Dose-response for adrenal suppression with hydrofluoroalkane formulations of fluticasone propionate and beclomethasone dipropionate

Paediatric reference range for overnight urinary cortisol corrected for creatinine

OBJECTIVES

Systemic activity of inhaled corticosteroids (ICS) may be assessed via urinary cortisol measurement. Overnight urinary free cortisol corrected for creatinine (OUFCC) has been extensively reported in adult studies. However, a paediatric mass spectrometric (MS) reference range for OUFCC is not established. MS methods for OUFCC avoid cross-reactivity with other steroid hormones and are thus preferable to immunoassays. The aim of the present study was to define an MS OUFCC normative range in children.

METHODS

This was a cross-sectional study of healthy pre-pubertal children from 5 to 11 years. Children collected urine from 10 pm or bedtime, whichever was earlier, until 8 am. Urinary free cortisol was measured via a liquid chromatography tandem mass spectrometry (LC-MS/MS) assay (Acquity UPLC with Xevo TQ-S Mass Spectrometer [Waters]) with in-house reagents. Urinary creatinine was measured using a commercial assay (Roche).

RESULTS

Complete urine collections were obtained from 72 males and 70 females, mean age (SD) 8.6 (1.9) (range 5.0-11.8) years. The OUFCC 95% prediction interval was 1.7-19.8 nmol/mmol. Geometric mean OUFCC was 5.7; range 1.1-24.8 nmol/mmol.

CONCLUSIONS

The obtained normative LC-MS/MS OUFCC reference data facilitate the use of mass spectrometry OUFCC assays in assessment of systemic activity of endogenous and exogenous corticosteroids in children.

A Pilot Study of the Normative Range of Overnight Urinary Free Cortisol Corrected for Creatinine in Children

BACKGROUND

For more than a decade, urinary free cortisol corrected for creatinine (OUFCC) has been used to assess the systemic bioactivity of inhaled corticosteroids in children with asthma. Paediatric normative ranges, however, have not been established. The aim of the present study was to define a preliminary range for OUFCC in Tanner stage 1 children.

METHODS

A post hoc analysis was performed of 26 Tanner stage one children (aged 5-11 years) with mild asthma only requiring prn (pro re nata) treatment with short-acting β₂-agonists, who participated in a 3-way cross-over knemometry study. The study comprised a run-in, two washout periods and three treatment periods (2 weeks each). Urine was collected at the end of each period. A normative range was derived using the 95% prediction interval for the geometric mean OUFCC, calculated from run-in and washout periods.

RESULTS

Twenty-six children contributed 41 OUFCC values. The geometric mean OUFCC was 9.0 nmol/mmol (95% PI: 3.6, 22.7 nmol/mmol).

CONCLUSIONS

The OUFCC preliminary normative range was 3.6 to 22.7 nmol/mmol in Tanner stage one children. A larger study in healthy children is warranted to confirm these findings and to assess potential differences in OUFCC across developmental stages and age groups, and by gender and race.

EUDRACT NUMBER

2013-004719-32, CLINICALTRIALS.

GOV IDENTIFIER

NCT02063139.

Adrenal suppression in patients taking inhaled glucocorticoids is highly prevalent and management can be guided by morning cortisol

CONTEXT

Up to 3% of US and UK populations are prescribed glucocorticoids (GC). Suppression of the hypothalamo-pituitary-adrenal axis with the potential risk of adrenal crisis is a recognized complication of therapy. The 250 μg short Synacthen stimulation test (SST) is the most commonly used dynamic assessment to diagnose adrenal insufficiency. There are challenges to the use of the SST in routine clinical practice, including both the staff and time constraints and a significant recent increase in Synacthen cost.

METHODS

We performed a retrospective analysis to determine the prevalence of adrenal suppression due to prescribed GCs and the utility of a morning serum cortisol for rapid assessment of adrenal reserve in the routine clinical setting.

