Binding kinetics of fluticasone propionate to the human glucocorticoid receptor

[Inhalation therapy in dogs and cats with chronic lower airway disease - a literature review]

Chronic respiratory diseases are prevalent medical conditions in dogs and cats requiring lifelong treatment. Mainstay of therapy for chronic inflammatory respiratory diseases are glucocorticoids. Concurrent treatment with bronchodilators may be necessary to control clinical signs sufficiently. Due to the successful use in people as well as subsequent reduction of adverse effects of long-term glucocorticoid therapy, inhalative therapy has become increasingly important in veterinary medicine as well. Primarily spacers or valved holding chambers, in combination with metered dose inhalers, are used in dogs and cats. The technical properties of these devices, as well as their use and maintenance will be described in the following article. Furthermore, the existing literature regarding efficacy of inhalative medications for therapy of chronic inflammatory airway diseases in dogs and cats will be summarized.

Quantitative Assessment of Pulmonary Targeting of Inhaled Corticosteroids Using Ex Vivo Receptor Binding Studies

The goal of locally acting inhaled corticosteroids is to achieve distinct pulmonary effects with reduced systemic side effects. The present work using an ex vivo receptor binding model in rats was interested in assessing pulmonary targeting for several commercially available corticosteroids by monitoring receptor occupancies in the lung and systemic organs (liver, kidney, spleen, and brain) after intravenous (IV) injection or intratracheal (IT) instillation of a dry powder administration at a dose of 100 μg/kg. Pulmonary targeting, defined as the difference in cumulative receptor occupancies (AUC_E) between the lung and kidney after pulmonary delivery, differed across the investigated corticosteroids (ΔAUC_E range, 33 ± 46 to 143 ± 52% *h) with the highest degree found for corticosteroids with high systemic clearance and pronounced lipophilicity (presumably allowing a long pulmonary residence time). Additionally, this study demonstrated differences in the receptor occupancies across systemic organs. Using kidney receptor occupancies as the comparator, liver receptor occupancies were reduced (ΔAUC_E range: - 157 ± 43 to 178 ± 42% *h) after IV and IT administration for corticosteroids with high intrinsic clearance, while they were increased for corticosteroid prodrugs due to hepatic activation. Spleen receptor occupancies were increased after IT (ΔAUC_E range: 33 ± 35 to 135 ± 28% *h), but not after IV administration. This was especially true for slowly dissolving drugs. Reduced brain uptake was also observed for ciclesonide (CIC) and des-ciclesonide (desCIC), two compounds previously not investigated. In summary, ex vivo receptor binding studies represent a powerful tool to assess the fate of ICSs.

Effects of fluticasone propionate and budesonide on the expression of immune defense genes in bronchial epithelial cells

BACKGROUND

COPD patients have increased risk of pneumonia when treated with fluticasone propionate (FP), whereas this is generally not the case with budesonide (BUD) treatment. We hypothesized that BUD and FP differentially affect the expression of immune defense genes.

METHODS

Human bronchial epithelial 16HBE cells and air-liquid interface (ALI)-cultured primary bronchial epithelial cells (PBECs) were pre-treated with clinically equipotent concentrations of BUD or FP (0.16-16 nM BUD and 0.1-10 nM FP), and the expression of immune defense genes was studied at baseline and after exposure to rhinovirus (RV16).

RESULTS

Using microfluidic cards, we observed that both BUD and FP significantly suppressed CXCL8, IFNB1 and S100A8 mRNA expression in unstimulated 16HBE cells. Interestingly, BUD, but not FP, significantly increased lactotransferrin (LTF) expression. The difference between the effect of BUD and FP on LTF expression was statistically significant and confirmed by qPCR and at the protein level by western blotting. RV16 infection of ALI-cultured PBECs significantly increased the expression of CCL20, IFNB1 and S100A8, but not of LTF or CAMP/LL-37. In these RV16-exposed cells, LTF expression was again significantly higher upon pre-treatment with BUD than with FP. The same was observed for S100A8, but not for CCL20, IFNB1 or CAMP/LL-37 expression.

CONCLUSIONS

Treatment of human bronchial epithelial cells with BUD results in significantly higher expression of specific immune defense genes than treatment with FP. The differential regulation of these immune defense genes may help to explain the clinical observation that BUD and FP treatment differ with respect to the risk of developing pneumonia in COPD.

Generation of Inducible Transgenic Lines of Arabidopsis Transcription Factors Regulated by MicroRNAs

Transcription factors play key regulatory roles in all the life processes across kingdoms. In plants, the genome of a typical model species such as Arabidopsis thaliana encodes over 1500 transcription factors that regulate the expression dynamics of all the genes in time and space. Therefore, studying their function by analyzing the loss and gain-of-function lines is of prime importance in basic plant biology and its agricultural application. However, the current approach of knocking out genes often causes embryonic lethal phenotype, while inactivating one or two members of a redundant gene family yields little phenotypic changes, thereby making the functional analysis a technically challenging task. In such cases, inducible knock-down or overexpression of transcription factors appears to be a more effective approach. Restricting the transcription factors in the cytoplasm by fusing them with animal glucocorticoid/estrogen receptors (GR/ER) and then re-localizing them to the nucleus by external application of animal hormone analogues has been a useful method of gene function analysis in the model plants. In this chapter, we describe the recent advancements in the GR and ER expression systems and their use in analyzing the function of transcription factors in Arabidopsis.

Glucocorticoid hormone-induced chromatin remodeling enhances human hematopoietic stem cell homing and engraftment

Efficient hematopoietic stem cell (HSC) homing is important for hematopoietic cell transplantation (HCT), especially when HSC numbers are limited, as in the use of cord blood (CB). In a screen of small-molecule compounds, we identified glucocorticoid (GC) hormone signaling as an activator of CXCR4 expression in human CB HSCs and hematopoietic progenitor cells (HPCs). Short-term GC pretreatment of human CB HSCs and HPCs promoted SDF-1-CXCR4-axis-mediated chemotaxis, homing, and long-term engraftment when these cells were transplanted into primary- and secondary-recipient NSG mice. Mechanistically, activated glucocorticoid receptor binds directly to a glucocorticoid response element in the CXCR4 promoter and recruits the SRC-1-p300 complex to promote H4K5 and H4K16 histone acetylation, facilitating transcription of CXCR4. These results suggest a new and readily available means to enhance the clinical efficacy of CB HCT.

Genomic Alterations in Cell-Free DNA and Enzalutamide Resistance in Castration-Resistant Prostate Cancer

Importance

The molecular landscape underpinning response to the androgen receptor (AR) antagonist enzalutamide in patients with metastatic castration-resistant prostate cancer (mCRPC) is undefined. Consequently, there is an urgent need for practical biomarkers to guide therapy selection and elucidate resistance. Although tissue biopsies are impractical to perform routinely in the majority of patients with mCRPC, the analysis of plasma cell-free DNA (cfDNA) has recently emerged as a minimally invasive method to explore tumor characteristics.

