Inhaled salmeterol/fluticasone propionate: a review of its use in asthma

Pharmacokinetic Models for Inhaled Fluticasone Propionate and Salmeterol Xinafoate to Quantify Batch-to-Batch Variability

Advair Diskus is an essential treatment for asthma and chronic obstructive pulmonary disease. It is a dry powder inhaler with a combination of fluticasone propionate (FP) and salmeterol xinafoate (SX). However, the pharmacokinetics (PK) batch-to-batch variability of the reference-listed drug (RLD) hindered its generic product development. This work developed the PK models for inhaled FP and SX that could represent potential batch variability. Two batches each of the reference and the test product (R1, R2, T1, T2) of Advair Diskus (100 μg FP/50 μg SX inhalation) were administered to 60 healthy subjects in a 4-period, 4-sequence crossover study. The failure of the bioequivalence (BE) between R1 and R2 confirmed the high between-batch variability of the RLD. Non-linear mixed effect modeling was used to estimate the population mean PK parameters for each batch. For FP, a 2-compartment model with a sequential dual zero-order absorption best described the PK profile. For SX, a 2-compartment model with a first-order absorption model best fit the data. Both models were able to capture the plasma concentration, the maximum concentration, and the total exposure (AUCinf) adequately for each batch, which could be used to simulate the BE study in the future. In vitro properties were also measured for each batch, and the batch with a higher fraction of the fine particle (diameter < 1 µm, < 2 µm) had a higher AUCinf. This positive correlation for both FP and SX could potentially assist the batch selection for the PK BE study.

A large particle size is required by a nano/micron sized-fluticasone propionate inhalable suspension for asthma treatment

The nano/micron sized-fluticasone propionate inhalable suspension (FPs) is used for asthma treatment, and this study aimed to elucidate the effects of particle size on the absorption of FPs by various pulmonary cells and the subsequent therapeutic efficacy for asthma. FPs of 727, 1136 and 1612 nm were prepared, and an increase in diameter diminished the endocytosis and macropinocytosis of FPs by alveolar epithelial cells (A549 and Calu-3 cells) but facilitated their uptake by M2-like macrophages; results about the transport across Calu-3 monolayer showed the mucus layer was the main rate-limiting step for the uptake of FPs by epithelial cells; the animal tests showed that although a decrease in diameter improved the pulmonary absorption of FPs, the particle size did not affect the lung distribution of FPs; a further detection revealed that larger FPs were taken more effectively by alveolar macrophages and lymphocytes and exerted a better therapeutic effect on asthma than the smaller ones. This study showed that the particle size of FPs had a significant impact on their absorption, elimination and cellular distribution in the lung after inhalation and further on their effectiveness in asthma treatment, and the particle size of the nano/micron sized-FPs should be designed and optimized for asthma treatment on the premise of meeting the requirements of inhalation preparations.

Assessment of the efficacy and safety of fluticasone propionate and salmeterol delivered as a combination dry powder via a capsule-based inhaler and a multi-dose inhaler in patients with asthma

BACKGROUND

In developing countries, there is a need for access to affordable inhaled respiratory medicines. This study tested the clinical non-inferiority of fluticasone propionate/salmeterol combination (FSC) 50/250 μg Rotacaps^®/Rotahaler^® compared with FSC 50/250 μg Diskus^®.

METHODS

A multi-centre, randomised, double-blind, double-dummy study evaluated 12 weeks, twice daily treatment of FSC 50/250 μg administered using Rotacaps/Rotahaler or Diskus inhaler in a crossover design in patients with asthma (pre-bronchodilator forced expiratory volume in 1 s (FEV₁) 40%-85% of predicted, FEV₁ reversibility ≥12%, prior stable dose with inhaled corticosteroid (ICS) or ICS/long acting beta-agonist). The primary efficacy endpoint, change from baseline in trough morning FEV₁ at Day 85, was analysed using a model for repeated measures analysis. The pre-defined criterion for non-inferiority was the lower limit of the CI (0.025, one-sided significance level) for the treatment difference (Rotacaps/Rotahaler-Diskus) in least squares (LS) mean change from baseline, being greater than -125 mL. Secondary endpoints included serial FEV₁ measurements, morning peak expiratory flow (PEF), rescue medication use, day- and night-time asthma symptoms, Asthma Control Test (ACT) scores, and serial cortisol measured over 12 h (area under the curve (AUC_0-12)).

