Lung deposition and systemic availability of fluticasone Diskus and budesonide Turbuhaler in children

A novel approach to improve detection of glucocorticoid doping in sport with new guidance for physicians prescribing for athletes

The systemic effect of glucocorticoids (GCs) following injectable routes of administration presents a potential risk to both improving performance and causing harm to health in athletes. This review evaluates the current GC antidoping regulations defined by the World Anti-Doping Agency and presents a novel approach for defining permitted and prohibited use of glucocorticoids in sport based on the pharmacological potential for performance enhancement (PE) and risk of adverse effects on health. Known performance-enhancing doses of glucocorticoids are expressed in terms of cortisol-equivalent doses and thereby the dose associated with a high potential for PE for any GC and route of administration can be derived. Consequently, revised and substance-specific laboratory reporting values are presented to better distinguish between prohibited and permitted use in sport. In addition, washout periods are presented to enable clinicians to prescribe glucocorticoids safely and to avoid the risk of athletes testing positive for a doping test.

Lung Deposition and Inspiratory Flow Rate in Patients with Chronic Obstructive Pulmonary Disease Using Different Inhalation Devices: A Systematic Literature Review and Expert Opinion

BACKGROUND

Our aim was to describe: 1) lung deposition and inspiratory flow rate; 2) main characteristics of inhaler devices in chronic obstructive pulmonary disease (COPD).

METHODS

A systematic literature review (SLR) was conducted to analyze the features and results of inhaler devices in COPD patients. These devices included pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), and a soft mist inhaler (SMI). Inclusion and exclusion criteria were established, as well as search strategies (Medline, Embase, and the Cochrane Library up to April 2019). In vitro and in vivo studies were included. Two reviewers selected articles, collected and analyzed data independently. Narrative searches complemented the SLR. We discussed the results of the reviews in a nominal group meeting and agreed on various general principles and recommendations.

RESULTS

The SLR included 71 articles, some were of low-moderate quality, and there was great variability regarding populations and outcomes. Lung deposition rates varied across devices: 8%-53% for pMDIs, 7%-69% for DPIs, and 39%-67% for the SMI. The aerosol exit velocity was high with pMDIs (more than 3 m/s), while it is much slower (0.84-0.72 m/s) with the SMI. In general, pMDIs produce large-sized particles (1.22-8 μm), DPIs produce medium-sized particles (1.8-4.8 µm), and 60% of the particles reach an aerodynamic diameter <5 μm with the SMI. All inhalation devices reach central and peripheral lung regions, but the SMI distribution pattern might be better compared with pMDIs. DPIs' intrinsic resistance is higher than that of pMDIs and SMI, which are relatively similar and low. Depending on the DPI, the minimum flow inspiratory rate required was 30 L/min. pMDIs and SMI did not require a high inspiratory flow rate.

CONCLUSION

Lung deposition and inspiratory flow rate are key factors when selecting an inhalation device in COPD patients.

Adrenal function in cystic fibrosis

Cystic fibrosis (CF) is not known to directly affect the adrenal gland, but commonly used CF therapies do impact the function of the hypothalamic-pituitary-adrenal (HPA) axis. By binding to the glucocorticoid receptor, medications such as inhaled and oral corticosteroids can enhance the systemic effects of cortisol and result in iatrogenic Cushing syndrome. Prolonged use suppresses the body's ability to make cortisol, resulting in iatrogenic adrenal insufficiency upon medication discontinuation. Chronic use of inhaled and oral corticosteroids can negatively affect bone health, growth, and glucose metabolism. This chapter provides practical guidelines regarding the screening, diagnosis, and treatment of iatrogenic adrenal insufficiency. As the guidelines are mainly derived from the asthma literature, this chapter also highlights the need for studies to evaluate the impact of CF therapies on adrenal function and other CF-endocrinopathies.

Therapeutic index of inhaled corticosteroids in asthma: A dose-response comparison on airway hyperresponsiveness and adrenal axis suppression

Aims

To compare the airway potency, systemic activity and therapeutic index of three inhaled corticosteroids that differ in glucocorticoid receptor binding affinity, physicochemical and pharmacokinetic properties.

Methods

This escalating‐dose, placebo‐controlled, cross‐over study randomised adults with asthma to 1 or 2 treatment periods with ≥25 days washout in‐between. Each treatment period comprised five 7‐day dose escalations (μg/d): fluticasone furoate (FF; 25 → 100 → 200 → 400 → 800), fluticasone propionate (FP; 50 → 200 → 500 → 1000 → 2000), budesonide (BUD; 100 → 400 → 800 → 1600 → 3200) or placebo. Airway hyperresponsiveness to adenosine‐5'‐monophosphate (AMP PC₂₀) was assessed on day 8. Plasma cortisol was assessed on day 1 (predose baseline) and from pre‐PM dose on day 6 to pre‐PM dose day 7 (24‐h weighted mean).

Results

Fifty‐four subjects were randomised. FF showed greater airway potency than FP and BUD (AMP PC₂₀ dose at which 50% of the maximum effect is achieved [ED₅₀] values: 48.52, 1081.27 and 1467.36 μg/d, respectively). Systemic activity (cortisol suppression) ED₅₀ values were 899.99, 1986.05 and 1927.42 μg/d, respectively. The therapeutic index (ED₅₀ cortisol suppression/ED₅₀ AMP PC₂₀) was wider for FF (18.55) than FP (1.84) and BUD (1.31). FF 100 μg/d and 200 μg/d were both comparable in terms of airway potency with high doses of FP (≥1000 μg twice daily [BID]) and BUD (≥1500 μg/BID). The systemic activity of FF 100 μg/d and 200 μg/d (cortisol suppression: 7.41% and 14.28%, respectively) was comparable with low doses of FP (100 μg/BID and 250 μg/BID) and BUD (100 μg/BID and 200 μg/BID).

Conclusion

This study provides evidence that FF can provide more protection against airway hyperresponsiveness, with less systemic activity, than FP or BUD. This suggests that all inhaled corticosteroids are not therapeutically similar and may differ in their therapeutic index. (203162; NCT02991859).

Inhalation devices, delivery systems, and patient technique

BACKGROUND

In real-life clinical settings, physicians often consider the properties of various inhaled corticosteroids (ICSs), but typically little consideration is given to the properties of different inhalers and formulations.

