Pharmacologic characteristics and adrenal suppression with newer inhaled corticosteroids: A comparison of ciclesonide and fluticasone propionate

Chemokines and chemokine receptors during COVID-19 infection

Chemokines are crucial inflammatory mediators needed during an immune response to clear pathogens. However, their excessive release is the main cause of hyperinflammation. In the recent COVID-19 outbreak, chemokines may be the direct cause of acute respiratory disease syndrome, a major complication leading to death in about 40% of severe cases. Several clinical investigations revealed that chemokines are directly involved in the different stages of SARS-CoV-2 infection. Here, we review the role of chemokines and their receptors in COVID-19 pathogenesis to better understand the disease immunopathology which may aid in developing possible therapeutic targets for the infection.

Recent insights on the use of topical steroids in eosinophilic esophagitis

INTRODUCTION

Eosinophilic Esophagitis (EoE) is an immune-mediated, chronic inflammatory disorder of the esophagus. Topical steroids have been used in the management of EoE for over 15 years. However, there are no Food and Drug Administration (FDA) approved drug therapies for EoE.

AREAS COVERED

This review discusses the current understanding of EoE and the role of topical steroids in the induction and maintenance of remission in patients with EoE. We performed a comprehensive review of the literature, summarized randomized control trials from 2006 to 2020, and provided a simplified management algorithm for EoE.

EXPERT OPINION

In patients with EoE, topical steroids are effective in inducing clinical and histologic remission. Formulations of topical steroids that maximize the exposure to esophageal mucosa have the highest efficacy. A majority of patients who achieve remission with topical steroids develop clinical and histologic relapse off therapy within a year. Current evidence suggests that maintenance therapy with long-term topical steroids decreases the risk of relapse and progression to fibrostenotic disease. While uncertainty over the dose and duration of maintenance topical steroids and their potential side effects exists, long-term maintenance therapy with topical steroids appears to be the way forward to improve long-term outcomes in patients with EoE.

Re-analysis of Single Cell Transcriptome Reveals That the NR3C1-CXCL8-Neutrophil Axis Determines the Severity of COVID-19

SARS-CoV-2 infection has recently been declared a pandemic. Some patients showing severe symptoms exhibit drastic inflammation and airway damage. In this study, we re-analyzed published scRNA-seq data of COVID-19 patient bronchoalveolar lavage fluid to further classify and compare immunological features according to the patient’s disease severity. Patients with severe symptoms showed DNA damage and apoptotic features of epithelial cells. Our results suggested that epithelial damage was associated with neutrophil infiltration. Myeloid cells of severe patients showed higher expression of proinflammatory cytokines and chemokines such as CXCL8. As a result, neutrophils were abundant in lungs of patients from the severe group. Furthermore, recruited neutrophils highly expressed genes related to neutrophil extracellular traps. Neutrophil-mediated inflammation was regulated by glucocorticoid receptor expression and activity. Based on these results, we suggest that severe COVID-19 symptoms may be determined by differential expression of glucocorticoid receptors and neutrophils.

Adrenal Insufficiency in Pediatric Eosinophilic Esophagitis Patients Treated with Swallowed Topical Steroids

Swallowed topical steroids (STS) are the only effective pharmacological therapy for eosinophilic esophagitis (EoE). Thus far, studies of small populations of EoE patients have reported conflicting results in relation to adrenal insufficiency (AI). We sought to measure AI in a clinical setting in children taking STS for EoE. We performed a quality improvement study of pediatric EoE patients seen in a multidisciplinary clinic, who were treated with STS for at least 3 months. Two hundred twenty-five patients completed questionnaires to assess for signs of AI. All patients were requested to have fasting morning cortisol levels completed and if abnormal (<5 μg/dL or 139 nmol/L) twice, endocrinology consultation, and low-dose adrenocorticotropic hormone stimulation test were performed. A peak stimulated cortisol level of <18 μg/dL or 500 nmol/L was diagnostic of AI. Five of 106 STS-treated EoE patients who had morning cortisol levels drawn had AI. All 5 of these patients had asthma and were on additional topical steroid treatments. The number of steroid modalities and dose of steroid were not significant risk factors. Despite this low percentage, the life-threatening potential of AI warrants patient screening, as patients with iatrogenic AI are typically asymptomatic until an emergency triggers adrenal crisis. Further multicenter studies are needed to better define the risk attributable to STS alone, particularly in patients receiving combined steroid modalities.