RESULTS

Treatment with FSC 50/250 μg via Rotacaps/Rotahaler or Diskus resulted in a similar LS mean increase from baseline in trough FEV₁ at Day 85 (231 mL and 203 mL respectively). The difference in the model-adjusted LS mean change was 28 mL (95% CI -24 mL, 80 mL), fulfilling the criterion for non-inferiority. Data for all secondary endpoints were similar for the two treatments, supporting the primary endpoint findings. Both treatments were well tolerated and demonstrated similar safety profiles.

CONCLUSION

This study demonstrated the clinical non-inferiority of FSC 50/250 μg when administered using Rotacaps/Rotahaler compared with administration using Diskus in patients with asthma, and suggests there is no difference in the risk:benefit profile between the two FSC inhalers.

Treatment of exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) describes the transient narrowing of the airways during, and particularly after exercise and occurs commonly in asthmatic individuals. Limitation of exercise capacity is a frequent complaint in all age groups, and severity of EIB ranges from mild impairment of performance to severe bronchospasm and a large reduction in FEV1. Treatment of EIB varies from daily to less frequent therapy, depending on the level of activity. In this article, the authors evaluate the treatment possibilities before, during, and after exercise. They also review medications currently used to treat EIB.

Long-term safety and efficacy of fluticasone/formoterol combination therapy in asthma

BACKGROUND

The long-term safety of a new asthma therapy combining fluticasone propionate and formoterol fumarate (fluticasone/formoterol; flutiform(®)) was assessed.

METHOD

In an open-label study, mild to moderate-severe asthmatics (≥12 years; N=472) were treated twice daily with fluticasone/formoterol 100/10 μg (n=224) or 250/10 μg (n=248) for 6 months (n=256) or 12 months (n=216). The primary and secondary objectives were the long-term safety and efficacy of fluticasone/formoterol, respectively.

RESULTS

In total, 413 (87.5%) patients completed the study (of which 175 participated for 12 months). Adverse events (AEs) were reported by 174 patients (36.9%): 67 (29.9%) in the 100/10 μg group and 107 (43.1%) in the 250/10 μg group. The most common AEs (>2%) were nasopharyngitis, dyspnea, pharyngitis, and headache; the majority were mild to moderate. Only 18 (3.8%) patients reported AEs considered study drug-related. Five patients per group experienced 12 serious AEs; none was study medication-related. Asthma exacerbations were reported by 53 patients (11.2%): 46 mild to moderate and nine severe. Clinical laboratory tests and vital signs showed no abnormal trends or clinically important or dose-response-related changes. The efficacy analyses showed statistically significant improvements at every time point throughout the study period at both doses.

CONCLUSION

Fluticasone/formoterol had a good safety and efficacy profile over the 6- and 12-month study periods.

Dual-pharmacology muscarinic antagonist and β₂ agonist molecules for the treatment of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is one of the leading causes of death in the world today. Bronchodilators, particularly muscarinic antagonists and β(2) agonists, are recommended for patients with moderate to severe COPD. Dual-pharmacology muscarinic antagonist- β(2) agonist (MABA) molecules present an exciting new approach to the treatment of COPD by combining muscarinic antagonism and β(2) agonism in a single entity. They have the potential to demonstrate additive or synergistic bronchodilation over either pharmacology alone. Due to this enticing prospect, several companies have now reported MABA discovery efforts through a conjugated/linked strategy with one candidate (GSK-961081) demonstrating clinical proof of concept. Several MABA crystal forms have been identified, satisfying the requirements for inhaled dosing devices. There are significant challenges in designing MABAs, but the potential to achieve enhanced bronchoprotection in patients and facilitate 'triple therapy' makes this an extremely important and exciting area of pharmaceutical research.

