Starting inhaled corticosteroids in asthma: when, how high, and how long

Effect of disease duration on dose-response of inhaled budesonide in asthma

BACKGROUND

Inhaled corticosteroids (ICS) represent first-line treatment in persistent asthma with clinical studies showing benefits of initiating therapy early. Whether treatment should be started with a high or low dose remains controversial. We investigated the importance of disease duration on the response to the starting dose of the ICS, budesonide, in asthma patients not previously treated with ICS.

METHODS

Forty patients with newly detected asthma (symptoms for <12 months) and 41 patients with established asthma (mean duration 5.2 years, range 2-11) were randomized (double-blind, parallel-group) to treatment with budesonide Turbuhaler 100 or 400microg twice daily or placebo for 12 weeks.

RESULTS

For morning peak expiratory flow (mPEF), all four budesonide treatments resulted in statistically significant improvements from baseline and, after 12 weeks, the changes in all four groups were statistically significantly greater than placebo. In patients receiving early treatment, no significant differences were seen between budesonide doses. In patients with established symptoms, 800 mg/day [corrected] improved mPEF significantly more than 200 mg/day [corrected] The 200 mg/day [corrected] dose in the early treatment group improved mPEF significantly more than in the delayed treatment group. Changes in forced expiratory volume in 1s (FEV(1)), the concentration of inhaled histamine causing a 20% drop in FEV(1), and use of as-needed medication behaved in very similar ways to mPEF. Asthma symptoms were reduced in all budesonide groups without a difference between doses.

CONCLUSION

In patients with newly detected asthma treated early the initial ICS dose is not important. In contrast, in patients with symptoms for a longer duration a high starting dose improves airway function and hyperresponsiveness significantly better than a low dose.

Step-down compared to fixed-dose treatment with inhaled fluticasone propionate in asthma

BACKGROUND

Inhaled corticosteroids (ICSs) are an effective treatment of asthma even when administered at a low dose. Once asthma is controlled, current guidelines recommend that the dose of ICS be reduced to the lowest possible and effective dose. Although the most appropriate strategy for the stepping down has not yet been defined, quantification of sputum eosinophils and bronchial hyperresponsiveness (BHR) are indeed measures of asthma control.

OBJECTIVE

To compare the efficacy of step-down and fixed-dose strategies in the control of BHR to methacholine and eosinophilic inflammation patients with mild-to-moderate asthma.

METHODS

We performed a double-blind, randomized study to compare inhaled fluticasone propionate (FP), 1,000 microg/d, then reduced to 200 microg/d (group 1; n = 18) to a fixed dose of FP, 200 microg/d (group 2; n = 17) administered for 6 weeks and then 8 weeks in reducing the provocative dose of methacholine causing a 20% fall in FEV1 (PD20) and sputum eosinophils in 35 patients. The duration of the efficacy was also followed subsequently after 8 weeks of placebo treatment.

RESULTS

PD20 remarkably increased with both treatment strategies, but differences between groups were not significant. Sputum eosinophils (median values, percentage) at baseline and after each treatment period were not different (group 1, 16.4 to 1.0 to 2.7%; group 2, 16.7 to 2.8 to 2.8%, respectively). The percentages of patients in whom sputum eosinophilia was normalized (< or = 3%) were as follows: group 1, 69% and 60%; group 2, 50% and 57%. After placebo treatment, sputum eosinophils were still "normalized" in approximately one third of patients.

CONCLUSION

Step-down and fixed-dose strategies with FP improved PD20 and sputum eosinophilia to a similar degree. The effect on sputum eosinophils persisted longer than that on methacholine.

Asthma control and steroid doses 5 years after early or delayed introduction of inhaled corticosteroids in asthma: a real-life study

We evaluated asthma control and medication use 5 years after introduction of an inhaled corticosteroid (budesonide via Turbuhaler) in 462 patients with persistent asthma and symptoms of different duration. An early treatment group with symptoms for <2 years (group A) was compared with a delayed treatment group (group B) (median duration 5 years and 3 months). Most patients received budesonide 400 microg twice daily as initial dose. We report 5-year follow-up data on 404 patients (group A n = 253; group B n = 151) and on a few more patients after treatment for 6 months, 1 year and 3 years. At 5 years the mean maintenance doses of budesonide were 412 microg (A) and 825 microg (B), respectively (P<0.001). Nevertheless, treatment goals (normal lung function, normal exercise tolerance, minimal use of reliever medication, no asthma exacerbations) were all statistically significantly more frequently achieved in group A. At 5 years group B patients also used significantly more additional asthma medications, e.g. inhaled long-acting beta2-agonists by 64% compared with 6% in group A. In group A 43 patients (17%) had been able to stop budesonide treatment compared to five patients (3%) in group B. A subgroup of group B patients with higher mean baseline FEV1 values than group A showed nevertheless significantly poorer response. No treatment-related serious adverse events were reported. Budesonide was well tolerated in both groups.

CONCLUSION

Duration of asthma symptoms when starting treatment with an inhaled corticosteroid is an important determinant for the response. Early treatment gives significantly better airway function and asthma control than delayed treatment and at lower maintenance doses.

Airway inflammation, basement membrane thickening and bronchial hyperresponsiveness in asthma

BACKGROUND

There are few data in asthma relating airway physiology, inflammation and remodelling and the relative effects of inhaled corticosteroid (ICS) treatment on these parameters. A study of the relationships between spirometric indices, airway inflammation, airway remodelling, and bronchial hyperreactivity (BHR) before and after treatment with high dose inhaled fluticasone propionate (FP 750 microg bd) was performed in a group of patients with relatively mild but symptomatic asthma.

METHODS

A double blind, randomised, placebo controlled, parallel group study of inhaled FP was performed in 35 asthmatic patients. Bronchoalveolar lavage (BAL) and airway biopsy studies were carried out at baseline and after 3 and 12 months of treatment. Twenty two normal healthy non-asthmatic subjects acted as controls.

RESULTS

BAL fluid eosinophils, mast cells, and epithelial cells were significantly higher in asthmatic patients than in controls at baseline (p<0.01). Subepithelial reticular basement membrane (rbm) thickness was variable, but overall was increased in asthmatic patients compared with controls (p<0.01). Multiple regression analysis explained 40% of the variability in BHR, 21% related to rbm thickness, 11% to BAL epithelial cells, and 8% to BAL eosinophils. The longitudinal data corroborated the cross sectional model. Forced expiratory volume in 1 second improved after 3 months of treatment with FP with no further improvement at 12 months. PD(20) improved throughout the study. BAL inflammatory cells decreased following 3 months of treatment with no further improvement at 12 months (p<0.05 v placebo). Rbm thickness decreased in the FP group, but only after 12 months of treatment (mean change -1.9, 95% CI -3 to -0.7 microm; p<0.01 v. baseline, p<0.05 v. placebo). A third of the improvement in BHR with FP was associated with early changes in inflammation, but the more progressive and larger improvement was associated with the later improvement in airway remodelling.

CONCLUSION

Physiology, airway inflammation and remodelling in asthma are interrelated and improve with ICS. Changes are not temporally concordant, with prolonged treatment necessary for maximal benefit in remodelling and PD(20). Determining the appropriate dose of inhaled steroids only by reference to symptoms and lung function, as specified in current international guidelines, and even against indices of inflammation may be over simplistic. The results of this study support the need for early and long term intervention with ICS, even in patients with relatively mild asthma.