Safety of hydrofluoroalkane-134a beclomethasone dipropionate extrafine aerosol

Improving the risk-to-benefit ratio of inhaled corticosteroids through delivery and dose: current progress and future directions

INTRODUCTION

Inhaled corticosteroids (ICS) are known to increase the risk of systemic and local adverse effects, especially with high doses and long-term use. Hence, considerable resources are invested to improve pharmacokinetic/pharmacodynamic (PK/PD) properties of ICS, effective delivery systems and novel combination therapies to enhance the risk-to-benefit ratio of ICS.

AREAS COVERED

There is an unmet need for new solutions to achieve optimal clinical outcomes with minimal dose of ICS. This paper gives an overview of novel treatment strategies regarding the safety of ICS therapy on the basis of the three most recent molecules introduced to our everyday clinical practice - ciclesonide, mometasone furoate, and fluticasone furoate. Advances in aerosol devices and new areas of inhalation therapy are also discussed.

EXPERT OPINION

Current progress in improving the risk-to-benefit ratio of ICS through dose and delivery probably established pathways for further developments. This applies both to the improvement of the PK/PD properties of ICS molecules but also includes technical aspects that lead to simplified applicability of the device with simultaneous optimal drug deposition in the lungs. Indubitably, the future of medicine lies not only in the development of new molecules but also in technology and digital revolution.

Dilemmas, Confusion, and Misconceptions Related to Small Airways Directed Therapy

During the past decade, there has been increasing evidence that the small airways (ie, airways < 2 mm in internal diameter) contribute substantially to the pathophysiologic and clinical expression of asthma and COPD. The increased interest in small airways is, at least in part, a result of innovation in small-particle aerosol formulations that better target the distal lung and also advanced physiologic methods of assessing small airway responses. Increasing the precision of drug deposition may improve targeting of specific diseases or receptor locations, decrease airway drug exposure and adverse effects, and thereby increase the efficiency and effectiveness of inhaled drug delivery. The availability of small-particle aerosols of corticosteroids, bronchodilators, or their combination enables a higher total lung deposition and better peripheral lung penetration and provides added clinical benefit, compared with large-particle aerosol treatment. However, a number of questions remain unanswered about the pragmatic approach relevant for clinicians to consider the role of small airways directed therapy in the day-to-day management of asthma and COPD. We thus have tried to clarify the dilemmas, confusion, and misconceptions related to small airways directed therapy. To this end, we have reviewed all studies on small-particle aerosol therapy systematically to address the dilemmas, confusion, and misconceptions related to small airways directed 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.

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.

A randomised controlled trial of small particle inhaled steroids in refractory eosinophilic asthma (SPIRA)

BACKGROUND

Some patients with refractory asthma have evidence of uncontrolled eosinophilic inflammation in the distal airways. While traditional formulations of inhaled steroids settle predominantly in the large airways, newer formulations with an extra-fine particle size have a more peripheral pattern of deposition. Specifically treating distal airway inflammation may improve asthma control.

METHODS

30 patients with refractory asthma despite high dose inhaled corticosteroids were identified as having persistent airway eosinophilia. Following 2 weeks of prednisolone 30 mg, patients demonstrating an improvement in asthma control were randomised to receive either ciclesonide 320 µg twice daily or placebo in addition to usual maintenance therapy for 8 weeks. The primary outcome measure was sputum eosinophil count at week 8. Alveolar nitric oxide was measured as a marker of distal airway inflammation.

RESULTS

There was continued suppression of differential sputum eosinophil counts with ciclesonide (median 2.3%) but not placebo (median 4.5%) though the between-group difference was not significant. When patients who had changed their maintenance prednisolone dose during the trial were excluded the difference between groups was significant (1.4% vs 4.5%, p=0.028). Though alveolar nitric oxide decreased with ciclesonide the value did not reach statistical significance.

CONCLUSIONS

These data demonstrate that patients with ongoing eosinophilic inflammation are not truly refractory, and that suppression of airway eosinophilia may be maintained with additional inhaled corticosteroid. Further work is needed with a focus on patient-orientated outcome measures such as exacerbation rate, with additional tests of small airway function.

TRIAL REGISTRATION NUMBER

NCT01171365. Protocol available at http://www.clinicaltrials.gov.

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.

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.

Treatment of the bronchial tree from beginning to end: targeting small airway inflammation in asthma

Asthma is a chronic respiratory disease, characterized by airway obstruction and inflammation. Increasing evidence shows that the small airways contribute significantly to the clinical expression and severity of asthma. Traditionally, high levels of disease activity are thought to be necessary before symptoms occur in the small airways because of their large reserve capacity. However, this concept is being challenged and increasing evidence shows small airway disease to be associated with symptoms, disease severity, and bronchial hyper-responsiveness. Particle size and distribution are of key importance when developing inhaled treatments for small airway disease. The availability of small-particle aerosols such as HFA-ciclesonide and HFA-beclomethasone dipropionate (HFA-BDP) enables a higher drug deposition into the peripheral lung and potentially provides additional clinical benefits compared with large-particle treatment. However, improved methods are needed to monitor and assess small airway disease and its response to treatment because conventional spirometry mainly reflects large airway function. This remains a challenging area requiring further research. The aim of the current manuscript is to review the clinical relevance of small airway disease and the implications for the treatment of asthma.