Measuring safety of inhaled corticosteroids in asthma

BACKGROUND

Despite evidence demonstrating generally excellent therapeutic ratios for inhaled corticosteroids (ICSs) in asthma treatment, many clinicians and patients have ongoing concerns regarding their safety. To frame discussions of ICS safety, it is important to understand how safety is measured.

OBJECTIVE

To discuss how ICS safety is and should be measured.

METHODS

Discussion is augmented by relevant articles from the literature.

RESULTS

The therapeutic value of corticosteroids depends on the activation and repression of thousands of genes. However, it is not fully known which genes cause the desirable, therapeutic effects and which cause the adverse effects. The drug development process attempts to elucidate the clinically significant therapeutic effects and adverse effects of a candidate molecule and then compare them to those of currently available corticosteroids. Approaches to monitoring safety include clinical trials, retrospective comparison to historical efficacy and safety data, surrogate markers, animal models, and in vitro assays. Both preclinical and clinical data are used to compare safety among corticosteroids; however, no specific pathway or model that can robustly predict therapeutic ratios has been identified. Furthermore, variation in adverse effects is influenced by isoforms of the glucocorticoid receptor, differences in corticosteroid characteristics, differences among patients, and environmental variation.

CONCLUSION

Although some preclinical and patient-based metrics have predictive value, there is a clear need for improved biomarkers of corticosteroid adverse effects. Integrated analysis of preclinical and clinical data, including long-term safety data, could be used to address this important unmet need.

Use of ICS/LABA (extra-fine and non-extra-fine) in elderly asthmatics

Age represents an exclusion criterion in randomized clinical trials designed to test the efficacy and safety of inhaled drugs in asthma. As a consequence, data on efficacy and safety of inhaled corticosteroid (ICS) and long-acting β2 agonist (LABA) combinations in elderly asthmatics are scanty. Older age is associated with an increased proportion of comorbid conditions; in addition, all organ functions undergo a process of senescence, thus reducing their ability to metabolize the agents. Overall, these age-associated conditions may variably, and often unpredictably, affect the metabolism and excretion of respiratory drugs. However, pharmacological treatment of asthma does not follow specific recommendations in the elderly. In the elderly, the ICS/LABA combinations may carry an increased risk of local indesiderable effects, primarily due to the lack of coordination between activation of the device and inhalation, and systemic adverse events, mainly due to the greater amount of active drug that is available because of the age-associated changes in organ functions as well as drug-to-drug and drug-to-concomitant disease interactions. The extra-fine formulations of ICSs/LABAs, which allow for a more favorable drug deposition in the lungs at a reduced dose, may contribute to overcome this issue. This review revises the efficacy and safety of treatment with ICSs/LABAs, focusing on the main pharmacodynamic and pharmacokinetic properties of the drugs and highlighting the potential risks in the elderly asthmatic population.

Inhaled corticosteroids increase blood neutrophil count by decreasing the expression of neutrophil adhesion molecules Mac-1 and L-selectin

OBJECTIVE

The objective was to investigate the effect of commonly used inhaled corticosteroids on white blood cell count (WBC) and to examine the mechanisms involved.

METHODS

This randomized comparative study comprised 60 healthy adults. We measured the effects of budesonide (by face mask inhalation or aerosol inhaler), fluticasone (by inhaler), and saline inhalation (control) on WBC and the differential leukocyte count, especially the absolute neutrophil count (ANC). To elucidate the mechanisms involved, we measured the expression of the adhesion neutrophil ligands Mac-1 (CD11b) and L-selectin (CD62L), and granulocyte colony-stimulating factor serum levels.

