Bronchodilator efficacy of the fixed combination of ipratropium and albuterol compared to albuterol alone in moderate-to-severe persistent asthma

Bronchodilator Responsiveness Measured by Spirometry and Impulse Oscillometry in Patients with Asthma After Short Acting Antimuscarinic and/or Beta-2-Agonists Inhalation

Background

Bronchodilator responsiveness (BDR) in asthma involves both the central and peripheral airways but is primarily relieved with beta-2-agonists and evaluated by spirometry. To date, antimuscarinics can be added as a reliever medication in more severe asthma. We hypothesize that combining both short-acting beta-2 agonist (SABA) and short-acting muscarinic antagonist (SAMA) could also improve the responsiveness in mild-moderate asthma. Therefore, we aimed to compare the direct effects of inhaling SABA alone, SAMA alone or combining both SABA and SAMA on the central and peripheral airways in asthma.

Methods

Twenty-three patients with mild-moderate BDR in asthma performed dynamic spirometry and impulse oscillometry before (baseline) and multiple timepoints within an hour after inhalation of SABA (salbutamol), SAMA (ipratropium bromide), or both SABA and SAMA at three different visits.

Results

The use of SAMA alone did not show any improvement compared to the use of SABA alone. Inhalation of SABA+SAMA, however, averaged either similar or better BDR than SABA alone in FEV1, MMEF, FVC, R5, R20 and R5-R20. Inhaling SABA+SAMA reached a stable BDR in more patients within 0-10 minutes and also reached the FEV1 (Δ%)>12% faster (3.5 minutes) than inhaling SABA alone (5.1 minutes). Inhaling SABA+SAMA was significantly better than SAMA alone in FEV1 (p = 0.015), MMEF (p = 0.0059) and R20 (p = 0.0049). Using these three variables highlighted a subgroup (30%, including more males) of patients that were more responsive to inhaling SABA+SAMA than SABA alone.

Conclusion

Overall, combining SAMA with SABA was faster and more consistent at increasing the lung function than SABA alone or SAMA alone, and the additive effect was best captured by incorporating peripheral-related variables. Therefore, SAMA should be considered as an add-on reliever for mild-moderate patients with BDR in asthma.

Development of a rapid and validated stability-indicating UPLC-PDA method for concurrent quantification of impurity profiling and an assay of ipratropium bromide and salbutamol sulfate in inhalation dosage form

The objective of the proposed work was to develop a rapid and new reverse phase ultra-performance liquid chromatographic (RP-UPLC) method for the simultaneous quantification of related impurities of ipratropium bromide and salbutamol sulfate in the combined inhalation dosage form. Herein, the chromatographic separation was achieved on Acquity BEH C18 (100mm×2.1mm, 1.7μm) column by following gradient elution of solvent A as 2mM potassium dihydrogen phosphate with 0.025% of 1-pentane sulphonic acid sodium salt (pH 3.0 buffer) and solvent B as pH 3.0 buffer, acetonitrile and methanol in the ratio of (32:50:18, v/v/v) at a flow rate of 0.3mL/min. The samples were detected and quantified at 220nm. To prove the stability-indicating potential of the method, forced degradation studies were performed using acidic, basic, oxidative, thermal, and photolytic conditions. After sufficient exposure, the resultant solutions were injected and found that all degradants and impurities formed during stress studies were well separated from each other and from the main peak compounds. The performance of the method was validated according to the present ICH Q2 (R1) guidelines. The method has good linearity (r≥0.999) and consistent recoveries were obtained with a range of 91.3-108.8% for all compounds. The % RSD obtained for the precision experiments was less than 5% and also there is a good sensitivity (LOQ≤0.5μg/mL) for all compounds. The intended method proved its applicability and that it can be beneficial to pharmaceutical industries for quick quantification of related impurities and assay in quality control department for analysis of ipratropium bromide and salbutamol sulfate inhalation dosage form.

Evaluation and management of the critically ill adult asthmatic in the emergency department setting

INTRODUCTION

Asthma is a common reason for presentation to the Emergency Department and is associated with significant morbidity and mortality. While patients may have a relatively benign course, there is a subset of patients who present in a critical state and require emergent management.

OBJECTIVE

This narrative review provides evidence-based recommendations for the assessment and management of patients with severe asthma.