OBJECTIVE

To discuss the effects of inhalation devices and user technique on efficacy, safety, and adherence with the aim of improving asthma management.

METHODS

Relevant publications were selected to augment discussion.

RESULTS

There are many types of devices available, each with advantages, disadvantages, ease of use, and rate of misuse. Aerosol particle size influences the deposition pattern of a drug in the lungs, and the optimal particle size range is 1 to 5 μm. Retrospective reviews suggest that smaller particles (1-2 μm) could provide improved asthma control, but randomized, prospective studies are needed. Multiple studies have demonstrated high misuse rates in patients for pressurized metered-dose inhalers and dry powder inhalers. Because of this, repeated education should include physical demonstrations of using the device, checking the patient's technique, correcting the technique, and rechecking the technique. This also means that dedicated, trained staff and placebo devices should be available for instructing patients. Furthermore, the device should be selected to be cost effective and to fit the patient's preference and ability to use it correctly to enhance compliance. Asthma management guidelines and algorithms are available to guide the clinician.

CONCLUSION

The choice of inhaler device should depend on cost effectiveness and the patient's preference and ability to use it correctly. Patient inhaler technique should be checked and, if necessary, corrected and rechecked, with retraining if needed, at every opportunity.

Performance of Turbuhaler((R)) in Patients with Acute Airway Obstruction and COPD, and in Children with Asthma : Understanding the Clinical Importance of Adequate Peak Inspiratory Flow, High Lung Deposition, and Low In Vivo Dose Variability

The dry-powder inhaler (DPI) Turbuhaler((R)) has been on the market for nearly two decades. Products containing terbutaline, formoterol, budesonide, and the combination budesonide/formoterol are widely used by patients with asthma and COPD. Most patients and physicians find Turbuhaler((R)) easy to use, and local side effects are rare. This is thought to arise from the lack of additives or only small amounts in the formulation, in addition to minimal deposition of the drug in the oropharynx and on the vocal cords during inspiration.The function of Turbuhaler((R)) has frequently been questioned. This article aims to review and clarify some key issues that have been challenged in the literature (e.g. the effectiveness of Turbuhaler((R)) in patients with more restricting conditions), to discuss the importance of lung deposition, and to explain the low in vivo variability associated with Turbuhaler((R)) and the lack of correlation with the higher in vitro variability.Turbuhaler((R)), like other DPIs, is flow dependent to some degree. However, a peak inspiratory flow (PIF) through Turbuhaler((R)) of 30 L/min gives a good clinical effect. These PIF values can be obtained by patients with conditions thought to be difficult to manage with inhalational agents, such as asthmatic children and adult patients with acute severe airway obstruction and COPD. Excellent clinical results with Turbuhaler((R)) in large controlled studies in patients with COPD and acute severe airway obstruction provide indirect evidence that medication delivered via Turbuhaler((R)) reaches the target organ.Due to the large amount of small particles and the moderate inbuilt resistance in Turbuhaler((R)), which opens up the vocal cords during inhalation, Turbuhaler((R)) is associated with a high lung deposition (25-40% of the delivered dose) compared with pressurized metered-dose inhalers (pMDIs) and other DPIs. A good correlation has been found between lung deposition and clinical efficacy. A high lung deposition always results in the best ratio between clinical efficacy and risk of unwanted systemic activity. Studies with Turbuhaler((R)) also show that the in vivo variation in lung deposition is significantly lower compared with a pMDI or, for example, the Diskus((R)) inhaler, and much lower than the in vitro dose variability seen in laboratory tests. Turbuhaler((R)) appears to be a reliable DPI which can be used with confidence by patients with airway diseases, including those with clinical conditions believed to be difficult to manage with inhalational therapy.

Inhaled corticosteroids: potency, dose equivalence and therapeutic index

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

Inhaled corticosteroids in children with persistent asthma: dose-response effects on growth

BACKGROUND

Inhaled corticosteroids (ICS) are the first-line treatment for children with persistent asthma. Their potential for growth suppression remains a matter of concern for parents and physicians.

OBJECTIVES

To assess whether increasing the dose of ICS is associated with slower linear growth, weight gain and skeletal maturation in children with asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov website up to March 2014.

SELECTION CRITERIA

Studies were eligible if they were parallel-group randomised trials evaluating the impact of different doses of the same ICS using the same device in both groups for a minimum of three months in children one to 17 years of age with persistent asthma.

DATA COLLECTION AND ANALYSIS

Two review authors ascertained methodological quality independently using the Cochrane Risk of bias tool. The primary outcome was linear growth velocity. Secondary outcomes included change over time in growth velocity, height, weight, body mass index and skeletal maturation.

MAIN RESULTS

Among 22 eligible trials, 17 group comparisons were derived from 10 trials (3394 children with mild to moderate asthma), measured growth and contributed data to the meta-analysis. Trials used ICS (beclomethasone, budesonide, ciclesonide, fluticasone or mometasone) as monotherapy or as combination therapy with a long-acting beta2 -agonist and generally compared low (50 to 100 μg) versus low to medium (200 μg) doses of hydrofluoroalkane (HFA)-beclomethasone equivalent over 12 to 52 weeks. In the four comparisons reporting linear growth over 12 months, a significant group difference was observed, clearly indicating lower growth velocity in the higher ICS dose group of 5.74 cm/y compared with 5.94 cm/y on lower-dose ICS (N = 728 school-aged children; mean difference (MD)0.20 cm/y, 95% confidence interval (CI) 0.02 to 0.39; high-quality evidence): No statistically significant heterogeneity was noted between trials contributing data. The ICS molecules (ciclesonide, fluticasone, mometasone) used in these four comparisons did not significantly influence the magnitude of effect (X(2) = 2.19 (2 df), P value 0.33). Subgroup analyses on age, baseline severity of airway obstruction, ICS dose and concomitant use of non-steroidal antiasthmatic drugs were not performed because of similarity across trials or inadequate reporting. A statistically significant group difference was noted in unadjusted change in height from zero to three months (nine comparisons; N = 944 children; MD 0.15, 95% CI -0.28 to -0.02; moderate-quality evidence) in favour of a higher ICS dose. No statistically significant group differences in change in height were observed at other time points, nor were such differences in weight, bone mass index and skeletal maturation reported with low quality of evidence due to imprecision.