Objective

To reveal genomic characteristics from cfDNA associated with clinical outcomes during enzalutamide treatment.

Design, Setting, and Participants

Plasma samples were obtained from August 4, 2013, to July 31, 2015, at a single academic institution (British Columbia Cancer Agency) from 65 patients with mCRPC. We collected temporal plasma samples (at baseline, 12 weeks, end of treatment) for circulating cfDNA and performed array comparative genomic hybridization copy number profiling and deep AR gene sequencing. Samples collected at end of treatment were also subjected to targeted sequencing of 19 prostate cancer-associated genes.

Exposure

Enzalutamide, 160 mg, daily orally.

Main Outcomes and Measures

Prostate-specific antigen response rate (decline ≥50% from baseline confirmed ≥3 weeks later). Radiographic (as per Prostate Cancer Working Group 2 Criteria) and/or clinical progression (defined as worsening disease-related symptoms necessitating a change in anticancer therapy and/or deterioration in Eastern Cooperative Group performance status ≥2 levels).

Results

The 65 patients had a median (interquartile range) age of 74 (68-79) years. Prostate-specific antigen response rate to enzalutamide treatment was 38% (25 of 65), while median clinical/radiographic progression-free survival was 3.5 (95% CI, 2.1-5.0) months. Cell-free DNA was isolated from 122 of 125 plasma samples, and targeted sequencing was successful in 119 of 122. AR mutations and/or copy number alterations were robustly detected in 48% (31 of 65) and 60% (18 of 30) of baseline and progression samples, respectively. Detection of AR amplification, heavily mutated AR (≥2 mutations), and RB1 loss were associated with worse progression-free survival, with hazard ratios of 2.92 (95% CI, 1.59-5.37), 3.94 (95% CI, 1.46-10.64), and 4.46 (95% CI, 2.28-8.74), respectively. AR mutations exhibited clonal selection during treatment, including an increase in glucocorticoid-sensitive AR L702H and promiscuous AR T878A in patients with prior abiraterone treatment. At the time of progression, cfDNA sequencing revealed mutations or copy number changes in all patients tested, including clinically actionable alterations in DNA damage repair genes and PI3K pathway genes, and a high frequency (4 of 14) of activating CTNNB1 mutations.

Conclusions and Relevance

Clinically informative genomic profiling of cfDNA was feasible in nearly all patients with mCRPC and can provide important insights into enzalutamide response and resistance.

Inhaled corticosteroid use in HIV-positive individuals taking protease inhibitors: a review of pharmacokinetics, case reports and clinical management

As a consequence of inhibition of the hepatic cytochrome P450 3A4 isozyme, treatment with HIV protease inhibitors can result in significant drug-drug interactions. One noteworthy interaction is between protease inhibitors and inhaled or intranasal corticosteroids. This interaction can result in adrenal insufficiency and iatrogenic Cushing's syndrome (with symptoms such as rapid weight gain, obesity, facial hirsutism and swelling), as well as hypertension, osteoporosis and decreased CD4 cell count. In this paper, we review and unite pharmacokinetic data, case reports and current research regarding this drug-drug interaction in order to suggest options for the clinical management of HIV-positive patients requiring treatment with protease inhibitors and inhaled or intranasal corticosteroids.

Assessment of HPA-Axis Suppression with Fluticasone Cream 0.05% in Patients with Extensive Psoriasis or Eczema

OBJECTIVE

This study evaluated the effects of fluticasone cream 0.05% on the hypothalamopituitary-adrenal (HPA) axis in patients with extensive psoriasis or eczema.

PATIENTS

Six inpatients in a hospital setting, three with extensive eczema and three with extensive psoriasis of at least 30% body surface involvement, were enrolled in this study.

METHODS

In an open-label design, all patients received fluticasone cream 0.05%, 15g applied twice daily without occlusion for 7 consecutive days. The primary outcome measures were HPA-axis suppression (determined by morning plasma cortisol and 24-hour urinary free cortisol concentrations), selected blood chemistries, urinalysis and haematology profile.

RESULTS

During the treatment phase, four of the six patients studied experienced insignificant changes in morning plasma cortisol concentrations. In one patient, a decrease in plasma cortisol concentrations occurred following several days of treatment; these concentrations recovered after 6 to 7 days of treatment. In the remaining patient, a marked decrease in morning plasma cortisol concentrations occurred, which may have been attributed to consumption of alcohol by this patient.

CONCLUSION

Fluticasone cream 0.05% was well tolerated in patients with extensive eczema or psoriasis and had a low potential for suppressing endogenous cortisol secretion, even when applied to extensive areas of diseased skin for 7 days.

The role of nasal corticosteroids in the treatment of rhinitis

Intranasal corticosteroids (INSs) are the first choice for rhinitis pharmacotherapy. This preference is because of their broad range of actions that result in reductions of proinflammatory mediators, cytokines, and cells. Over the past 30 years, INSs have been modified to improve their pharmacodynamic, pharmacokinetic, and delivery system properties, with attention to improving characteristics such as receptor binding affinity, lipophilicity, low systemic bioavailability, and patient preference. Clinically, they have been shown to be the most effective class of nasal medications for treating allergic rhinitis and nonallergic rhinopathy, with no clear evidence that any specific INS is superior to others.

Topical fluticasone propionate: intervention and maintenance treatment options of atopic dermatitis based on a high therapeutic index

Fluticasone propionate (FP), a medium potent glucocorticoid (class III) of carbothioate nature with a favourable benefit/risk ratio, has emerged as a standard medication for the topical treatment of inflammatory skin disorders, in particular atopic dermatitis (AD). FP is available as a 0.05% cream and a 0.005% ointment formulation. The glucocorticoid is characterized by high lipophilicity, high affinity binding to the glucocorticoid receptor and a rapid hepatic biotransformation. Though skin blanching following topical application of FP surpasses that given with glucocorticoids of medium strength, clinical trials show a low potential of FP for local and systemic adverse effects. Even in paediatric patients with AD as well as in difficult-to-treat areas like face, eyelids and intertriginous areas, FP proved to be both effective and safe. Thus, the therapeutic effects of FP clearly outweigh the unwanted effects. Correspondingly, a therapeutic index of 2.0 can be attributed to this glucocorticoid. In this respect, topical FP does not differ from other topical glucocorticoids with increased benefit-to-risk ratio, e.g. prednicarbate, methylprednisolone aceponate and mometasone furoate. However, randomized controlled trials do not only support conventional intervention but also innovative maintenance treatment.