DISCUSSION

It is important to consider a broad differential diagnosis for the cause and potential mimics of asthma exacerbation. Once the diagnosis is determined, the majority of the assessment is based upon the clinical examination. First line therapies for severe exacerbations include inhaled short-acting beta agonists, inhaled anticholinergics, intravenous steroids, and magnesium. Additional therapies for refractory cases include parenteral epinephrine or terbutaline, helium‑oxygen mixture, and consideration of ketamine. Intravenous fluids should be administered, as many of these patients are dehydrated and at risk for hypotension if they receive positive pressure ventilatory support. Noninvasive positive pressure ventilation may prevent the need for endotracheal intubation. If mechanical ventilation is required, it is important to avoid breath stacking by setting a low respiratory rate and allowing permissive hypercapnia. Patients with severe asthma exacerbations will require intensive care unit admission.

CONCLUSIONS

This review provides evidence-based recommendations for the assessment and management of severe asthma with a focus on the emergency clinician.

Efficacy and safety of ipratropium bromide/albuterol compared with albuterol in patients with moderate-to-severe asthma: a randomized controlled trial

BACKGROUND

Many patients with asthma require frequent rescue medication for acute symptoms despite appropriate controller therapies. Thus, determining the most effective relief regimen is important in the management of more severe asthma. This study's objective was to evaluate whether ipratropium bromide/albuterol metered-dose inhaler (CVT-MDI) provides more effective acute relief of bronchospasm in moderate-to-severe asthma than albuterol hydrofluoroalkaline (ALB-HFA) alone after 4 weeks.

METHODS

In this double-blind, crossover study, patients who had been diagnosed with asthma for ≥1 year were randomized to two sequences of study medication "as needed" for symptom relief (1-7 day washout before second 4-week treatment period): CVT-MDI/ALB-HFA or ALB-HFA/CVT-MDI. On days 1 and 29 of each sequence, 6-hour serial spirometry was performed after administration of the study drug. Co-primary endpoints were FEV1 area under the curve (AUC0-6) and peak (post-dose) forced expiratory volume in 1 s (FEV1) response (change from test day baseline) after 4 weeks. The effects of "as needed" treatment with ALB-HFA/CVT-MDI were analyzed using mixed effect model repeated measures (MMRM).

RESULTS

A total of 226 patients, ≥18 years old, with inadequately controlled, moderate-to-severe asthma were randomized. The study met both co-primary endpoints demonstrating a statistically significant treatment benefit of CVT-MDI versus ALB-HFA. FEV1 AUC0-6h response was 167 ml for ALB-HFA, 252 ml for CVT-MDI (p <0.0001); peak FEV1 response was 357 ml for ALB-HFA, 434 ml for CVT-MDI (p <0.0001). Adverse events were comparable across groups.

CONCLUSIONS

CVT-MDI significantly improved acute bronchodilation over ALB-HFA alone after 4 weeks of "as-needed" use for symptom relief, with a similar safety profile. This suggests additive bronchodilator effects of β2-agonist and anticholinergic treatment in moderate-to-severe, symptomatic asthma.

TRIAL REGISTRATION

ClinicalTrials.gov No.: NCT00818454 ; Registered November 16, 2009.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

Role of anticholinergics in asthma management: recent evidence and future needs

PURPOSE OF REVIEW

Anticholinergic antimuscarinic bronchodilators play a major role in the treatment of chronic obstructive pulmonary disease, but their role in asthma has long been limited to acute management. More recently, the role of long-acting antimuscarinic bronchodilators (LAMAs) in chronic asthma management has been explored. This review will examine the pharmacological rationale for use of inhaled anticholinergics in the treatment of asthma, and provide an overview of the current literature supporting this use, as well as describe future research needs in this area.

RECENT FINDINGS

Short-acting anticholinergic bronchodilators have a role as add-on agents in the treatment of acute asthma. Preliminary clinical studies suggest that inhaled LAMAs may be comparable to long-acting beta2-agonists (LABAs) as an add-on therapy in patients not controlled by inhaled corticosteroids (ICS) alone, and may also have added benefit in patients not controlled on combined ICS-LABA. Mechanistic studies suggest that apart from their bronchodilator activity, LAMAs may have anti-inflammatory and antiremodeling influences on the airways. Further research is needed to clarify the clinical relevance of these experimental observations.

