Long-acting beta2-agonists versus theophylline for maintenance treatment of asthma

A narrative review of theophylline: is there still a place for an old friend?

Background and Objective

Theophylline has been used for decades in human medicine for its psychostimulant, anti-inflammatory, and bronchodilator effects. Historically, in pulmonary medicine, theophylline has been used in the treatment of obstructive pulmonary diseases such as bronchial asthma (BA) or chronic obstructive pulmonary disease (COPD). This review aims to determine whether theophylline still has its place in the therapy of obstructive pulmonary diseases or whether we can even extend its use to other diagnoses such as atropine-resistant cardiac arrests, apnea of prematurity, or others. Moreover, we also aim to determine if there is a rationale for using low-dose theophylline due to its immunomodulatory and anti-inflammatory effect, or if the future of methylxanthines lies in newly synthesized derivates of theophylline such as bamifylline, or doxofylline.

Methods

The narrative review is based on a literature search of the articles indexed in the PubMed database in 2023. We searched the database since the year 2009 using the MeSH terms "theophylline", "aminophylline", and "methylxanthines" and we included original articles in the English language.

Key Content and Findings

Theophylline has a number of adverse drug reactions (ADRs), the most serious of which is its effect on the cardiovascular system. It can cause severe arrhythmias or even cardiac arrest when overdosed. On the other hand, there is still a substantial amount of its applications in current clinical practice.

Conclusions

There is considerable controversy associated with its use in current medicine, which can be attributed both to its narrow therapeutic range and its mentioned cardiotoxic effect. Herein, we summarize the current state-of-art of theophylline and its use in human medicine.

Characteristics of medicine use for children with asthma in China: a nationwide population-based study

OBJECTIVE

To analyze the asthma medication use in Chinese children of different age groups, regions, and levels of cities in China, based on the 2015 Healthcare Insurance Data in China.

METHODS

The China Healthcare Insurance Research Association (CHIRA) database was searched for children from 0 to 14 years old diagnosed as asthma based on the "J45" and "J46" coded in ICD-10. A cross-sectional study design was employed.

RESULTS

A total of 308,550 children were identified, all of whom were treated under the coverage of healthcare insurance. Among them, 2,468 children were eligible for inclusion in the present study. Compared with the current status of asthma care in European and American countries, under the guidelines for the diagnosis and treatment of asthma in China, the use percentages of ICS and short-acting β2 receptor agonist in children with asthma in China were lower, but the use percentages of oral corticosteroids, long-acting β2 receptor agonist, and theophylline (especially intravenous theophylline) were higher, especially in the Central and West China.

CONCLUSION

The asthma medication use was attributed to many factors, thus efforts are still needed to further popularize the GINA programs and China's guidelines for asthma diagnosis and treatment, especially in the Central and West China.

Guidelines for the management of asthma in adults and adolescents: Position statement of the South African Thoracic Society - 2021 update

Asthma prevalence is increasing worldwide, and surveys indicate that most patients in developed and developing countries, including South Africa, do not receive optimal care and are therefore not well controlled. Standard management guidelines adapted to in-country realities are important to support optimal care. The South African Thoracic Society (SATS) first published a guideline for the management of chronic persistent asthma in 1992, which has subsequently been revised several times.

The main aim of the present document was to revise and update SATS’ statement on the suggested management of chronic asthma, based on the need to promote optimal care and control of asthma, together with the incorporation of new concepts and drug developments. This revised document reinforces optimal care and incorporates the following primary objectives to achieve the recent advances in asthma care:

continued emphasis on the use of inhaled corticosteroids (ICS) as the foundation of asthma treatment

to reduce the reliance on short-acting beta-2 agonist (SABA) monotherapy for asthma symptoms

to incorporate the evidence and strategy for the use of the combination of an ICS and formoterol for acute symptom relief (instead of a SABA)

to incorporate the evidence and strategy for the use of as-needed ICS-long-acting beta agonists (LABA) for patients with infrequent symptoms or ‘mild’ asthma

to incorporate the evidence and strategy for the use of a long-acting muscarinic antagonist (LAMA) in combination with ICS-LABA; and

to incorporate the evidence and strategy for the use of and management with a biologic therapy in severe asthma.