RESULTS

In total, 2773 patients underwent 3603 SSTs in a large secondary/tertiary centre between 2008 and 2013 and 17.9% (n=496) failed the SST. Of 404 patients taking oral, topical, intranasal or inhaled GC therapy for non-endocrine conditions, 33.2% (n=134) had a subnormal SST response. In patients taking inhaled GCs without additional GC therapy, 20.5% (34/166) failed an SST and suppression of adrenal function increased in a dose-dependent fashion. Using receiver operating characteristic curve analysis in patients currently taking inhaled GCs, a basal cortisol ≥348 nmol/l provided 100% specificity for passing the SST; a cortisol value <34 nmol/l had 100% sensitivity for SST failure. Using these cut-offs, 50% (n=83) of SSTs performed on patients prescribed inhaled GCs were unnecessary.

CONCLUSION

Adrenal suppression due to GC treatment, particularly inhaled GCs, is common. A basal serum cortisol concentration has utility in helping determine which patients should undergo dynamic assessment of adrenal function.

Impact of study design on the evaluation of inhaled and intranasal corticosteroids' effect on hypothalamic-pituitary-adrenal axis function

In part I of this review, an overview of the designs of hypothalamic-pituitary-adrenal (HPA) axis studies in the setting of inhaled corticosteroids (ICS) or intranasal corticosteroids (INS) use was discussed. Part II provides detailed discussion on the HPA axis evaluation results for each common ICS and INS, and how these results are possibly affected by the factors of study design. Significant adrenal suppression at conventional ICS/INS doses appears to be rare in clinical settings. The magnitude of cortisol suppression varies widely among different study designs. Factors potentially impacting this variability include: the choice of dose, dosing duration, assay sensitivity, statistical methodology, study population, and compliance. All of these factors have the potential to affect the extent of HPA axis effects detected and should be considered when designing or interpreting the results of a HPA axis study.

Pharmacological consequences of inhaled drug delivery to small airways in the treatment of asthma

Small peripheral airways are an important target for the anti-inflammatory treatment of asthma. To make anti-inflammatory drugs (inhaled corticosteroids [ICS]) effectively reach small airways, they should be delivered using inhalation techniques containing high proportions of fine or super-fine particles. Higher proportions of fine particles are associated with higher systemic absorption of ICS leading to an increased risk of endogenous cortisol suppression. Ciclesonide, despite the highest proportion of fine and super-fine particle fractions, is the only ICS not associated with an increased risk of systemic adverse effects, including cortisol suppression. In contrary to ICS, bronchodilators should not be administered to peripheral airways. This does not improve their efficacy and may increase their risk of cardiotoxicity. Thus, from a pharmacological point of view and the theory of aerosols' deposition, fixed combinations of ICS and long-acting beta agonists are always suboptimal. In many cases, the best solution may be to use fine-particle ciclesonide and a non-fine particle beta agonist administered from separate inhalers.

Impact of study design on the evaluation of inhaled and intranasal corticosteroids' effect on hypothalamic-pituitary-adrenal axis function, part I: general overview of HPA axis study design

Inhaled and intranasal corticosteroids (ICS and INS) are among the mainstays of the treatment for asthma and allergic rhinitis, respectively, and also carry the potential to suppress the hypothalamic-pituitary-adrenal (HPA) axis. Several important factors affect the interpretability of trials investigating the impact of ICS and INS on the HPA axis. This paper reviews 106 published clinical trials, peer-reviewed articles, and New Drug Application reviews of approved ICS and INS, using MEDLINE and Drugs@FDA database. The trials included in this review evaluated the potential impact on HPA axis function of eight approved single-ingredient ICS and INS (beclomethasone dipropionate, budesonide, ciclesonide, flunisolide, fluticasone furoate, flucticasone propionate, mometasone furoate, and triamcinolone acetonide) and combination products containing these ingredients. The most commonly utilized design was blinded, placebo controlled, and short term (<6 weeks) for adult trials and blinded, placebo controlled, and long term (≥6 weeks) for pediatric trials. Factors potentially affecting trial results include the choice of dose, dosing duration, assay sensitivity, statistical methodology, and the study population evaluated (patients or healthy volunteers). All of these factors have the potential to affect the level of adrenal suppression detected. In conclusion, to be informative, a HPA axis study should be well designed and carefully implemented to minimize variability in results and improve the overall interpretability of data obtained.

Prospective follow-up of novel markers of bone turnover in persistent asthmatics exposed to low and high doses of inhaled ciclesonide over 12 months

CONTEXT

In asthmatic patients receiving long-term inhaled corticosteroid therapy, there are concerns regarding the potential for developing systemic adverse effects on bone metabolism, possibly even in the absence of adrenal suppression.