RESULTS

Six hours after a single-dose inhalation of budesonide, mean increases of 23.4% in WBC (95% confidence interval [CI], 11.3-35.4) and 30.1% in ANC (95% CI, 7.2-53.0) were noted. The percentage of neutrophils increased from 54.6% to 58.1% (P< .001). Inhaled fluticasone increased WBC and ANC by 12.6% (95% CI, 1.5-23.7) and 22.7% (95% CI, 6.2-39.2), respectively (P< .01 for both). The absolute lymphocyte and eosinophil counts did not change significantly from baseline. The expression of Mac-1 and L-selectin decreased by 51.0% (P< .01) and 30.9% (P= .02), respectively, following face mask inhalation of budesonide and by 39.8% (P= .01) and 17.4% (P= .17), respectively, following inhalation of fluticasone. No significant changes in granulocyte colony-stimulating factor levels were noted.

CONCLUSIONS

Glucocorticoid inhalation increases WBC by increasing ANC. Reduced neutrophil adhesion to the endothelial surface, mediated by decreased adhesion molecule expression on neutrophils, is a plausible mechanism. Physicians should be aware of the effect of inhaled corticosteroids on WBC, as it may influence clinical decisions, especially in the emergency department.

Erratum to: Safety Considerations of Inhaled Corticosteroids in the Elderly

Inhaled corticosteroids (ICSs) are widely used in the treatment of patients with chronic obstructive pulmonary diseases. However, high-dose regimens and long-term use of ICSs have the potential to cause a variety of local and systemic side effects such as candidiasis, cataracts, glaucoma, and osteoporosis. The use of ICSs can also be associated with the risk of bone fractures, diabetes mellitus and pneumonia. These ICS-related side effects are of particular importance in elderly patients due to the presence of comorbidities and age-related behavioral, cognitive, and psychological problems, which can all interact with inhaled treatment. We reviewed the available literature on the clinically relevant side effects of ICSs in the elderly to provide practical measures to properly monitor and manage the risk of ICSs in the geriatric population. Inspection of the mouth, monitoring of ocular pressure, and use of bone-protective drugs may be necessary in patients on prolonged ICS therapy. Above all, the use of the lowest possible ICS dose and a careful re-assessment of the inhalation procedure should be recommended. Taken together, these observations suggest that physicians should use ICSs appropriately for those patients in whom the benefit will outweigh the risk, especially chronic obstructive pulmonary disease (COPD) patients with previous frequent exacerbations. Given the paucity of information on the topic and the need to extrapolate the results from studies with broader age ranges, we strongly encourage the design of specifically tailored clinical studies in the elderly.

Iatrogenic Cushing's Syndrome After Topical Steroid Therapy for Psoriasis

Glucocorticoids are used for the treatment of many diseases, such as inflammatory, allergic, autoimmune, and neoplastic diseases. They can be used in the form of topical, oral, inhalable, rectal, and intra-articular agents. Many topical steroid-related iatrogenic Cushing's syndrome cases affecting especially children have been reported in the literature. Topical steroid-related Cushing's syndrome is rarely seen in adults. In this report, we present the case of a 32-year-old male patient with iatrogenic Cushing's syndrome related to long-term clobetasol propionate treatment for psoriasis. In the context of such treatment, the glucocorticoid withdrawal problem has to be overcome. At present there is no consensus on steroid withdrawal. Patients on long-term glucocorticoid treatment must be evaluated for potential adverse effects and withdrawal symptoms by their physician and their endocrinologist.

Swallowed glucocorticoid therapy for eosinophilic esophagitis in children does not suppress adrenal function

OBJECTIVE

The purpose of this study was to examine the effect of chronic swallowed glucocorticoids on adrenal function during the treatment of eosinophilic esophagitis (EoE) in children.

METHODS

Serum cortisol levels were obtained in children with EoE pre- and post-treatment with swallowed glucocorticoids. Exclusion criteria included those on any additional steroid therapy. Once diagnosed with EoE by esophageal biopsy, subjects were treated based on current standard of care with either swallowed fluticasone or budesonide. At the time of follow-up, esophagogastroduodenoscopy and blood sampling was repeated. Both pre- and post-treatment serum cortisol samples were collected fasting, between 07:00 and 10:00, and determined using a competitive binding method assay. The distribution of differences in cortisol levels between the pre- and post-treatment samples satisfied the assumption for normality and were subsequently analyzed using the paired t-test.

