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

New Versus Old: The Impact of Changing Patterns of Inhaled Corticosteroid Prescribing and Dosing Regimens in Asthma Management

Inhaled corticosteroid (ICS)-containing therapies are the mainstay of pharmacological management of asthma. They can be administered alone or in combination with a long-acting bronchodilator, depending on asthma severity, and may also be supplemented with short-acting bronchodilators for as-needed rescue medication. Adherence to asthma therapies is generally poor and characterized by underuse of ICS therapies and over-reliance on short-acting bronchodilators, which leads to poor clinical outcomes. This article reviews efficacy versus systemic activity profiles for various dosing regimens of budesonide (BUD) and fluticasone propionate (FP). We performed a structured literature review of BUD and FP regular daily dosing, and BUD/formoterol (FOR) as-needed dosing, to explore the relationship between various dosing patterns of ICS regimens and the risk–benefit profile in terms of the extent of bronchoprotection and cortisol suppression. In addition, we explored how adherence could potentially affect the risk–benefit profile, in patients with mild, moderate, and moderate-to-severe asthma. With a specific focus on BUD or FP-containing treatments, we found that regular daily ICS and ICS/long-acting β₂-agonist (LABA) dosing had a greater degree of bronchoprotection than as-needed BUD/FOR dosing or BUD/FOR maintenance and reliever therapy (MART) dosing, and still maintained low systemic activity. We also found that the benefits of regular daily ICS dosing regimens were diminished when adherence was low (50%); the shorter duration of bronchoprotection observed was similar to that seen with typical as-needed BUD/FOR usage. These findings have implications for aiding clinicians with selecting the most suitable treatment option for asthma management, and subsequent implications for the advice clinicians give their patients.

Inhaled corticosteroid (ICS)-containing therapies can be administered in a variety of ways depending on a patient’s asthma severity. Patients with mild asthma tend to experience symptom relief with as-needed or regular daily use of an ICS alone, whereas patients with more severe asthma may require regular daily use of an ICS plus a long-acting β₂-agonist (LABA) to experience sufficient asthma control. However, failure to correctly adhere to ICS-containing therapies or an over-reliance on short-acting bronchodilators for symptom relief hinders optimal asthma management, thus negatively affecting overall patient health and wellbeing. Understanding how different dosing regimens affect the degree of bronchoprotection (efficacy) and cortisol suppression (systemic activity) of ICS treatments would benefit physicians by helping them to prescribe the most appropriate treatment for their patient’s asthma. We performed a structured literature review of two ICS molecules—budesonide (BUD) (alone and combined with formoterol [FOR]) and fluticasone propionate (FP)—to explore the relationship between various ICS dosing regimens, and then used these findings to construct models for ICS risk–benefit profiles. Our models factored in different ICS dosing regimens—as-needed, regular daily dosing, and maintenance and reliever therapy (MART)—and various degrees of treatment adherence. We found that regular daily ICS and ICS/LABA dosing provided better bronchoprotection than as-needed BUD/FOR dosing or BUD/FOR MART dosing, but this benefit was diminished with low adherence. Regular daily dosing maintained low cortisol suppression, which indicated a fairly low risk of negative side effects. Our findings have subsequent implications for optimizing treatment in patients with asthma.

Direct and indirect bronchoprovocation tests in dose-response studies of inhaled corticosteroids: Past, present, and future directions

Inhaled corticosteroids (ICS) are a mainstay of treatment in eosinophilic asthma. Many studies have explored the dose-response effect of different formulations of ICS through direct or indirect bronchoprovocation testing. Such studies are important for investigating efficacy and identifying the relative potency between formulations. However, lack of consistency in methods and designs has hindered the comparability of study findings. This review discusses current knowledge of the dose-response, or lack thereof, of different formulations of ICS through direct and indirect bronchoprovocation testing. The strengths and weaknesses of past studies inform recommendations for future methodological considerations in this field, such as utilizing a randomized double-blind crossover design, enrolling participants likely to respond to ICS therapy, and carefully selecting treatment durations and washout periods to assess incremental improvement in airway hyperresponsiveness while reducing the likelihood of a carryover effect.