SUMMARY

Accumulating evidence supports the use of inhaled LAMAs as an add-on therapy in patients with asthma, who remain symptomatic despite guideline-based therapy with ICS with or without LABAs. Further studies are warranted to help define mechanisms of action of LAMAs, apart from their role as bronchodilators, and determine how these other actions impact asthma outcomes over time. Furthermore, future studies need to examine the long-term efficacy and safety of LAMAs in asthma and identify a subgroup of patients who would benefit from such therapies to facilitate early, personalized therapy.

Anticholinergics/antimuscarinic drugs in asthma

Anticholinergic alkaloids have been used for thousands of years for the relief of bronchoconstriction and other respiratory symptoms, and their use in the treatment of chronic obstructive pulmonary disease is well established. Acetylcholine, acting through muscarinic receptor (M) receptor, modulates multiple physiologic functions pertinent to asthma including airway muscle tone, mucus gland secretion, and various parameters of inflammation and remodeling. In addition, activation of M receptors may inhibit beta2 adrenoreceptor. These observations offer the rationale for the use of M receptors antagonists in the treatment of asthma. Short-acting antimuscarinic agents may be effective alone or in combination with short-acting beta agonists for the relief of acute symptoms. Long-acting antimuscarinic agents have emerged as potentially useful in the long-term treatment of difficult-to-control asthma. This review will analyze the mechanisms of action and therapeutic role of antimuscarinic agents on asthma including current guidelines regarding antimuscarinic drugs, recent studies in asthma, special populations to consider, and possible predictors of response.

Efficacy of anticholinergic drugs in asthma

Although bronchial hyperresponsiveness to cholinergic agents is a main feature of asthma, the role of anticholinergic drugs in chronic asthma management has been largely underestimated. Several single-dose studies comparing acute bronchodilation induced by ipratropium bromide with salbutamol have shown that salbutamol was more effective than ipratropium in asthma treatment. Recently, tiotropium has been studied in asthma, when added to low-dose inhaled corticosteroids in unselected moderate asthmatics or in patients with uncontrolled asthma, or patients with chronic obstructive pulmonary disease and history of asthma. Later, studies on patients with Arg/Arg β(2)-receptor polymorphism demonstrated a similar efficacy of tiotropium in comparison with salmeterol when both were added to low-dose inhaled corticosteroids. Further long-term studies are currently in progress, for the evaluation of the efficacy of tiotropium on clinical asthma control, and on the rate and severity of asthma exacerbations, as well as the potential modification of inflammatory mechanisms and varying efficacy in specific asthma phenotypes (such as smoking asthmatics).

Anti-leukotriene agents compared to inhaled corticosteroids in the management of recurrent and/or chronic asthma in adults and children

BACKGROUND

Anti-leukotrienes (5-lipoxygenase inhibitors and leukotriene receptors antagonists) serve as alternative monotherapy to inhaled corticosteroids (ICS) in the management of recurrent and/or chronic asthma in adults and children.

OBJECTIVES

To determine the safety and efficacy of anti-leukotrienes compared to inhaled corticosteroids as monotherapy in adults and children with asthma and to provide better insight into the influence of patient and treatment characteristics on the magnitude of effects.

SEARCH METHODS

We searched MEDLINE (1966 to Dec 2010), EMBASE (1980 to Dec 2010), CINAHL (1982 to Dec 2010), the Cochrane Airways Group trials register, and the Cochrane Central Register of Controlled Trials (Dec 2010), abstract books, and reference lists of review articles and trials. We contacted colleagues and the international headquarters of anti-leukotrienes producers.

SELECTION CRITERIA

We included randomised trials that compared anti-leukotrienes with inhaled corticosteroids as monotherapy for a minimum period of four weeks in patients with asthma aged two years and older.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the methodological quality of trials and extracted data. The primary outcome was the number of patients with at least one exacerbation requiring systemic corticosteroids. Secondary outcomes included patients with at least one exacerbation requiring hospital admission, lung function tests, indices of chronic asthma control, adverse effects, withdrawal rates and biological inflammatory markers.

