Albuterol HFA is as effective as albuterol CFC in preventing exercise-induced bronchoconstriction

Albuterol/budesonide for the treatment of exercise-induced bronchoconstriction in patients with asthma: The TYREE study

BACKGROUND

PT027 is a fixed-dose combination of albuterol (salbutamol) and budesonide in a single pressurized metered-dose inhaler.

OBJECTIVE

To evaluate the efficacy and safety of albuterol/budesonide compared with placebo in patients with asthma and exercise-induced bronchoconstriction (EIB).

METHODS

In this randomized, double-blind, 2-period, single-dose crossover study, adolescents and adults with asthma and EIB (defined by ≥20% decrease from pre-exercise challenge forced expiratory volume in 1 second [FEV₁]) were randomized to albuterol/budesonide (180/160 µg) followed by placebo (n = 29) or the reverse sequence (n = 31). Subjects were stratified by background therapy (as-needed short-acting β₂-agonist alone or low-to-medium dose inhaled corticosteroid plus as-needed short-acting β₂-agonist). FEV₁ was measured 5 minutes pre-dose, 30 minutes postdose (5 minutes pre-exercise challenge [baseline]), and 5, 10, 15, 30, and 60 minutes postexercise. The primary end point was maximum percentage fall from baseline in FEV₁ up to 60 minutes postexercise challenge.

RESULTS

Least squares mean maximum percentage fall in FEV₁ up to 60 minutes postexercise challenge was 5.45% with albuterol/budesonide vs 18.97% with placebo (difference, -13.51% [95% confidence interval, -16.94% to -10.09%]; P < .001). More subjects were fully protected (maximum percentage fall in FEV₁ post-exercise challenge < 10%) with albuterol/budesonide than with placebo (78.3% vs 28.3%; P < .001). The treatment effect was consistent irrespective of background inhaled corticosteroid therapy, and albuterol/budesonide was well tolerated.

CONCLUSION

In adolescents and adults with asthma and EIB, a single dose of albuterol/budesonide 180/160 µg taken approximately 30 minutes before exercise was significantly more effective than placebo in preventing EIB.

Novel albuterol multidose dry powder inhaler in patients with exercise-induced bronchoconstriction: A single-dose, double-blind, randomized, 2-way crossover study

BACKGROUND

A novel, inhalation-driven, multidose dry powder inhaler (MDPI) was developed that eliminates the need to coordinate device actuation with inhalation as is required with conventional metered-dose inhalers.

OBJECTIVE

To evaluate albuterol MDPI efficacy and safety in patients with exercise-induced bronchoconstriction (EIB).

METHODS

This single-dose, double-blind, 2-way crossover study randomized adolescents and adults with EIB (≥20% fall from pre-exercise challenge FEV(1)) to treatment sequences of albuterol MDPI (180 μg [2 inhalations of 90 μg each])/placebo MDPI (n = 19) or the reverse sequence (n = 19). FEV(1) was measured 30 and 5 min predose, 30 min postdose (ie, 5 min before treadmill exercise challenge; baseline) and 5, 10, 15, 30, and 60 min after exercise challenge. The primary efficacy endpoint was maximum percentage fall from baseline in FEV(1) up to 60 min post-exercise challenge.

RESULTS

Mean maximum percentage fall in FEV(1) within 60 min post-exercise challenge was 6.2 ± 1.4% for albuterol MDPI versus 22.4 ± 1.4% for placebo MDPI (between-treatment difference: -16.2%; 95% CI: -20.2% to -12.1%; P < 0.0001). A significantly higher percentage of albuterol MDPI-treated patients were protected against EIB (<10% maximum FEV(1) fall post-exercise challenge) versus placebo MDPI (84.2% vs 15.8%; P < 0.0001). Protection with albuterol MDPI was evident within 5 min and maintained through 30 min; recovery was complete for both groups at 60 min. Treatment with a single dose of albuterol MDPI was generally well tolerated.

CONCLUSIONS

Albuterol MDPI provides clinically significant protection from EIB in adolescents and adults with EIB; no new safety issues were observed with short-term albuterol MDPI use. ClinicalTrials.gov identifier NCT01791972.

Beta₂-agonists for exercise-induced asthma

BACKGROUND

It is well known that physical exercise can trigger asthma symptoms and can induce bronchial obstruction in people without clinical asthma. International guidelines on asthma management recommend the use of beta2-agonists at any stage of the disease. At present, however, no consensus has been reached about the efficacy and safety of beta2-agonists in the pretreatment of exercise-induced asthma and exercise-induced bronchoconstriction. For the purpose of the present review, both of these conditions are referred to by the acronymous EIA, independently from the presence of an underlying chronic clinical disease.