OBJECTIVE

The aim of this study was to investigate whether exposure to inhaled ciclesonide at high vs. low doses over 1 yr causes any significant systemic adverse effect on sensitive biomarkers of bone turnover in asthmatic patients.

DESIGN

Post hoc analysis of stored samples was performed in a subgroup of patients from a prospective, randomized parallel group trial with 1 yr follow-up.

SETTING

We conducted a primary care study in Tayside, Scotland.

PARTICIPANTS

A total of 164 mild-moderate persistent asthmatics aged 18-65 yr with evidence of airway hyperresponsiveness using mannitol bronchial challenge were enrolled into the original study. Of the 119 completed patients per protocol, 100 participants had bone marker samples available for analysis.

INTERVENTIONS

Ciclesonide was titrated to control persistent asthma against either mannitol bronchial challenge [airway hyperresponsiveness (AHR) strategy] or a control group (based on symptoms, reliever use, and pulmonary function) over 1 yr.

OUTCOME MEASURES

We measured markers of bone formation [amino-terminal propeptide of type I collagen (PINP), amino-terminal propeptide of type III collagen (PIIINP)], resorption [carboxy-terminal telopeptide of type I collagen (ICTP), type I collagen cross-linked C-telopeptide (CTx)], and adrenal suppression (overnight urinary cortisol/creatinine ratio) at 0 and 12 months.

RESULTS

Mean ciclesonide doses after 12 months were: AHR, 507 μg/d (n = 50); and controls, 202 μg/d (n = 50) (P < 0.00001). There were no significant differences between AHR and control groups either at baseline or after 12 months in PINP, PIIINP, ICTP, or CTx; or in ratios of bone turnover as PINP/ICTP, PIIINP/CTx, or overnight urinary cortisol/creatinine ratio.

CONCLUSION

Higher doses of inhaled ciclesonide do not adversely affect sensitive markers of bone turnover in persistent asthmatics over 12 months.

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

Background

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

Methods

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

Results

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

Conclusions

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

Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone.

The risk for AS can be minimized through increased awareness and early recognition of at-risk patients, regular patient follow-up to ensure that the lowest effective ICS doses are being utilized to control asthma symptoms, and by choosing an ICS medication with minimal adrenal effects. Screening for AS should be considered in any child with symptoms of AS, children using high ICS doses, or those with a history of prolonged oral corticosteroid use. Cases of AS should be managed in consultation with a pediatric endocrinologist whenever possible. In patients with proven AS, stress steroid dosing during times of illness or surgery is needed to simulate the protective endogenous elevations in cortisol levels that occur with physiological stress.

This article provides an overview of current literature on AS as well as practical recommendations for the prevention, screening and management of this serious complication of ICS therapy.

Targeting small airways, a step further in asthma management

INTRODUCTION

During the last decade, small airway (SA) involvement in asthma and Chronic Obstructive Pulmonary Disease (COPD) have reached increasing attention. Originally referred to as the 'silent zone', SA may not be that silent after all. Important clinical correlates are asthma exacerbations and airways remodelling, exercise asthma and nocturnal asthma. Thus, to control pathology in the SA has become a desirable goal in asthma management.

OBJECTIVES

The scope of this review is to give a brief overview of the current status on SA in asthma, how to monitor and to diagnose SA inflammation and finally highlight some important treatment strategies.

RESULTS/CONCLUSION

New tools have been developed to monitor SA function; these implies the use of imaging techniques and respiratory physiology, targeting SA function. Fractional exhaled nitric oxide and the combined use of hyperresponsiveness testing with impulsoscillometry is another option. The introduction of ultrafine aerosols has provided new tools for to treat SA inflammation. The challenge for the future will be to define the optimal particle size and device for maximal deposition in entire lung, including the small airways. Moreover, we also need strategies for increasing the therapeutic ratio, i.e. increasing lung deposition without increasing systemic side effects. Another challenge is to design and to perform clinical trials, targeting effects in SA, proving the clinical importance of SA treatment in a large number of patients. The latter also imply education of our medical authorities, communicating that asthma is more than a beta-2 agonist responsive central airway disorder of the lungs.