AUTHORS' CONCLUSIONS

In prepubescent school-aged children with mild to moderate persistent asthma, a small but statistically significant group difference in growth velocity was observed between low doses of ICS and low to medium doses of HFA-beclomethasone equivalent, favouring the use of low-dose ICS. No apparent difference in the magnitude of effect was associated with three molecules reporting one-year growth velocity, namely, mometasone, ciclesonide and fluticasone. In view of prevailing parents' and physicians' concerns about the growth suppressive effect of ICS, lack of or incomplete reporting of growth velocity in more than 86% (19/22) of eligible paediatric trials, including those using beclomethasone and budesonide, is a matter of concern. All future paediatric trials comparing different doses of ICS with or without placebo should systematically document growth. Findings support use of the minimal effective ICS dose in children with asthma.

PLAIN LANGUAGE SUMMARY

Does altering the dose of inhaled corticosteroids make a difference in growth among children with asthma?

BACKGROUND

Asthma guidelines recommend inhaled corticosteroids (ICS) as the first choice of treatment for children with persistent asthma that is not well controlled when only a reliever inhaler is used to treat symptoms. Steroids work by reducing inflammation in the lungs and are known to control underlying symptoms of asthma. However, parents and physicians remain concerned about the potential negative effect of ICS on growth.

REVIEW QUESTION

Does altering the dose of inhaled corticosteroids make a difference in the growth of children with asthma? WHAT EVIDENCE DID WE FIND?: We studied whether a difference could be seen in the growth of children with persistent asthma who were using different doses of the same ICS molecule and the same delivery device. We found 22 eligible trials, but only 10 of them measured growth or other measures of interest. Overall, 3394 children included in the review combined 17 group comparisons (i.e. 17 groups of children with mild to moderate asthma using a particular dose and type of steroid in 10 trials). Trials used different ICS molecules (beclomethasone, budesonide, ciclesonide, fluticasone or mometasone) either on their own or in combination with a long-acting beta2 -agonist (a drug used to open up the airways) and generally compared low doses of corticosteroids (50 to 100 μg) with low to medium (200 μg) doses of corticosteroids (converted in μg HFA-beclomethasone equivalent) over 12 to 52 weeks.

RESULTS

We found a small but statistically significant group difference in growth over 12 months between these different doses clearly favouring the lower dose of ICS. The type of corticosteroid among newer molecules (ciclesonide, fluticasone, mometasone) did not seem to influence the impact on growth over one year. Differences in corticosteroid doses did not seem to affect the change in height, the gain in weight, the gain in bone mass index and the maturation of bones. QUALITY OF THE EVIDENCE: This review is based on a small number of trials that reported data and were conducted on children with mild to moderate asthma. Only 10 of 22 studies measured the few outcomes of interest for this review, and only four comparisons reported growth over 12 months. Our confidence in the quality of evidence is high for this outcome, however it is low to moderate for several other outcomes, depending on the number of trials reporting these outcomes. Moreover, a few outcomes were reported only by a single trial; as these findings have not been confirmed by other trials, we downgraded the evidence for these outcomes to low quality. An insufficient number of trials have compared the effect of a larger difference in dose, for example, between a high dose and a low dose of ICS and of other popular molecules such as budesonide and beclomethasone over a year or longer of treatment.

CONCLUSIONS

We report an evidence-based ICS dose-dependent reduction in growth velocity in prepubescent school-aged children with mild to moderate persistent asthma. The choice of ICS molecule (mometasone, ciclesonide or fluticasone) was not found to affect the level of growth velocity response over a year. The effect of corticosteroids on growth was not consistently reported: among 22 eligible trials, only four comparisons reported the effects of corticosteroids on growth over one year. In view of parents' and clinicians' concerns, lack of or incomplete reporting of growth is a matter of concern given the importance of the topic. We recommend that growth be systematically reported in all trials involving children taking ICS for three months or longer. Until further data comparing low versus high ICS dose and trials of longer duration are available, we recommend that the minimal effective ICS dose be used in all children with asthma.

Which factors affect the choice of the inhaler in chronic obstructive respiratory diseases?

Inhalation is the preferred route of drug administration in chronic respiratory diseases because it optimises delivery of the active compounds to the targeted site and minimises side effects from systemic distribution. The choice of a device should be made after careful evaluation of the patient's clinical condition (degree of airway obstruction, comorbidities), as well as their ability to coordinate the inhalation manoeuvre and to generate sufficient inspiratory flow. These patient factors must be aligned with the specific advantages and limitations of each inhaler when making this important choice. Finally, adherence to treatment is not the responsibility of the patient alone, but should be shared also by clinicians. Clinicians have access to a wide selection of pressurised metered dose inhalers (pMDIs) and dry powder inhalers (DPIs) that can be used effectively when matched to the needs of individual patients; this should be perceived as an opportunity rather than a limitation.

How to match the optimal currently available inhaler device to an individual child with asthma or recurrent wheeze

Inhaled medications are the cornerstone of treatment in early childhood wheezing and paediatric asthma. A match between patient and device and a correct inhalation technique are crucial for good asthma control. The aim of this paper is to propose an inhaler strategy that will facilitate an inhaler choice most likely to benefit different groups of children. The main focus will be on pressurised metered dose inhalers and dry powder inhalers. In this paper we will discuss (1) practical difficulties with the devices and with inhaled therapy and (2) the optimal location for deposition of medicines in the lungs, and (3) we will propose a practical and easy way to make the best match between the inhaler device and the individual patient. We hope that this paper will contribute to an increased likelihood of treatment success and improved adherence to therapy.

Inhaled corticosteroids in children with persistent asthma: dose-response effects on growth

BACKGROUND

Inhaled corticosteroids (ICS) are the first-line treatment for children with persistent asthma. Their potential for growth suppression remains a matter of concern for parents and physicians.

OBJECTIVES

To assess whether increasing the dose of ICS is associated with slower linear growth, weight gain and skeletal maturation in children with asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov website up to March 2014.

SELECTION CRITERIA

Studies were eligible if they were parallel-group randomised trials evaluating the impact of different doses of the same ICS using the same device in both groups for a minimum of three months in children one to 17 years of age with persistent asthma.

DATA COLLECTION AND ANALYSIS

Two review authors ascertained methodological quality independently using the Cochrane Risk of bias tool. The primary outcome was linear growth velocity. Secondary outcomes included change over time in growth velocity, height, weight, body mass index and skeletal maturation.

