What is new with the beta2-agonists: issues in the management of asthma

Contributing Factors for Underutilization of Inhaled Corticosteroids Among Asthmatic Patients Attending at Adama Hospital Medical College, Adama, Ethiopia

INTRODUCTION

Inhaled corticosteroids (ICSs) are a cornerstone medicine for preventive therapy of persistent severe asthma. Although ICs are very effective for the treatment of severe persistent asthma, the majority of the prescribers worldwide aren't aware of ICs use for the treatment of severe persistent asthma.

OBJECTIVE

To evaluate factors contributing to underutilization of ICS by asthmatic patients.

METHODS

Patient interview was conducted among asthmatic patients using a cross-sectional study design who were attending at the Adama Hospital Medical College from March 1 to July 25, 2017. The total number of patients involved in the study was 94. Semi-structured questionnaire through patient interview was used for data collection and data from physicians who were working at the chest clinic of AHMC were collected by self-administered semi-structured questionnaire focusing their perspectives and experiences on patients' ICS.

RESULTS

Generally 73.5% of underutilization of ICS was reported from the total number of patients involved in the study according to the patient's perception. Monthly income, comorbid disease, and behaviors of ICS use were the main factors contributing to underutilization of ICS. According to patient's report, some of the reasons for underutilization of ICS were unaffordability, using the drugs only when symptoms appear, inaccessibility, side effects and recommendation by physicians. There were also similar reports by the physicians working in the AHMC.

CONCLUSION

In our study setting, prevalence of underutilization of ICS was high and the contributing factors were increased cost of ICS, inaccessibility of ICS, poor knowledge of the patients on asthma disease and ICS, bad attitude toward ICS, and lack of recently reviewed local guideline for asthma treatment. Thus, concerned experts need to take actions that guarantee accessibility of ICS at a reasonable price and increase awareness of patients about asthma disease and use of ICS.

Assessment of inhaled corticosteroids use and associated factors among asthmatic patients attending Tikur Anbessa Specialized Hospital, Ethiopia

Background

Inhaled corticosteroids (ICSs) are cornerstone therapy for persistent asthma. However, underutilization of ICSs is common and little is known about factors contributing toward this undesirable use.

Methods

A cross-sectional study was conducted through interview and chart review among persistent asthmatic patients attending chest clinic of Tikur Anbessa Specialized Hospital from 1 May to 31 September 2014. A total of 131 eligible patients who attended the clinic during study period were included in the study. A multivariate logistic regression was used to examine the association between independent and dependent variables.

Results

Overall, extent of underutilization of ICSs was found to be 68%. Monthly income, comorbidity and types of ICSs products prescribed showed significant association with reported underutilization. Patients’ reported reasons for underutilization includes; unaffordability (44%), using only when symptoms exacerbate (21%), fear of side effects (10%), practitioners’ recommendation (10%) and unavailability of ICSs in the local market (7%). Physicians also stated unaffordability, fear of side effects and dependency, lack of local guideline for asthma management and unavailability of ICSs as the contributing factors.

Conclusion

In this setting, extent of underutilization of ICSs was found to be high and seems the result of complex interaction of various factors. Financial problem combined with inconsistent availability of ICSs in the local market, patients’ poor knowledge of asthma and ICSs, negative attitude toward ICSs, absence of local guidelines for asthma management are found to be essential elements dictating an extent of ICSs use.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-017-2645-2) contains supplementary material, which is available to authorized users.