Hydrofluoroalkane-beclomethasone dipropionate effectively improves airway eosinophilic inflammation including the distal airways of patients with mild to moderate persistent asthma as compared with fluticasone propionate in a randomized open double-cross study

BACKGROUND

To evaluate whether hydrofluoroalkane-beclomethasone dipropionate (HFA-BDP) controls eosinophilic inflammation, including that in the distal airways, more effectively than fluticasone propionate (FP) Diskus.

METHODS

Fifty patients with well-controlled mild to moderate persistent asthma using FP for more than 6 months were randomly assigned to FP and HFA-BDP groups, and the treatment regimens of the two groups were switched twice between FP and HFA-BDP in a double cross-over manner at 3-month intervals after 2-week washout periods. Evidence of eosinophilic inflammation in blood and induced sputum samples was assessed, together with pulmonary function testing and an Asthma-related Quality of Life Questionnaire (AQLQ) survey after each treatment period.

RESULTS

The peripheral blood differential eosinophil count and sputum levels of eosinophil cationic protein (ECP) showed reciprocal changes during the study periods in both groups. The blood differential eosinophil count was significantly lower during the HFA-BDP than during the FP treatment period in both the FP (p = 0.004) and the HFA-BDP (p = 0.020) group. The late-phase induced sputum ECP level was significantly decreased during the HFA-BDP treatment period in both the FP (p = 0.016) and the HFA-BDP group (p = 0.023). The significant elevation of surfactant protein D values in the late-phase sputum observed in both groups indicated that late-phase sputum was obtained mainly from proximal peripheral airways. Both symptom and activity limitation domains of the AQLQ in the HFA-BDP group significantly increased after switching from FP to HFA-BDP. There were no significant changes in pulmonary function indices in either group at any time during the study.

CONCLUSIONS

HFA-BDP improved residual eosinophilic inflammation in asthmatic airways, including distal airways, more effectively than FP.

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

BACKGROUND

Inhaled corticosteroids (ICSs) are the most potent anti-inflammatory choice for patients with asthma. Selecting the most appropriate ICS for a patient requires a thorough understanding of the pharmacologic properties of each drug.

OBJECTIVE

This review details the pharmacologic properties of ciclesonide (CIC) and fluticasone propionate (FP) and reviews the available data on suppression of the hypothalamic-pituitary-adrenal axis as a measure of systemic exposure and safety profile.

METHODS

Clinical studies and case reports were identified through a MEDLINE and EMBASE search of English-language articles. The databases were searched for the years 1990 to April 2005 using the terms ciclesonide, fluticasone, ICS, and adrenal suppression. All studies were clinical trials of pharmacologic properties of the ICSs in humans.

RESULTS

A total of 1082 articles were identified. CIC and FP are 2 of the most potent ICSs. Both have high receptor-binding affinities (12 times and 18 times that of dexamethasone, respectively), and both may provide enhanced respiratory effects through a prolonged pulmonary residence time. The CIC metered dose inhaler dispenses smaller and more highly respirable particles than FP (1.1-2.1 pm vs 2.8-3.2 microm, respectively). Therefore, a greater percentage of administered CIC is topically deposited in the lungs (52% vs 12% to 13% for FP). CIC is delivered as an inactive parent compound, which is converted to its active metabolite, desisobutyryl-CIC (des-CIC), by esterases in the airways. More than 50% of a dose of CIC is deposited and distributed evenly throughout the lungs of healthy adults; lipid conjugation in the lung also may increase lung residence time. On entering the systemic circulation, both corticosteroids are rapidly cleared by the liver (elimination half-life of 3.5 hours for CIC vs 7.8 hours for FP). However, plasma protein binding is greater with CIC/des-CIC (99%/ approximately 99%) than FP (90%), resulting in reduced amounts of des-CIC (<I%) versus FP (10%) circulating free in the plasma. Although studies of low or medium doses of FP have produced conflicting results, high doses of FP (>660 pg/d) may result in adrenal suppression. CIC has not been reported to produce any significant adrenal suppression throughout its studied dose range (up to 1280 micro/d).

CONCLUSIONS

A review of the literature suggests that CIC, as compared with FP, achieves greater pulmonary deposition, causes fewer adverse oropharyngeal effects, deposits less biologically active drug in the systemic circulation, and has less potential for adrenal suppression.