MAIN RESULTS

Among 22 eligible trials, 17 group comparisons were derived from 10 trials (3394 children with mild to moderate asthma), measured growth and contributed data to the meta-analysis. Trials used ICS (beclomethasone, budesonide, ciclesonide, fluticasone or mometasone) as monotherapy or as combination therapy with a long-acting beta2-agonist and generally compared low (50 to 100 μg) versus low to medium (200 μg) doses of hydrofluoroalkane (HFA)-beclomethasone equivalent over 12 to 52 weeks. In the four comparisons reporting linear growth over 12 months, a significant group difference was observed, clearly indicating lower growth velocity in the higher ICS dose group of 5.74 cm/y compared with 5.94 cm/y on lower-dose ICS (N = 728 school-aged children; mean difference (MD)0.20 cm/y, 95% confidence interval (CI) 0.02 to 0.39; high-quality evidence): No statistically significant heterogeneity was noted between trials contributing data. The ICS molecules (ciclesonide, fluticasone, mometasone) used in these four comparisons did not significantly influence the magnitude of effect (X(2) = 2.19 (2 df), P value 0.33). Subgroup analyses on age, baseline severity of airway obstruction, ICS dose and concomitant use of non-steroidal antiasthmatic drugs were not performed because of similarity across trials or inadequate reporting. A statistically significant group difference was noted in unadjusted change in height from zero to three months (nine comparisons; N = 944 children; MD 0.15, 95% CI -0.28 to -0.02; moderate-quality evidence) in favour of a higher ICS dose. No statistically significant group differences in change in height were observed at other time points, nor were such differences in weight, bone mass index and skeletal maturation reported with low quality of evidence due to imprecision.

AUTHORS' CONCLUSIONS

In prepubescent school-aged children with mild to moderate persistent asthma, a small but statistically significant group difference in growth velocity was observed between low doses of ICS and low to medium doses of HFA-beclomethasone equivalent, favouring the use of low-dose ICS. No apparent difference in the magnitude of effect was associated with three molecules reporting one-year growth velocity, namely, mometasone, ciclesonide and fluticasone. In view of prevailing parents' and physicians' concerns about the growth suppressive effect of ICS, lack of or incomplete reporting of growth velocity in more than 86% (19/22) of eligible paediatric trials, including those using beclomethasone and budesonide, is a matter of concern. All future paediatric trials comparing different doses of ICS with or without placebo should systematically document growth. Findings support use of the minimal effective ICS dose in children with asthma.

The clinical relevance of dry powder inhaler performance for drug delivery

BACKGROUND

Although understanding of the scientific basis of aerosol therapy with dry powder inhalers (DPIs) has increased, some misconceptions still persist. These include the beliefs that high resistance inhalers are unsuitable for some patients, that extra fine (<1.0 μm) particles improve peripheral lung deposition and that inhalers with flow rate-independent fine particle fractions (FPFs) produce a more consistent delivered dose to the lungs.

OBJECTIVES

This article aims to clarify the complex inter-relationships between inhaler design and resistance, inspiratory flow rate (IFR), FPF, lung deposition and clinical outcomes, as a better understanding may result in a better choice of DPI for individual patients.

METHODS

The various factors that determine the delivery of drug particles into the lungs are reviewed. These include aerodynamic particle size distribution, the inspiratory manoeuvre, airway geometry and the three basic principles that determine the site and extent of deposition: inertial impaction, sedimentation and diffusion. DPIs are classed as either dependent or independent of inspiratory flow rate and vary in their internal resistance to inspiration. The effects of these characteristics on drug deposition in the airways are described using data from studies directly comparing currently available inhaler devices.

RESULTS

Clinical experience shows that most patients can use a high resistance DPI effectively, even during exacerbations. Particles in the aerodynamic size range from 1.5-5 μm are shown to be optimal, as particles <1.0 μm are very likely to be exhaled again while those >5 μm may impact on the oropharynx. For DPIs with a constant FPF at all flow rates, less of the delivered dose reaches the central and peripheral lung when the flow rate increases, risking under-dosing of the required medication. In contrast, flow rate-dependent inhalers increase their FPF output at higher flow rates, which compensates for the greater impaction on the upper airways as flow rate increases.

CONCLUSIONS

The technical characteristics of different inhalers and the delivery and deposition of the fine particle dose to the lungs may be important additional considerations to help the physician to select the most appropriate device for the individual patient to optimise their treatment.

Lung effects of inhaled corticosteroids in a rhesus monkey model of childhood asthma

BACKGROUND

The risks for infants and young children receiving inhaled corticosteroid (ICS) therapy are largely unknown. Recent clinical studies indicate that ICS therapy in pre-school children with symptoms of asthma result in decreased symptoms without influencing the clinical disease course, but potentially affect postnatal growth and development. The current study employs a primate experimental model to identify the risks posed by ICS therapy.

OBJECTIVE

To (1) establish whether ICS therapy in developing primate lungs reverses pulmonary pathobiology associated with allergic airway disease (AAD) and (2) define the impact of ICS on postnatal lung growth and development in primates.

METHODS

Infant rhesus monkeys were exposed, from 1 through 6 months, to filtered air (FA) with house dust mite allergen and ozone using a protocol that produces AAD (AAD monkeys), or to FA alone (Control monkeys). From three through 6 months, the monkeys were treated daily with ICS (budesonide) or saline.

RESULTS

Several AAD manifestations (airflow restrictions, lavage eosinophilia, basement membrane zone thickening, epithelial mucin composition) were reduced with ICS treatment, without adverse effects on body growth or adrenal function; however, airway branching abnormalities and intraepithelial innervation were not reduced. In addition, several indicators of postnatal lung growth and differentiation: vital capacity, inspiratory capacity, compliance, non-parenchymal lung volume and alveolarization, were increased in both AAD and Control monkeys that received ICS treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Incomplete prevention of pathobiological changes in the airways and disruption of postnatal growth and differentiation of airways and lung parenchyma in response to ICS pose risks for developing primate lungs. These responses also represent two mechanisms that could compromise ICS therapy's ability to alter clinical disease course in young children.

Age-dependent deterioration of peak inspiratory flow with two kinds of dry powder corticosteroid inhalers (Diskus and Turbuhaler) and relationships with asthma control

BACKGROUND

Inhaled corticosteroid (ICS) therapy has improved the quality of life (QOL) for many asthmatics and reduced mortality rates associated with asthma. However, some patients do not obtain therapeutic benefit despite satisfactory adherence.