Efficacy and safety of inhaled corticosteroids relative to fluticasone propionate: a systematic review of randomized controlled trials in asthma

INTRODUCTION

Many trials have been published comparing inhaled corticosteroid (ICS) treatments in asthma. However, mixed results necessitate the summarization of available evidence to aid in decision-making. Areas covered: This systematic review evaluated randomized controlled trials (RCTs) that compared the efficacy and safety of inhaled fluticasone propionate (FP) with other ICS including beclomethasone dipropionate (BDP), budesonide (BUD) and ciclesonide (CIC). PubMed was searched and 54 RCTs that fit pre-determined criteria were included. Endpoints evaluated included lung function, asthma symptom control, exacerbation frequency, reliever use, quality of life and steroid-related side effects. Expert commentary: Across all studies, FP was associated with either more favorable or at least similar efficacy and safety, in comparison with BDP or BUD. This observation may be related to FP's higher relative potency and almost negligible oral bioavailability. FP was comparable to CIC for efficacy. However, CIC appeared to have a smaller impact on cortisol levels than FP, which is likely due to CIC's incomplete conversion to active metabolite (des-CIC) and the lower potency of des-CIC compared with FP. Although there were no significant differences in evaluated outcomes after treatment with different ICS in the majority of studies, some observed differences could be explained by their respective pharmacodynamic and pharmacokinetic properties.

Effect of inhaled corticosteroid particle size on asthma efficacy and safety outcomes: a systematic literature review and meta-analysis

Background

Inhaled corticosteroids (ICS) are the primary treatment for persistent asthma. Currently available ICS have differing particle size due to both formulation and propellant, and it has been postulated that this may impact patient outcomes. This structured literature review and meta-analysis compared the effect of small and standard particle size ICS on lung function, symptoms, rescue use (when available) and safety in patients with asthma as assessed in head-to-head randomized controlled trials (RCTs).

Methods

A systematic literature search of MEDLINE was performed to identify RCTs (1998–2014) evaluating standard size (fluticasone propionate-containing medications) versus small particle size ICS medication in adults and children with asthma. Efficacy outcomes included forced expiratory volume in 1 s (FEV₁), morning peak expiratory flow (PEF), symptom scores, % predicted forced expiratory flow between 25 and 75% of forced vital capacity (FEF_25–75%)_, and rescue medication use. Safety outcomes were also evaluated when available.

Results

Twenty-three independent trials that met the eligibility criteria were identified. Benefit-risk plots did not demonstrate any clinically meaningful differences across the five efficacy endpoints considered and no appreciable differences were noted for most safety endpoints. Meta-analysis results, using a random-effects model, demonstrated no significant difference between standard and small size particle ICS medications in terms of effects on mean change from baseline FEV₁ (L) (−0.011, 95% confidence interval [CI]: −0.037, 0.014 [N = 3524]), morning PEF (L/min) (medium/low doses: −3.874, 95% CI: −10.915, 3.166 [N = 1911]; high/high-medium doses: 5.551, 95% CI: −1.948, 13.049 [N = 749]) and FEF_{25–75% predicted} (−2.418, 95% CI: −6.400; 1.564 [N = 115]).

Conclusions

Based on the available literature, no clinically significant differences in efficacy or safety were observed comparing small and standard particle size ICS medications for the treatment of asthma.

Trial registration

GSK Clinical Study Register No: 202012.

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

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

Impact of inhaled corticosteroids on cortisol suppression in adults with asthma: a quantitative review

BACKGROUND

Studies examining the effects of inhaled corticosteroids (ICSs) on cortisol suppression show inconsistent results, and there is uncertainty regarding the dose-response relationship between ICSs and cortisol suppression.

OBJECTIVE

To determine, using meta-analysis, the extent of cortisol suppression after administration of clinically relevant ICS doses in adults with asthma.