RESULTS

Pre- and post-treatment serum cortisol levels were examined in 14 children who met clinical and histological diagnostic criteria for EoE. Mean age was 10.1 years (range 2-17 years) with 71% male and 29% female subjects. Swallowed glucocorticoid treatment included fluticasone in 79% and budesonide in 21% of subjects. Mean dosage of fluticasone was 704 μg daily (range 220-880 μg daily) and budesonide 0.8 mg daily (range 0.5-1 mg daily), along with a mean treatment length of 17 weeks (range 8-43 weeks). No significant difference in serum cortisol was found following treatment with swallowed fluticasone or budesonide (mean change 1.9 μg/dL, p=0.75, SD of the change=21.2).

CONCLUSIONS

Swallowed glucocorticoid therapy does not appear to significantly affect the adrenal axis in children, and therefore, may represent a safe therapy for EoE.

Safety considerations of inhaled corticosteroids in the elderly

Inhaled corticosteroids (ICSs) are widely used in the treatment of patients with chronic obstructive pulmonary diseases. However, high-dose regimens and long-term use of ICSs have the potential to cause a variety of local and systemic side effects such as candidiasis, cataracts, glaucoma, and osteoporosis. The use of ICSs can also be associated with the risk of bone fractures, diabetes mellitus and pneumonia. These ICS-related side effects are of particular importance in elderly patients due to the presence of comorbidities and age-related behavioral, cognitive, and psychological problems, which can all interact with inhaled treatment. We reviewed the available literature on the clinically relevant side effects of ICSs in the elderly to provide practical measures to properly monitor and manage the risk of ICSs in the geriatric population. Inspection of the mouth, monitoring of ocular pressure, and use of bone-protective drugs may be necessary in patients on prolonged ICS therapy. Above all, the use of the lowest possible ICS dose and a careful re-assessment of the inhalation procedure should be recommended. Taken together, these observations suggest that physicians should use ICSs appropriately for those patients in whom the benefit will outweigh the risk, especially chronic obstructive pulmonary disease (COPD) patients with previous frequent exacerbations. Given the paucity of information on the topic and the need to extrapolate the results from studies with broader age ranges, we strongly encourage the design of specifically tailored clinical studies in the elderly.

Inhaled corticosteroids: potency, dose equivalence and therapeutic index

Glucocorticosteroids are a group of structurally related molecules that includes natural hormones and synthetic drugs with a wide range of anti-inflammatory potencies. For synthetic corticosteroid analogues it is commonly assumed that the therapeutic index cannot be improved by increasing their glucocorticoid receptor binding affinity. The validity of this assumption, particularly for inhaled corticosteroids, has not been fully explored. Inhaled corticosteroids exert their anti-inflammatory activity locally in the airways, and hence this can be dissociated from their potential to cause systemic adverse effects. The molecular structural features that increase glucocorticoid receptor binding affinity and selectivity drive topical anti-inflammatory activity. However, in addition, these structural modifications also result in physicochemical and pharmacokinetic changes that can enhance targeting to the airways and reduce systemic exposure. As a consequence, potency and therapeutic index can be correlated. However, this consideration is not reflected in asthma treatment guidelines that classify inhaled corticosteroid formulations as low-, mid- and high dose, and imbed a simple dose equivalence approach where potency is not considered to affect the therapeutic index. This article describes the relationship between potency and therapeutic index, and concludes that higher potency can potentially improve the therapeutic index. Therefore, both efficacy and safety should be considered when classifying inhaled corticosteroid regimens in terms of dose equivalence. The historical approach to dose equivalence in asthma treatment guidelines is not appropriate for the wider range of molecules, potencies and device/formulations now available. A more robust method is needed that incorporates pharmacological principles.