Effects of long-term inhaled corticosteroids on adrenal function in patients with asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are effective asthma controllers, but long-term use could lead to adverse effects.

OBJECTIVE

To examine adrenal responsiveness of patients with persistent asthma treated with long-term ICSs.

METHODS

Morning plasma cortisol levels before and 30 minutes after adrenocorticotropic hormone (ACTH) (1 microg intravenously) stimulation were compared. Primary end points included mean prestimulation and poststimulation cortisol levels; secondary end points included morning cortisol level of 5 microg/dL or less, post-ACTH stimulation cortisol level of 18 microg/dL or less, and/or a net change of 7 microg/dL or less from baseline.

RESULTS

A total of 103 asthmatic patients (29 in the triamcinolone acetonide group, 18 in the flunisolide group, 45 in the fluticasone propionate group, and 11 in the oral corticosteroids group [positive controls]) completed the study. Mean daily ICS doses and durations were as follows: triamcinolone acetonide: 448 microg for 36 months; flunisolide: 1,181 microg for 41 months; and fluticasone propionate: 745 microg for 19 months. Eleven of 30 patients taking high-dose ICSs (10 of 28 taking fluticasone propionate and 1 of 2 taking flunisolide) had both low morning cortisol levels and abnormal post-ACTH stimulation cortisol levels. Few patients taking lower doses of any ICS had abnormal results.

CONCLUSIONS

Patients who require long-term treatment with high-dose ICSs may have abnormal morning plasma cortisol levels and reduced responsiveness to ACTH stimulation. Careful monitoring of adrenal function should be considered in such patients.

Pharmacokinetic and pharmacodynamic properties of inhaled beclometasone dipropionate delivered via hydrofluoroalkane-containing devices

Inhaled corticosteroids have a key role in the treatment of asthma and chronic obstructive pulmonary disease. In recent times, beclometasone dipropionate has been reformulated in pressurised metered dose inhalers (pMDIs), using hydrofluoroalkanes (HFAs) as a propellant. Extensive toxicological testing has shown that HFA-propellants are well tolerated. Among the reformulated beclometasone dipropionate-containing pMDIs, only the characteristics of the two Qvar formulations have been thoroughly explored. Compared to the reference beclometasone dipropionate formulation, the mass median aerodynamic diameter of the Qvar formulations are substantially smaller (1.1 vs 4.0 microm), whereas that of Modulite averages 2.6 microm. Scintigraphic and pharmacokinetic studies indicate a higher lung deposition for both the Qvar and the Beclazone formulations, compared with reference beclometasone dipropionate formulation. Since the 2- to 3-fold increase in pulmonary deposition results in a 2.6- to 3-fold difference in relative efficacy for Qvar, half the dose of the reference beclometasone dipropionate formulation has been currently recommended in adult patients with asthma, a recommendation that is supported by a large number of clinical trials. Conversely, the design of the studies conducted to compare the efficacy of Qvar with fluticasone propionate and budesonide does not allow establishing their equivalence on a milligram per milligram basis. Good studies on the bioequivalence between the reference beclometasone dipropionate formulation and the Modulite or Beclazone formulations are not available.

Ciclesonide, a novel inhaled steroid, does not affect hypothalamic-pituitary-adrenal axis function in patients with moderate-to-severe persistent asthma

BACKGROUND

Inhaled corticosteroids (ICSs) reduce local airway inflammation, which is an underlying cause of asthma symptoms. However, potential systemic side effects associated with ICS use are a major concern for asthmatic patients.

METHODS

Adult patients (n = 60; > or = 18 years of age) with moderate-to-severe asthma were randomized to receive 4 weeks of treatment with ciclesonide (CIC), 320 microg bid (CIC 640), CIC, 640 microg bid (CIC 1280), fluticasone propionate (FP), 440 microg bid (FP 880), FP 880 microg bid (FP 1760), or placebo (PBO) [all doses expressed as ex-actuator; comparable to ex-valve doses of 800 and 1,600 microg/d for CIC and 1,000 and 2,000 microg/d for FP, respectively].