MAIN RESULTS

Sixty-five trials met the inclusion criteria for this review. Fifty-six trials (19 paediatric trials) contributed data (representing total of 10,005 adults and 3,333 children); 21 trials were of high methodological quality; 44 were published in full-text. All trials pertained to patients with mild or moderate persistent asthma. Trial durations varied from four to 52 weeks. The median dose of inhaled corticosteroids was quite homogeneous at 200 µg/day of microfine hydrofluoroalkane-propelled beclomethasone or equivalent (HFA-BDP eq). Patients treated with anti-leukotrienes were more likely to suffer an exacerbation requiring systemic corticosteroids (N = 6077 participants; risk ratio (RR) 1.51, 95% confidence interval (CI) 1.17, 1.96). For every 28 (95% CI 15 to 82) patients treated with anti-leukotrienes instead of inhaled corticosteroids, there was one additional patient with an exacerbation requiring rescue systemic corticosteroids. The magnitude of effect was significantly greater in patients with moderate compared with those with mild airway obstruction (RR 2.03, 95% CI 1.41, 2.91 versus RR 1.25, 95% CI 0.97, 1.61), but was not significantly influenced by age group (children representing 23% of the weight versus adults), anti-leukotriene used, duration of intervention, methodological quality, and funding source. Significant group differences favouring inhaled corticosteroids were noted in most secondary outcomes including patients with at least one exacerbation requiring hospital admission (N = 2715 participants; RR 3.33; 95% CI 1.02 to 10.94), the change from baseline FEV(1) (N = 7128 participants; mean group difference (MD) 110 mL, 95% CI 140 to 80) as well as other lung function parameters, asthma symptoms, nocturnal awakenings, rescue medication use, symptom-free days, the quality of life, parents' and physicians' satisfaction. Anti-leukotriene therapy was associated with increased risk of withdrawals due to poor asthma control (N = 7669 participants; RR 2.56; 95% CI 2.01 to 3.27). For every thirty one (95% CI 22 to 47) patients treated with anti-leukotrienes instead of inhaled corticosteroids, there was one additional withdrawal due to poor control. Risk of side effects was not significantly different between both groups.

AUTHORS' CONCLUSIONS

As monotherapy, inhaled corticosteroids display superior efficacy to anti-leukotrienes in adults and children with persistent asthma; the superiority is particularly marked in patients with moderate airway obstruction. On the basis of efficacy, the results support the current guidelines' recommendation that inhaled corticosteroids remain the preferred monotherapy. 

Management of severe asthma exacerbation in children

BACKGROUND

Asthma is a common disease in children and acute severe asthma exacerbation can be life-threatening. This article aims to review recent advances in understanding of risk factors, pathophysiology, diagnosis and treatment of severe asthma exacerbation in children.

DATA SOURCES

Articles concerning severe asthma exacerbation in children were retrieved from PubMed. Literatures were searched with MeSH words "asthma", "children", "severe asthma exacerbation" and relevant cross references.

RESULTS

Severe asthma exacerbation in children requires aggressive treatments with β2-agonists, anticholinergics, and corticosteroids. Early initiation of inhaled β-agonists and systemic use of steroids are recommended. Other agents such as magnesium and aminophylline have some therapeutic benefits. When intubation and mechanical ventilation are needed, low tidal volume, controlled hypoventilation with lower-than-traditional respiratory rates and permissive hypercapnia can be applied.

CONCLUSIONS

Researchers should continue to detect the risk factors, pathophysiology, diagnosis and treatment of severe asthma exacerbation in children. More studies especially randomized controlled trials are required to evaluate the efficacy and safety of standard and new therapies.

Centrilobular opacities in the asthmatic lung successfully treated with inhaled ciclesonide and tiotropium: with assessment of alveolar nitric oxide levels

BACKGROUND

Despite the fact that bronchioles are involved in asthma, there have been limited asthmatic cases showing marked centrilobular opacities on computed tomography (CT) chest scans. Systemic corticosteroids have been administered in such cases, but the efficacy of extra-fine particle inhaled corticosteroids has not been assessed.