Cushing's syndrome with adrenal suppression induced by inhaled budesonide due to a ritonavir drug interaction in a woman with HIV infection

A 48-year-old woman with HIV infection developed Cushingoid features while she was taking ritonavir-boosted darunavir. Cushing's syndrome was confirmed due to the drug interaction between ritonavir and budesonide. Diagnosis of iatrogenic Cushing's syndrome in HIV-positive patients who are on ritonavir-boosted protease inhibitors (PIs) presents a clinical challenge due to similar clinical features of lipohypertrophy related to ritonavir-boosted PIs. Although this complication has been widely described with the use of inhaled fluticasone, the interaction with inhaled budesonide at therapeutic dose is not widely recognized.

Moderate dose inhaled corticosteroid-induced symptomatic adrenal suppression: case report and review of the literature

Inhaled corticosteroids (ICS) are drugs of choice for persistent asthma. Less than 500 µg/d of fluticasone are believed to be safe. We found 92 cases of adrenal suppression in PubMed; among these cases there were 13 children who took 500 µg/d or less of fluticasone. Adrenal insufficiency was diagnosed in a 7-year-old boy on 460 µg ICS for 16 months, with a diagnosis of chronic persistent asthma. A random cortisol was nondetectable as was an early morning cortisol. ICS have greatly improved the day-to-day lives of children with chronic persistent asthma. Parents of children younger than 12 years, who use at least 400 µg of inhaled fluticasone (or bioequivalent), must be given oral and written instructions about warning symptoms of hypocortisolism. Major stress such as surgery, gastrointestinal, bronchopulmonary, or other systemic infections, and heat stress may mandate a written plan of action for use by hospital physicians.

[Inhaled corticosteroids in asthma: which have the best tolerance?]

Asthmatic syndrome, better definition of asthma, is an inflammatory chronic disease, probably the most frequent in pediatrics. An important characteristic of asthma is the bronchial inflammation with a complex network of cells and inflammatory mediators of pivotal importance in the pathogenesis. The long term control and treatment of this disease are cardinal points of the management of asthmatic syndrome. Inhaled corticosteroids (ICS) are the first-line treatment for persistent asthma in children of any age. The adverse events of the inhaled steroids on growth, bone mineralization, and hypothalamic-pituitary adrenal (HPA) axis function are the main concerns for the pediatricians. The long-term effects on growth and bone mineralization are actually reassuring. Good tolerance is achieved on hypothalamic-pituitary adrenal axis function with low to moderate doses in children. Scientific and clinical researches are pointed to find out molecules able to improve clinical efficacy of ICS with better tolerance and higher reduction of adverse events.

Significance of protein binding in pharmacokinetics and pharmacodynamics

The significance of plasma protein binding on drug efficacy and, subsequently, the clinical relevance of changes in protein binding has been controversially discussed for decades. The uncertainty concerning the impact of plasma protein binding on a drug's pharmacological activity is, in part, related to the approach used when investigating and interpreting protein binding effects in vitro and in vivo. Frequently, a generalized one-size-fits-all approach, such as "protein binding does matter/does not matter," may not be applicable. An appropriate analysis requires careful consideration of both pharmacokinetic and pharmacodynamic processes, as they both contribute to the safety and efficacy of drugs. Therefore, the aim of this article is to provide a concise review of the theoretical concepts of protein binding, and to discuss relevant examples where applicable.

The utility of antifungal agents for asthma

PURPOSE OF REVIEW

Recent work demonstrates that patients with refractory asthma are likely to be sensitized to environmental fungi and that specific antifungal treatments may be of benefit to this group.

RECENT FINDINGS

The relationships among fungal sensitization, exposure and asthma severity are imperfectly understood. Exposure to environmental fungi occurs ubiquitously and there is emerging evidence that internal airways colonization could be a source of ongoing exposure. Antifungal treatments appear to improve asthma-related quality of life. Such treatments are generally well tolerated but there are potential side-effects. The mechanisms behind the clinical improvements are not yet fully established.

SUMMARY

Antifungal treatments are used in some centres for patients with refractory asthma. Further research needs to explore the questions of patient selection, optimum duration of therapy and the prediction and management of azole-corticosteroid drug interactions. Advances in our understanding of the fungal molecular allergome and in our understanding of the allergic importance of small hyphal fragments may help to more precisely define the relationships among fungal sensitization, exposure and asthma severity.