RESULTS

After 29 days of treatment, CIC 640, CIC 1280, and FP 880 had no significant effect on the mean serum cortisol area under the curve for 0 to 24 h (AUC0-24h). FP 1760 produced a statistically significant suppression in mean serum cortisol AUC0-24h compared to PBO (p = 0.0009; 95% confidence interval [CI] -117.5 [corrected] to -32.1). Results obtained with cosyntropin stimulation revealed no statistically significant differences among the groups. The CIC 640 group demonstrated a significant increase compared to the PBO group in 24-h urinary cortisol levels from baseline at week 4 (p = 0.0224; 95% CI, 0.0023 to 0.0283), while the other treatment groups revealed no change in this parameter. The incidence of treatment-emergent adverse events was similar in all groups, and all adverse events were mild or moderate in severity.

CONCLUSION

Treatment with moderate and high doses of CIC does not result in hypothalamic-pituitary-adrenal-axis suppression as compared with PBO.

Effects of mometasone furoate dry powder inhaler and beclomethasone dipropionate hydrofluoroalkane and chlorofluorocarbon on the hypothalamic-pituitary-adrenal axis in asthmatic subjects

STUDY OBJECTIVES

Mometasone furoate dry powder inhaler (MF-DPI) [400 mug] is an inhaled corticosteroid (ICS) that is effective in the treatment of asthma. MF-DPI has a low potential for suppression of the hypothalamic-pituitary-adrenal (HPA) axis at its clinical dose. The effect of MF-DPI, 400 microg qd, on the HPA axis was compared to that of beclomethasone dipropionate (BDP) using hydrofluoroalkane (HFA) and chlorofluorocarbon (CFC) propellants via metered-dose inhalers (MDIs) twice daily.

DESIGN AND INTERVENTIONS

This randomized, third-party blind, parallel-group study compared the effects of MF-DPI 400 mug one puff qd in the morning (n = 18), HFA-BDP 200 microg two puffs MDI bid (n = 18), and CFC-BDP 400 microg two puffs MDI bid (n = 17) for 14 days on the area under the 24-h serum cortisol concentrations curve (AUC(0-24)) and on total 24-h urinary free cortisol excretion in mild asthmatic subjects. Effects on morning/evening peak expiratory flow (PEF) and on inhaled albuterol use were also assessed. Adverse events that occurred during or > or = 30 days after the study were recorded.

RESULTS

The mean decrease from baseline in the serum cortisol concentrations AUC(0-24) in the MF-DPI group was significantly less than in either the HFA-BDP (p = 0.024) or the CFC-BDP (p = 0.011) groups. Decreases in serum cortisol concentrations AUC(0-24) in the two BDP groups did not differ from one another. The MF-DPI group trended toward higher morning and evening PEF than either BDP group. Treatment-associated adverse events were reported by seven subjects in the MF-DPI group, vs one subject in the HFA-BDP and three subjects in the CFC-BDP groups; these were mild, and no subject discontinued treatment due to an adverse event.

CONCLUSIONS

Fourteen days of treatment with MF-DPI 400 microg qd was associated with a significantly lesser decrease in the serum cortisol concentrations AUC(0-24) compared with HFA-BDP 200 microg MDI or CFC-BDP 400 microg MDI bid.

Adrenal Suppression with Dry Powder Formulations of Fluticasone Propionate and Mometasone Furoate

Mometasone furoate (MF) and fluticasone propionate (FP) are high potency inhaled corticosteroids. The systemic bioavailability of MF is claimed to be negligible, leading to a minimal potential for systemic adverse effects. We assessed the overnight urinary cortisol/creatinine as the primary outcome of adrenal suppression in 21 patients with persistent asthma (mean FEV1 = 91%). Patients were randomized in a crossover fashion to receive 2 weekly consecutive doubling incremental doses of either FP Accuhaler (500, 1,000, and 2,000 microg/day) or MF Twisthaler (400, 800, and 1,600 microg/day). For the 21 per protocol completed patients, there was significant suppression of overnight urinary cortisol/creatinine with high and medium doses of both drugs-as geometric mean fold suppression (95% confidence interval) from baseline: FP 2,000 microg, 1.85 (1.21-2.82, p = 0.002); FP 1,000 microg, 1.45 (1.07-1.96, p = 0.02); MF 1,600 microg, 1.92 (1.26-2.93, p = 0.001); and MF 800 microg, 1.39 (1.04-1.88, p = 0.02). For secondary outcomes of 8:00 A.M. plasma cortisol, serum osteocalcin, and early morning urinary cortisol/creatinine, there was significant suppression with MF and FP at the highest dose. Our data refute the assertion that MF has negligible systemic bioavailability and a lower potential for systemic adverse effects compared with FP.