METHODS

Database searches (MEDLINE, EMBASE, and The Cochrane Library) using appropriate indexed terms were performed to identify eligible articles for review. Articles reporting the effects of ICSs on cortisol levels in asthmatic adults, measured using the cumulative serum or plasma cortisol, morning serum or plasma cortisol, or cumulative overnight urinary free cortisol method, were identified. All available cortisol measurements were extracted. Cortisol suppression was estimated, and treatment arms were grouped into low-, medium-, and high-dose ranges according to the Global Initiative for Asthma guidelines. A multivariate model was used to determine relationships between ICS dose and cortisol suppression and to explore sources of heterogeneity among trials.

RESULTS

Thirty-one studies providing information on 216 measures of cortisol suppression were included in this meta-analysis. Cortisol suppression in the low-, medium-, and high-dose groups were estimated to be 17.92% (95% confidence interval [CI], 11.08%-24.77%), 26.55% (95% CI, 17.29%-35.80%), and 36.31% (95% CI, 26.48%-46.13%), respectively.

CONCLUSIONS

Statistically significant cortisol suppression was evident at low doses of ICSs and increased with dose. These results support an impact of all ICSs on endogenous cortisol levels and underscore the importance of titrating ICS doses to the minimum required to maintain symptom control.

Fluticasone versus beclomethasone or budesonide for chronic asthma in adults and children

BACKGROUND

Beclomethasone dipropionate (BDP) and budesonide (BUD) are commonly prescribed inhaled corticosteroids for the treatment of asthma. Fluticasone propionate (FP) is newer agent with greater potency in in-vitro assays.

OBJECTIVES

To compare the efficacy and safety of Fluticasone to Beclomethasone or Budesonide in the treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trial register (January 2007) and reference lists of articles. We contacted trialists and pharmaceutical companies for additional studies and searched abstracts of major respiratory society meetings (1997 to 2006).

SELECTION CRITERIA

Randomised trials in children and adults comparing Fluticasone to either Beclomethasone or Budesonide in the treatment of chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed articles for inclusion and methodological quality. One reviewer extracted data. Quantitative analyses were undertaken using RevMan analyses 1.0.1.

MAIN RESULTS

Seventy-one studies (14,602 participants) representing 74 randomised comparisons met the inclusion criteria. Methodological quality was fair. Dose ratio 1:2: FP produced a significantly greater end of treatment FEV1 (0.04 litres (95% CI 0 to 0.07 litres), end of treatment and change in morning PEF, but not change in FEV1 or evening PEF. This applied to all drug doses, age groups, and delivery devices. No difference between FP and BDP/BUD were seen for trial withdrawals. FP led to fewer symptoms and less rescue medication use. When given at half the dose of BDP/BUD, FP led to a greater likelihood of pharyngitis. There was no difference in the likelihood of oral candidiasis. Plasma cortisol and 24 hour urinary cortisol was measured frequently but data presentation was limited. Dose ratio 1:1: FP produced a statistically significant difference in morning PEF, evening PEF, and FEV1 over BDP or BUD. The effects on exacerbations were mixed. There were no significant differences incidence of hoarseness, pharyngitis, candidiasis, or cough.

AUTHORS' CONCLUSIONS

Fluticasone given at half the daily dose of beclomethasone or budesonide leads to small improvements in measures of airway calibre, but it appears to have a higher risk of causing sore throat and when given at the same daily dose leads to increased hoarseness. There are concerns about adrenal suppression with Fluticasone given to children at doses greater than 400 mcg/day, but the randomised trials included in this review did not provide sufficient data to address this issue.