Drug metabolism and pharmacokinetics

In this article, aspects of absorption, distribution, metabolism, and excretion have been described bearing in mind the pathogenesis of allergic diseases and their possible therapeutic opportunities. The importance of the routes of administration of the different therapeutic groups has been emphasized. The classical aspects of drug metabolism and disposition related to oral administration have been reviewed, but special emphasis has been given to intranasal, cutaneous, transdermal, and ocular administration as well as to the absorption and the subsequent bioavailability of drugs. Drug-metabolizing enzymes and transporters present in extrahepatic tissues, such as nasal mucosa and the respiratory tract, have been particularly discussed. As marketed antiallergic drugs include both racemates and enantiomers, aspects of stereoselective absorption, distribution, metabolism, and excretion have been discussed. Finally, a new and promising methodology, microdosing, has been presented, although it has not yet been applied to drugs used in the treatment of allergic diseases.

Effects of fluticasone propionate dosage in an experimental model of feline asthma

Cats with inflammatory bronchial disease are usually treated with glucocorticoid (GC) drugs to reduce airway inflammation. Inhalant GC delivery can preserve airway effects while systemic effects are minimized. An appropriate dosage regimen for inhaled GC in cats has not been investigated. A blinded, randomized, cross-over study design was used to investigate the ability of three different dosages of the inhalant GC fluticasone propionate delivered by metered dose inhaler to ameliorate eosinophilic airway inflammation in cats with experimentally induced allergic airway inflammation. Further, suppression of the hypothalamic-pituitary-adrenal axis (HPAA) at each dose was assessed. Fluticasone administered at dosages of 44, 110, or 220 microg q 12h reduced airway eosinophilia by 74%, 82%, or 81%, respectively (no difference). None of the dose regimens tested caused HPAA suppression. We conclude that a twice daily dosage of 44 microg fluticasone should be evaluated for the management of cats with naturally occurring inflammatory bronchial disease.

Pregnancy outcomes in women using inhaled fluticasone during pregnancy: a case series

BACKGROUND

The aim of the study was to report the maternal and fetal outcomes of women with respiratory illnesses who were treated with inhaled fluticasone during pregnancy.

MATERIAL AND METHODS

We identified 12 cases treated with inhaled fluticasone during pregnancy out of women who received obstetric and teratogen-risk evaluation at the Korean Motherisk Program. A detailed medical and obstetric history was obtained and cases were followed-up until either spontaneous or voluntary pregnancy termination or delivery occurred.

RESULTS

None of the participants had any obstetric complication. However, in addition to fluticasone, most of the 12 cases were simultaneously exposed to a variety of medications. There were 3 abortions (one spontaneous and 2 requested by the patients arguing personal reasons). Live born babies without any evidence of major congenital malformations included 8 singleton babies and 2 twins. Of them, 3 babies were born prematurely.

CONCLUSIONS

Our results are in agreement with previous large studies where no increased rate of adverse outcomes was reported with the use of inhaled corticosteroids during pregnancy.

Key barriers to optimal management of adult asthma in Australia: physician and patient perspectives

OBJECTIVE

Despite recent advances in asthma treatment, its management in many patients remains sub-optimal. The aim of the Global Asthma Physicians and Patient (GAPP) survey was to identify barriers to optimal asthma management and to explore the content and dynamics of physician-patient communications. Here we present the key findings for adults with asthma in Australia.

RESEARCH DESIGN AND METHODS

Patients with asthma aged > or = 18 years and physicians who treat adults (generalists; specialists) participated in telephone interviews conducted in May-June 2005, using close-end questionnaires. The survey examined physicians' beliefs and prescribing habits; patients' experiences with asthma; doctor-patient communication; satisfaction with asthma medications and interest in new asthma treatment.

RESULTS

A total of 101 adults with asthma and 100 physicians treating asthma patients in Australia completed the survey. Overall, key barriers to optimal asthma management included medication side effects, treatment compliance and patient education. These barriers may be exacerbated by poor patient-physician communication that fails to address patients concerns regarding side effects and may lead to poor treatment compliance. Both physicians and patients expressed safety concerns regarding the long-term use of inhaled corticosteroid and both groups would welcome new treatment options with improved safety profiles, efficacy and once-daily dosing.