Hydrofluoroalkane preparations of fluticasone propionate

Fluticasone propionate is approved for the long-term maintenance therapy of persistent asthma of all severities, and its safety and efficacy has been well established in clinical trials and practice. With the need to phase out chlorofluorocarbons (CFCs) as propellants in pressurized metered-dose inhalers (pMDIs), hydrofluoroalkane (HFA) propellants have been introduced as a safer, environmentally friendly alternative. A HFA formulation of fluticasone propionate has been developed as a microgram-equivalent replacement for the traditional CFC pMDI. Clinical trials have demonstrated that the fluticasone propionate HFA pMDI is an acceptable clinical alternative for the CFC pMDI with similar safety and efficacy.

Salmeterol/fluticasone propionate combination in the treatment of COPD

Chronic obstructive pulmonary disease (COPD) is characterized by poorly reversible airway obstruction and progressive airway inflammation. The long-acting beta2-agonist salmeterol and the corticosteroid fluticasone propionate can be administered in a combination inhaler. Four double-blind, placebo-controlled, randomized clinical trials have demonstrated that salmeterol/fluticasone propionate improves pulmonary function and health status, and also decreases exacerbation rates in COPD patients. The TORCH (Towards a Revolution in COPD Health) study confirmed that the effects of combined therapy with salmeterol/fluticasone propionate are greater than the monocomponents. The TORCH data are also indicative of a beneficial effect of salmeterol/fluticasone propionate on mortality, although there is much debate about this issue. This review critically appraises the pharmacology of salmeterol/fluticasone propionate, the evidence for efficacy in COPD and its potential use in combination with other drugs.

The treatment of vasomotor rhinitis with intranasal corticosteroids

Objective

Intranasal steroids (INS) are firmly established as the therapy for choice for allergic rhinitis, but their role in vasomotor rhinitis (VMR) is not fully characterized. This review examines the potential mechanisms of action and reported efficacy of INS in patients with VMR.

Results

INS, through intracellular activation of the glucocorticoid receptor, down-regulate the recruitment and activation of inflammatory cells (T-lymphocytes, eosinophils, mast cells, basophils, neutrophils, macrophages), increase degradation of neuropeptides, and reduce epithelial cell activity, vascular permeability, and chemokine secretion. It is likely that more than vasoconstriction is responsible for the clinical effects of INS.

Eight INS can be prescribed for rhinitis in the US; only 4 have been studied for VMR. Seventy-four percent of patients treated with beclomethasone dipropionate considered themselves symptom-free or greatly improved versus 31% with placebo. Budesonide significantly reduced rhinitis symptoms and methacholine-induced nasal secretions compared with placebo. Fluticasone propionate compared with placebo provided significantly greater relief from nasal obstruction; computed tomographic scans showed significant reductions in the mucosal area of the lower turbinates. Mometasone furoate produced numerically better rhinitis symptom scores and, when discontinued, lower relapse rates than placebo.

Conclusion

Data supports INS as beneficial pharmacotherapy for VMR.

Molecular and clinical pharmacology of intranasal corticosteroids: clinical and therapeutic implications

Intranasal corticosteroids (INSs) are effective treatments for allergic rhinitis, rhinosinusitis, and nasal polyposis. In recent years, increased understanding of corticosteroid and glucocorticoid receptor pharmacology has enabled the development of molecules designed specifically to achieve potent, localized activity with minimal risk of systemic exposure. Pharmacologic potency studies using affinity and other assessments have produced similar rank orders of potency, with the most potent being mometasone furoate, fluticasone propionate, and its modification, fluticasone furoate. The furoate and propionate ester side chains render these agents highly lipophilic, which may facilitate their absorption through nasal mucosa and uptake across phospholipid cell membranes. These compounds demonstrate negligible systemic absorption. Systemic absorption rates are higher among the older corticosteroids (flunisolide, beclomethasone dipropionate, triamcinolone acetonide, and budesonide), which have bioavailabilities in the range of 34-49%. Studies, including 1-year studies with mometasone furoate, fluticasone propionate, and budesonide that evaluated potential systemic effects of INSs in children have generally found no adverse effects on hypothalamic-pituitary-adrenal axis function or growth. Clinical data suggest no significant differences in efficacy between the INSs. Theoretically, newer agents with lower systemic availability may be preferable, and may come closer to the pharmacokinetic/pharmacologic criteria for the ideal therapeutic choice.

Human receptor kinetics and lung tissue retention of the enhanced-affinity glucocorticoid fluticasone furoate

Fluticasone furoate (FF)--USAN approved name, a new topically active glucocorticoid has been recently identified. The aim of this study was to characterise the binding affinity of this compound to the human lung glucocorticoid receptor in relation to other glucocorticoids. Additionally, we sought to determine the binding behaviour of fluticasone furoate to human lung tissue. The glucocorticoid receptor binding kinetics of fluticasone furoate revealed a remarkably fast association and a slow dissociation resulting in a relative receptor affinity (RRA) of 2989 +/- 135 with reference to dexamethasone (RRA: 100 +/- 5). Thus, the RRA of FF exceeds the RRAs of all currently clinically used corticosteroids such as mometasone furoate (MF; RRA 2244), fluticasone propionate (FP; RRA 1775), ciclesonide's active metabolite (RRA 1212 - rat receptor data) or budesonide (RRA 855). FP and FF displayed pronounced retention in human lung tissue in vitro. Lowest tissue binding was found for MF. There was no indication of instability or chemical modification of FF in human lung tissue. These advantageous binding attributes may contribute to a highly efficacious profile for FF as a topical treatment for inflammatory disorders of the respiratory tract.

Inhaled corticosteroids in children with asthma: pharmacologic determinants of safety and efficacy and other clinical considerations

The role of inhaled corticosteroids (ICS) in the treatment of childhood asthma has been well established. An ideal corticosteroid should demonstrate high pulmonary deposition and residency time, in addition to a low systemic bioavailability and rapid systemic clearance. The lung depositions of the ICS have been compared, with beclomethasone (beclometasone)-hydrofluoroalkane (HFA) and ciclesonide showing the highest lung deposition. Lung deposition is influenced by not only the inhalation device and type of propellant (HFA or chlorofluorocarbon), but also by whether the aerosol is a solution or suspension, and the particle size of the respirable fraction. Pulmonary residency time increases when budesonide and des-ciclesonide undergo reversible fatty acid esterification. The bioavailability of the drug depends on the oral bioavailable fraction and the amount absorbed directly from the pulmonary vasculature. The clearance rate of des-ciclesonide is very high (228 L/h), increasing its safety profile by utilizing extra-hepatic clearance mechanisms. Both des-ciclesonide and mometasone have a high protein binding fraction (98-99%). The volume of distribution (Vd) is proportional to the lipophilicity of the drug, with the Vd of fluticasone being 332L compared with 183L for budesonide. Increasing the Vd will also increase the elimination half-life of a drug. The pharmacodynamics of ICS depend on both the receptor binding affinity and the dose-response curve. Among the ICS, fluticasone and mometasone have the highest receptor binding affinity (1800 and 2200, respectively), followed by budesonide at 935 (relative to dexamethasone = 100). Compared with other nonsteroid asthma medications (long-acting beta-agonists, theophylline, and montelukast) ICS have proven superiority in improving lung function, symptom-free days, and inflammatory markers. One study suggests that early intervention with ICS reduces the loss in lung function (forced expiratory volume in 1 second) over 3 years. Whether airway remodeling is reduced or prevented in the long term is unknown. Potential adverse drug effects of ICS include adrenal and growth suppression. While in low-to-medium doses ICS have shown little suppression of the adrenal pituitary axis, in high doses the potential for significant adrenal suppression and adrenal crisis exists. Several longitudinal studies evaluating the effect of ICS on growth have shown a small decrement in growth velocity (approximate 1-2 cm) during the first year of treatment. However, when investigators followed children treated with budesonide for up to 10 years, no change in target adult height was noted. In conclusion, the development of optimal delivery devices for young children, as well as optimizing favorable pharmacokinetic properties of ICS should be priorities for future childhood asthma management.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Management of 13 cases of canine respiratory disease using inhaled corticosteroids