Special considerations for adolescent athletic and asthmatic patients

Asthma is defined as a chronic inflammatory disorder of the airways with bronchial hyperresponsiveness and variable bronchoconstriction, and is one of the most common diseases in childhood and adolescence. Exercise-induced asthma-like symptoms and asthma are also frequently seen in highly trained athletes. Exercise-induced asthma (EIA) and exercise-induced bronchoconstriction (EIB) are found in 8%–10% of healthy school-aged children and in 35% of children with asthma. Highly increased ventilation, inhalation of cold, dry air and air pollutants (eg, chlorine) are thought to be important triggers for EIA and EIB. EIA is often experienced concurrently with vocal cord dysfunction, which needs to be considered during the differential diagnosis. The pharmacological treatment of EIA is similar to the treatment of asthma in nonexercising adolescents. The therapy is based on anti-inflammatory drugs (eg, inhaled glucocorticosteroids) and bronchodilators (eg, β₂-agonists). The treatment of EIB is comparable to the treatment of EIA and leukotriene modifiers offer a new and promising treatment option, particularly in EIB. Generally, athletes may not use β₂-agonists according to the prohibited list of the World Anti-Doping Agency (WADA). However, the WADA list contains specific β₂-agonistic substances that are permitted to be used by inhalation.

Comparative efficacy of inhaled albuterol between two hand-held delivery devices in horses with recurrent airway obstruction

REASONS FOR PERFORMING STUDY

Studies investigating the clinical efficacy of albuterol administered with the same propellant and commercially available delivery devices in horses with recurrent airway obstruction (RAO) are not currently available.

OBJECTIVES

To determine the efficacy of aerosolised albuterol administered to horses with RAO by means of 2 commercially available, hand-held delivery devices.

METHODS

Ten horses with RAO were kept in a dusty environment and fed mouldy hay to induce airway obstruction. Lung mechanics were measured before and after the procedure. ΔP(max) was measured 5 min after administration of 180 µg of albuterol from a pressurised metered dose inhaler, using an aerosol delivery device chosen randomly. This process was repeated every 5 min until maximal bronchodilation was achieved. After a 24 h washout period, lung mechanics data were again collected using the other aerosol delivery device.

RESULTS

Aerosolised albuterol induced a significant and rapid bronchodilation in the horses using both aerosol delivery devices. No statistically significant difference in pulmonary function was observed in response to albuterol therapy between the 2 devices. The dose required to achieve 50% of maximal bronchodilation was not statistically different between the 2 devices (173.35 ± 78.35 µg with Device 1 and 228.49 ± 144.99 µg with Device 2, P = 0.26). The decrease in lung resistance tended to be more pronounced after albuterol administration with Device 1 (P = 0.066).

CONCLUSIONS

Aerosolised albuterol is an effective bronchodilator in horses with recurrent airway obstruction. There is no statistically significant difference between the 2 commercially available aerosol delivery devices in terms of efficacy.

POTENTIAL RELEVANCE

Aerosolised albuterol is effectively delivered using currently available devices leading to maximal bronchodilation in horses with RAO at an average dose of 540 µg.

Ergogenic effects of inhaled beta2-agonists in non-asthmatic athletes

The potential ergogenic effects of asthma medication in athletes have been controversially discussed for decades. The prevalence of asthma is higher in elite athletes than in the general population. The highest risk for developing asthmatic symptoms is found in endurance athletes and swimmers. In addition, asthma seems to be more common in winter-sport athletes. Asthmatic athletes commonly use inhaled beta2-agonists to prevent and treat asthmatic symptoms. However, beta2-agonists are prohibited according to the "Prohibited List of the World Anti-Doping Agency" (WADA). Until the end of 2009 an exception was only allowed for the substances formoterol, salbutamol, salmeterol, and terbutaline by inhalation, as long as a so-called therapeutic use exemption has been applied for and was granted by the relevant anti-doping authorities. From 2010 salbutamol and salmeterol are allowed by inhalation requiring a so called declaration of use.

Pharmacogenetic response to albuterol among asthmatics

Pharmacogenetics offers to individualize asthma treatment by identifying genetic variants associated with drug efficacy or adverse events. Several studies have focused on pharmacogenetic associations with albuterol, the most commonly prescribed medication for asthma worldwide. However, pharmacogenetic associations have varied within and between studies and across populations. Herein, we focus on pharmacogenetic associations between genetic variants in the beta(2)-adrenergic receptor gene and bronchodilator response to albuterol among subjects with asthma.