Urinary pharmacokinetic methodology to determine the relative lung bioavailability of inhaled beclometasone dipropionate

AIM

Urinary pharmacokinetic methods have been identified to determine the relative lung and systemic bioavailability after an inhalation. We have extended this methodology to inhaled beclometasone dipropionate (BDP).

METHOD

Ethics Committee approval was obtained and all subjects gave consent. Twelve healthy volunteers received randomized doses, separated by >7 days, of 2000 µg BDP solution with (OralC) and without (Oral) 5 g oral charcoal, 10,100 µg inhalations from a Qvar(®) Easibreathe metered dose inhaler (pMDI) with (QvarC) and without (Qvar) oral charcoal and eight 250 µg inhalations from a Clenil(®) pMDI (Clenil). Subjects provided urine samples at 0, 0.5, 1, 2, 3, 5, 8, 12 and 24 h post study dose. Urinary concentrations of BDP and its metabolites, beclometasone-17-monopropionate (17-BMP) and beclometasone (BOH) were measured.

RESULTS

No BDP, 17-BMP or BOH were detected in any samples post OralC dosing. Post oral dosing no BDP was detected in all urine samples and no 17-BMP or BOH was excreted in the first 30 min. Significantly more (P < 0.001) BDP, 17-BMP and BOH were excreted in the first 30 min and the cumulative 24 h urinary excretions post Qvar and Clenil compared with Oral. The mean ratio (90% confidence interval) of the 30 min urinary excretions for Qvar compared with Clenil was 231.4 (209.6, 255.7) %.

CONCLUSION

The urinary pharmacokinetic methodology to determine the relative lung and systemic bioavailability post inhalation, using 30 min and cumulative 24 h post inhalation samples, applies to BDP. The ratio between Qvar and Clenil is consistent with related clinical and lung deposition studies.

Small airway disease in asthma and COPD: clinical implications

Asthma and COPD have a high personal, societal, and economic impact. Both diseases are characterized by airway obstruction and an inflammatory process. The inflammatory process affects the whole respiratory tract, from central to peripheral airways that are <2 mm in internal diameter, the so-called small airways. There is an increased interest in small airway disease, and some new insights have been gained about the contribution of these small airways to the clinical expression of asthma and COPD, as reviewed in this article. Newly developed devices enable drugs to target the small airways, and this may have implications for treatment of patients with asthma, particularly those not responding to large-particle inhaled corticosteroids or those with uncontrollable asthma. The first studies in COPD are promising, and results from new studies are eagerly awaited.

Targeting small airways in asthma: improvement in clinical benefit?

BACKGROUND AND AIM

Disease control is not achieved in a substantial proportion of patients with asthma. Recent advances in aerosol formulations and delivery devices may offer more effective therapy. This review will focus on the importance and potential clinical benefit of targeting the lung periphery in adult asthma by means of ultra-fine aerosols.

RESULTS

Ultra-fine formulations of inhaled corticosteroids (ICS) have improved lung deposition up to at least 50%, primarily in the peripheral airways. Ultra-fine formulations of ICS provide equivalent asthma control to non-ultra-fine ICS at approximately half the daily dose, with no increased risk of systemic effects. Clinical studies of adults with asthma have shown a greater effect of ultra-fine ICS, compared with non-ultra-fine ICS, on quality of life, small airway patency, and markers of pulmonary and systemic inflammation, but no difference with regard to conventional clinical indices of lung function and asthma control.

CONCLUSIONS

Asthma patients treated with ultra-fine ICS, compared with non-ultra-fine ICS, have at least similar chance of achieving asthma control at a lower daily dose. Further clinical studies are needed to explore whether treatment with ultra-fine formulations of ICS will change the natural history of asthma and prevent airway remodelling in both the large and small airways.

Particle size of inhaled corticosteroids: does it matter?

A question with respect to asthma therapy revolves around the issue of whether better efficacy occurs with an ultrafine-particle inhaled corticosteroid because of better lung deposition into the distal airways. This article reviews particle size and delivery devices of different steroids, clinical outcomes of small- versus large-particle steroids, and the issue of pharmacoeconomics.

Efficacy of beclomethasone dipropionate HFA 200 microg once daily in chronic obstructive pulmonary disease and bronchial asthma

The efficacy and safety of once-daily beclomethasone dipropionate (BDP; 200 microg), in combination with the propellant hydrofluoroalkane-134a (HFA) was compared with that of budesonide turbuhaler (BUD-TH) 400 microg twice daily and fluticasone propionate inhaler (FP-IH) 250 microg twice daily in 40 patients with bronchial asthma or chronic obstructive pulmonary disease. All patients had used inhaled corticosteroids for at least 1 month. On randomization, 20 patients were switched to HFA-BDP and 20 patients remained on their existing BUD-TH or FP-IH treatment. After 8 weeks, HFA-BDP demonstrated a greater improvement in spirometric values, respiratory symptoms and beta2-agonist use. No significant local adverse effects were observed. Blood cortisol levels remained in the normal range in both groups. We conclude that HFA-BDP (200 microg once-daily) offered more benefit in terms of clinical and spirometry indices than BUD-TH (400 microg twice daily) or FP-IH (250 microg twice daily) in patients with moderate asthma and chronic obstructive pulmonary disease.