OBJECTIVES

To determine the value of inhaled corticosteroids in the management of chronic inflammatory airway disease in dogs.

METHODS

Medical records of dogs that were presented for the investigation of respiratory disease were reviewed retrospectively. Criteria for inclusion were knowledge of previous medical treatment including side effects, diagnosis of the underlying disease, use of inhaled corticosteroids and at least two-months follow-up data.

RESULTS

Thirteen dogs that fulfilled the criteria were identified. Ten dogs were diagnosed with chronic bronchitis and three with eosinophilic bronchopneumopathy. Four dogs had not previously received corticosteroid treatment for their respiratory disease, and all these showed a reduction or a resolution of clinical signs without obvious side effects after inhaled corticosteroid therapy. Nine dogs had previously received oral or parenteral corticosteroids for treatment of their respiratory disease, and all had exhibited side effects. Five of these dogs were treated with inhaled corticosteroids alone, and all exhibited an improvement in clinical signs without observable side effects. The remaining four dogs were treated with a combination of inhaled and oral corticosteroids, and all showed improvement in clinical signs and reduction in side effects. Inhaled medication was well tolerated in all dogs.

CLINICAL SIGNIFICANCE

Inhaled corticosteroids were used for the management of chronic bronchitis and eosinophilic bronchopneumopathy in 13 dogs, and these may have the advantage of reducing side effects associated with oral corticosteroids.

Use of the low-dose corticotropin stimulation test for the monitoring of children with asthma treated with inhaled corticosteroids

OBJECTIVE

Subnormal hypothalamic-pituitary-adrenal (HPA) function and rare cases of adrenal crisis have been reported in asthmatic children treated with inhaled corticosteroids. We investigated subnormal HPA activity and followed up affected patients until recovery of normal HPA functions.

STUDY DESIGN

100 children with persistent asthma underwent low-dose corticotropin testing, with the administration of 1 microg of 1-24 ACTH intravenously. Treatments were beclomethasone dipropionate as a metered-dose inhaler, n = 14, budesonide as a dry-powder inhaler, n = 16, fluticasone propionate as a metered-dose inhaler n = 31 or a dry-powder inhaler n = 39. The mean commercially labelled dose was 520 +/- 29 microg/day (mean +/- SEM, range: 160-1,000) and the equipotent dose (which compares the efficiency of these drugs for treating asthma and their responsibility for systemic effects) was 890 +/- 55 microg/day (range: 200-2,000).

RESULTS

The mean stimulated cortisol level +/- SEM (and range) of the patient was 482 +/- 12 (148-801), and that of 40 age-matched controls was 580 +/- 12.5 (439-726), (SD = 79). The result was subnormal (more than 2 SD below the mean of the controls) in28 of the 100 patients. One-four stepwise decreases of 10-100% in the daily equipotent doses received by the patients with abnormal low-dose corticotropin testing results led to normal results in subsequent low-dose corticotropin testing in 27 retested patients. The mean time interval between two tests was 5 months (range: 2-6 months) and the mean period required for normalization of the test was 13 months (range: 2-21). Only one case of asthma exacerbation and no adrenal crisis were observed over these periods.

CONCLUSIONS

Decreasing daily equipotent doses led to recovery of normal HPA function without asthma exacerbation. Thus, a revision of the doses of inhaled corticosteroids used in asthmatic children with a progressive decrease to the consensus-recommended doses should decrease the systemic effects of inhaled corticosteroids, while minimizing the risk of asthma exacerbation.

Effects of glucocorticoids on the hypothalamic-pituitary-adrenal axis in children and adults

Inhaled and intranasal corticosteroids are widely used as effective, first-line treatments for asthma and allergic rhinitis. Despite a good safety profile of these formulations, there is increasing concern about their propensity to produce systemic adverse effects. Suppression of the hypothalamic-pituitary-adrenal axis is one of the most important potential complications. This article reviews the effects of inhaled and intranasal corticosteroids on the hypothalamic-pituitary-adrenal axis function in adults and children.

Glucocorticoids for Human Skin: New Aspects of the Mechanism of Action

Topical glucocorticoids have always been considered first-line drugs for inflammatory diseases of the skin and bronchial system. Applied systemically, glucocorticoids are used for severe inflammatory and immunological diseases and the inhibition of transplant rejection. Owing to the progress in molecular pharmacology, the knowledge of the mechanism of action has increased during the last years. Besides distinct genomic targets, which are due to the activation of specific cytoplasmatic receptors resulting in the (trans-) activation or (trans-) repression of target genes, there are non-genomic effects on the basis of the interference with membrane-associated receptors as well as with membrane lipids. In fact, various glucocorticoids appear to differ with respect to the relative influence on these targets. Thus, the extended knowledge of glucocorticoid-induced cellular signalling should allow the design and development of even more specifically acting drugs - as it has been obtained with other steroids, e.g. estrogens for osteoporosis prevention.

Safety and Efficacy of Fluticasone Propionate in the Topical Treatment of Skin Diseases

Fluticasone propionate - the first carbothioate corticosteroid - has been classified as a potent anti-inflammatory drug for dermatological use. It is available as 0.05% cream and 0.005% ointment formulations for the acute and maintenance treatment of patients with dermatological disorders such as atopic dermatitis, psoriasis and vitiligo. This glucocorticoid is characterized by high lipophilicity, high glucocorticoid receptor binding and activation, and a rapid metabolic turnover in skin. Although skin blanching following fluticasone propionate exceeds that of corticosteroids of medium strength, several clinical trials demonstrate a low potential for cutaneous and systemic side-effects, even in difficult-to-treat areas like the face, the eyelids and intertriginous areas. Even among paediatric patients with atopic dermatitis, fluticasone propionate proved to be safe and effective. These pharmacological and clinical properties are reflected by the high therapeutic index of this glucocorticoid.