Isoliquiritigenin, a flavonoid from licorice, relaxes guinea-pig tracheal smooth muscle in vitro and in vivo: role of cGMP/PKG pathway

Licorice root is used to treat asthma as a component of Shaoyao-Gancao-tang, a traditional Chinese medicine formula. In this study, we investigated the tracheal relaxation effects of isoliquiritigenin, a flavonoid isolated from the roots of Glycyrrhiza glabra (a kind of Licorice), on guinea-pig tracheal smooth muscle in vitro and in vivo. The tension changes of isolated tracheal rings were isometrically recorded on a polygraph. The large-conductance Ca2+-activated K+ channels (BKCa) were measured by inside-out patch-clamp techniques and intracellular Ca2+concentrations ([Ca2+]i) were tested by microfluorometric method in guinea-pig tracheal smooth muscle cells (TSMCs). Isoliquiritigenin produced concentration-dependent relaxation in isolated guinea-pig tracheal rings precontracted with acetylcholine, KCl, and histamine. Pretreatments with charybdotoxin, ODQ and KT5823 attenuated the relaxation induced by isoliquiritigenin. Isoliquiritigenin significantly increased intracellular cGMP level in cultured TSMCs and inhibited the activity of phosphodiesterase (PDE) 5 in human platelets. Moreover, isoliquiritigenin increased by 9-fold the probability of BKCa channel openings of TSMCs in inside-out patches and markedly reduced [Ca2+]i rise induced by acetylcholine inTSMCs, pretreatment with KT5823 attenuated above two responses to isoliquiritigenin. In vivo experiment isoliquiritigenin significantly prolonged the latency time of histamine-acetylcholine aerosol-induced collapse and inhibited the increase of lung overflow induced by intravenously administered histamine dose-dependently. These data indicate that isoliquiritigenin relaxes guinea-pig trachea through a multiple of intracellular actions, including sGC activation, inhibition of PDEs, and associated activation of the cGMP/PKG signaling cascade, leading to the opening of BKCa channels and [Ca2+]i decrease through PKG-dependent mechanism and thus to tracheal relaxation.

Rationale for the major changes in the pharmacotherapy section of the National Asthma Education and Prevention Program guidelines

Numerous changes have been incorporated into the new National Asthma Education and Prevention Program's Expert Panel Report 3. In the pharmacotherapy section of the report, many of these changes are minor in that they do not alter the basic philosophy of treatment recommendations from the previous Expert Panel Report but only add new formulations, change dosing or dosage forms, or add discussion of risks. However, 4 major changes have been identified, and the rationales for 3 are discussed in detail here. The treatment of childhood asthma is divided into 2 distinct age groups, infants less than 5 years of age and children 5 to 12 years of age, because of the availability of more data suggesting differences in response in these patients, as well as a relative paucity of quality data in the younger patients. Omalizumab, a humanized mAb to IgE, is the only new entity approved for the treatment of asthma since the previous guidelines, and its recommendations were reviewed. The indication for combination therapy with inhaled corticosteroids and long-acting inhaled beta(2)-agonists (LABAs) has been modified in lieu of the recent black box warning concerning the increased risk of severe asthma exacerbations and death associated with LABA use. However, the inhaled corticosteroids/LABAs are still recommended for patients with moderate-to-severe persistent asthma. The rationale for the continued recommendation is provided.

Reducing asthma health disparities in poor Puerto Rican children: the effectiveness of a culturally tailored family intervention

BACKGROUND

Island and mainland Puerto Rican children have the highest rates of asthma and asthma morbidity of any ethnic group in the United States.

OBJECTIVE

We evaluated the effectiveness of a culturally adapted family asthma management intervention called CALMA (an acronym of the Spanish for "Take Control, Empower Yourself and Achieve Management of Asthma") in reducing asthma morbidity in poor Puerto Rican children with asthma.

METHODS

Low-income children with persistent asthma were selected from a national health plan insurance claims database by using a computerized algorithm. After baseline, families were randomly assigned to either the intervention or a control group.