OBJECTIVES

To assess the effects of inhaled short- and long-acting beta2-agonists, compared with placebo, in the pretreatment of children and adults with exercise-induced asthma (or exercise-induced bronchoconstriction).

SEARCH METHODS

Trials were identified by electronic searching of the Cochrane Airways Group Specialised Register of Trials and by handsearching of respiratory journals and meetings. Searches are current as of August 2013.

SELECTION CRITERIA

We included randomised, double-blind, placebo-controlled trials of any study design, published in full text, that assessed the effects of inhaled beta2-agonists on EIA in adults and children. We excluded studies that did not clearly state diagnostic criteria for EIA.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by The Cochrane Collaboration.

MAIN RESULTS

We included 53 trials consisting of 1139 participants. Forty-eight studies used a cross-over design, and five were performed in accordance with a parallel-group design. Forty-five studies addressed the effect of a single beta2-agonist administration, and eight focused on long-term treatment. We addressed these two different intervention regimens as different comparisons.Among primary outcomes for short-term administration, data on maximum fall in forced expiratory volume in 1 second (FEV1) showed a significant protective effect for both short-acting beta-agonists (SABA) and long-acting beta-agonists (LABA) compared with placebo, with a mean difference of -17.67% (95% confidence interval (CI) -19.51% to -15.84%, P = 0.00001, 799 participants from 72 studies). The subgroup analysis of studies performed in adults compared with those performed in children showed high heterogeneity confined to children, despite the comparable mean bronchoprotective effect.Secondary outcomes on other pulmonary function parameters confirmed a more positive and protective effect of beta2-agonists on EIA compared with placebo. Occurrence of side effects was not significantly different between beta2-agonists and placebo.Overall evaluation of the included long-term studies suggests a beta2-agonist bronchoprotective effect for the first dose of treatment. However, long-term use of both SABA and LABA induced the onset of tolerance and decreased the duration of drug effect, even after a short treatment period.

AUTHORS' CONCLUSIONS

Evidence of low to moderate quality shows that beta2-agonists, both SABA and LABA, when administered in a single dose, are effective and safe in preventing EIA.Long-term regular administration of inhaled beta2-agonists induces tolerance and lacks sufficient safety data. This finding appears to be of particular clinical relevance in view of the potential for prolonged regular use of beta2-agonists as monotherapy in the pretreatment of EIA, despite the warnings of drug agencies (FDA, EMA) regarding LABA.

Pharmacotherapy for exercise-induced asthma: allowing normal levels of activity and sport

Exercise-induced bronchoconstriction (EIB) is experienced by the majority of an estimated 300 million individuals who have asthma, a condition that affects all ages and is increasing globally. Respiratory water loss with dehydration of the airways causing mediator release and airway narrowing is considered the cause of EIB, the severity of which will be increased if the inhaled air is cold or polluted. Adequate control of asthma is essential to minimize or prevent EIB and permit normal levels of physical activity and sport. This is important because exercise is a necessary component of daily living, assists in obtaining and maintaining a healthy body and has been demonstrated to benefit asthmatics. Inhaled glucocorticosteroids and inhaled β(2)-adrenoceptor agonists (IβA) are the pharmacological agents of choice to manage asthma and minimize EIB, assisted when necessary, by other drugs including leukotriene receptor antagonists and chromones. Tolerance from daily use of IβA is of concern and more flexible drug therapy needs to be considered. Optimal use of inhalers to deliver drugs effectively requires closer attention. Pharmacogenetics may hold the key to future drug therapy.

Aerosol drug delivery: developments in device design and clinical use

Aerosolised drugs are prescribed for use in a range of inhaler devices and systems. Delivering drugs by inhalation requires a formulation that can be successfully aerosolised and a delivery system that produces a useful aerosol of the drug; the particles or droplets need to be of sufficient size and mass to be carried to the distal lung or deposited on proximal airways to give rise to a therapeutic effect. Patients and caregivers must use and maintain these aerosol drug delivery devices correctly. In recent years, several technical innovations have led to aerosol drug delivery devices with efficient drug delivery and with novel features that take into account factors such as dose tracking, portability, materials of manufacture, breath actuation, the interface with the patient, combination therapies, and systemic delivery. These changes have improved performance in all four categories of devices: metered dose inhalers, spacers and holding chambers, dry powder inhalers, and nebulisers. Additionally, several therapies usually given by injection are now prescribed as aerosols for use in a range of drug delivery devices. In this Review, we discuss recent developments in the design and clinical use of aerosol devices over the past 10-15 years with an emphasis on the treatment of respiratory disorders.