Sub-Micrometer Particle Production by Pressurized Metered Dose Inhalers

Evidence from both the air pollution and inhaled aerosol therapy fields suggests that the physiological impact of fine and ultrafine aerosols (defined as those below 1000 and 100 nm aerodynamic diameter, respectively) may be greater than their mass or volume of active agent alone might suggest. Traditionally, Andersen impactors and liquid impingers have been used for the sizing of particles produced by pressurized metered dose inhalers (pMDIs). However, these fail adequately to size particles in the ultrafine range (<100 nm aerodynamic diameter). In this paper, we report on a method of sizing pMDI particles down to 10 nm, using an electrical low pressure impactor (size range 30 nm to 10 microm) and a scanning mobility particle sizer (size range 3-150 nm). A range of pMDI drug formulations were assessed, including Flixotide (HFA-fluticasone propionate, GSK [Glaxo Smith Klein]), Salbulin (HFA-salbutamol sulphate, 3M), Qvar (HFA-beclomethasone dipropionate, 3M), Ventolin (HFA-salbutamol sulphate, GSK), Atrovent Forte (CFC-ipratropium bromide, Boehringer Ingelheim), Becotide (CFC-beclomethasone dipropionate, GSK), Pulmicort (CFC-budesonide, Astra Zeneca), and Serevent (CFC-Salmeterol xinafoate, GSK). All devices yielded high numbers of fine and ultrafine particles, with number median aerodynamic diameters (NMAD) of Qvar 68 nm, Becotide 73 nm, Salbulin 85 nm, and Pulmicort 89 nm, and %<100 nm Qvar 76%, Becotide 65%, Salbulin 61%, and Pulmicort 60%. We found a general trend of HFA-propelled pMDIs to produce smaller particles than the CFC units, but this trend was not statistically significant. These findings support previous published work, which suggests that significant bioactivity of pMDIs may reside in the ultrafine fraction.

Safety of the newer inhaled corticosteroids in childhood asthma

Inhaled corticosteroids (ICS) remain a vital part of the management of persistent asthma, but concerns have been raised about their potential adverse effects in children. This review examines the safety data on three new ICS - fluticasone propionate, mometasone, and extrafine beclomethasone in hydrofluoroalkane (HFA-134a) propellant (QVAR The use of tradenames is for product identification purposes only and does not imply endorsement. formulation) in relation to the older corticosteroids. Topical adverse effects such as thrush and dysphonia are rare, but dental erosion is a possibility with powder forms of ICS because of their low pH. Thus, it is important to stress mouth rinsing after administration and maintaining good dental hygiene to minimize this risk. Biochemical adrenal suppression can be readily demonstrated, particularly with high doses of all ICS. The clinical relevance of this was uncertain in the past, but there have now been >50 reported cases of acute adrenal crises in children receiving ICS, most of whom were on fluticasone propionate. In order to minimize the risk of symptomatic adrenal suppression, it is important to back-titrate the ICS dose and alert families of children receiving high-dose ICS of this potential adverse effect. A pediatric endocrine opinion should be sought if adrenal suppression is suspected. The older ICS cause temporary slowing of growth velocity, but the limited data available do not show any significant compromise of final adult height. The effect on growth of fluticasone propionate may not be as great as with the older ICS, but the studies have been short term and only used low doses of fluticasone propionate. There have been case reports of growth suppression in children receiving high doses of fluticasone propionate. The limited studies performed on the effect of ICS on bone mineral density in children did not show any adverse effects, but there may be an increased risk of fractures. Hydrofluoroalkane beclomethasone (QVAR) is essentially the same drug as chlorofluorocarbon beclomethasone, but with double the lung deposition owing to the smaller particle size. Thus, it could be expected that any adverse effects seen with chlorofluorocarbon beclomethasone would be the same with hydrofluoroalkane beclomethasone. However, some of the published data, particularly in adults, suggest that hydrofluoroalkane beclomethasone may be less systemically active than chlorofluorocarbon beclomethasone, even at equipotent doses. As yet, there are no long-term data on mometasone, but initial studies in adults suggest there may be less suppression of the hypothalamic-pituitary-adrenal axis, although further studies are required, particularly in children.ICS will remain a cornerstone in the management of persistent pediatric asthma, provided that the diagnosis of asthma is secure. It is very important to use ICS appropriately and to ensure the lowest possible doses are used to achieve symptom control, thus minimizing the risk of serious adverse effects.