Human receptor kinetics, tissue binding affinity, and stability of mometasone furoate

Mometasone furoate (MF) is a topically used glucocorticoid with high anti-inflammatory potency. In contrast to the wealth of data derived from clinical studies, information about the molecular pharmacology of the compound is lacking or contradictory. Thus, we elucidated the characteristics of receptor binding kinetics and receptor affinity in a bioassay. Metabolite formation was determined in human plasma and lung tissue as well as binding affinity to human lung tissue. Fast and extensive association of MF to the human glucocorticoid receptor was observed while the dissociation of the MF-receptor complex was faster compared to fluticasone propionate (FP). The relative receptor affinity of MF was calculated as 2200 (dexamethasone = 100, FP = 1800) and confirmed in a bioassay measuring the induction of the glucocorticoid regulated protein CD163 in human monocytes. In plasma and human lung tissue MF formed a 9,11-epoxy degradation product. The binding affinity of MF to human lung tissue was low compared to FP due to fast redistribution from tissue into plasma. These molecular pharmacological properties are in accordance with clinical data.

Significant receptor affinities of metabolites and a degradation product of mometasone furoate

Mometasone furoate (MF) is a highly potent glucocorticoid used topically to treat inflammation in the lung, nose and on the skin. However, so far no information has been published on the human glucocorticoid receptor activity of the metabolites or degradation products of MF. We have now determined the relative receptor binding affinities of the known metabolite 6beta-OH MF and the degradation product 9,11-epoxy MF to understand their possible contribution to undesirable systemic side effects. In competition experiments with human lung glucocorticoid receptors we have determined the relative receptor affinities (RRA) of these substances with reference to dexamethasone (RRA = 100). We have discovered that 6beta-OH MF and 9,11-epoxy MF display RRAs of 206 +/- 15 and 220 +/- 22, respectively. This level of activity is similar to that of the clinically used inhaled corticosteroid flunisolide (RRA 180 +/- 11). Furthermore we observed that 9,11-epoxy MF is a chemically reactive metabolite. In recovery experiments with human plasma and lung tissue we found a time dependent decrease in extractability of the compound. Hence, we provide data that might contribute to the understanding of the pharmacokinetics as well as the clinical effects of MF.

Effect of inhaled fluticasone propionate on BAL TGF-β1 and bFGF concentrations in clinically stable lung transplant recipients

BACKGROUND

Inhaled fluticasone propionate (FP) therapy decreases inflammation and sub-basement membrane thickness in asthmatic airways. Bronchiolitis obliterans syndrome (BOS) in lung transplant recipients (LTRs) involves progressive airway fibrosis and obliteration. Therefore, augmented immunosuppression may be of some benefit in treating BOS. In this study, we examined the effect of 3 months of treatment with high-dose inhaled FP on the concentrations of 2 fibrogenic factors, transforming growth factor (TGF)-beta(1) and beta fibrogenic growth factor (bFGF) in bronchoalveolar lavage (BAL) fluid from clinically stable LTRs.

METHODS

We conducted a randomized, double-blind, placebo-controlled, parallel group study with inhaled FP (750 microg, twice/day for 3 months) in 28 LTRs (15 FP and 13 placebo). We recruited 23 healthy controls. We performed spirometry, bronchoscopy, and bronchoalveolar lavage procedures before treatment and after 3 months of treatment. We used commercially available enzyme-linked immunosorbent assay kits to measure BAL fluid TGF-beta(1) and bFGF concentrations.

RESULTS

In LTRs before treatment, BAL TGF-beta(1) concentrations (but not bFGF concentrations), total cell counts, and neutrophil percentage increased compared with controls (p < 0.05). We found no significant differences between FP and placebo groups at baseline measurements. After treatment, BAL TGF-beta(1) concentrations significantly increased in the FP group (p = 0.03), but we found no difference between FP and placebo groups; BAL bFGF concentrations increased during treatment in both groups compared with controls (p < 0.05), but not significantly within either patient group (p > 0.05). We found a reverse correlation between forced expiratory volume in 1 second (FEV(1)) and BAL TGF-beta(1) concentration in the FP group (r = -0.53, p = 0.04), and between FEV(1) and BAL TGF-beta(1) concentration in the placebo group (r = -0.74, p = 0.004). Multivariable analysis indicated no significant independent effects of inhaled FP in either BAL TGF-beta(1) or bFGF concentrations.

CONCLUSIONS

Bronchoalveolar fluid TGF-beta(1) concentrations increased in LTRs after transplantation and may correlate with the decrease in lung function. Inhaled FP added to conventional immunosuppression had no effect on TGF-beta(1) or bFGF production in BAL fluid.

The role of intracellular esterification in budesonide once-daily dosing and airway selectivity

BACKGROUND

Since their introduction in the 1970s, inhaled corticosteroids (ICSs) have been used to control airway inflammation associated with asthma. Budesonide is one of the ICSs recommended as first-line therapy for mild to moderate persistent asthma.

OBJECTIVE

This article describes the esterification of budesonide and how it results in prolonged, location-specific retention of drug in the airways, allowing once-daily dosing.

RESULTS

Studies conducted over the past decade have shown that budesonide forms reversible fatty acid esters within the cells of airway tissue, resulting in the formation of an intracellular depot pool of inactive drug. As the intracellular concentration of free budesonide decreases, these budesonide esters are hydrolyzed back to their active state. This process increases budesonide's retention in the airways, prolongs its duration of action, and lowers the risk of systemic effects.

CONCLUSIONS

By extending budesonide's local anti-inflammatory effect and increasing its airway selectivity, the esterification process appears to contribute to the drug's efficacy, particularly during once-daily administration. Reducing the number of required daily inhalations may increase patient compliance with asthma therapy, although this remains to be evaluated.

The effect of a steroid "burst" and long-term, inhaled fluticasone propionate on adrenal reserve

BACKGROUND

Although widely used, the effects of steroid "bursts" on the hypothalamic-pituitary-adrenal axis, especially with long-term, concomitant topical steroids use, have not been studied.

OBJECTIVE

To examine the effect of a prednisone burst, long-term intranasal steroids, and inhaled fluticasone propionate on the suppression and recovery of adrenal function.

METHODS

Adult patients taking long-term intranasal steroids, either moderate-dose (440 microg/d) or high-dose (880 microg/d) inhaled fluticasone propionate, underwent a low-dose cosyntropin stimulation test (LDCST) before and 2 days after a prednisone burst. Suppressed adrenal responses were monitored with a weekly LDCST. Persistent abnormal LDCST results were confirmed by 8-hour cosyntropin infusion. Inhaled fluticasone dosages were decreased; adrenal recovery was evaluated by a monthly LDCST. Adverse effects of steroids were monitored by questionnaires.