New insights into the pathophysiology of the small airways in asthma

Airway inflammation and remodeling in asthma occur in the central airways and also in the small airways and in the lung parenchyma. The small airways and the lung parenchyma can produce many Th2 cytokines, chemokines, and mediators involved in initiation and perpetuation of the inflammatory process. The distal lung has been recognized as a predominant site of airflow obstruction in asthmatics. Distal inflammation has been described as more severe than large airway inflammation, and strong evidence of remodeling in the lung periphery is emerging. Recognition of asthma as a disease of the entire respiratory tract has clinical significance, highlighting the need to target the distal lung in any strategy for effective treatment of this disease.

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.

Propellant-driven metered-dose inhalers for pulmonary drug delivery

The current market for pulmonary drug delivery is at a bottleneck. The therapeutic advantages of inhalation aerosols, and the potential for the lungs as a route for systemically acting drugs, vaccines and gene therapeutic agents, have resulted in a rapid growth of the industry. Alongside this, the environment of inhaler design and formulation has changed markedly in recent years. Environmental concerns over propellants, the commercial success of dry powder inhalers, and the apparent lack of advancement of propellant-driven metered-dose inhalers (pMDIs) has led to a less clear future for these devices. This review critically assesses these pressures and also potential opportunities for the pMDI. It is proposed that the future role of pMDIs will be determined by several important forces that can be classified under 'technology development' or 'market climate' categories. Technology development forces will be strengthened by the ability of the industry to have a systematic understanding of mechanisms of spray formation, perform subsequent and continued device and formulation advances, and a focus on all patient groups: particularly paediatric and geriatric populations. The ability to succeed in these areas will be largely determined by the willingness to invest in fundamental research of pMDI technologies.

Comparison of the systemic pharmacodynamic effects and pharmacokinetics of salmeterol delivered by CFC propellant and non-CFC propellant metered dose inhalers in healthy subjects

This was a randomised, double-blind, placebo-controlled, cross-over study comparing the systemic pharmacodynamic effects (heart rate and serum potassium) and pharmacokinetics of salmeterol delivered by the non-CFC hydrofluoralkane (HFA) propellant 134a and the CFC propellant (propellant 11/12) metered dose inhalers (MDI) in healthy subjects. At the therapeutic dose (50 microg), salmeterol-mediated systemic pharmacodynamics were equivalent for the HFA and CFC MDIs. Higher doses of salmeterol (150 and 300 microg) produced dose-related beta-agonist pharmacodynamic effects irrespective of the propellant. However, these effects were lower with salmeterol HFA MDI than with the salmeterol CFC MDI at all dose levels. Overall, salmeterol Cmax and AUC(0-t) values were lower for salmeterol HFA compared with salmeterol CFC MDI. At the highest dose (300 microg), where a full pharmacokinetic profile was obtained, exposure to salmeterol delivered by the HFA MDI compared with the salmeterol CFC MDI was 27% and 30% lower for Cmax and AUC(0-t), respectively. Maximum plasma concentrations were generally seen in the first plasma samples taken 5 min after the start of dosing. Salmeterol HFA was well-tolerated. At supratherapeutic doses, adverse events were typical for high-dose salmeterol with fewer adverse events occurring with the HFA compared with the CFC formulation. These data indicate that the salmeterol HFA MDI would not be associated with a significantly different pharmacodynamic, safety and tolerability profile compared with the salmeterol CFC MDI.

The efficacy and safety of QVAR (hydrofluoroalkane-beclometasone diproprionate extrafine aerosol) in asthma (part 1): an update of clinical experience in adults

In 1999, a robust dose-finding study showed that the chlorofluorocarbon (CFC) -free formulation of beclometasone dipropionate (BDP), QVAR (hydrofluoroalkane-134a BDP), produced equivalent asthma control to CFC-BDP at approximately half the daily dose in adults. Since then, a wealth of clinical and pharmaco-vigilance studies have been undertaken to confirm these results and establish dose-potency ratios with other inhaled corticosteroids (ICS). This review summarises the results of studies performed by the manufacturer that have been published since the last comprehensive review of the efficacy and safety of QVAR in 2000. Long-term comparisons with CFC-BDP have confirmed the durability of the 2:1 daily dosing ratio of CFC-BDP:QVAR in adults. Clinical comparisons with other ICS in both symptomatic and asymptomatic patients have established dose-potency ratios of 2: 1 for budesonide:QVAR and 1:1 for fluticasone:QVAR. Furthermore, QVAR has been associated with benefits on asthma symptomatology and quality of life, compared with other ICS that probably arises from its peripheral deposition in the lung.

Deposition and effects of inhaled corticosteroids

Inhaled corticosteroids are now recommended as maintenance therapy for all but the mildest cases of asthma, and may be delivered by a variety of devices and formulations. Drug delivery may be assessed by both in vitro and in vivo methods. Although drug deposition in the lungs is expected to predict clinical response, this relationship is often masked by the flat nature of corticosteroid dose-response curves. The effects of inhaled corticosteroids depend not only upon the pharmacology of the drug being administered, but also upon its delivery system, with more efficient devices not only improving therapeutic effect but also potentially increasing systemic adverse effects. Modern delivery systems that enhance drug targeting to the lungs make it possible to use lower dosages of inhaled corticosteroid, such that the clinical response is maintained but systemic exposure reduced.