Evidence-based selection of inhaled corticosteroid for treatment of chronic asthma

Published literature relevant to comparison of various inhaled corticosteroids (ICSs) was reviewed. Marked heterogeneity was found in the reported results. The efficacy and side effects of ICSs depend on their formulation, dosing and device used, and the subjects' age, severity of asthma, and inhaler technique. All these factors have not been included uniformly in most study designs. Notwithstanding this limitation, it appears that fluticasone is generally very effective and safe in low-to-medium doses and may be used for most patients. Budesonide is the only Pregnancy Category B ICSs, all others being Category C, and it is available as nebulizer suspension suitable for use in children over 6 months of age. Budesonide, also available as dry powder inhaler, and beclomethasone, available as metered-dose inhaler, are equal in efficacy, and side effects and may be chosen according to the patient's ability to handle the device. Flunisolide causes fewer side effects but is also relatively less effective. Triamcinolone is generally less effective and causes more side effects than most of the other ICSs. Mometasone may be preferred if once-daily dosing is desired. Ciclesonide has been found highly effective in once-daily dose and without side effects even in high doses. Further studies comparing it with other ICSs over longer periods of use will determine its place in treatment of chronic asthma.

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

OBJECTIVES

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

DATA SOURCES

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

STUDY SELECTION

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

RESULTS

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

CONCLUSIONS

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

Fluticasone versus HFA-beclomethasone dipropionate for chronic asthma in adults and children

BACKGROUND

The relative efficacy of fluticasone (FP) and beclomethasone (BDP) propelled with CFCs has been well established. The potency of HFA-BDP is thought to have been improved with new propellant and some studies suggest that it may equipotent at half the dose of CFC propelled-BDP. There is a need to revisit this question in the light of a potentially more potent new non-CFC propellant.

OBJECTIVES

To determine the relative efficacy of FP and HFA-propelled BDP in chronic asthma.

SEARCH STRATEGY

The Cochrane Airways Group Specialised Register was searched using pre-specified terms. Searches were current as of January 2006.

SELECTION CRITERIA

Randomised controlled trials were eligible for inclusion in the review. We compared either CFC or HFA-propelled FP with HFA-propelled BDP. We made a distinction between HFA-BDP and HFA-BDP extra fine, which dispenses smaller particles of drug, leading to different, usually more peripheral distribution in the airways. Any inhaler device was considered, and there was no restriction on studies with or without spacers. We included studies which assessed HFA-BDP given via either pMDI, breath-actuated MDI, or DPI.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed studies for inclusion in the review. Data were extracted and entered in to RevMan 4.2 using standard meta-analytical techniques with predefined criteria for exploring statistical heterogeneity.

MAIN RESULTS

Eight studies (1260 participants) met the inclusion criteria of the review. One study was conducted in children. Study reporting quality was fair, but all studies were of short duration (three to twelve weeks). Only studies assessing HFA-BDP extra fine in comparison with FP were identified. Lung function was not significantly different between extra fine BDP and FP when compared at the same dose in parallel studies, change in FEV1: 0.04 litres (95% CI -0.03 to 0.11 litres; three studies, 659 adults); change in am PEF: -0.69 litres (95% CI -11.21 to 9.83 litres; two studies, 364 adults). Individual studies reported non-significant findings in symptom scores and quality of life questionnaires. There was no significant difference between FP and HFA-BDP in the risk of study withdrawal, dysphonia or when data were reported as any adverse event.

AUTHORS' CONCLUSIONS

There was no significant difference between FP and extra fine HFA-BDP on FEV(1) or peak flow at a dose ratio of 1:1. However, the number of studies and width of the confidence intervals in the analyses do not exclude a clinically meaningful difference between these two drugs. Difficulty in the successful manipulation of the devices studied may be a barrier to the widespread use of MDIs. One paediatric study was included in the review, so extrapolation of the findings of this review to children is limited. Further longer term studies in adults and children with moderate and severe asthma are required.

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.

Fluticasone versus HFA-beclomethasone dipropionate for chronic asthma in adults and children

BACKGROUND

The relative efficacy of fluticasone (FP) and beclomethasone (BDP) propelled with CFCs has been well established. The potency of HFA-BDP is thought to have been improved with new propellant and some studies suggest that it may equipotent at half the dose of CFC propelled-BDP. There is a need to revisit this question in the light of a potentially more potent new non-CFC propellant.