RESULTS

Sixty-three patients participated in the study. Three of 31 patients not taking inhaled steroids and 1 of 13 patients taking moderate-dose fluticasone had abnormal LDCST results on day 2 after the prednisone burst, which normalized by the second week. In the high-dose fluticasone group, 14 of 19 patients had suppressed LDCST responses on day 2 and adrenal function recovered in 10 of 19 patients by the fourth week. These patients complained significantly of decreased libido (P = 0.02), listlessness (P = 0.03), and weight loss (P = 0.05). High-dose fluticasone (r = 0.66, P < 0.001) and duration of use (r = 0.32, P = 0.01) were statistically correlated with adrenal impairment. Of the 4 patients with persistent adrenal impairment, 3 patients successfully reduced dosages of inhaled fluticasone and adrenal function recovered in 2 to 10 months.

CONCLUSIONS

Prednisone bursts induce brief adrenal impairment. Intranasal steroids and moderate-dose fluticasone had no effect on adrenal function. High-dose, inhaled fluticasone caused mild-to-significant adrenal suppression and delayed the recovery after a steroid burst. Avoiding or limiting the duration of high-dose inhaled steroids would minimize systemic adverse effects.

Inhaled glucocorticoids and adrenal function: an update

For the vast majority of asthmatic children, treatment with inhaled glucocorticoids is safe and effective. Mild impairment of adrenal function of doubtful clinical significance is known to occur in some children inhaling > or = 400 micro g/day budesonide and beclomethasone or > or = 200 micro g fluticasone. Recent reports of life-threatening adrenal failure in asthmatic children inhaling glucocorticoids, some of whom were prescribed licensed doses, have prompted the recommendation that the use of high-dose inhaled glucocorticoids, particularly fluticasone, should be avoided. However, the importance of correctly diagnosing asthma, of using the minimum dose of inhaled glucocorticoid required for symptom control and of regular growth-velocity assessment cannot be over-emphasised. Appropriate asthma management including the early introduction of steroid-sparing agents such as a long-acting beta-agonist or leukotriene antagonist may reduce the morbidity associated with inhaled glucocorticoid use but some children, for reasons as yet unknown, may exhibit increased sensitivity to the systemic effects of inhaled glucocorticoid treatment. Possible explanations for this, with reference to the pharmacology and molecular mechanisms of glucocorticoid action, are accompanied in this review by a summary of the recent case reports and discussion of assessment of adrenal function.

Intranasal corticosteroids for allergic rhinitis

Intranasal corticosteroids are accepted as safe and effective first-line therapy for allergic rhinitis. Several intranasal corticosteroids are available: beclomethasone dipropionate, budesonide, flunisolide, fluticasone propionate, mometasone furoate, and triamcinolone acetonide. All are efficacious in treating seasonal allergic rhinitis and as prophylaxis for perennial allergic rhinitis. In general, they relieve nasal congestion and itching, rhinorrhea, and sneezing that occur in the early and late phases of allergic response, with studies showing almost complete prevention of late-phase symptoms. The rationale for topical intranasal corticosteroids in the treatment of allergic rhinitis is that adequate drug concentrations can be achieved at receptor sites in the nasal mucosa. This leads to symptom control and reduces the risk of systemic adverse effects. Adverse reactions usually are limited to the nasal mucosa, such as dryness, burning and stinging, and sneezing, together with headache and epistaxis in 5-10% of patients regardless of formulation or compound. Differences among agents are limited to potency, patient preference, dosing regimens, and delivery, device and vehicle.

Efficacy and safety of fluticasone propionate 250 microg administered once daily in patients with persistent asthma treated with or without inhaled corticosteroids

BACKGROUND

Studies have shown fluticasone propionate (FP) 100, 200, and 500 microg administered once daily to be effective in the treatment of asthma. The efficacy of a once daily regimen of FP 250 microg has not been evaluated previously.

OBJECTIVE

We sought to evaluate the efficacy and safety of inhaled FP 250 microg administered once daily in patients currently receiving inhaled short-acting beta-agonists (SABA) alone or inhaled corticosteroids (ICS).

METHODS

In two separate studies, 408 patients in the SABA study and 401 patients in the ICS study were randomly assigned to receive FP 250 microg or placebo for 12 weeks through the Diskus device (GlaxoSmithKline, Research Triangle Park, NC) each morning.

RESULTS

At the study endpoint, SABA patients treated with FP and placebo had mean increases in forced expiratory volume in 1 second from baseline of 0.23 +/- 0.03 L and 0.10 +/- 0.03 L, respectively (P < 0.001). ICS patients treated with FP had a mean increase of 0.08 +/- 0.02 L compared with a decrease in forced expiratory volume in 1 second of -0.08 +/- 0.03 L with placebo (P < 0.001). Changes of similar magnitude in morning peak expiratory flow rates were seen with FP in both the SABA and ICS studies. Fewer FP-treated ICS study patients were withdrawn from the study as a result of predetermined asthma stability criteria and, therefore, those patients had a greater probability of remaining in the study than placebo-treated patients (P < 0.001).

CONCLUSIONS

FP 250 microg, once daily, produced greater improvements in pulmonary function and asthma symptom control than placebo. This new treatment regimen provides clinicians with an additional therapeutic option for patients with asthma previously treated with either beta2-agonists alone or ICS.

Lung deposition of hydrofluoroalkane-134a beclomethasone is greater than that of chlorofluorocarbon fluticasone and chlorofluorocarbon beclomethasone : a cross-over study in healthy volunteers

STUDY OBJECTIVES

To compare the lung deposition of radiolabeled hydrofluoroalkane-134a beclomethasone dipropionate (HFA-BDP) with chlorofluorocarbon fluticasone propionate (CFC-FP) and chlorofluorocarbon beclomethasone (CFC-BDP).

DESIGN

Six-day, open-label, nonrandomized, crossover study.

SETTING

Clinical research laboratory.

PARTICIPANTS

Nine healthy, nonsmoking, adult volunteers.

INTERVENTIONS

On each study day, participants inhaled one or two puffs of 99mTc-labeled HFA-BDP, CFC-FP, or CFC-BDP. All products delivered 50 micro g per puff ex-valve. Subjects used a respiratory training and monitoring device to meet predefined, standardized inhalation patterns. Immediately after inhalation of radiolabeled study drug, planar gamma camera images were obtained.

MEASUREMENTS AND RESULTS

Radiolabeled HFA-BDP had a higher deposition in the lungs (53% ex-actuator) compared with CFC-FP (12 to 13%) and CFC-BDP (4%). Conversely, CFC-FP and CFC-BDP had a much higher distribution to the oropharynx (72 to 78%, and 82%, respectively) than HFA-BDP (29%). HFA-BDP was deposited evenly throughout the lungs, while CFC-FP and CFC-BDP deposition was primarily in the large central and intermediate airways. Andersen particle size sampling gave mass median aerodynamic diameters for HFA-BDP, CFC-FP, and CFC-BDP of 0.9 micro m, 2.0 micro m, and 3.5 micro m, respectively.

