Comparing the effects of two inhaled glucocorticoids on allergen-induced bronchoconstriction and markers of systemic effects, a randomised cross-over double-blind study
© Lötvall et al; licensee BioMed Central Ltd. 2011
Received: 25 August 2011
Accepted: 31 October 2011
Published: 31 October 2011
Inhaled glucocorticoids are efficient in protecting against asthma exacerbations, but methods to compare their efficacy vs systemic effects have only been attempted in larger multi-centre studies. The aim of the current study was therefore to directly compare the effects of two separate inhaled glucocorticoids, mometasone and budesonide, to compare the effects on the early and late asthmatic responses to inhaled allergen in patients with mild allergic asthma, and sputum eosinophils, and to relate the clinical positive effects to any systemic effects observed.
Twelve patients with documented early and late asthmatic responses (EAR and LAR) to inhaled allergen at a screening visit were randomized in a double-blind fashion to treatment with mometasone (200 μg × 2 or 400 μg × 2), budesonide (400 μg × 2) or placebo in a double-blind crossover fashion for a period of seven days. Challenge with the total allergen dose causing both an EAR and LAR was given on the last day of treatment taken in the morning. Lung function was assessed using FEV1, and systemic glucocorticoid activity was quantified using 24 h urinary cortisol.
Mometasone and budesonide attenuate both EAR and LAR to allergen to a similar degree. No significant dose-related effects on the lung function parameters were observed. Both treatments reduced the relative amount of sputum eosinophils (%) after allergen. At the dose of 800 μg daily, mometasone reduced 24 h urinary cortisol by approximately 35%. Both drugs were well tolerated.
Mometasone and budesonide are equieffective in reducing early and late asthmatic responses induced by inhaled allergen challenge. Mometasone 800 μg given for seven days partially affects the HPA axis.
Keywordsallergen asthma budesonide mometasone inflammation
Asthmatic patients with allergies often develop early (EAR) and in some patients also a late asthmatic response (LAR) when a relevant allergen is inhaled [1–3]. Allergen exposure can also increase non-specific bronchial hyperresponsiveness to stimuli such as methacholine or histamine . The LAR and the bronchial hyperresponsiveness are often associated with increase of eosinophils in the blood, and influx of eosinophils into the airways [3, 5].
The anti-inflammatory effects of inhaled glucocorticoids in asthma are well documented [1, 6, 7], shown by attenuation of the EAR, LAR and allergen-induced sputum eosinophils. Glucocorticoids are also more effective than anti-leukotrienes in attenuating the LARs and improve the bronchial hyperresponsiveness in mild asthmatic patients . Mometasone and budesonide are corticosteroids that have been shown having a significant effect on late events induced by allergen, including attenuation of the LAR and reductions in eosinophil and neutrophil recruitment and activation [5, 9, 10].
The aim of the present study was to directly compare the effects of inhaled mometasone with inhaled budesonide and placebo on allergen-induced airway responses in mild asthmatic patients. Treatments were given for seven days and the allergen challenge was performed on Day 7 of treatment. Lung function was measured to assess the development of EAR and LAR. Sputum and blood were analysed in order to assess inflammatory processes. To determine whether any differences in systemic effects of the drugs could be detected, urinary cortisol was measured.
Materials and methods
Characteristics of the patients
Exclusion criteria were inability to produce sputum after inhalation of hypertonic saline, ongoing treatment with inhaled or oral glucocorticoid or long-acting inhaled β-2-agonist, ongoing smoker and pregnancy. Patients with other significant diseases were also excluded.
This was a randomized, double-blind, placebo-controlled, cross-over study at one single centre. Approval was obtained by the Swedish Medical Product Agency and the Local Ethics Committee. Written informed consent was received form all patients before enrolment. All patients received four different interventions including mometasone 2 × 200 μg, mometasone 2 × 400 μg, budesonide 2 × 400 μg and placebo with one week wash-out between treatments. The study was performed during 2001-2003, before the requirement to register clinical trials in clinicaltrials.gov.
The study medication for one treatment period was brought home by the patient and the study treatment was initiated after a telephone contact with the patient one to two weeks after randomisation. Study medications were given as one dose in the morning and evening for 7 days (only in the morning on Day 7).
The patient returned to the clinic on day 7. The cumulative allergen dose titrated on the screening day was given as a single dose allergen challenge (after the morning dose of inhaled treatment) in each treatment period. Induction of sputum was performed 24 h after allergen challenge.