p38 mitogen-activated protein kinase-γ inhibition by long-acting β2 adrenergic agonists reversed steroid insensitivity in severe asthma

Corticosteroid insensitivity (CI) is a major barrier to treating severe asthma. Despite intensive research, the molecular mechanism of CI remains uncertain. The aim of this study was to determine abnormality in corticosteroid action in severe asthma and to identify the molecular mechanism of the long-acting β(2)-adrenergic agonists (LABAs) formoterol and salmeterol on restoration of corticosteroid sensitivity in severe asthma in vitro. Peripheral blood mononuclear cells (PBMCs) were obtained from 16 subjects with severe corticosteroid-insensitive asthma, 6 subjects with mild corticosteroid-sensitive asthma, and 11 healthy volunteers. Corticosteroid (dexamethasone) sensitivity was determined on tumor necrosis factor-α (TNF-α)-induced interleukin (IL)-8 production. Glucocorticoid receptor (GR) phosphorylation and kinase phosphorylation were evaluated by immunoprecipitation-Western blotting analysis and kinase phosphorylation array in IL-2/IL-4-treated corticosteroid insensitive model in PBMCs. In vitro corticosteroid sensitivity on TNF-α-induced IL-8 production was significantly lower in patients with severe asthma than in healthy volunteers and patients with mild asthma. This CI seen in severe asthma was associated with reduced GR nuclear translocation and with hyperphosphorylation of GR, which were reversed by LABAs. In IL-2/IL-4-treated PBMCs, LABAs inhibited phosphorylation of Jun-NH(2)-terminal kinase and p38 mitogen-activated protein kinase-γ (p38MAPK-γ) as well as GR. In addition, cells with p38MAPK-γ knockdown by RNA interference did not develop CI in the presence of IL-2/IL-4. Furthermore, p38MAPK-γ protein expression was up-regulated in PBMCs from some patients with severe asthma. In conclusion, p38 MAPK-γ activation impairs corticosteroid action and p38 MAPK-γ inhibition by LABAs has potential for the treatment of severe asthma.

Asthma in elite athletes

Asthma is frequently found among elite athletes performing endurance sports such as swimming, rowing and cross-country skiing. Although these athletes often report symptoms while exercising, they seldom have symptoms at rest. Moreover, compared with nonathletic asthmatic individuals, elite athletes have been shown to have a different distribution of airway inflammation and unequal response to bronchial provocative test. Elite athletes display signs of exercise-induced symptoms, for example, nonasthmatic inspiratory wheeze, vocal cord dysfunction and cardiac arrhythmias, which could limit their physical capacity. Elite athletes should undergo comprehensive assessment to confirm an asthma diagnosis and determine its degree of severity. Treatment should be as for any other asthmatic individual, including the use of β2-agonist, inhaled steroid as well as leukotriene-antagonist. It should, however, be noted that daily use of β-agonists could expose elite athletes to the risk of developing tolerance towards these drugs. Use of β2-agonist should be replaced with daily inhaled corticosteroid treatment, the most important treatment of exercise-induced asthma. All physicians treating asthma should be aware of the doping aspects. Systemic β2-agonist intake is strictly prohibited, whereas inhaled treatment is allowed in therapeutic doses when asthma is documented and dispensation has been granted when needed.

Asthma in elite athletes: pathogenesis, diagnosis, differential diagnoses, and treatment

Elite athletes have a high prevalence of asthma and exercise-induced bronchoconstriction. Although respiratory symptoms can be suggestive of asthma, the diagnosis of asthma in elite athletes cannot be based solely on the presence or absence of symptoms; diagnosis should be based on objective measurements, such as the eucapnic voluntary hyperpnea test or exercise test. When considering that not all respiratory symptoms are due to asthma, other diagnoses should be considered. Certain regulations apply to elite athletes who require asthma medication for asthma. Knowledge of these regulations is essential when treating elite athletes. This article is aimed at physicians who diagnose and treat athletes with respiratory symptoms. It focuses on the pathogenesis of asthma and exercise-induced bronchoconstriction in elite athletes and how the diagnosis can be made. Furthermore, treatment of elite athletes with asthma, anti-doping regulations, and differential diagnoses such as exercise-induced laryngomalacia are discussed.