Effects on lung function, symptoms, and bronchial hyperreactivity of low-dose inhaled beclomethasone dipropionate given with HFA-134a or CFC propellant

The aim of this study was to compare the efficacy of BDP 200 microg bid via metered dose inhaler, using HFA-134a (Chiesi Farmaceutici S.p.A., Parma, Italy) versus CFC (Becotide, Allen & Hanburys, U.K.) as a propellant. 172 adult patients (86 in each group) with stable mild persistent asthma who completed a 7-day run-in period were randomized to receive a 6-week treatment in a double-blind, double dummy, parallel-group design; 164 patients completed the study. Morning and evening PEFR, use of rescue salbutamol, number of day-time and night-time asthma attacks, number of night-time awakenings and clinical symptoms were recorded daily on a diary card. Pulmonary function tests (FEV(1), FVC, PEFR, and MEF(50)) were measured at the clinic before and after the 1-week run-in period, and after 3 and 6 weeks of treatment. A challenge test with inhaled methacholine was completed at baseline and at the end of the treatment period to assess potential bronchial hyper-reactivity in a subgroup of subjects (n = 65; 34 HFA, 31 CFC). In accordance with asthma of mild severity (FEV(1) predicted over 90% in both groups), a small improvement in lung function compared to baseline was seen for both treatments, significantly for FEV(1) in BDP HFA and MEF(50) in both groups. The two formulations of BDP had similar efficacy for the primary outcome variable morning PEFR (ITT population mean difference 5.8 L/min; C.I. -4.9 to +16.5) as well as for the secondary outcomes of evening PEFR and clinic FEV(1). There were small improvements in methacholine PD(20) and PC20 in both groups, with no significant difference between treatments. A total of 22 and 19 drug-related adverse events were reported in the BDP HFA and CFC groups, respectively; most events were of seasonal nature or were local effects due to the use of inhaled corticosteroids. It can be concluded that the newly developed formulation of BDP given via HFA-134a seems to provide similar asthma control, compared with the same low daily dose of the active drug delivered via CFC. Further studies are needed using higher doses in moderate to severe asthma to confirm these preliminary findings.

Contribution of the distal lung to the pathologic and physiologic changes in asthma: potential therapeutic target Roger S. Mitchell lecture

Pathologic and physiologic evidence has emerged in the last few years suggesting that the airway inflammation and remodeling that characterize asthma occur not only in the central airways but extend to the distal lung and the lung parenchyma. The distal airways are capable of producing T helper (Th) type 2 cytokines and chemokines, and, more recently, they have been recognized as a predominant site of airflow obstruction in asthmatic patients. In the lung parenchyma, a similar Th2 cytokine profile and infiltration of inflammatory cells also has been reported. The inflammation at this distal site has been described as being more severe when compared to the large amount of airway inflammation, and evidence of remodeling in the lung periphery is emerging. The recognition of asthma as a disease of the entire respiratory tract has an important clinical significance highlighting the need to also consider the distal lung as a target in any therapeutic strategy for effective treatment of this disease.

Efficacy and safety of beclomethasone dipropionate extrafine aerosol in childhood asthma: a 12-week, randomized, double-blind, placebo-controlled study

BACKGROUND

Beclomethasone dipropionate (BDP) has been formulated as an extrafine aerosol (hydrofluoroalkane-134a [HFA]-BDP) [QVAR; 3M Pharmaceuticals; St Paul, MN], which gives improved lung deposition compared with chlorofluorocarbon (CFC)-BDP. The clinical efficacy of HFA-BDP has been established in adult asthma at a required dose below that of CFC-BDP, but has not been evaluated in children.

OBJECTIVE

To examine the efficacy and safety of HFA-BDP in childhood asthma.

DESIGN

A 12-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study involving 353 children aged 5 to 12 years with moderate, symptomatic asthma. After a 2-week run-in period, patients were randomized to HFA-BDP, 80 micro g/d (n = 120); HFA-BDP, 160 micro g/d (n = 117); or HFA-placebo (n = 116) administered twice daily.

SETTING

Hospital outpatient.

RESULTS

HFA-BDP, 80 micro g/d and 160 micro g/d, produced a significant, dose-related increase from baseline in FEV(1) percent predicted compared with placebo. At week 12, mean changes from baseline in FEV(1) percent predicted were 9.2% (p < or = 0.01 vs placebo), 10% (p < or = 0.01 vs placebo), and 3.9% for the HFA-BDP 80 micro g/d, HFA-BDP 160 micro g/d, and placebo groups, respectively. There was also a significant decrease in daily beta-agonist use, improvement in peak expiratory flow, and increase [correction] in the percentage of days free from asthma symptoms (p < or = 0.05 for HFA-BDP, 160 micro g/d, vs placebo at weeks 11 to 12). HFA-BDP was well tolerated, with no significant differences in the incidence or nature of adverse events between HFA-BDP and placebo groups. Neither were there significant differences between groups in mean percentage change from baseline in the morning plasma cortisol level at week 12 or in the percentage of patients with morning plasma cortisol levels below the reference range at baseline and week 12. In a subgroup tested, the percentage of patients with an abnormal response to low-dose adrenocorticotropic hormone stimulation at week 12 was low and similar among all groups.