Albuterol HFA for the management of obstructive airway disease

Albuterol (salbutamol outside the USA) is used to acutely relieve symptoms related to airway obstruction and prevent exercise-induced bronchospasm. Albuterol is most commonly administered by metered-dose inhaler (MDI). MDIs had used chlorofluorocarbon (CFC) propellants, but CFCs accumulate in the stratosphere and contribute to ozone catabolism. Loss of the 'ozone layer', which filters UVB rays, has public health concerns. Albuterol has been reformulated in MDIs using hydrofluoroalkane (HFA) propellants, which do not affect the ozone layer. Albuterol HFA MDIs deliver the same amount of drug per puff with similar particle size distributions as albuterol CFC MDIs, resulting in comparable bronchodilator efficacy of the two products. The highly favorable safety profile of albuterol has not been altered with reformulation. The propellant HFA-134a appears to be devoid of safety concerns.

An evaluation of levalbuterol HFA in the prevention of exercise-induced bronchospasm

Background

Exercise-induced bronchospasm (EIB) affects up to 90% of all patients with asthma.

Objective

This study evaluated the ability of levalbuterol hydrofluoroalkane (HFA) 90 μg (two actuations of 45 μg) administered via metered dose inhaler (MDI) to protect against EIB in mild-to-moderate asthmatics.

Methods

This was a randomized, double-blind, placebo-controlled, two-way cross-over study. Patients with asthma (n = 15) were ≥18 years, had a ≥6-month history of EIB, ≥70% baseline predicted forced expiratory volume in 1 second (FEV₁), and a 20% to 50% decrease in FEV₁ after treadmill exercise challenge using single-blind placebo MDI. Levalbuterol or placebo was self-administered 30 minutes before exercise. Treatment sequences were separated by a 3-to 7-day washout period. Spirometry was performed predose, 20 minutes postdose/pre-exercise, and 5, 10, 15, 30, and 60 minutes post-exercise. The primary endpoint was the maximum percent decrease in FEV₁ from baseline (postdose/pre-exercise). The percentage of protected (≤20% decrease in post-exercise FEV₁) patients was also assessed.

Results

Levalbuterol had significantly smaller maximum percent post-exercise decrease in FEV₁ compared with placebo (LS mean ± SE; −4.8% ± 2.8% versus −22.5% ± 2.8%, respectively). For levalbuterol, 14/15 (93.3%) patients had <20% decrease in post-exercise FEV₁ compared with 8/15 (53.3%) for placebo (p = 0.0143). Treatment was well tolerated.

Conclusion

Levalbuterol HFA MDI (90 μg) administered 30 minutes before exercise was significantly more effective than placebo in protecting against EIB after a single exercise challenge and was well tolerated.

Clinical Implications

Levalbuterol HFA MDI when administered before exercise was effective in protecting adults with asthma from EIB.

Propellant-driven metered-dose inhalers for pulmonary drug delivery

The current market for pulmonary drug delivery is at a bottleneck. The therapeutic advantages of inhalation aerosols, and the potential for the lungs as a route for systemically acting drugs, vaccines and gene therapeutic agents, have resulted in a rapid growth of the industry. Alongside this, the environment of inhaler design and formulation has changed markedly in recent years. Environmental concerns over propellants, the commercial success of dry powder inhalers, and the apparent lack of advancement of propellant-driven metered-dose inhalers (pMDIs) has led to a less clear future for these devices. This review critically assesses these pressures and also potential opportunities for the pMDI. It is proposed that the future role of pMDIs will be determined by several important forces that can be classified under 'technology development' or 'market climate' categories. Technology development forces will be strengthened by the ability of the industry to have a systematic understanding of mechanisms of spray formation, perform subsequent and continued device and formulation advances, and a focus on all patient groups: particularly paediatric and geriatric populations. The ability to succeed in these areas will be largely determined by the willingness to invest in fundamental research of pMDI technologies.

Salmeterol HFA is as effective as salmeterol CFC in children and adults with persistent asthma