Long-term safety of mometasone furoate/formoterol combination for treatment of patients with persistent asthma

Objective: The combination of inhaled corticosteroid (ICS) and long-acting β₂-agonist is recommended for treatment of patients with persistent asthma inadequately controlled on ICS monotherapy. This study was conducted to evaluate the long-term safety of mometasone furoate/formoterol (MF/F) administered through metered-dose inhaler (MDI) in patients with persistent asthma previously on medium- to high-dose ICS. Methods: This was a 52-week, randomized, multicenter, parallel-group, open-label, evaluator-blinded study. At baseline, 404 patients (aged >12 years) were stratified according to their previous ICS dose (medium or high), then randomized 2:1 to receive twice-daily treatment of MF/F (200/10 or 400/10 μg) or fluticasone propionate/salmeterol (FP/S; 250/50 or 500/50 μg). The primary endpoint was the number and percentage of patients reporting any adverse event (AE). Additional safety evaluations included plasma cortisol 24-hour area under the curve (AUC_0–24h) and ocular changes. Pulmonary function, asthma symptoms, and use of rescue medication were monitored. Results: The incidence of >1 treatment-emergent AE was similar across treatment groups (MF/F 200/10 μg, 77.3% [n = 109]; FP/S 250/50 μg, 82.4% [n = 56]; MF/F 400/10 μg, 79.2% [n = 103]; FP/S 500/50 μg, 76.9% [n = 50]). Rates of treatment-related AEs were also similar across treatment groups (MF/F 200/10 μg, 28.4%; FP/S 250/50 μg, 23.5%; MF/F 400/10 μg, 23.1%; FP/S 500/50 μg, 20.0%). Headache (3.7%) and dysphonia (2.7%) were the most common treatment-related AEs overall. The nature and frequency of AEs and the decreases in plasma cortisol AUC_{0–24 h} observed with MF/F treatment were similar to those observed with FP/S treatment. Ocular events were rare (2–6% overall incidence among treatment groups); in particular, no posterior subcapsular cataracts were reported. Only three patients discontinued the study because of treatment-related ocular AEs (two for lens disorders in the MF/F 400/10 μg group; one for reduced visual acuity in the FP/S 250/50 μg group) and no asthma-related deaths occurred. Furthermore, MF/F showed numerical improvement in lung function and clinical benefits by reducing asthma symptoms and rescue medication use. Conclusions: One-year treatment with the new combination therapies -twice-daily MF/F-MDI 200/10 and 400/10 μg — is safe and well tolerated in patients with persistent asthma.

Extrafine beclomethasone dipropionate/formoterol hydrofluoroalkane-propelled inhaler in asthma

The fixed combination of beclomethasone and formoterol (BDP/F) is an extrafine hydrofluoroalkane-propelled formulation characterized by a small particle size and high particle deposition in the lower airways. The product is manufactured using a specific technology known as Modulite((R)), the advantages of which include a stable and uniform dose delivery and flexibility to tailor particle size. The high fraction of drug available for lung deposition and the resulting low fraction remaining in the upper airways account for a high efficacy coupled with a low systemic bioavailability, therefore making this combination competitive compared with other inhaled corticosteroid/long-acting beta(2)-agonist (ICS/LABA) fixed combinations currently available. A 6-month study comparing BDP/F fixed combination with BDP and formoterol administered via separate inhalers showed a comparable efficacy on lung function and a greater efficacy in favor of the BDP/F fixed combination in terms of improvements in symptom scores and asthma control. Comparative studies in moderate-to-severe asthmatics have shown that the BDP/F combination displays a comparable efficacy to that of ICS/LABA combinations across the different asthma outcomes measured. The smaller particle size of this BDP/F combination in comparison with other ICS/LABA combinations makes it potentially more effective on small airways, a specific target for asthma treatment. This should be confirmed by specifically designed studies. Future development of this combination will include the evaluation of efficacy in maintaining asthma control using a step-down approach and the assessment of its use as maintenance and reliever therapy, since formoterol has already been shown to be an effective reliever medication in asthma in another inhaler containing budesonide/formoterol.