Allergen extracts (cat, dog, or horse) from Copenhagen Allergology Laboratory (ALK), Copenhagen, Denmark, were used. The screening allergen provocation protocol started with the diluents, and the pre titrated allergen dose given was 32 standard quality units (SQU/ml). There was a twofold increase between every dose step. The highest allergen dose was 64 000 SQ-U/ml. FEV1 was measured 5 and 10 min after each dose (the best of two manoeuvres with 1 min between). When FEV1 had fallen at least 20% from the baseline value, the allergen provocation was stopped (EAR). After the last allergen dose FEV1 was measured at 15, 20, 30, 45 and 60 min during the first hour, and then every hour up to 10 h. The cumulative allergen dose titrated on the screening day was given as a single dose on day 7 in all four treatment periods. The FEV1 was measured at the same time-points as above.
The LAR was defined as a fall in FEV1 of 15% from baseline value on at least one time point between 3 and 7 h after the allergen dose that caused the EAR.
Methacholine challenge was performed 24 h after the allergen challenge at the screening and on Day 8. At a starting concentration of 0.03 mg/ml, twofold increasing concentrations were administered every fifth minute. FEV1 was measured at 90 and 180 s after the inhalations. When FEV1 had fallen with ≥ 20%, the provocation was stopped (Provocative Concentration changing FEV1 by 20% = PC20).
The dosimeter ME.FAR MB3 (Mefar, Brescia, Italy) was used for all bronchial challenges (allergen and methacholine). The patient inhaled slowly the dose of aerosol by means of an inspiratory capacity breath, followed by 5 s of breath holding. For each dose of allergen or methacholine, five inhalations were given. The nebulization time was set to 1 s. The patients were instructed to use a home spirometer (One Flow soft 1.0 from STI) for the FEV1 measurements 1 h to 10 h after allergen exposure.
Sputum induction was performed using a modification of the method of Pin et al.  with an aerosol of hypertonic saline. Inhalations started with 3% concentrations of saline for 7 min. If FEV1 had dropped less than 10% from baseline, the next saline concentration (4 and 5%, respectively) was administered. If the fall in FEV1 was between 10 and 20% from baseline, the same saline concentration was given for the next 7 min. The nebulization was stopped if the fall in FEV1 was more than 20% from baseline. The sputum was coughed up into a container and further analysed. After the sputum induction at the screening and on day eight, a single oral dose of 30 mg of prednisolone was given to reverse any remaining effects on LAR, as used previously .
Sputum cell analysis
Sputum samples were examined within 2 h (kept cold) using a modified method described by Pizzichini et al.1996 [12–14]. Sputum cells were prepared as described earlier and the total number of cells and cell viability was assessed . Percentage of eosinophils (%) were identified by differential counts using a combination of luxol fast blue and chloroacetate esterase staining.
Samples for blood eosinophils and ECP were collected at the screening and on day 7 both before and 24 h after allergen challenge. Urinary samples for analysing cortisol and creatinine analyses were collected 24 h post allergen (Day 8).
Power calculations showed that less than five patients are required to document a 50% reduction of LAR with 90% power [15, 16]. To document a similar reduction of sputum eosinophils (%), a similar number of patients are required . Therefore, a study including twelve patients further increases the statistical power. Comparisons were made using student's paired t-test, and a p-value < 0.05 was considered statistically significant.
All twelve subjects who entered the study (Figure 1) also completed all the four arms of the crossover study. There was no significant difference between treatment groups in baseline FEV1 prior to allergen; the values were 3.30 L after placebo, 3.40 L after Mometasone (400 μg), 3.38 L after Mometasone (800 μg) and 3.30 L after treatment with budesonide (800 μg).
Early allergen response (EAR)
Late asthmatic response (LAR)
Twenty-four hours after allergen challenge the methacholine PC20 was 6.3, 11.1, 16.7 and 9.9 mg/ml during placebo, 400 μg mometasone, 800 μg mometasone and 800 μg budesonide treatment respectively. The result in all three treatment groups was statistically different from placebo. The low and high doses of mometasone reduced methacholine responsiveness with 2.6 and 2.8 doubling doses respectively in relation to placebo treatment (P = 0.004, P = 0.011), and the treatment with budesonide resulted in a doubling dose shift of of 2.4 vs placebo (P = 0.005). No significant differences were observed among treatments.