CONCLUSIONS

HFA-BDP, 80 to 160 micro g/d, is effective and safe in childhood asthma.

Clinical studies in asthmatics with a new non-extra fine HFA formulation of beclometasone dipropionate (BDP Modulite)

The main objective of the clinical development programme for BDP Modulite, a new non-extra fine formulation of beclometasone dipropionate (BDP) in hydrofluoroalkane (HFA), has been to demonstrate therapeutic equivalence compared with standard BDP chlorofluorocarbon (CFC) products at the recommended posology (delivered dose and patient population). A total of 1158 asthmatic patients were included in five clinical studies and 658 patients were treated with BDP Modulite. Four studies were undertaken in mild or moderate-to-severe asthmatic adults, while one study was carried out in children. The duration of treatment was 12 weeks in three studies and 6 weeks in the other two studies. A range of doses of BDP Modulite from 200 micrograms bid up to 1500 micrograms bid was evaluated against CFC comparators. The primary efficacy variable in all studies was morning PEFR while secondary variables included other lung function parameters, symptom scores and salbutamol use. All studies demonstrated equivalence of efficacy for morning PEFR for BDP Modulite versus BDP-CFC when compared on a microgram for microgram basis. The secondary outcome variables also consistently support similar efficacy of the two products. The safety and tolerability profile for BDP Modulite was similar to BDP-CFC; the incidence of adverse events was comparable between treatments and plasma and urinary cortisol were generally unchanged in patients receiving 1000 micrograms day-1 for 6-12 weeks. In conclusion, the results of the clinical studies with BDP Modulite show that this new HFA formulation allows a seamless transition to CFC-free BDP, thus simplifying the changeover.

Switching from conventional to extrafine aerosol beclomethasone dipropionate therapy in children: a 6-month, open- label, randomized trial

BACKGROUND

In adults with asthma, hydrofluoralkane-134a beclomethasone dipropionate (HFA-BDP) extrafine aerosol provides equivalent asthma control at half the daily dose of conventional chlorofluorocarbon (CFC)-BDP.

OBJECTIVE

We sought to compare the efficacy and tolerability of switching from CFC-BDP to HFA-BDP at half the daily dose in children with stable asthma.

METHODS

This 6-month, open-label, randomized, multicenter study enrolled 520 children aged 5 to 11 years with well-controlled asthma receiving inhaled CFC-BDP or budesonide 200 to 800 microg/d x. (Four hundred fifty-two patients were using doses within the recommended range of 200-400 microg and were analyzed separately.) During a 4-week run-in period, patients used CFC-BDP plus a spacer (CFC-BDP+S) at approximately the same dose as they were using before study entry. Patients were then randomized in a 1:3 ratio to continue on CFC-BDP+S or switch to HFA-BDP Autohaler at half the daily dose.

RESULTS

The change from baseline in morning peak expiratory flow was significantly greater in patients receiving 100-200 microg of HFA-BDP compared with those receiving 200-400 microg of CFC-BDP+S at weeks 7 to 8 (8.5 and 0.4 L/min, respectively; P =.014), with continuing improvement in both groups over 6 months (12.2 and 12.4 L/min, respectively, at month 6). There were no significant differences between treatments in mean change from baseline in FEV(1), percentage of days or nights without asthma symptoms, and daily beta-agonist use over the 6-month treatment period. The proportion of patients who had one or more asthma exacerbations, the incidence of adverse events, and the percentage change from baseline in 24-hour urinary free cortisol levels were similar in the 2 treatment groups.

CONCLUSIONS

This study confirms that asthma control can be well maintained in children when switching from CFC-BDP+S to an HFA-BDP Autohaler at doses as low as 100 to 200 microg/d.

Asthma medications and their potential adverse effects in the elderly: recommendations for prescribing