RESULTS

No significant differences between control and intervention group were found for the primary outcome of symptom-free days. However, children in the CALMA intervention group had 6.5% more symptom-free nights, were 3 times more likely to have their asthma under control, and were less likely to visit the emergency department and be hospitalized as compared to the control group. Caregivers receiving CALMA were significantly less likely to feel helpless, frustrated, or upset because of their child's asthma and more likely to feel confident to manage their child's asthma.

CONCLUSION

A home-based asthma intervention program tailored to the cultural needs of low income Puerto Rican families is a promising intervention for reducing asthma morbidity.

Non-corticosteroid therapy for the long-term control of asthma

The non-corticosteroids approved for the maintenance therapy of persistent asthma include the long-acting inhaled beta(2) agonists (LABAs), leukotriene modifiers, chromones, theophylline and omalizumab. This review assesses the benefits and risks of each in relation to the inhaled corticosteroids and each other. Neither the LABAs nor omalizumab should be used as monotherapy for persistent asthma. There is no evidence of clinically significant differences in efficacy between the chromones, theophylline and leukotriene modifiers as monotherapy in mild-moderate persistent asthma; thus the choice of one therapy over the other is a clinical decision based upon differences in safety, acceptability to the patient and ease of use. Although there is significant variability in response to various therapies, non response to one therapy is not predictive of response to another. Neither studies of phenotypes nor genotypes have provided acceptable determinants of response as yet. As adjunctive therapy to the inhaled corticosteroids for moderate-severe persistent asthma, the LABAs provide superior improvement in lung function and reduction in exacerbations relative to higher doses of inhaled corticosteroids and the other noncorticosteroids used as adjunctive therapy. Thus, LABAs remain the adjunctive therapy of choice in patients not adequately controlled on low-medium dose inhaled corticosteroids. Omalizumab has not been compared with the other adjunctive therapies, so its relative efficacy is unknown. However, it is the only adjunctive therapy added to the combination of an inhaled corticosteroid plus LABA to demonstrate further improvement in a controlled clinical trial.

Getting to the heart of asthma: can "beta blockers" be useful to treat asthma?

beta(2)-adrenoceptor agonists are the mainstay for the acute symptomatic treatment of asthma and provide effective bronchoprotection to a wide range of bronchoconstrictor agents. However, over the past 4 decades there has been a continuing debate concerning whether regular chronic treatment with these drugs may be doing more harm than good. The FDA's recent decision to add black box warnings concerning the regular use of salmeterol- and formoterol-containing compounds, as well as their decision not to recommend agents containing long-acting beta(2)-adrenoceptor agonists as first-line therapy, seems to confirm the concerns regarding the regular use of the long-acting beta(2)-adrenoceptor agonists. A similar debate arose in the late 1980s concerning the use of beta-adrenoceptor agonists in the treatment of heart failure. In this disease, short-term use of beta agonists is associated with increased cardiac index and stroke volume, yet their long-term use is associated with increased morbidity and mortality. Moreover, certain beta blockers that are initially detrimental when used short term are now considered beneficial in the treatment of this disease when used chronically. Here, there is a parallel, as beta blockers are contraindicated in patients with asthma but the use of beta blockers chronically has never been evaluated. This begs the question of whether a similar paradigm shift is applicable in the treatment of asthma and whether under certain circumstances the long-term use of certain beta blockers may be useful in the treatment of this disease.

Do inhaled beta(2)-agonists have an ergogenic potential in non-asthmatic competitive athletes?

The prevalence of asthma is higher in elite athletes than in the general population. The risk of developing asthmatic symptoms is the highest in endurance athletes and swimmers. Asthma seems particularly widespread in winter-sport athletes such as cross-country skiers. Asthmatic athletes commonly use inhaled beta(2)-agonists to prevent and treat asthmatic symptoms. However, beta(2)-agonists are prohibited according to the Prohibited List of the World Anti-Doping Agency. An exception can be made only for the substances formoterol, salbutamol, salmeterol and terbutaline by inhalation, as long as a therapeutic use exemption has been applied for and granted. In this context, the question arises of whether beta(2)-agonists have ergogenic benefits justifying the prohibition of these substances. In 17 of 19 randomised placebo-controlled trials in non-asthmatic competitive athletes, performance-enhancing effects of the inhaled beta(2)-agonists formoterol, salbutamol, salmeterol and terbutaline could not be proved. This is particularly true for endurance performance, anaerobic power and strength performance. In three of four studies, even supratherapeutic doses of salbutamol (800-1200 microg) had no ergogenic effect. In contrast to inhaled beta(2)-agonists, oral administration of salbutamol seems to be able to improve the muscle strength and the endurance performance. There appears to be no justification to prohibit inhaled beta(2)-agonists from the point of view of the ergogenic effects.