CONCLUSIONS

Lung deposition was greater with HFA-BDP compared with CFC-FP and CFC-BDP. Deposition values appeared to be related to the particle size distribution of each inhaler, with the smaller particles of HFA-BDP providing the greatest lung deposition and least oropharyngeal deposition.

Comparative efficacy, safety, and effect on quality of life of triamcinolone acetonide and fluticasone propionate aqueous nasal sprays in patients with fall seasonal allergic rhinitis

BACKGROUND

The topical potency of fluticasone propionate (FP) is known to be four times greater than that of triamcinolone acetonide (TAA). However, the significance of this difference has not been proven in the clinical treatment of seasonal allergic rhinitis (SAR).

OBJECTIVE

To compare the efficacy, safety, and effect on health-related quality of life (HRQL) of FP and TAA aqueous nasal sprays in patients with SAR.

METHODS

Single-blind, parallel-group, active-controlled design. Patients were randomized to 3-week treatment with TAA 220 microg (n = 172) or FP 200 microg (n = 180) as two sprays/nostril once daily AM. Twelve-hour reflective symptom evaluations (nasal discharge, stuffiness, itching; sneezing; ocular itching/tearing/redness) were performed AM/PM, beginning at pretreatment baseline period. Incidences of specific treatment-related side effects were collected in daily questionnaires. HRQL was evaluated at baseline and end-of-treatment with a validated disease-specific, quality-of-life instrument.

RESULTS

TAA and FP produced similar improvement in daily total nasal symptom scores overall (49.4% and 52.7%, respectively; P = 0.332) and at every weekly time point (P > 0.05). There were no significant differences between TAA and FP in any individual symptom score at any time point except week 2 (FP provided greater reduction in sneezing, P = 0.046). No significant difference was found between groups in overall occurrence of specific treatment-related side effects. Overall Rhinoconjunctivitis Quality of Life Questionnaire scores were similar for TAA and FP at end-of-treatment.

CONCLUSIONS

Despite differing molecular potencies, FP and TAA demonstrated comparable efficacy in the treatment of SAR, and produced similar occurrences of specific treatment-related side effects and similar improvements in overall patient HRQL.

Circadian rhythm of serum cortisol after repeated inhalation of the new topical steroid ciclesonide

The new inhalative glucocorticoid ciclesonide which is activated in lung to a more potent metabolite was hypothesized to have low risk for systemic and local side-effects in man. Therefore, a placebo-controlled, randomized, double-blind, four-period, change-over equivalence study in 12 healthy male volunteers (age 21-28 yr, body weight 62-90 kg) was conducted to assess the influence of three dosage regimens (800 microg in the morning, 800 microg in the evening, 400 microg twice daily for 7 d, metered inhalers) on the circadian time serum cortisol rhythm.

RESULTS

Serum cortisol showed the typical circadian rhythm. The geometric mean of the 24-h mesor (AUC((0-24 h))/24 h) was 7.22 microg/dl for placebo, 6.75 microg/dl for the 800 microg ciclesonide morning dose, 7.08 microg/dl for the 800 microg evening dose, and 6.75 microg/dl for 400 microg ciclesonide inhaled twice daily. Because there was also no influence on cortisol amplitude and acrophase (time of maximum), the profiles after ciclesonide were equivalent to the placebo control. The small differences were considered not to be of clinical significance. In conclusion, inhaled ciclesonide in daily doses of 800 microg for 7 d is without clinically relevant effects on the hypothalamic-pituitary-adrenal axis independent of the time of administration.

Safety of fluticasone propionate cream 0.05% for the treatment of severe and extensive atopic dermatitis in children as young as 3 months

BACKGROUND

Topical corticosteroids are useful for the treatment of pediatric dermatoses. However, concerns regarding possible systemic and topical toxicities have limited the use of moderate-potency corticosteroids in children.

OBJECTIVE

Our purpose was to characterize the safety of fluticasone propionate cream in children.

METHODS

Children between 3 months and 5 years 11 months (n = 32) and 3 up to 6 years of age (n = 19) with moderate to severe atopic dermatitis (> or =35% body surface area; mean body surface area treated, 64%) were treated with fluticasone propionate cream, 0.05% twice daily for 3 to 4 weeks. Serum cortisol response, fluticasone levels, skin changes, and adverse events were analyzed.

RESULTS

Mean cortisol levels were similar at baseline (13.76 +/- 6.94 microg/dL prestimulation and 30.53 +/- 7.23 microg/dL poststimulation) and at end of treatment (12.32 +/- 6.92 microg/dL prestimulation and 28.84 +/- 7.16 microg/dL poststimulation). Only 2 of 43 children had end-treatment poststimulation values less than 18.0 microg/dL. No significant adverse cutaneous effects were noted.

CONCLUSION

Fluticasone propionate cream 0.05% appears to be safe for the treatment of severe eczema for up to 4 weeks in children 3 months of age and older.

Prolonged airway activity and improved selectivity of budesonide possibly due to esterification

We addressed the question of whether the prolonged local retention of the glucocorticoid (GC) budesonide (BUD) within airway tissue, due to reversible fatty acid esterification, is associated with protracted topical anti-inflammatory activity and improved airway selectivity, when compared with fluticasone propionate (FP). BUD or FP at 25 nmol/kg was administered intratracheally or subcutaneously to adrenalectomized rats, followed by lipopolysaccharide (LPS) intratracheal instillation. The trachea and main bronchi were lavaged 6 h after LPS, and tumor necrosis factor-alpha (TNF-alpha) concentration and cell number in the lavage fluid were measured. Instilled 1 h before LPS, both GCs reduced TNF-alpha by 70% (p < 0.05) and mononuclear cells by 55% (p < 0.01), with no reduction in neutrophils. Instilled 6 h before LPS, a significant reduction of TNF-alpha (59%, p < 0.02) and mononuclear cells (47%, p < 0.05) was achieved only with BUD. After subcutaneous administration, no significant effects were observed. BUD did not exert higher systemic activity than FP, measured as plasma corticosterone suppression. In conclusion, BUD exerted a more prolonged topical anti-inflammatory activity, and a higher airway selectivity than FP, possibly because of its reversible fatty acid esterification within airway tissue. This may contribute to the high efficacy and safety of BUD in asthma, even with once-daily inhalation.