OBJECTIVES

To determine whether asthmatic patients were using ICS devices appropriately, and to clarify relationships between these results and QOL.

SUBJECTS AND METHODS

We studied 100 adult asthmatics, divided into two groups: 50 patients consecutively registered as using Diskus (fluticasone; D-group) and 50 consecutively registered as using Turbuhaler (budesonide; T-group). We measured peak inspiratory flows (PIFs) using the In-Check Dial device. Subjects also completed the Asthma Control Test for evaluation of QOL.

RESULTS

In the D-group, no patients showed PIF below the optimal range (30-90 L/min), whereas 52% of patients had PIF≥91 L/min. In the T-group, 6% of patients showed PIF over the optimal range (60-90 L/min), and 44% had PIF≤59 L/min. When patients in the T-group were required to deliberately make a maximal inhalation, 14% still had PIF≤59 L/min. The proportion of patients with poor control was significantly greater in the T-group than in the D-group. According to univariate logistic regression analyses, low PIF tended to be associated with poor asthma control in the T-group. No significant correlation was found between PIF and age in the D-group, but PIF decreased significantly with age in the T-group.

CONCLUSIONS

Appropriate measures for patients in whom PIF has been judged as lower than optimal include adequate education for inhalation and/or changing to a different inhalation device. These measures should be kept in mind for elderly asthma patients in particular, where appropriate selection of a corticosteroid inhalation device in the early stages of therapy would also be important.

Effects of inhaled steroids on growth, bone metabolism and adrenal function

Inhaled corticosteroids are a first-line therapy for persistent asthma in children. Major safety concerns of long-term inhaled corticosteroid therapy include suppression of adrenal function, growth and bone development. Proper interpretation of inhaled corticosteroid safety studies requires knowledge of the differences among various inhaled corticosteroid drug/delivery device systems. Dosage, type of inhaler device used, patient technique and characteristics of the individual drug influence the systemic effects of inhaled corticosteroids. Systemic side effects can occur when continuous high-dose treatment is required for severe asthma or when the dosage prescribed is excessive and compliance unusually good. Overall, however, recent studies confirm that benefits of inhaled corticosteroids, properly prescribed and used, clearly outweigh not only their potential adverse effects, but also the risks associated with poorly controlled asthma.

The bioavailability and airway clearance of the steroid component of budesonide/formoterol and salmeterol/fluticasone after inhaled administration in patients with COPD and healthy subjects: a randomized controlled trial

Background

Airway absorption and bioavailability of inhaled corticosteroids (ICSs) may be influenced by differences in pharmacokinetic properties such as lipophilicity and patient characteristics such as lung function. This study aimed to further investigate and clarify the distribution of budesonide and fluticasone in patients with severe chronic obstructive pulmonary disease (COPD) by measuring the systemic availability and sputum concentration of budesonide and fluticasone, administered via combination inhalers with the respective long-acting β₂-agonists, formoterol and salmeterol.

Methods

This was a randomized, double-blind, double-dummy, two-way crossover, multicenter study. Following a run-in period, 28 patients with severe COPD (mean age 65 years, mean forced expiratory volume in 1 second [FEV₁] 37.5% predicted normal) and 27 healthy subjects (mean age 31 years, FEV₁ 103.3% predicted normal) received two single-dose treatments of budesonide/formoterol (400/12 μg) and salmeterol/fluticasone (50/500 μg), separated by a 4–14-day washout period. ICS concentrations were measured over 10 hours post-inhalation in plasma in all subjects, and over 6 hours in spontaneously expectorated sputum in COPD patients. The primary end point was the area under the curve (AUC) of budesonide and fluticasone plasma concentrations in COPD patients relative to healthy subjects.

Results

Mean plasma AUC values were lower in COPD patients versus healthy subjects for budesonide (3.07 μM·hr versus 6.21 μM·hr) and fluticasone (0.84 μM·hr versus 1.50 μM·hr), and the dose-adjusted AUC (geometric mean) ratios in healthy subjects and patients with severe COPD for plasma budesonide and fluticasone were similar (2.02 versus 1.80; primary end point). In COPD patients, the T_max and the mean residence time in the systemic circulation were shorter for budesonide versus fluticasone (15.5 min versus 50.8 min and 4.41 hrs versus 12.78 hrs, respectively) and C_max was higher (1.08 μM versus 0.09 μM). The amount of expectorated fluticasone (percentage of estimated lung-deposited dose) in sputum over 6 hours was significantly higher versus budesonide (ratio 5.21; p = 0.006). Both treatments were well tolerated.

Conclusion

The relative systemic availabilities of budesonide and fluticasone between patients with severe COPD and healthy subjects were similar. In patients with COPD, a larger fraction of fluticasone was expectorated in the sputum as compared with budesonide.

Trial registration

Trial registration number NCT00379028

Assessment methods of inhaled aerosols: technical aspects and applications

The pulmonary route has been used with success for the treatment of both lung (asthma) and systemic diseases (diabetes). The fate of an inhaled drug (absorption and deposition) within human lungs has great importance, particularly in drug development and quality control. This article focuses on the various methods that are now applied for aerosol fate investigation. Several assessment methods, ranging from in vitro assays (impaction and optical systems) to in vivo experiments (imaging and pharmacological methods), are described. In vitro assays measure particle size distribution and emitted drug dose, which could be predictive of lung deposition pattern in vivo. However, in vivo methods provide direct information about the concentration and the location of inhaled drug within lung. Advantages and limitations of the different techniques are identified. In addition to these experimental techniques, mathematical deposition models, elaborated in more realistic conditions and designed to predict the fate of inhaled particles, are also illustrated.

Dry powder inhalers (DPIs)--a review of device reliability and innovation

A wide range of dry powder inhaler (DPI) devices are currently available on the market to deliver drugs into lungs with a view to maximise drug delivery with low variability. DPIs also face numerous clinical challenges, particularly related to variable patient factors such as age, clinical condition and inspiratory flow. Due to the drug formulation and the design of devices, different DPIs do not show the same performance and manufacturers are taking a variety of device design approaches. The characteristics of an ideal DPI, recent innovations in powder formulation and device design are not universally reliable in terms of dose variability, clinical efficacy, user friendliness and economy. This mini review examines whether device reliability is more important than innovation. This study enables a comparison of the relative merits of optimising existing DPIs or seeking to develop novel devices.