Current trends in the treatment of asthma: focus on the simultaneous administration of salmeterol/fluticasone

Asthma is a chronic disease of the airways that affects over 20 million people in the United States. It is a complex disease that involves airway infiltration by different types of cells and cell mediators causing chronic inflammation of the airway as well as hyper-responsiveness and edema. Management of asthma symptoms often requires combination therapy with multiple medications. Long-acting beta-2 agonists and inhaled corticosteroids have become key medications in the prevention of asthma exacerbations. The bronchodilatory effects of the beta-2 agonists coupled with the anti-inflammatory action of the corticosteroids combat the multi-factorial causes of asthma. The combination inhaler containing salmeterol and fluticasone is one such product that has been proven safe and effective for asthma therapy.

Salmeterol/fluticasone propionate: a review of its use in asthma

Salmeterol/fluticasone propionate (Seretide/Advair Diskus [dry powder inhaler] or Seretide/Advair inhalation aerosol [metered-dose inhaler]) is a fixed-dose combination inhalation agent containing a long-acting beta2-adrenoceptor agonist (LABA) plus a corticosteroid. In patients with symptomatic asthma, twice-daily salmeterol/fluticasone propionate maintenance therapy improves lung function and asthma symptoms to a greater extent than monotherapy with inhaled corticosteroids (ICS), such as fluticasone propionate, oral montelukast with or without fluticasone propionate, or sustained-release theophylline plus fluticasone propionate. The greater efficacy achieved with salmeterol/fluticasone propionate versus fluticasone propionate alone was sustained for 1 year in a well designed trial. Salmeterol/fluticasone propionate is also associated with a corticosteroid-sparing effect. Results of studies comparing fixed dosages of salmeterol/fluticasone propionate with formoterol/budesonide in adults and adolescents are equivocal. Twice-daily salmeterol/fluticasone propionate is associated with clinically meaningful improvements from baseline in health-related quality of life (HR-QOL), and improvements were greater than those reported with fluticasone propionate alone. Salmeterol/fluticasone propionate is generally well tolerated in adults, adolescents and children aged 4-11 years, and the fixed-combination inhaler ensures the appropriate use of a LABA in combination with an ICS. In cost-utility analyses in patients with uncontrolled asthma, salmeterol/fluticasone propionate compares favourably with fluticasone propionate alone or oral montelukast. Thus, salmeterol/fluticasone propionate provides an effective, well tolerated and cost-effective option for maintenance treatment in patients with asthma.

Comparison of salmeterol/fluticasone propionate (FP) combination with FP+sustained release theophylline in moderate asthma patients

OBJECTIVES

To compare the efficacy and safety of the salmeterol/fluticasone propionate combination product with concurrent sustained release theophylline plus fluticasone propionate in adult Japanese patients with persistent asthma.

DESIGN

Multicentre, randomised, double-blind, double-dummy, parallel-group study.

PATIENTS AND INTERVENTIONS

Three hundred and eighty-three asthmatic patients receiving sustained release theophylline 200-400mg/day entered the study and were randomised to receive either salmeterol/fluticasone propionate combination (SFC) 50microg/250microg+1 placebo tablet, fluticasone propionate 250microg+1 sustained release theophylline 200mg (SR-T+FP), twice daily for 8 weeks.

RESULTS

The adjusted mean change morning peak expiratory flow (PEF) over 8 weeks was 29.8L/min in the SFC group and 16.3L/min in the SR-T+FP group, with a treatment difference of 13.4L/min (p=0.0004). SFC improved evening PEF, FEV1, V50 and V25 at the completion of treatment to a greater extent than SR-T+FP (all p<0.05). A higher percentage of patients on SFC were symptom free (p=0.0286) and rescue free (ns) than those on SR-T+FP. There was not a statistically significant difference between treatments in symptom scores. Both treatments were well tolerated.