CONCLUSION

From both a physician and patient perspective, the safety profile of asthma medication constitutes a key factor in promoting treatment compliance and, ultimately, treatment outcomes. The results highlight discrepancies in perceived patient-physician communication and a need for improved patient education in asthma management.

Corticosteroids (inhaled and/or intranasal) in the treatment of respiratory allergy in children: safety vs. efficacy

BACKGROUND

Topical administration of Corticosteroids (CS) can reduce the total dose of CS required to treat the patient and minimize side effects. Topical CS is extremely effective and has an excellent safety profile. Nonetheless, care must be taken when multiple sites such as lungs, nose and skin are being treated. CS mechanisms of action on the inflammatory process are complex. The aim of this study is to review such mechanisms and the adverse events secondary to it.

METHODS

Review English database (Embase, PubMed, Scielo) searching words: CS, adverse events, inhaled CS, intranasal CS, and children.

RESULTS

There is a classic mechanism involving a genomic effect of CS and a non-genomic effect, independently of gene transcription process. This mechanism acts by reducing mucosal blood flow in the asthmatic airways. Second-generation topical CS is the treatment of choice in allergic diseases control because of their good anti-inflammatory activity, poor absorption and first-pass hepatic metabolism. When comparing different CS, it is important to compare therapeutically equivalent doses. Although topical CS reduces systemic side effects, local and even systemic side effects can occur. Many factors affect the amount of drug that reaches the lung, including inhaler technique and inhaler type, fine particle dose and particle distribution.

CONCLUSION

Most patients with allergic diseases respond to CS treatment, but there is a small subset of them whose response is unsatisfactory even with high doses of CS. They are classified as corticosteroid-resistant asthmatics. Pro-inflammatory cytokines appear to up regulate the expression of GRb that has been associated with CS resistance.

Evaluation of tests of hypothalamic-pituitary-adrenal axis function used to measure effects of inhaled corticosteroids

OBJECTIVES

To review the evidence supporting the evaluation of hypothalamic-pituitary-adrenal (HPA) axis function as a measure of systemic exposure and clinical adverse events, discuss factors that affect systemic exposure to inhaled corticosteroids (ICSs), and review the effects of various ICSs that are currently available or under development on HPA axis function from a therapeutic perspective.

DATA SOURCES

Randomized published clinical trials and review articles on the topic of HPA axis suppression were retrieved in MEDLINE. Searches dating back to 1988 were restricted to human studies published in English.

STUDY SELECTION

Studies that evaluated HPA axis function and the methods used to measure its activities and the effects of ICSs (fluticasone propionate, budesonide, beclomethasone dipropionate, mometasone furoate, and ciclesonide) were selected.

RESULTS

Factors that influence adverse events caused by ICSs include pharmacokinetic and pharmacodynamic properties, delivery devices, and therapeutic dose and duration. Basal measurements of blood and urinary cortisol levels, reflecting basal HPA axis function, are the most sensitive markers for assessing systemic ICS bioavailability but, compared with dynamic stimulation tests, are poor clinical predictors of adrenal dysfunction.

CONCLUSIONS

Basal serologic and urinary cortisol tests provide the best measures of assessing and comparing systemic ICS exposure. Long-term clinical studies are needed to determine whether such tests are predictive of ICS toxicity.

Novel therapeutic interventions for allergic rhinitis

Allergic rhinitis is a high-prevalence disease, affecting 10 - 20% of the general population. Allergic rhinitis is sustained by an IgE-mediated reaction and by a complex inflammatory network of cells, mediators and cytokines that becomes chronic when exposure to allergen persists. A T(H)2-biased immune response is the background of the allergic inflammation. The current therapeutic strategy is mainly based on drugs (antihistamines, nasal corticosteroids, cromones and decongestants) and allergen immunotherapy. Drugs are (overall) effective in controlling symptoms but do not modify the immune background that leads to allergic inflammation and safety concerns may be present, especially for prolonged treatments. Immunotherapy can modify the allergic response but there is still room for improvement. Nowadays, several approaches are under investigation to optimise the management of allergic rhinitis. On one hand, new drugs and antimediators are being developed. On the other hand, attempts are being made to selectively block relevant signal pathways of allergic reaction. Finally, one of the major goals is to modify the T(H)2-biased immune response by improving the characteristics and modes of action of allergen immunotherapy.