In accordance with the Montreal Protocol 1987, initiatives to phase out and replace ozone-depleting chlorofluorocarbon (CFC) propellants with non-ozone-depleting propellants in metered-dose inhalers (MDIs) in the treatment of asthma and chronic obstructive pulmonary disease are underway. In view of this, two multi-centre, randomised, parallel-group, double-blind studies were conducted to compare the safety and efficacy of salmeterol xinafoate delivered by an MDI using the hydrofluoroalkane (HFA) 134a propellant with the licensed CFC formulation (Serevent) in asthmatic populations of children (4-11 years) and adults (12 years). Patients on a stable dose of inhaled corticosteroids with a scope for improvement based on mean morning peak expiratory flow (PEF) and symptoms were randomised to receive salmeterol HFA MDI 50 microg twice daily or salmeterol CFC MDI 50 microg twice daily for 12 weeks. The primary efficacy variable was mean morning PEF and secondary variables included other lung function parameters, symptom scores, use of relief medication and safety assessments. The difference between the treatments in adjusted mean morning PEF (salmeterol HFA-salmeterol CFC) were 2.5 and -3.2 L/min for per-protocol populations of children and adults, respectively. The lower limit of 95% confidence intervals for both populations was within the pre-defined limit (-15 L/min) set for non-inferiority. Similar results were observed in intent-to-treat (ITT) populations. In children, the two formulations resulted in a lack of any statistically significant difference in secondary efficacy parameters. A significant difference at endpoint in clinic forced expiratory volume in 1s was reported in favour of the HFA formulation in the adult population, although the magnitude of this effect was not considered clinically significant. The incidences of adverse events (AEs) were similar for both formulations and populations, and no safety concerns were generated. Together these data demonstrate salmeterol HFA MDI to be as effective as salmeterol CFC MDI in adults and children.

Comparison of the systemic pharmacodynamic effects and pharmacokinetics of salmeterol delivered by CFC propellant and non-CFC propellant metered dose inhalers in healthy subjects

This was a randomised, double-blind, placebo-controlled, cross-over study comparing the systemic pharmacodynamic effects (heart rate and serum potassium) and pharmacokinetics of salmeterol delivered by the non-CFC hydrofluoralkane (HFA) propellant 134a and the CFC propellant (propellant 11/12) metered dose inhalers (MDI) in healthy subjects. At the therapeutic dose (50 microg), salmeterol-mediated systemic pharmacodynamics were equivalent for the HFA and CFC MDIs. Higher doses of salmeterol (150 and 300 microg) produced dose-related beta-agonist pharmacodynamic effects irrespective of the propellant. However, these effects were lower with salmeterol HFA MDI than with the salmeterol CFC MDI at all dose levels. Overall, salmeterol Cmax and AUC(0-t) values were lower for salmeterol HFA compared with salmeterol CFC MDI. At the highest dose (300 microg), where a full pharmacokinetic profile was obtained, exposure to salmeterol delivered by the HFA MDI compared with the salmeterol CFC MDI was 27% and 30% lower for Cmax and AUC(0-t), respectively. Maximum plasma concentrations were generally seen in the first plasma samples taken 5 min after the start of dosing. Salmeterol HFA was well-tolerated. At supratherapeutic doses, adverse events were typical for high-dose salmeterol with fewer adverse events occurring with the HFA compared with the CFC formulation. These data indicate that the salmeterol HFA MDI would not be associated with a significantly different pharmacodynamic, safety and tolerability profile compared with the salmeterol CFC MDI.

The influence of inhaler selection on efficacy of asthma therapies

Many different devices are available to aid inhalational drug delivery. Although each device is claimed to have advantages over its rivals, the evidence to support greater efficacy of a particular device is scanty. Most comparative studies are underpowered or flawed in their design. They may use inappropriate end-points, or involve healthy subjects, whose response may be very different from the patient with acute severe asthma. The dosage of drug used in a trial may be at the shallow part of the dose-response curve, masking differences in devices. Only in a few cases have clinical trials detected a significant difference between devices, and trials have rarely taken patient preference into account. The most efficacious device in practice is likely to be the one that the patient will use regularly and in accordance with a health care workers' recommendations.

Activity-induced asthma

Exercise is the most common trigger of persistent childhood asthma. The history for EIA can be complicated by the lack of perception of significant airway obstruction during exercise. One must carefully identify those children with EIA from the group of children who report low level of activity because of lack of interest or because they are out of shape. Baseline spirometry of children with persistent asthma is frequently normal. Spirometry is important to identify those children with EIA who underrecognize their disease, but normal results should not be used as evidence of absence of disease. Formal exercise testing should be considered when the diagnosis is unclear or if there seems to be a lack of bronchoprotection with inhaled albuterol. The goal of treatment of EIA should be the attainment of a normal activity level for children and adolescents. Identification of the limits imposed by EIA and establishment of goals of therapy with the child and family should be the initial action. Inactivity or reduced exertion, in the presence of this diagnosis. should not be accepted. Therapy for EIA starts with control of the underlying persistent asthma. Inhaled corticosteroids are the most effective initial treatment of both EIA and persistent asthma in children and adolescents. Exercise-induced asthma is a common aspect of a prevalent disease that warrants proper diagnosis and treatment. With appropriate therapy, children with EIA should be able to participate in sports and maintain normal activity. They should strive to compete in the same playing field as their peers and have the same goals as those children and athletes who do not have exercise-induced asthma.