A novel specific bioassay for the determination of glucocorticoid bioavailability in human serum

OBJECTIVE

Some patients develop side-effects even on relatively low doses of topically administered glucocorticoids (GCs), while others appear to be less sensitive to GCs. We have developed and validated a bioassay which can measure glucocorticoid bioavailability directly from small amounts of human serum to help elucidate underlying mechanisms.

METHODS

We have stably transfected the human embryonic kidney cell line HEK293 with a plasmid expressing the glucocorticoid receptor, and a plasmid containing the luciferase gene preceded by three concatenated steroid response elements, bringing luciferase expression under control of the liganded glucocorticoid receptor.

RESULTS

The assay, with an intra- and interassay coefficient of variance (CV) better than 10%, showed the expected difference in potency between different GCs (fluticasone propionate > budesonide > dexamethasone > hydrocortisone). No cross-reactivity was detected with other steroid hormones such as progesterone, testosterone and oestradiol. The bioassay easily detects the rise and subsequent fall of bioavailable GCs in human serum following ingestion of only 0.5 mg dexamethasone, and clearly reflects the diurnal cortisol rhythm. Moreover, systemic availability following inhalation of 2 x 250 micro g fluticasone propionate using a pressure dose inhaler could be demonstrated.

CONCLUSIONS

This assay can be used to determine levels of bioavailable GCs in serum, both endogenous and administered, and thus may help in optimizing treatment regimens. The small amount of serum needed to perform an analysis makes this assay applicable even to infants.

Dose response and therapeutic index of inhaled corticosteroids in asthma

Inhaled glucocorticoids play an indispensable role in the therapy of asthma. Development of new compounds was initially directed to increase the potency of the individual corticosteroid; thereafter, pharmacokinetic characteristics were modified to reduce unwanted systemic effects. Target of the present development is to attain compounds with the most favorable risk-to-benefit ratios. Since then, there has been substantial discussion about how to rank and weigh the different glucocorticoids. This article provides an evaluation of the relevant clinical studies published between May 2001 and June 2002, identifying the main determinants of the therapeutic value of inhaled glucocorticoids.

Airway and systemic effects of hydrofluoroalkane fluticasone and beclomethasone in patients with asthma

BACKGROUND

With the transition to hydrofluoroalkane-134a propellants in metered dose inhalers, it is important to consider the efficacy and safety profiles of formulations containing inhaled corticosteroids. We examined the airway and systemic effects of hydrofluoroalkane-134a fluticasone propionate (FLU-HFA) and beclomethasone dipropionate (BEC-HFA) at recommended labelled doses.

METHODS

Twenty mild to moderate asthmatics were randomised in crossover fashion to receive 6 weeks of 500 micro g/day followed by 1000 micro g/day FLU-HFA and BEC-HFA. Measurements were made at baseline after placebo run in and washout, and after each randomised treatment. The primary airway outcome for benefit was the dose of methacholine provoking a fall in forced expiratory volume in 1 second (FEV(1)) of 20% or more (methacholine PD(20)) and for systemic adverse effects was overnight urinary cortisol/creatinine (OUCC).

RESULTS

For mean responses, both doses of BEC-HFA and FLU-HFA produced significant improvements in PD(20) compared with baseline. The improvement was not significantly greater with 1000 micro g/day FLU-HFA versus BEC-HFA, a 1.69 fold difference (95% CI 0.94 to 3.04). Both doses of BEC-HFA but not FLU-HFA caused significant suppression of OUCC compared with baseline, with significantly (p<0.05) lower values at 1000 micro g/day for BEC-HFA versus FLU-HFA (1.97 fold difference (95% CI 1.28 to 3.02)).

CONCLUSION

There was no difference in the airway and systemic effects in patients with mild to moderate asthma between FLU-HFA and BEC-HFA at a dose of 500 micro g/day. At 1000 micro g/day there was increased systemic bioactivity with BEC-HFA compared with FLU-HFA, without any gain in airway efficacy.