The incidence of drug-induced adverse effects is likely to increase as a result of advanced age and exposure of elderly patients to polypharmacy. Therefore, pharmacological therapy of asthma and chronic obstructive pulmonary disease (COPD) in the elderly patient can be potentially hazardous. beta(2)-agonists, administered as therapy for asthma and COPD, have recognised systemic sequelae, such as hypokalaemia and chronotropic effects, which may be life-threatening in susceptible patients. Adverse effects such as hypokalaemia can be aggravated by concomitant treatment with other drugs promoting potassium loss including diuretics, corticosteroids and theophyllines. In addition, relatively minor adverse events associated with the administration of beta(2)-agonists, such as tremor and blood pressure changes, may be of significance to the elderly patient leading to impairment in the quality of life. However, long-term treatment with beta(2)-agonists may reduce the incidence of drug-induced adverse effects as a result of beta-receptor subsensitivity. Oral and inhaled corticosteroids have been used for the treatment of acute asthma and COPD in the elderly patient. Long-term treatment with oral corticosteroids can result in serious systemic adverse effects such as suppressed adrenal function, bone loss, skin thinning and cataract formation. In contrast to beta(2)-agonists, oral corticosteroids can upregulate beta(2)-adrenoceptors and thereby potentiate the systemic sequelae of beta(2)-agonists. Hence, oral corticosteroids should be administered with caution for as short a duration as possible. Inhaled corticosteroids appear to be relatively well tolerated when administered at doses below approximately 1000 microg. However, larger doses of inhaled corticosteroids may affect hypothalamic-pituitary-adrenal function and bone turnover. In the case of inhaled corticosteroids, spacer devices, often used in older patients who cannot operate metered dose inhalers, can potentiate the systemic sequelae of both corticosteroids and beta(2)-agonists. The use of theophyllines in the treatment of COPD or chronic asthma is controversial. Theophyllines have a wide adverse effect profile and are prone to drug-drug interactions. The adverse effects may be mild or life threatening and include nausea and vomiting or sinus and supraventricular tachycardias. Therefore, theophyllines should be prescribed with extreme caution to elderly patients with asthma or COPD. In contrast, inhaled anticholinergic drugs such as ipratropium bromide and oxitropium bromide are generally safe in elderly patients and have useful bronchodilator function. Commonly reported adverse effects are an unpleasant taste and dryness of the mouth. When used as first-line therapy, anticholinergic drugs may optimise the bronchodilator effects of low-dose inhaled beta(2)-agonists in patients with chronic airflow obstruction, and hence obviate the need for higher doses.

A randomized, double-blind comparison of beclomethasone dipropionate extrafine aerosol and fluticasone propionate

BACKGROUND

Inhaled corticosteroids provide first-line treatment for asthma. An advance to improve potency was to produce new molecules with increased glucocorticoid receptor affinity (eg, fluticasone propionate [FP]). An alternative is to deliver more medication to both the large and small airway inflammation of asthma by using an extrafine aerosol (eg, beclomethasone dipropionate extrafine aerosol [BDP-extrafinel).

OBJECTIVE

To demonstrate clinical equivalence of BDP-extrafine (400 microg daily) and FP (400 microg daily) in symptomatic asthmatic patients over the course of 6 weeks.

METHODS

This was a double-blind, double-dummy, parallel-group, multicenter, 6-week study in adults with asthma taking conventional FP 100 to 250 microg daily or equivalent, and displaying signs/symptoms of active disease requiring additional therapy.

RESULTS

Eighty-eight patients were randomized to BDP-extrafine (and FP-placebo) and 84 to FP (and BDP-placebo). There were no significant differences between treatments with respect to symptom control, as evidenced by mean change from baseline in percentage days without asthma symptoms/nights without sleep disturbance observed at weeks 1 to 2, 3 to 4, or 5 to 6. Mean changes from baseline in AM PEFR at weeks 5 to 6 for BDP-extrafine (19.0) and FP (30.5) were equivalent (P = 0.022 for equivalence). There were significant (P < 0.001) within-treatment-group differences in mean change from baseline in AM PEFR at weeks 1 to 2 for both treatments. There was no difference in the incidence of patients reporting at least one adverse event during the study (BDP-extrafine 41%; FP 37%). Mean percentage change from baseline for AM plasma cortisol at week 6 was + 17.7% for BDP-extrafine and +4.2% for FP (P = 0.066 for difference).

CONCLUSIONS

BDP-extrafine and FP at doses of 400 microg daily provided equivalent asthma control in patients with symptomatic asthma and exhibited similar safety profiles.

Long-term safety and efficacy of a chlorofluorocarbon-free beclomethasone dipropionate extrafine aerosol

BACKGROUND

Beclomethasone dipropionate (BDP) extrafine aerosol, a newly developed pressurized metered dose inhaler (pMDI) with a hydrofluoroalkane-134a (HFA) propellant (HFA-BDP; Qvar, 3M Pharmaceuticals, St. Paul, MN), has been shown to be effective in controlling asthma symptoms at approximately half the daily dose of chlorofluorocarbon (CFC)-BDP.

OBJECTIVE

This study evaluated the long-term efficacy and safety of switching patients with asthma maintained on a stable dose of CFC-BDP pMDI to therapy with HFA-BDP pMDI at approximately half their previous daily dose of CFC-BDP.

METHODS

This was an open-label, randomized, parallel-group multicenter trial. Patients with at least a 6-month history of asthma whose symptoms were controlled on CFC-BDP, 400 to 1600 microg daily, during a 2-week run-in period were randomized in a 1:3 ratio to CFC-BDP at the same daily dose or HFA-BDP at approximately half the daily dose of CFC-BDP for 12 months.

RESULTS

A total of 473 patients were randomized: 354 to HFA-BDP, 119 to CFC-BDP. There were no statistically significant differences between groups in mean change from baseline in morning (AM) peak expiratory flow rate or forced expiratory volume in one second throughout the study. There were no consistent differences between treatment groups in individual asthma symptoms or daily beta2-agonist use during the study. There was an increase in the percentage of symptom-free days between baseline and month 12 in the HFA-BDP group (11.5%) and the CFC-BDP group (4.6%). No statistically significant differences in serum osteocalcin levels or adverse events were seen during the study or in AM plasma cortisol levels at month 12.