Comparative kinetics of metabolism of beclomethasone propionate esters in human lung homogenates and plasma

The systemic availability of inhaled beclomethasone dipropionate (BDP) is the net result of the absorption of the glucocorticoid from the lower respiratory and gastrointestinal tracts, and metabolism in the lung, plasma, and other sites. The metabolism kinetics of BDP and its active metabolite, beclomethasone 17-monopropionate (17-BMP), in human lung 1000 x g supernatant (HLu) and human plasma (HP) at 37 degrees C were compared. The effect of MgCl(2) and/or an NADPH-generating system on the decomposition of BDP and 17-BMP in HLu was also investigated. The concentrations of BDP and its metabolites were determined by HPLC with UV detection at 242 nm. Kinetics of decomposition of BDP and 17-BMP in HLu and HP were qualitatively and quantitatively different. The decomposition of BDP in HLu involved only hydrolysis. In comparison, three reactions are involved following incubation of BDP in HP; namely, hydrolysis, transesterification, and loss of hydrogen chloride. The hydrolysis of BDP and 17-BMP in HLu seem to be inhibited appreciably by MgCl(2) with the NADPH-generating system. Effective activation of BDP in HLu, in combination with transesterification of 17-BMP in HP, might favor a high ratio of local antiinflammatory activity to systemic side effects following inhalation of BDP.

Long-term efficacy and safety of fluticasone propionate powder administered once or twice daily via inhaler to patients with moderate asthma

OBJECTIVE

To evaluate the efficacy and safety of fluticasone propionate administered as a once-daily or twice-daily regimen over a period of 1 year to patients with moderate asthma.

DESIGN

Double-blind, randomized, parallel group, and placebo-controlled phase (12 weeks) and an open-label phase (54 weeks).

SETTING

Multicenter study in an outpatient setting.

PARTICIPANTS

Patients (n = 253; age, > or = 12 years) with a mean FEV(1) of 67% predicted normal were stratified according to baseline therapy of maintenance inhaled corticosteroids vs beta(2)-agonists alone.

MEASUREMENTS AND INTERVENTIONS

Fluticasone propionate (250 microg bid or 500 microg qd) or placebo (bid) was administered via the Diskus multidose powder inhaler (Glaxo Wellcome; Research Triangle Park, NC) for 12 weeks. During open-label treatment, patients were re-randomized to once-daily or twice-daily fluticasone propionate.

RESULTS

Compared to placebo, fluticasone propionate administered qd or bid significantly improved FEV(1) (p < 0.001), morning (p < 0.001) and evening peak expiratory flow (PEF; p < 0.001), asthma symptom scores (p < or = 0.001), and albuterol use (p </= 0.001), and decreased nighttime awakenings. By the end of 12 weeks, withdrawal due to lack of efficacy was significantly higher in the placebo group than in the once-daily (p = 0.001) or twice-daily (p < 0.001) groups. When comparing the two active dosing regimens, significant differences in favor of twice-daily dosing were noted in FEV(1), albuterol use, and withdrawal due to lack of efficacy. During 54 weeks of open-label treatment, FEV(1) and PEF continued to improve with both regimens, and improvements seen in the first 12 weeks were maintained in patients who switched from twice-daily to once-daily dosing. Fluticasone propionate treatment over a 54-week period was well tolerated, with few drug-related adverse events, which were primarily topical effects of inhaled corticosteroids.

CONCLUSIONS

Fluticasone propionate powder improved lung function when administered either qd or bid over a 1-year period to patients with moderate asthma, with twice-daily dosing demonstrating significantly greater improvement in some efficacy parameters than once-daily dosing over the first 12 weeks of treatment. Fluticasone propionate treatment was not associated with significant systemic effects.

Transcriptional potencies of inhaled glucocorticoids

Glucocorticoids (GC) are the most effective anti-inflammatory drugs used in asthma. By a process called trans-activation, they increase the transcription of genes involved in either beneficial processes or certain side effects. Through trans-repression, they inhibit the transcription factors nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1), thereby decreasing the expression of many genes encoding inflammatory mediators such as the cytokine RANTES. We have measured the trans-activation and trans-repression potencies of the five currently available inhaled GC using reporter gene assays. The rank order of trans-activation potencies in HeLa cells stably transfected with a GC-inducible luciferase gene was fluticasone propionate > budesonide and triamcinolone acetonide > beclomethasone dipropionate and flunisolide. For all GC except beclomethasone dipropionate, there was a highly significant correlation between their potency to trans-activate in HeLa cells and their capacity to induce the gluconeogenic enzyme tyrosine aminotransferase in hepatoma tissue culture (HTC) cells. The rank order of trans-repression potencies in A549 lung cells transiently transfected with an AP-1- or NF-kappaB-dependent luciferase gene was fluticasone propionate > budesonide > beclomethasone dipropionate, triamcinolone acetonide, and flunisolide. The same rank order was found for inhibition of RANTES release. Thus, determination of trans-repression and trans-activation potencies of GC may help to predict their capacity to produce anti-inflammatory and side effects, respectively.

Chemical-inducible systems for regulated expression of plant genes

Chemical regulation of transgene expression presents a powerful tool for basic research in plant biology and biotechnological applications. Various chemical-inducible systems based on de-repression, activation and inactivation of the target gene have been described. The utility of inducible promoters has been successfully demonstrated by the development of a marker-free transformation system and large-scale gene profiling. In addition, field applications appear to be promising through the use of registered agrochemicals (e.g. RH5992) as inducers.

Effects of inhaled fluticasone and oral prednisolone on clinical and inflammatory parameters in patients with asthma

BACKGROUND

Guidelines state that oral and inhaled corticosteroids are the cornerstone of asthma treatment. The effect of both types of treatment can be assessed by measuring lung and systemic parameters. Treatment for two weeks with either oral prednisolone (30 mg/day), high dose fluticasone propionate (2000 microg/day, FP2000), or lower dose FP (500 microg/day, FP500), both given by a dry powder inhaler, were compared.

METHODS

One hundred and twenty patients with asthma were treated for two weeks in a double blind parallel group design. Lung function, asthma symptoms, airway hyperresponsiveness (PC(20) methacholine and adenosine-5'-monophosphate), sputum eosinophil and eosinophilic cationic protein (ECP) levels were measured as lung parameters. In addition, morning serum blood cortisol, blood eosinophil, and serum ECP levels were measured as systemic parameters.

RESULTS

PC(20) methacholine and adenosine-5'-monophosphate showed significantly greater improvement with FP2000 (1.99 and 4.04 doubling concentrations (DC), respectively) than prednisolone (0.90 DC, p = 0.02; 2.15 DC, p = 0. 05) and marginally more than with FP500 (1.69 and 3.54 DC). Changes in sputum eosinophil and ECP concentrations showed similar trends; the decrease in ECP was significantly greater with FP2000 than with FP500. In contrast, the systemic parameters of steroid activity (cortisol, peripheral blood eosinophils, and serum ECP) decreased to a similar extent with FP2000 and prednisolone but significantly less with FP500.

CONCLUSIONS

Oral prednisolone (30 mg/day) was inferior to FP2000 in improving airway hyperresponsiveness to both methacholine and AMP, with similar trends in forced expiratory volume in one second (FEV(1)), sputum eosinophil and ECP concentrations. Systemic effects were similar with prednisolone and FP2000 and less with FP500.