treatment caused the expected reduction in the eosinophilic infiltrate induced by OA challenge in the airways without affecting the other cells. In the presence of both latent adenoviral infection and OA challenge, steroid treatment had no effect on allergen-induced eosinophilia but reduced CD8(+) cells in the airways and CD8(+) cells, CD4(+) cells, and B cells in the parenchyma.

CONCLUSION

Latent adenoviral infection and OA challenge result in different types of lung inflammation, and the presence of latent adenoviral infection causes OA-induced eosinophilic airway inflammation to become steroid resistant.

Mometasone furoate administered once daily is as effective as twice-daily administration for treatment of mild-to-moderate persistent asthma

BACKGROUND

Despite current recommendations, many patients with persistent asthma are still treated with bronchodilators alone.

OBJECTIVE

The safety and efficacy of two once daily dosing regimens (200 microg and 400 microg) of mometasone furoate (MF) administered in the morning by using a dry-powder inhaler (DPI) were compared with those of a twice daily dosing regimen (200 microg administered twice daily) in patients with mild-to-moderate persistent asthma previously taking only inhaled beta(2)-adrenergic agonists.

METHODS

All patients (306 patients; age range, 12-70 years) were given a diagnosis of asthma for at least 6 months before enrollment in this 12-week, placebo-controlled, double-blind, randomized study. The primary efficacy variable was change in FEV(1) from baseline to endpoint (last evaluable visit).

RESULTS

At endpoint, FEV(1) was significantly improved (P < or =.02) after MF-DPI 400 microg once daily morning treatment and MF-DPI 200 microg twice daily treatment (16.0% and 16.1%, respectively) compared with placebo (5.5%). The improvement seen with MF-DPI 200 microg once daily morning treatment (10.4%) was not significantly different from that with placebo. Secondary efficacy variables also showed significant improvement for the MF-DPI 400 microg once daily morning treatment group and the MF-DPI 200 microg twice daily treatment group compared with the placebo group. All doses of MF administered by means of a DPI were well tolerated.

CONCLUSION

This is the first study to demonstrate that a total daily dose of 400 microg of MF administered by means of a DPI is an effective treatment for patients with mild-to-moderate persistent asthma previously taking only inhaled beta(2)-adrenergic agonists. This treatment was equally effective when administered either as a once daily or twice daily regimen.

A double-blind, placebo-controlled dose-response study with budesonide Turbuhaler in Japanese asthma patients. Japanese Pulmicort Turbuhaler study group

OBJECTIVE

The aim of this study was to investigate the dose-response for inhaled budesonide via Turbuhaler in Japanese patients with mild to moderate asthma.

METHODOLOGY

Inhaled budesonide 100 microg, 200 microg, 400 microg or placebo was administered twice daily via Turbuhaler for 6 weeks, to 267 adult Japanese patients (mean age 51 years) with mild-to-moderate, non-steroid-dependent bronchial asthma, in a double-blind, placebo-controlled, randomized, parallel group study. The patients had to be symptomatic for more than 3 days/week and have an average morning peak expiratory flow (PEF) 50-80% of predicted normal value.

RESULTS

The response to budesonide was rapid, all treatments showing a significant improvement in morning PEF after 1 week (P<0.05). During week 6, mean improvements of 15, 45, 53 and 71 L/min were observed for the placebo, 200 microg, 400 microg and 800 microg budesonide groups, respectively. Compared with placebo all improvements in the budesonide groups were statistically significant and a significant dose-response was demonstrated (P<0.001). The difference between the 200 microg and 800 microg doses was significant. Also, for several secondary efficacy variables (e.g. evening PEF, symptom score, treatment score, daily activity score and sleep score) significant dose-responses were shown. Other variables included the investigators' assessments of improvement and usefulness. They also showed statistically significant dose-response relationships and confirmed the rapid onset of action. Budesonide was well tolerated at all tested doses, with a low incidence of adverse events, all of which were minor in severity.

CONCLUSIONS

Budesonide Turbuhaler in the doses 100 microg to 400 microg twice daily was effective, well tolerated and showed a rapid onset of action in patients with mild-to-moderate asthma. Dose-response was demonstrated for several variables of clinical efficacy.