OBJECTIVES

To determine the relative efficacy of FP and HFA-propelled BDP in chronic asthma.

SEARCH STRATEGY

The Cochrane Airways Group Specialised Register was searched using pre-specified terms. Searches were current as of March 2005.

SELECTION CRITERIA

Randomised controlled trials were eligible for inclusion in the review. We compared either CFC or HFA-propelled FP with HFA-propelled BDP. We made a distinction between HFA-BDP and HFA-BDP extra fine, which dispenses smaller particles of drug, leading to different, usually more peripheral distribution in the airways. Any inhaler device was considered, and there was no restriction on studies with or without spacers. We included studies which assessed HFA-BDP given via either pMDI, breath-actuated MDI, or DPI.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed studies for inclusion in the review. Data were extracted and entered in to RevMan 4.2 using standard meta-analytical techniques with predefined criteria for exploring statistical heterogeneity.

MAIN RESULTS

Seven studies (1230 participants) met the inclusion criteria of the review. One study was conducted in children. Study reporting quality was fair, but all studies were of short duration (three to twelve weeks). Only studies assessing HFA-BDP extra fine in comparison with FP were identified. Lung function was not significantly different between extra fine BDP and FP when compared at the same dose in parallel studies, change in FEV1: 0.04 litres (95% CI -0.03 to 0.11 litres; three studies, 659 adults); change in am PEF: -0.69 litres (95% CI -11.21 to 9.83 litres; two studies, 364 adults). Individual studies reported non-significant findings in symptom scores and quality of life questionnaires. There was no significant difference between FP and HFA-BDP in the risk of study withdrawal, dysphonia or when data were reported as any adverse event.

AUTHORS' CONCLUSIONS

There was no significant difference between FP and extra fine HFA-BDP on FEV(1) or peak flow at a dose ratio of 1:1. However, the number of studies and width of the confidence intervals in the analyses do not exclude a clinically meaningful difference between these two drugs. Difficulty in the successful manipulation of the devices studied may be a barrier to the widespread use of MDIs. One paediatric study was included in the review, so extrapolation of the findings of this review to children is limited. Further longer term studies in adults and children with moderate and severe asthma are required.

Inhaled fluticasone versus inhaled beclomethasone or inhaled budesonide for chronic asthma in adults and children

BACKGROUND

Beclomethasone dipropionate (BDP) and budesonide (BUD) are commonly prescribed inhaled corticosteroids for the treatment of asthma. Fluticasone propionate (FP) is newer agent with greater potency in in-vitro assays.

OBJECTIVES

To compare the efficacy and safety of Fluticasone to Beclomethasone or Budesonide in the treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trial register (January 2004) and reference lists of articles. We contacted trialists and pharmaceutical companies for additional studies and searched abstracts of major respiratory society meetings (1997 to 2003).

SELECTION CRITERIA

Randomised trials in children and adults comparing Fluticasone to either Beclomethasone or Budesonide in the treatment of chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed articles for inclusion and methodological quality. One reviewer extracted data. Quantitative analyses were undertaken using RevMan analyses 1.0.1.

MAIN RESULTS

Fifty six studies (12, 119 participants) met the inclusion criteria. Methodological quality was variable. Dose ratio 1:2: FP produced a significantly greater FEV1 (0.14 litres, 95% Confidence Interval (CI) 0.06 to 0.22), morning PEF (11.10 L/min, 95%CI 3.12 to 19.09 L/min) and evening PEF (9.31 L/min, 95%CI 5.12 to 13.5 L/min). This applied to all drug doses, age groups, and delivery devices. No difference between FP and BDP/BUD were seen for trial withdrawals. Symptoms and rescue medication use were widely reported but few trials provided sufficient data for analysis. When given at half the dose of BDP/BUD, FP led to a greater likelihood of pharyngitis. There was no difference in the likelihood of oral candidiasis. Plasma cortisol and 24 hour urinary cortisol was measured frequently but data presentation was limited. Dose ratio 1:1: FP produced a statistically significant difference in am PEF (9.58 L/min (95% CI 5.20 to 13.97)), pm PEF (7.41 L/min (95% CI 2.61 to 12.22)), and FEV1 (0.09 L (0.02 to 0.17)). The effects on exacerbations were mixed. There was an increase in the incidence of hoarseness, but no significant difference in pharyngitis, candidiasis, or cough.