Comparison between treatments
2 × 400 μg
2 × 400 μg
This cross-over double blind placebo controlled study shows that one week treatment with both Mometasone 400 and 800 μg and Budesonide 800 μg affected physiological early and late asthmatic responses induced by inhaled allergen provocation, as well as inflammatory markers such as sputum eosinophils. The data suggests that Mometasone was more effective in attenuating the early asthmatic response than budesonide was at the same microgram daily doses. Furthermore, methacholine responsiveness 24 h after allergen provocation was significantly improved with all treatments. In parallel, effects of the inhaled glucocorticoids on serum cortisol was evaluated to determine airway effects vs systemic effects, showing only significant reduction of this parameter with the higher dose of mometasone.
This direct comparison between mometasone and budesonide suggests very similar inhibitory effects on allergen induced physiological responses in asthmatic patients with these two inhaled glucocorticoids, although mometasone at the higher dose cause a significantly greater inhibition of the early asthmatic response. The reduction of both the early and the late asthmatic response with the treatments was similar to what can be observed with other inhaled glucocorticoids [6, 8, 16]. It must be recognized that our main aim was to relate airway effects vs systemic effects, and therefore quite high doses of inhaled glucocorticoids were tested. Thus, it may be difficult to compare the exact potency of these drugs, as no full dose response could be performed with this complicated provocation protocol. In fact, such a full dose-response evaluation has not been reported with any inhaled glucocorticoid on allergen-induced asthma responses to date.
The three different active treatments all significantly and strongly reduced the sputum eosinophilia observed 24 h after airway allergen exposure, with no differences observed between them. This argues that both drugs and the doses tested are sufficient to efficiently attenuate the inflammatory response associated with the late asthmatic response, as has been previously documented [2, 9, 18]. The exact mechanism by which inhaled glucocorticoids have such pronounced effect on eosinophilic inflammation are not clear, although inhibitory effects on T-lymphocyte responses may be crucial .
Methacholine responsiveness, measured 24 h after the allergen provocation, was significantly attenuated by both doses of mometasone, as well as the single studied dose of budesonide. Importantly, this attenuation of bronchial hyperresponsiveness has two components to it. Firstly, the inhaled glucocorticoid significantly improves baseline bronchial hyperresponsivness [20, 21], and secondly, it is also known that inhaled glucocorticoids can attenuate the increase in hyperresponsiveness induced by allergen exposure [15, 16, 22, 23]. Thus, the attenuation of hyperresponsiveness observed in the current study is a composite effect of the inhaled glucocorticoid therapy on general bronchial hyperresponsiveness and the increased hyperresponsivness induced by the experimental allergen exposure. It is unlikely that the two studied inhaled glucocorticoids have fundamentally and mechanistically different effects on these separate explanations for the methacholine responsivenss value measured 24 h after allergen exposure.
With both doses of mometasone, and the single dose of budesonide studied, pronounced and highly significant inhibitory effects on allergen-induced sputum eosinophils were observed, and no dose-related effects of mometasone were obvious. This argues that the doses of inhaled glucocorticoids used in the current study was quite high for attenuating sputum eosinophils, and arguing that the anti-inflammatory efficacy of the doses studied were high.
Quite high doses of inhaled glucocorticoids were studied, to add the potential of studying also systemic effects of the two different inhaled glucocorticoids. Furthermore, we decided to study two doses of mometasone, to allow for documentation of some dose-related effects on either anti-asthma effects or systemic effects. Indeed, some differences in both airway and systemic effects were observed, with greater inhibition on the early asthmatic response with the higher dose of mometasone. However, in parallel a slightly increased effect on 24 h urinary cortisol was observed, which thus means that the higher dose of mometasone also expressed some systemic effects. Thus, the additive effect with the higher dose of mometasone was associated with greater systemic effect, arguing against any major difference in therapeutic ratio between the two different inhaled glucocorticoids.
In summary, both mometasone and budesonide at the doses studied (daily doses 400 and 800 μg for mometasone and 800 μg for budesonide) are highly effective in attenuating allergen-induced immediate airway responses, and strongly attenuate eosinophilic inflammation in the airways. Increased efficacy in the airways with the higher dose of mometasone was associated with a slightly higher degree of systemic effects, suggesting that increasing the dose is not necessarily associated with an improved therapeutic ratio. Inhaled glucocorticoids are efficient anti-inflammatory treatments in allergic asthma, and documenting any key differences in therapeutic effects and therapeutic ratio may deem difficult.
Early asthmatic responses
Eosinophil Cationic Protein
Forced expiratory volume over 1 s
Late asthmatic responses
Provocative concentration changing FEV1 by 20%
Area under the plasma concentration - time curve
The authors thank Schering-Plough Sweden for financial support to perform this study, as well as Birgitta Aronsson, Helen Törnqvist and Mary-Anne Raneklint for performing the challenges and monitoring the patients.
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