Plasma concentrations of fluticasone propionate and budesonide following inhalation: effect of induced bronchoconstriction

AIMS

To determine whether and to what extent bronchoconstriction affects plasma concentrations of fluticasone and budesonide following inhalation.

METHODS

Twenty people with mild asthma inhaled 1000 microg fluticasone (Accuhaler) plus 800 microg budesonide (Turbohaler) on two visits. On one occasion, prior to drug inhalation, FEV(1) was decreased by at least 25% using inhaled methacholine. Plasma drug concentrations were measured for each drug over 5 h and area under the plasma concentration-time curve (AUC(0,5 h)) compared between visits.

RESULTS

The mean difference in FEV(1) prior to drug inhalation on the 2 days was 33%. AUC(0,5 h) values for fluticasone and budesonide were lower by a median of 60% (IQR 36-75) and 29% (IQR 2-44), respectively, when administered following bronchoconstriction; the reduction was greater for fluticasone than for budesonide, P = 0.007.

CONCLUSIONS

The lower plasma concentrations of fluticasone and, to a lesser extent, budesonide seen when the drugs were inhaled following induced bronchoconstriction, is likely to reflect variations that will occur with fluctuations in airway caliber in asthma.

The effects of inhaled corticosteroids on intrinsic responsiveness and histology of airways from infant monkeys exposed to house dust mite allergen and ozone

Inhaled corticosteroids (ICS) are recommended to treat infants with asthma, some with intermittent asthma. We previously showed that exposing infant monkeys to allergen/ozone resulted in asthma-like characteristics of their airways. We evaluated the effects of ICS on histology and intrinsic responsiveness of allergen/ozone-exposed and normal infant primate airways. Infant monkeys were exposed by inhalation to (1) filtered air and saline, (2) house dust mite allergen (HDMA)+ozone and saline, (3) filtered air and ICS (budesonide) or (4) HDMA+ozone and ICS. Allergen/ozone exposures started at 1 month and ICS at 3 months of age. At 6 months of age, methacholine-induced changes in luminal area of airways in proximal and distal lung slices were determined using videomicrometry, followed by histology of the same slices. Proximal airway responsiveness was increased by allergen/ozone and by ICS. Eosinophil profiles were increased by allergen/ozone in both proximal and distal airways, an effect that was decreased by ICS in distal airways. In both allergen/ozone- and air-exposed monkeys, ICS increased the number of alveolar attachments in distal airways, decreased mucin in proximal airways and decreased epithelial volume in both airways. ICS increased smooth muscle in air-exposed animals while decreasing it in allergen/ozone-exposed animals in both airways. In proximal airways, there was a small but significant positive correlation between smooth muscle and airway responsiveness, as well as between alveolar attachments and responsiveness. ICS change morphology and function in normal airways as well as allergen/ozone-exposed airways, suggesting that they should be reserved for infants with active symptoms.

[Fluticasone propionate in children and infants with asthma]

The known efficacy of fluticasone propionate in adults, comparable at half-dosage of corticosteroids has been validated by the market authorization (MA) and by the national and international guidelines for beclomethasone. This could be partly explained by its pharmacological properties, affinity for glucocorticosteroid receptors, lung deposition and lipophilicity. The limited systemic adverse events is due to its low bioavailability, optimal hepatic clearance, high plasma protein binding. The efficacy in asthmatic children has been confirmed in clinical studies showing a "plateau" efficacy between 100 and 200 microg/d for the majority of children. Most children are controlled by such dosages: the added value of increasing posology on asthma control exists but is small. A high off-label posology does not allow more quickly asthma control and therefore is not justified. A twice daily dosing is more efficient, particularly for initiation of maintenance therapy, than a once daily dosing. A literature survey confirms that, at MA recommended daily doses in children (100-200 microg), fluticasone propionate has no clinically significant effect either on hypothalamic-pituitary-adrenal (HPA) axis (basal function or stimulation tests), bone or growth velocity. However, high daily doses (higher to 500 microg/day) for long periods expose to systemic adverse effects with measurable consequences on growth rate, bone density (decreasing biochemical makers of bone formation) and HPA function. Several cases of adrenal insufficiency that may have led to acute adrenal crisis have been reported in 4- to 10-year-old children receiving fluticasone propionate in doses between 500 to 2000 microg daily. In case of surgery or infection, a preventive treatment of adrenal insufficiency with hydrocortisone should be proposed for children treated for more than 6 months with such high daily doses. Such children need definitely an advice from paediatricians specialized in chest diseases as well as in endocrinology. It is important to recall that the clinical benefit of daily doses of inhaled corticosteroids higher than recommended is low and that the good use of inhaled corticosteroids particularly in children lays on the careful search of the minimal efficient daily doses.

Airway selectivity: an update of pharmacokinetic factors affecting local and systemic disposition of inhaled steroids

Topical corticosteroids remain the most efficacious single treatment for asthma and rhinitis, despite the emergence of newer drugs in recent years. The antiinflammatory properties of these products, combined with the targeting of formulations and optimization of the intrinsic pharmacokinetic features of the newer corticosteroid molecules has resulted in substantially improved airway selectivity. This review sets out to summarize the pharmacokinetic properties of inhaled corticosteroids that are important for the achievement of high levels of airway selectivity, with additional focus on the use of prodrugs/softdrugs relative to those of conventional corticosteroid molecules, mechanisms (such as esterification) by which retention at the target site is achieved while minimizing systemic exposure, and the role of plasma protein binding.

Paediatric pulmonary drug delivery: considerations in asthma treatment

Aerosol therapy, the preferred route of administration for glucocorticosteroids and short-acting beta(2)-adrenergic agonists in the treatment of paediatric asthma, may be given via nebulisers, metered-dose inhalers and dry powder inhalers. For glucocorticosteroids, therapy with aerosolised medication results in higher concentrations of drug at the target organ with minimal systemic side effects compared with oral treatments. The dose of drug that reaches the airways in children with asthma is dependent on both the delivery device and patient-related factors. Factors that affect aerosol drug delivery are reviewed briefly. Advantages and disadvantages of each device and device-specific factors that influence patient preferences are examined. Although age-based device recommendations have been made, the optimal choice for drug delivery is the one that the patient or caregiver prefers to use, can use correctly and is most likely to use consistently.

