Effect of salmeterol/fluticasone propionate combination on airway hyper-responsiveness in patients with well-controlled 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.

Effect of fluticasone and salmeterol on tracheal responsiveness to ovalbumin and lung inflammation, administrated during and after sensitization

The effect of duration of administration of fluticasone propionate and salmeterol on tracheal responsiveness to ovalbumin and total and differential white blood cell in sensitized guinea pig was examined. Six groups of guinea pigs (n=7) were sensitized to ovalbumin. Three groups of them were subjected to inhaled fluticasone propionate and salmeterol, one group during sensitization (A), one group after that (for 18 days, B), and the other one during sensitization but with 18 days delay before measurements (C). Three other groups were treated with placebo in the same manner. The tracheal responsiveness to ovalbumin and total and differential white blood cells of three placebo groups were significantly higher than those of control group (P<0.001 for all cases). Tracheal responsiveness to ovalbumin and total and differential white blood cell in treated groups with fluticasone propionate and salmeterol were significantly decreased compared to those of placebo groups (nonsignificant to P<0.001). The improvement in all variables in treatment groups A and C were more pronounced than group B. The results showed that fluticasone propionate and salmeterol had a prevention effect on tracheal hyperresponsiveness to ovalbumin and lung inflammation which was more pronounced when administered during than after sensitization.

Effects of low-dose fluticasone propionate/salmeterol combination therapy on exhaled nitric oxide and nitrite/nitrate in breath condensates from patients with mild persistent asthma

OBJECTIVE

The long-acting β2-agonist salmeterol in combination with the corticosteroid fluticasone propionate is used in clinical practice for the treatment of mild persistent asthma. Although the effect of fluticasone propionate alone in asthmatic patients is well documented, the effect of fluticasone propionate/salmeterol (FSC) combination therapy on airway inflammation and airway hyperresponsiveness (AHR) is not well characterized. Thus, we evaluated AHR, exhaled nitric oxide (FE(NO)), and nitrite and nitrate in exhaled breath condensates (EBCs) from mild persistent asthmatic patients treated with a low-dose FSC (100/50).

METHODS

In this open label study, 18 mild persistent, steroid-naïve asthmatics (age, 22-62 years, forced expiratory volume in 1 s (FEV(1)) > 70% predicted, provocative dose resulting in 20% reduction (PD(20)) < 10 mg/mL) were treated with FSC 100/50 for 4 weeks. PD(20) to methacholine, FEV(1), FE(NO), and EBC nitrite and nitrate was measured before and after treatment.

RESULTS

After 4 weeks of therapy with FSC 100/50, FE(NO) decreased from 74 ppb (SD = 37) to 34 ppb (SD = 15) (p < .001). FEV(1) (% predicted) increased from 89.4 (SD = 10.7) to 93.3 (SD = 9.5) (p < .01). The PD(20) for methacholine increased from 3.0 (±3.2) to 10.3 (±8.4) mg/mL (p < .01) in 3 of 18 patients reaching the maximum allowable dose (25 mg/mL). FE(NO) correlated with the log of the methacholine dose. There was no statistically significant change in EBC nitrite and nitrate before and after treatment.

CONCLUSIONS

Treatment of mild persistent, steroid-naïve asthmatics with low-dose combination therapy is effective in rapidly reducing airway inflammation and AHR. Our results suggest different metabolic origins for nitrite, nitrate, and FE(NO) in this group of patients.