CONCLUSIONS

Asthma control was maintained in patients switched from a stable dose of CFC-BDP (400 to 1600 microg daily) to HFA-BDP at approximately half the CFC-BDP dose (200 to 800 microg daily), and was maintained over the next 12 months. HFA-BDP demonstrated a similar safety profile to CFC-BDP; there were no differences between the agents with regard to systemic effects.

Optimizing drug delivery to the lung: design of a CFC-free corticosteroid metered-dose aerosol system

The mandatory replacement of chlorofluorocarbons (CFCs) with ozone-friendly propellants, such as hydrofluoroalkanes (HFAs), has provided an opportunity to optimize aerosol design and improve drug delivery to pulmonary tissue. Asthma is an inflammatory disorder of the lungs that appears to affect both small and large airways, so ideally, inhaled corticosteroid should reach both central and peripheral sites. This review considers the development of an aerosol system containing beclomethasone dipropionate in hydrofluoroalkane-134a (HFA) propellant (Qvar, 3M Health Care, Loughborough, UK) designed to target medication delivery throughout the bronchopulmonary tree and to improve the therapeutic ratio (topical efficacy: systemic safety), thereby offering potential clinical benefits to asthma patients.

Efficacy and safety overview of a new inhaled corticosteroid, QVAR (hydrofluoroalkane-beclomethasone extrafine inhalation aerosol), in asthma

Chlorofluorocarbon (CFC)-containing inhalers are gradually being phased out and replaced with hydrofluoroalkane (HFA)-based alternatives. The reformulation provided the opportunity to improve the inhalation technology and physical characteristics of corticosteroid formulations. QVAR contains HFA-beclomethasone dipropionate (HFA-BDP) with the steroid in solution rather than suspension, which, in combination with improved inhaler technology, produces an extrafine aerosol with a mass median aerodynamic diameter of 1.1 microm (smaller than the 3.5-4.0 microm found with CFC-BDP). It was predicted and demonstrated that the smaller particle size of QVAR would be deposited in the lung to a greater extent than that found with CFC-BDP, particularly in the small airway, a major site of inflammation. Increased lung deposition of QVAR permits a reduction in dosage relative to CFC-BDP. Clinical evidence confirms that adult and elderly patients required approximately half the dose of QVAR to achieve the same degree of asthma control as with CFC-BDP. In long-term assessments, patients taking CFC-BDP could be switched to QVAR at half the daily dose without exacerbation of their asthma symptoms. QVAR was associated with a low overall incidence of side effects and, at the maximum recommended dose of 640 microg/d, caused no more adrenal suppression than 672 microg/d CFC-BDP.

Pulmonary function and adrenal gland suppression with incremental doses of aerosolized beclomethasone dipropionate in horses with recurrent airway obstruction

OBJECTIVE

To evaluate clinical response, pulmonary function, and adrenal gland response to incremental doses of beclomethasone dipropionate in horses with recurrent airway obstruction.

DESIGN

Crossover trial.

ANIMALS

8 horses with recurrent airway obstruction.

PROCEDURE

Horses randomly assigned to 4 groups were treated twice daily via aerosol administration of placebo or 500, 1,000, or 1,500 micrograms of beclomethasone dipropionate in a crossover design with a 10-day minimum washout period. Subjective assessment of airway obstruction, serum cortisol concentration, and maximum change in pleural pressure during tidal breathing (delta Pplmax) were determined daily prior to morning drug administration, and delta Pplmax was reevaluated 15 minutes after morning drug administration. Pulmonary resistance and dynamic compliance were determined at baseline and approximately 12 hours after the final treatment.

RESULTS

An immediate treatment effect was not identified. Within 24 hours, delta Pplmax and airway obstruction were lower in horses receiving beclomethasone. Onset and magnitude of response was similar among the 3 beclomethasone dose regimens. Pulmonary resistance was improved only after administration of all 3 doses of beclomethasone, whereas dynamic compliance was improved after administration of 1,000 micrograms and 1,500 micrograms of beclomethasone. Reduction in serum cortisol concentration occurred with all 3 beclomethasone dose regimens; however, the magnitude of adrenal gland suppression was greater in horses receiving 1,000 or 1,500 micrograms of beclomethasone.

CONCLUSIONS AND CLINICAL RELEVANCE

Low-dose (500 micrograms) beclomethasone administration caused similar, improvement in pulmonary function, compared with high-dose beclomethasone (1,000 and 1,500 micrograms), with the exception of dynamic compliance, and caused less suppression of endogenous cortisol production.

Aerosol therapy for asthma

Inhaled drugs play an important role in asthma management. The correct use of an appropriate delivery device is necessary to achieve the desired therapeutic effects of the drug. Currently, chlorofluorocarbon-propelled metered-dose inhalers, with or without spacers, are the most popular aerosol delivery devices. With the planned phase out of the chlorofluorocarbon metered-dose inhalers, the use of other delivery devices is being emphasized. To achieve optimal therapeutic effects, the drug and the delivery device should be considered a "couple". Aerosol delivery devices should provide an adequate "drug dose to the lung", be cost effective, simple to operate, minimize oropharyngeal deposition and systemic side effects, and match the patient's requirements. A new generation of aerosol delivery devices, incorporating the latest advances in aerosol technology, is likely to fulfill many of the goals mentioned above.