CASE SUMMARY

A previously healthy 64-year-old man presented with a four-month history of productive cough and progressive dyspnea despite a combination therapy with inhaled salmeterol (50 μg bid) and fluticasone (500 μg bid), sustained-release theophylline, and pranlukast because of suspicion of asthma. Physical examination revealed wheezing at the end of forced expiration. High resolution CT chest scan showed diffuse centrilobular opacities, bronchiectatic changes, and bronchial wall thickening. Transbronchial lung biopsy, bronchoalveolar lavage fluid, and transbronchial biopsy all showed predominant eosinophil infiltrates, suggesting that eosinophilic inflammation across the entire airway tree caused the abnormal CT findings. Alveolar fraction of exhaled nitric oxide level, a non-invasive marker of eosinophilic peripheral airway inflammation, was also elevated. Because he refused systemic corticosteroids, inhaled ciclesonide (400 μg bid) and inhaled tiotropium were added on to his current medication under careful observation. His symptoms, pulmonary function and CT findings promptly improved, and he had fully recovered at follow-up.

DISCUSSION

Extra-fine particle inhaled corticosteroids could be an alternative approach in centrilobular opacities caused by eosinophilic peripheral airway inflammation.

Application of the classical Einthoven model of bronchoconstriction to the study of inhaled bronchodilators in rodents

INTRODUCTION

The discovery of novel bronchodilators that treat human respiratory disorders has been guided by an array of animal models of bronchoconstriction which differ in technical complexity and experimental endpoints. Here, we apply methodology in which ventilation pressure provides a surrogate measure of airway tone (Einthoven, 1892) to assess the potency and duration of muscarinic antagonists and β(2)-adrenergic agonists in two rodent species. The purpose of this study was to validate the Einthoven model of bronchoconstriction by testing two classes of bronchodilators that are approved for clinical use.

METHODS

Conscious guinea pigs or rats, placed in an inhalation chamber, were dosed by nebulization with vehicle or test compound. Prior to testing, animals were anesthetized, tracheotomized and artificially ventilated. Changes in ventilation pressure were measured via a pressure transducer. Guinea pigs were challenged with doses of methacholine (1-32 μg/kg, i.v.) or histamine (1-64 μg/kg, i.v.) and rats were challenged with an infusion of methacholine (5-80 μg/kg, i.v.). Changes in ventilation pressure (cmH(2)O) were calculated as peak post-challenge ventilation pressure-peak baseline ventilation pressure. The potency [ID(50), nebulizer concentration] and duration of bronchoprotective activity of ipratropium, tiotropium, albuterol, salmeterol and indacaterol were determined.

RESULTS

In guinea pig, ipratropium [ID(50)=5.7 μg/mL] and tiotropium [ID(50)=5.4 μg/mL] were equipotent, whereas albuterol [ID(50)=117 μg/mL], was 65-fold and 23-fold less potent than salmeterol [ID(50)=1.8 μg/mL] and indacaterol [ID(50)=5.2 μg/mL], respectively. Only tiotropium and indacaterol exhibited 24h bronchoprotection. In the rat, ipratropium [ID(50)=4.4 μg/mL] and tiotropium [6.0 μg/mL] were equipotent. The bronchoprotective duration of tiotropium in the rat was ≥ 24 h.

DISCUSSION

The Einthoven model accurately determined the rank order of potency and duration of clinically used bronchodilators. The decreased experimental variability and reproducibility associated with the methodology of Einthoven model may offer significant advantages over other models of bronchoconstriction and thereby support the discovery of novel bronchodilators.

Increased vagal airway tone in fatal asthma

Slow-onset asthma deaths are characterized by eosinophilic airway infiltrates and thickening of the basal membrane, while rapid-onset asthma deaths are associated with fewer airway inflammatory changes, suggesting that bronchospasm may be responsible for the latter events. Airway tone is primarily controlled by the autonomous nervous system and can be pharmacologically modified. Therapies that stimulate the sympathetic beta(2) adrenoreceptor or inhibit the muscarinic receptor signal transduction induce bronchodilation. Parasympathetic (vagal) airway tone is enhanced in some asthmatics due to a number of stimuli, while in others it is constitutively heightened. Mainstream asthma therapy, however, only consists of corticosteroids and beta(2) agonists, not addressing this aspect. In this publication, I propose that increased vagal airway tone resulting in overwhelming bronchoconstriction and mucus plugging could be responsible for the near-fatal or fatal events observed in a number of asthmatics, in spite of their adequate treatment with standard therapies. On the basis of this hypothesis, I recommend that vagal airway tone be assessed in all patients with asthma, particularly in those with a history of near-fatal events. If the airway tone is increased, individuals should be treated with a triple combination of long-acting beta(2) agonists, inhaled steroids, and inhaled anticholinergics to prevent vagally mediated fatal events.