Developing the ideal inhaled corticosteroid

Inhaled corticosteroids (ICS) are considered the most effective asthma therapy, but concerns remain about side effects. The ideal ICS would have a larger therapeutic ratio than currently available agents, allowing doses to be increased but without greatly increasing the frequency or severity of adverse events. The ideal ICS would possess the following pharmacokinetic properties to maximize efficacy and minimize side effects: high pulmonary deposition, conversion to an active metabolite, high receptor potency, high pulmonary retention, low oral bioavailability, extensive metabolism, and rapid elimination. The new ICS ciclesonide has been shown to possess many of these characteristics. Ciclesonide has also been shown to improve lung function, to treat the underlying inflammation, to be effective as monotherapy in patients with persistent asthma, to have reduced side effects compared with other ICS, and to be easy to use with once-daily dosing. However, as with all new products, the advantages witnessed in clinical trials still have to be demonstrated to be beneficial long-term in general clinical use. ICS with an improved therapeutic index may have the potential to increase patient adherence, enhance the use of ICS monotherapy in the primary care setting, and increase the range of patients for whom ICS monotherapy would be appropriate.

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.

Safety and tolerability of inhaled budesonide in children in the Steroid Treatment As Regular Therapy in early asthma (START) trial

The safety and tolerability of asthma medications are still a concern to many asthma patients receiving long-term treatment. Therefore, more safety data from long-term, controlled trials are needed. The aim of this study was to evaluate the safety and tolerability of long-term treatment with once-daily budesonide in children aged 5-10 yrs with mild persistent asthma of recent onset in the inhaled Steroid Treatment As Regular Therapy in early asthma (START) study. Children aged 5-10 yrs with early asthma were randomized to double-blind treatment with budesonide 200 microg or placebo once daily via Turbuhaler in addition to usual asthma therapy, for 3 yrs. Adverse events were recorded from both spontaneous reports and responses to standard questions, and asthma-related events and asthma control were recorded between visits and subsequently graded by the blinded investigators. Of the study population of 1981 children (1004 budesonide and 977 usual care), 81% (812 of 1004) in the budesonide group and 82% (797 of 977) in the usual care group experienced a total of 6414 events listed by preferred term (3209 budesonide plus usual care and 3205 placebo plus usual care). The most commonly reported events included respiratory infection, pharyngitis, rhinitis, viral infection and bronchitis, and there were no clinically relevant differences in incidence between treatments. There were no reports of tuberculosis or aspergillosis, and no evidence of increased risk of systemic or ocular adverse events with budesonide relative to placebo. There were 106 serious adverse events in the budesonide group and 128 with usual care. The most frequent, aggravated asthma, was more common with usual care than with budesonide. There were no deaths among children participating in START. In conclusion, the addition of once-daily inhaled budesonide 200 microg via Turbuhaler to usual care is safe and well tolerated in children with recent-onset mild persistent asthma.

Effects of inhaled steroids on growth, bone metabolism, and adrenal function

For children who have persistent asthma of any degree, ICS treatment is recommended. Although topical airway corticosteroid therapy has improved the control of asthma markedly while lessening the risk of corticosteroid side effects, the use of ICS continues to be accompanied by a fear of potential adverse systemic effects. Unfortunately, these fears result in some children being deprived of appropriate and effective treatment or even exposed to a greater risk of periodic oral corticosteroid treatment. Nevertheless, because these agents may be used for long periods of time in a large number of children, safety issues are paramount. Important overall conclusions seem well supported by the literature. First, ICS used in small doses present no significant risk for systemic side effects. When ICS are used at higher dosages and continuously for long periods of time, important differences in drug characteristics, in particular the efficiency of inactivation of swallowed drug (which does not exert a therapeutic effect prior to gaining access to the systemic circulation), affect the ratio of therapeutic to systemic effect of individual ICS. From a practical viewpoint, the long-term clinical history of ICS therapy is informative. Clinically significant suppression of the HPA axis resulting from ICS therapy alone is rare. Detectable suppression of childhood growth can occur when ICS with relatively poor first-pass inactivation are administered at doses greater than or equal to 400 microg per day; this effect on 1-year growth is reduced when clinically equivalent doses of ICS with improved first-pass inactivation of swallowed drug are used. Administration of ICS alone, however, is not associated with any detectable effects on final adult height. Harmful effects of ICS on bone metabolism, although not yet studied adequately, are not expected with the use of an ICS dosage that does not suppress basal HPA axis function or childhood growth. An important caveat to these conclusions is that they refer to the use of ICS used alone and in recommended doses, not in combination with intranasal or other topical corticosteroids. Differences in safety profiles among the available ICS exist, but there are few direct comparative studies attempting to establish rank in benefit-to-risk ratios. The safety profile of all ICS preparations, which focus anti-inflammatory effects on the lung, is markedly better than that of oral glucocorticoids. Risk of adverse effects is minimized by using the lowest effective dosage, by limiting systemic availability of the drug through careful selection of the inhalation device and proper technique, by the adjunct use of alternative anti-inflammatory agents, and, when higher doses are required, by choice of ICS medication. Monitoring growth in children is a sensitive method of detecting significant ICS systemic effects and can enhance a family's confidence in the safety of the medication. When long-term, high-dose therapy is required, periodic evaluations of adrenal function and bone density may be advisable. ICS are highly effective and, because their benefits clearly exceed potential risks, can be used safely in children who have persistent asthma.

Idealhalers or realhalers? A comparison of Diskus and Turbuhaler

Medication for the treatment of asthma and chronic obstructive pulmonary disease should be given locally by inhalation. There is, however, no such thing as an ideal inhaler, or 'Idealhaler', which has all desired properties with no drawbacks. In this short review, we have compared the relative merits of the two most commonly used dry powder inhalers -- Turbuhaler and Diskus. Clinical effect is related to the amount of inhaled drug that reaches the lungs, and this in turn depends on the amount of fine particles generated at inhalation. Turbuhaler is more than twice as effective as Diskus at generating fine particles, and the higher lung deposition with Turbuhaler is accompanied by a lower variability in lung deposition. Compared with Diskus, the lung deposition with Turbuhaler is affected less by factors such as humidity.