AUTHORS' CONCLUSIONS

Fluticasone given at half the daily dose of beclomethasone or budesonide leads to small improvements in measures of airway calibre, but it appears to have a higher risk of causing hoarseness when given at the same daily dose. Future studies should attempt to establish the relative efficacy of inhaled steroids delivered with CFC-free propellants.

Comparative cutoff points for adenosine monophosphate and methacholine challenge testing

BACKGROUND

Current use of the PC20 (provocation concentration that causes a decrease in forced expiratory volume in 1 second of 20%) cutoff point for bronchial challenge precludes its use in patients with more severe airflow obstruction.

OBJECTIVE

To evaluate the efficacy and safety of lower cutoff points for adenosine monophosphate (AMP) and methacholine (MCH) bronchial challenge tools to monitor response to treatment in chronic asthma.

METHODS

We retrospectively examined data from 5 previously published studies (2 using AMP, 2 using MCH, and 1 with MCH and AMP arms) and recalculated 10% and 15% cutoff points for AMP and MCH. Data were analyzed for correlation of single results and doubling dose shifts after anti-inflammatory treatment intervention.

RESULTS

A total of 175 individual MCH challenges and 152 AMP challenges were evaluated. Evaluating the doubling dose shift produced by the addition of anti-inflammatory treatment (inhaled corticosteroids or montelukast) produced the following Pearson correlation coefficients: MCH PD20 (provocation dose that causes a decrease in forced expiratory volume in 1 second of 20%) vs PD15, 0.80; MCH PD20 vs PD10, 0.65; AMP PC20 vs PC15, 0.96; and AMP PC20 vs PC10, 0.84 (P < .001 for all). Subgroup analysis of AMP for before and after inhaled corticosteroids only (n = 41) shows AMP PC20 vs PC15 of 0.92 and AMP PC20 vs PC10 of 0.84 (P < .001 for both).

CONCLUSIONS

The 10% and 15% cutoff points strongly predict the 20% cutoff value for AMP and MCH, as do the doubling dose shifts after anti-inflammatory treatment. The lower thresholds are suitable for monitoring response to therapy, and they expose patients to significantly less provocation agent.

Rapid effect of inhaled steroids on nocturnal worsening of asthma

BACKGROUND

Inhaled steroids are the most commonly used anti-inflammatory agents for asthma and are increasingly recognised as having a more rapid onset of action than was previously thought. We have investigated the effect of a single dose of inhaled steroid on nocturnal worsening of asthma.

METHODS

Ten patients with steroid naive moderate asthma and nocturnal asthma participated in a randomised, double blind, placebo controlled, crossover trial. Participants spent three nights in the laboratory, one week apart. On each night they underwent spirometric testing at 16.00 hours and received one of the three treatments (placebo, beclomethasone 1000 micro g, or fluticasone 1000 micro g) delivered by metered dose inhaler. Spirometric tests were repeated at 04.00 hours the following morning.

RESULTS

Following placebo administration the mean (SE) overnight fall in FEV(1) was 0.65 (0.27) l compared with -0.02 (0.13) l following fluticasone (p=0.019) and 0.23 (0.12) l following beclomethasone (p=0.048 v placebo).

CONCLUSION

A single dose of inhaled steroid (within the therapeutic range) reduced the fall in FEV(1) in patients with nocturnal asthma when administered at 16.00 hours. Nocturnal worsening of asthma is a useful model for testing inhaled steroid activity in a single night study.