Beta2-agonists and bronchial hyperresponsiveness

Bronchial hyperresponsiveness (BHR) is a characteristic feature of asthma, and individuals with this disease respond to a range of physiological and chemical insults that are otherwise innocuous to healthy subjects, suggesting that the mechanisms underlying this phenomenon are characteristic of the asthma phenotype. BHR can be increased following exposure to environmental allergens in suitably sensitized individuals, pollutants, and certain viruses and can also be exacerbated by exposure to certain drugs, including nonsteroidal anti-inflammatory agents and beta-blockers. Although beta2-agonists administered acutely remain the treatment for the symptoms of asthma, paradoxically, regular treatment with these drugs can result in an increase in BHR, and this has been suggested to contribute to the increase in asthma morbidity and mortality that has been reported by numerous investigators. This article highlights our current understanding of this phenomenon and examines the potential mechanisms responsible for this effect.

Targeting G protein-coupled receptor signaling in asthma

The complex disease asthma, an obstructive lung disease in which excessive airway smooth muscle (ASM) contraction as well as increased ASM mass reduces airway lumen size and limits airflow, can be viewed as a consequence of aberrant airway G protein-coupled receptor (GPCR) function. The central role of GPCRs in determining airway resistance is underscored by the fact that almost every drug used in the treatment of asthma directly or indirectly targets either GPCR-ligand interaction, GPCR signaling, or processes that produce GPCR agonists. Although many airway cells contribute to the regulation of airway resistance and architecture, ASM properties and functions have the greatest impact on airway homeostasis. The theme of this review is that GPCR-mediated regulation of ASM tone and ASM growth is a major determinant of the acute and chronic features of asthma, and multiple strategies targeting GPCR signaling may be employed to prevent or manage these features.

Implementing practice guidelines: a workshop on guidelines dissemination and implementation with a focus on asthma and COPD

The present supplement summarizes the proceedings of the symposium "Implementing practice guidelines: A workshop on guidelines dissemination and implementation with a focus on asthma and COPD", which took place in Quebec City, Quebec, from April 14 to 16, 2005. This international symposium was a joint initiative of the Laval University Office of Continuing Medical Education (Bureau de la Formation Médicale Continue), the Canadian Thoracic Society and the Canadian Network for Asthma Care, and was supported by many other organizations and by industrial partners. The objectives of this meeting were to examine the optimal implementation of practice guidelines, review current initiatives for the implementation of asthma and chronic obstructive pulmonary disease (COPD) guidelines in Canada and in the rest of the world, and develop an optimal strategy for future guideline implementation. An impressive group of scientists, physicians and other health care providers, as well as policy makers and representatives of patients' associations, the pharmaceutical industry, research and health networks, and communications specialists, conveyed their perspectives on how to achieve these goals. This important event provided a unique opportunity for all participants to discuss key issues in improving the care of patients with asthma and COPD. These two diseases are responsible for an enormous human and socioeconomic burden around the world. Many reports have indicated that current evidence-based guidelines are underused by physicians and others, and that there are many barriers to an effective translation of recommendations into day-to-day care. There is therefore a need to develop more effective ways to communicate key information to both caregivers and patients, and to promote appropriate health behaviours. This symposium contributed to the initiation of what could become the "Canadian Asthma and COPD Campaign", aimed at improving care and, hence, the quality of life of those suffering from these diseases. It is hoped that this event will be followed by other meetings that focus on how to improve the transfer of key recommendations from evidence-based guidelines into current care, and how to stimulate research to accomplish this.