Inhaled steroids for children: effects on growth, bone, and adrenal function

Inhaled corticosteroids are the first-line therapy for persistent asthma in children. Major safety concerns of long-term inhaled corticosteroid therapy include suppression of adrenal function and impaired growth and bone development. Proper interpretation of inhaled corticosteroid safety requires knowledge of differences among various drug devices. Dosage, type of inhaler device used, patient technique, and characteristics of the individual drug influence systemic effects of inhaled corticosteroids. Systemic side effects can occur when continuous high-dose treatment is required for severe asthma or when prescribed dosage is excessive and compliance is unusually good. Recent studies confirm that benefits of inhaled corticosteroids outweigh potential adverse effects and the risks associated with poorly controlled asthma.

Relationship between systemic corticosteroid exposure and growth velocity: development and validation of a pharmacokinetic/pharmacodynamic model

BACKGROUND

Use of high-dose oral corticosteroids (CSs) can reduce growth velocity (GV) in children, whereas use of low-dose topical CSs has either no effect or transient effects on short-term growth and no effect on final adult height Despite the large body of literature on this topic, some fundamental questions remain concerning the relationship between CS exposure and growth effects.

OBJECTIVES

The aims of this study were to determine the relationship between CS exposure and GV in children receiving CS therapy for asthma or rhinitis, and to examine whether there is likely to be a link between GV and cortisol suppression.

METHODS

Data from 32 published studies of the effect on growth of inhaled, intranasal, and oral CSs, including delivery by dry powder inhaler, metered-dose inhaler, and aqueous nasal spray, were consolidated by expressing CS exposure in cortisol equivalents using a physiologically based pharmacokinetic/pharmacodynamic approach. The relationship between change in GV and CS exposure in cortisol equivalents was described using a nonlinear sigmoid maximum-effect (E(max)) model with the following parameters: E(max) = -5.9 cm/y; steady-state unbound AUC for 50% reduction in GV, in cortisol equivalents = 20,000 ng.h/L; Hill constant = 1.2; and change in GV at zero systemic exposure = 0.06 cm/y. Validation was achieved by comparing the model's predictions with data from 5 studies that were not included in the model development The model was also used to predict the potential of various CS regimens to reduce GV.

RESULTS

Exploratory data analysis established that change in GV was highly correlated with exposure in cortisol equivalents (P < 0.001). CSs with high systemic bioavailability by the intranasal route were predicted to have short-term growth effects exceeding the clinical equivalence limit for change in GV (+/-0.8 cm/y), whereas those with lower bioavailability were predicted to produce systemic exposures below the threshold for significant effects on GV The findings were similar for inhaled CSs and for regimens combining delivery by the intranasal and inhaled routes. In descending order, the model predicted the following ranking of the potential of the various intranasal, inhaled, and oral regimens to reduce GV, expressed as fractions or multiples of the pediatric dose (in microg/d): oral prednisolone 5000 microg/d, 0.14; inhaled beclomethasone dipropionate metered-dose inhaler 400 microg/d, 0.54; inhaled budesonide dry powder inhaler 400 microg/d, 0.66; intranasal triamcinolone acetonide aqueous nasal spray 220 microg/d, 0.74; inhaled triamcinolone acetonide metered-dose inhaler 400 microg/d, 0.75; intranasal beclomethasone dipropionate aqueous nasal spray 336 pg/d, 0.89; inhaled mometasone furoate dry powder inhaler 200 microg/d, 2.4; intranasal budesonide aqueous nasal spray 128 microg/d, 2.5; inhaled fluticasone propionate dry powder inhaler 200 microg/d, 2.6; intranasal mometasone furoate aqueous nasal spray 100 microg/d, 120; and intranasal fluticasone propionate aqueous nasal spray 100 pg/d, 150. Values >1 are predictive of no significant effect on GV. The model predicted that a 10% to 15% reduction in plasma cortisol concentration should be detectable at the lower equivalence limit for growth reduction (-0.8 cm/y). The validation procedure showed that the model was capable of predicting the results of the 5 comparative growth studies not included in model development with a correlation coefficient of 0.98.

CONCLUSIONS

Growth effects appear to be nonlinearly related to CS exposure; therefore, no-effect exposure should be possible for CSs with low systemic exposure. Growth inhibition appears unlikely to occur in the absence of detectable reductions in cortisol concentrations.

Factors guiding the choice of delivery device for inhaled corticosteroids in the long-term management of stable asthma and COPD: focus on budesonide

Inhaled corticosteroids (ICSs) have become the mainstay of chronic controller therapy to treat airways inflammation in asthma and to reduce exacerbations in chronic obstructive pulmonary disease. An array of ICSs are now available that are aerosolized by a range of delivery systems. Such devices include pressurized (or propellant) metered-dose inhalers (pMDIs), pMDIs plus valved holding chambers or spacers, breath-actuated inhalers, and nebulizers. More recently, dry-powder inhalers (DPIs) were developed to help overcome problems of hand-breath coordination associated with pMDIs. The clinical benefit of ICSs therapy is determined by a complex interplay between the nature and severity of the disease, the type of drug and its formulation, and characteristics of the delivery device together with the patient's ability to use the device correctly. The ICSs budesonide is available by pMDI, DPI, and nebulizer-allowing the physician to select the best device for each individual patient. Indeed, the availability of budesonide in three different delivery systems allows versatility for the prescribing physician and provides continuity of drug therapy for younger patients who may remain on the same ICSs as they mature.

Systemic effects of inhaled corticosteroids in children

PURPOSE OF REVIEW

Inhaled corticosteroids (ICS) are first-line therapy for persistent asthma in children. Major safety concerns about long-term ICS therapy include suppression of adrenal function, growth, and bone development. Proper interpretation of ICS safety studies requires knowledge of differences between various ICS drug/delivery device systems.

RECENT FINDINGS

Dosage, type of inhaler device used, patient technique, and characteristics of the individual drug influence systemic effects of ICS. Reports of adrenal insufficiency occur but are rare and are confined to children receiving high doses of ICS. Dose-related inhibition of growth is detectable as ICS dosage increases, but appears temporary, more pronounced in childhood, and is not associated with reduction in final height. Moderate-dose ICS therapy is not associated with significant changes in measurements of bone density, but more studies of high doses and of therapy in adolescents are needed.

SUMMARY

Recent studies confirm that benefits of ICS, properly prescribed and used, clearly outweigh not only their potential adverse effects but also the risks associated with poorly controlled asthma.