CONCLUSIONS

The finding that SFC was associated with greater improvements in lung function than SR-T+FP, a commonly employed treatment for asthmatic patients in Japan, suggests that SFC should be the preferred therapeutic option in these patients.

A modified prescription-event monitoring study to assess the introduction of Seretide Evohaler in England: an example of studying risk monitoring in pharmacovigilance

INTRODUCTION

Monitoring was required for the introduction of non-chlorofluorocarbon (CFC) propellants in metered dose inhalers (MDIs) to ensure that there were no unexpected adverse events due to the new products. A postmarketing surveillance study has been conducted to evaluate the introduction of the MDI Seretide Evohaler (hydrofluoroalkane-134a inhaler containing salmeterol and fluticasone propionate).

OBJECTIVES

To summarise the modified prescription-event monitoring (PEM) study conducted to evaluate the introduction of Seretide Evohaler and discuss the relevance of this type of study towards pharmacovigilance risk-management planning.

METHODS

Modified PEM methodology was used to examine the introduction of Seretide Evohaler into general practice in England. Patients were identified from the first National Health Service prescriptions dispensed in England for Seretide Evohaler. One postal questionnaire was sent to the prescribing doctor, requesting demographic information, severity of the indication, concomitant medication for this condition, smoking history, event data 3 months prior to and 3 months after the first prescription for Seretide Evohaler and also reason for stopping if it had been stopped. Pregnancies, deaths and selected events were followed up. Incidence density ratios were calculated to compare event rates 3 months prior to and 3 months after the introduction of Seretide Evohaler. A matched cohort analysis examined oral corticosteroid use and hospital admissions between the pre- and post-exposure periods.

RESULTS

The cohort comprised 13,464 patients prescribed Seretide Evohaler, with a response rate of 62%. There was no significant difference in the length of courses of oral corticosteroid use when the pre- and post-exposure periods were compared. A matched cohort analysis showed there was no increase in the use of oral corticosteroids (relative risk [RR] 0.95; 95% CI 0.90, 0.99) or hospital admissions in the post-exposure period (RR 0.87; 95% CI 0.73, 1.04). When the number of patients with events were compared for the periods 3 months before and 3 months after exposure, fewer events were reported in the post-exposure period. There were 64 patients who experienced adverse events within an hour of using Seretide Evohaler, including one report of paradoxical bronchospasm and one of myocardial infarction with fatal outcome that were both assessed as possibly related to treatment.

DISCUSSION

The results of the study suggest that the introduction of Seretide Evohaler was generally well tolerated. The modified methodology has allowed a comparison of the event rates before and after the introduction of this CFC-free inhaler into general practice.

Effects of salmeterol xinafoate and fluticasone propionate on immunological activation of human cultured mast cells

BACKGROUND

The clinical efficacy of combination therapy comprising a long acting beta(2)-agonist (LABA) and corticosteroid is widely recognized for the treatment of adult asthma. Here we examine the effect of salmeterol xinafoate (SX) and fluticasone propionate (FP) alone and in combination on the immunological activation of human cultured mast cells (HCMC)in vitro.

METHODS

HCMC were passively sensitized with IgE antibody and then activated by challenging with anti-IgE antibody. The effect of drugs on the activation of mast cells was examined by measuring the amount of released chemical mediators (histamine, leukotrienes (LT) and prostaglandin D(2) (PGD(2))) and granulocyte macrophage colony stimulating factor (GM-CSF).

RESULTS

The release of each chemical mediator was inhibited by 10-9-10-8M SX but not by 10-10-10-7M FP. The production of GM-CSF was inhibited by a concentration of 10-8M in both drugs and the inhibition was augmented by combined treatment with 10-11M of each drug.

CONCLUSIONS

The immunological release of chemical mediators (histamine, LT, PGD(2)) from HCMC was inhibited by SX but not by FP. SX and FP inhibited the production of GM-CSF by HCMC and both drug showed synergistic inhibition in the production of GM-CSF.