Inhaled beclomethasone (BDP) with non-CFC propellant (HFA 134a) is equivalent to BDP-CFC for the treatment of asthma

As part of a development programme for a range of new CFC-free beclomethasone dipropionate (BDP) inhalers, two multicentre double-blind studies have been conducted to compare the therapeutic equivalence of a new HFA-134a propellant-formulated BDP metered-dose inhaler (Norton Healthcare Ltd, London, U.K.) with a CFC counterpart for the management of adult patients with all grades of asthma. Doses of 100 micrograms qds for 6 weeks were administered in a low dose study and in a high dose study 500 micrograms qds doses were given for 12 weeks. Efficacy assessments included lung function (FEV1) in the clinic and asthma symptoms, peak flow rates and bronchodilator use by patients on diary cards. Safety parameters measured included routine haematology and biochemistry (including serum cortisols), clinical adverse events and throat swabs for Candida spp. Both CFC and HFA-formulations of inhaled BDP produced similar and significant improvements in lung function and asthma symptoms. In the low dose study, baseline to endpoint FEV1 increased from 2.2 +/- 0.51 to 2.5 +/- 0.81 (P = 0.0001) with BDP-CFC and from 2.2 +/- 0.51 to 2.6 +/- 0.81 with BDP-HFA (P = 0.0001), with no significant difference between treatments. In the high dose study, corresponding increases were 2.1 +/- 0.71 to 2.4 +/- 0.91 (P = 0.0002) for BDP-CFC and 2.1 +/- 0.71 to 2.3 +/- 0.71 (P = 0.017) for BDP-HFA. PEF also improved similarly on both treatments in both studies. Both formulations were well tolerated with no difference in the pattern of adverse events, effect on serum cortisol or Candida colonization. These studies showed that, in the management of asthma, the new HFA-formulated BDP metered dose inhaler is equivalent to, and directly substitutable for, the older CFC-formulated product at the same dose, making change-over for patients straightforward.

Inhaled corticosteroids for adult asthma: impact of formulation and delivery device on relative pharmacokinetics, efficacy and safety

Metered dose inhalers (MDIs) are the mainstay of inhaled steroid therapy for asthma. With the phasing out of traditional chlorofluorocarbon (CFC) propellants and their replacement with a new generation of CFC-free products, it is becoming clear that formulation and inhaler characteristics can markedly affect the drug delivery. It now seems necessary to compare inhalers not only on the basis of the properties of the steroid molecules but also to take into account the effect of propellants and other inhaler characteristics. The impact of formulation and delivery device on relative pharmacokinetics, therapeutic efficacy and tolerability is illustrated by a new preparation of beclomethasone dipropionate (BDP) in an inhaler containing hydrofluoroalkane (HFA) propellant, called Qvar (3M Health Care, U.K.). This drug preparation delivers the majority of particles (60%) in the fine particle range. This appears to be associated with improved lung deposition, a halving of dose requirements of BDP, but no evidence of clinically relevant adrenal suppression when used in therapeutic doses. Prescribers need to be aware of the impact of formulation on pharmacokinetics of inhaled steroids in order to offer the lowest effective dose and give clear instructions to patients who are changing to a CFC-free product.

Hydrofluoroalkane-134a beclomethasone dipropionate extrafine aerosol provides equivalent asthma control to chlorofluorocarbon beclomethasone dipropionate at approximately half the total daily dose

The mandatory requirement to eliminate chlorofluorocarbons (CFCs) as propellants in pharmaceutical aerosols has provided the opportunity to enhance significantly the delivery of aerosol drugs to the respiratory tract. This randomized, parallel-group, double-blind, double-dummy, multicentre study was undertaken to assess whether beclomethasone dipropionate (BDP) in hydrofluoroalkane-134a (HFA) provided equivalent control of moderately severe asthma to BDP in CFC but at approximately half the total daily dose, as might be expected from the improved lung deposition of the HFA-BDP extrafine aerosol. The novel study design included a 10-12 day run-in period to confirm that patients met established criteria of moderately severe asthma and were symptomatic on current therapy (inhaled beta-agonist plus CFC-BDP 400-800 micrograms day-1). This run-in period was followed by a short course of oral steroid therapy (prednisolone 30 mg day-1 for 7-13 days) to demonstrate steroid responsiveness [> or = 15% improvement in morning peak expiratory flow (PEF)] and to provide a within-study baseline of improved asthma control. A total of 233 patients were randomized to treatment for 12 weeks with HFA-BDP 800 micrograms day-1 (116 patients) or CFC-BDP 1500 micrograms day-1 (117 patients). The mean change from oral steroid treatment in morning PEF with HFA-BDP was equivalent to that seen with CFC-BDP at all time intervals. Changes in other measures of pulmonary function, asthma symptom scores and beta-agonist use were equivalent in the two treatment groups throughout the 12 week treatment period. The safety profile of HFA-BDP compared favourably with that of CFC-BDP with no unexpected adverse events reported. Fewer patients on HFA-BDP than on CFC-BDP had plasma cortisol levels below the normal reference range after 12 weeks of therapy (5.1% vs. 17.3%, respectively). In conclusion, HFA-BDP extrafine aerosol was found to provide equivalent control of moderately severe asthma to CFC-BDP at approximately half the daily dose with a favourable safety profile, suggesting an improved therapeutic ratio.