Targeted interventions for difficult-to-treat asthma

Chronic persistent asthma has a significant burden in terms of healthcare-related expenses, decreased productivity and reduced quality of life for patients. Currently available guideline-directed therapy can control the majority of patients, but roughly one-third of patients will require additional care. This article reviews the barriers that hinder the ability of practitioners and patients to gain and maintain control of asthma, including inaccurate assessment measures, variability in patient response, and poor adherence. Strategies aimed at controlling difficult-to-treat disease, such as the use of biomarkers to assess control, are discussed. Newer and developing therapies that cater to specific types of asthmatic patients and may lead to improved outcomes in those patients for whom standard care is insufficient are also looked at.

[Treatment of iatrogenic Cushing syndrome: questions of glucocorticoid withdrawal]

Iatrogenic Cushing's syndrome is the most common form of hypercortisolism. Glucocorticoids are widely used for the treatment of various diseases, often in high doses that may lead to the development of severe hypercortisolism. Iatrogenic hypercortisolism is unique, as the application of exogenous glucocorticoids leads to the simultaneous presence of symptoms specific for hypercortisolism and the suppression of the endogenous hypothalamic-pituitary-adrenal axis. The principal question of its therapy is related to the problem of glucocorticoid withdrawal. There is considerable interindividual variability in the suppression and recovery of the hypothalamic-pituitary-adrenal axis, therefore, glucocorticoid withdrawal and substitution can only be conducted in a stepwise manner with careful clinical follow-up and regular laboratory examinations regarding endogenous hypothalamic-pituitary-adrenal axis activity. Three major complications which can be associated with glucocorticoid withdrawal are: i. reactivation of the underlying disease, ii. secondary adrenal insufficiency, iii. steroid withdrawal syndrome. Here, the authors summarize the most important aspects of this area based on their clinical experience and the available literature data.

Adrenal toxicology: a strategy for assessment of functional toxicity to the adrenal cortex and steroidogenesis

The adrenal is the most common toxicological target organ in the endocrine system in vivo and yet it is neglected in regulatory endocrine disruption screening and testing. There has been a recent marked increase in interest in adrenal toxicity, but there are no standardised approaches for assessment. Consequently, a strategy is proposed to evaluate adrenocortical toxicity. Human adrenal conditions are reviewed and adrenocortical suppression, known to have been iatrogenically induced leading to Addisonian crisis and death, is identified as the toxicological hazard of most concern. The consequences of inhibition of key steroidogenic enzymes and the possible toxicological modulation of other adrenal conditions are also highlighted. The proposed strategy involves an in vivo rodent adrenal competency test based on ACTH challenge to specifically examine adrenocortical suppression. The H295R human adrenocortical carcinoma cell line is also proposed to identify molecular targets, and is useful for measuring steroids, enzymes or gene expression. Hypothalamo-pituitary-adrenal endocrinology relevant to rodent and human toxicology is reviewed (with an emphasis on multi-endocrine axis effects on the adrenal and also how the adrenal affects a variety of other hormones) and the endocrinology of the H295R cell line is also described. Chemicals known to induce adrenocortical toxicity are reviewed and over 60 examples of compounds and their confirmed steroidogenic targets are presented, with much of this work published very recently using H295R cell systems. In proposing a strategy for adrenocortical toxicity assessment, the outlined techniques will provide hazard assessment data but it will be regulatory agencies that must consider the significance of such data in risk extrapolation models. The cases of etomindate and aminoglutethimide induced adrenal suppression are clearly documented examples of iatrogenic adrenal toxicity in humans. Environmentally, sentinel species, such as fish, have also shown evidence of adrenal endocrine disruption attributed to exposure to chemicals. The extent of human sub-clinical adrenal effects from environmental chemical exposures is unknown, and the extent to which environmental chemicals may act as a contributory factor to human adrenal conditions following chronic low-level exposures will remain unknown unless purposefully studied.