A computational approach to drug repurposing against SARS-CoV-2 RNA dependent RNA polymerase (RdRp)

The spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) caused a worldwide outbreak of coronavirus disease 19 (COVID-19), which rapidly evolved as a global concern. The efforts of the scientific community are pointed towards the identification of promptly available therapeutic options. RNA-dependent RNA polymerase (RdRp) is a promising target for developing small molecules to contrast SARS-CoV-2 replication. Modern computational tools can boost identification and repurposing of known drugs targeting RdRp. We here report the results regarding the screening of a database containing more than 8800 molecules, including approved, experimental, nutraceutical, illicit, withdrawn and investigational compounds. The molecules were docked against the cryo-electron microscopy structure of SARS-CoV-2 RdRp, optimized by means of molecular dynamics (MD) simulations. The adopted three-stage ensemble docking study underline that compounds formerly developed as kinase inhibitors may interact with RdRp.Communicated by Ramaswamy H. Sarma.

A Current Perspective of Allergic Asthma: From Mechanisms to Management

Asthma is a result of heterogenous, complex gene-environment interactions with variable clinical phenotypes, inflammation, and remodeling. It affects more than 330 million of people worldwide throughout their educational and working lives, while exacerbations put a heavy cost/burden on productivity. Childhood asthma is characterized by a predominance of allergic sensitization and multimorbidity, while in adults polysensitization has been positively associated with asthma occurrence. Despite significant improvements in recent decades, asthma management remains challenging. Recently, a group of specialists suggested that the term "asthma" should be preferably used as a descriptive term for symptoms. Moreover, type 2 inflammation has emerged as a pivotal disease mechanism including overlapping endotypes of specific IgE production, while type 2-low asthma includes several disease endotypes. Optimal asthma control requires both appropriate pharmacological interventions, tailored to each patient, as well as trigger avoidance measures. Regular monitoring for maintenance of symptom control, preservation of lung function, and detection of treatment-related adverse effects are warranted. Allergen-specific immunotherapy and the advent of new targeted therapies for patients with difficult to control asthma offer diverse treatment options. The current review summarizes up-to-date knowledge on epidemiology, definitions, diagnosis, and current therapeutic strategies.

Usage of long-acting muscarinic antagonists and biologics as add-on therapy for patients in the United States with moderate-to-severe asthma

Many asthma patients remain uncontrolled on inhaled corticosteroids (ICS) and long-acting beta agonists (LABAs), but guidance for selecting add-on therapies, including long-acting muscarinic antagonists (LAMAs) or biologics, is limited. We describe how prescribing practices for add-on LAMA and biologic therapy have changed with increased treatment options and revised treatment guidelines. We further identify differences in treatment initiation and discontinuation rates by patient characteristics, including concomitant COPD.

This retrospective cohort study analyzed insurance claims in the IBM Marketscan database for adult US asthma patients treated with medium- or high-dose ICS/LABA between 2012 and 2019 (n = 277,373). We used negative binomial regression models to evaluate LAMA and biologic initiation rates and their association with patient characteristics, and survival analysis methods for assessing discontinuation rates.

Between 2012 and 2019, LAMA and biologic uptake increased approximately 5-fold and 20-fold, respectively. LAMA initiation was significantly higher among patients with concomitant COPD, a group typically unstudied in clinical trials, versus those with asthma only (rate ratio of 5.90, 95% CI: 5.76-6.04). High-dose ICS/LABA treatment and the need for oral corticosteroid (OCS) bursts had stronger associations with biologic initiation. Probability of discontinuation (i.e. non-persistence) in the first year was 40.5% and 22.7% for those initiating LAMAs and biologics, respectively, with higher LAMA discontinuation rates among patients with asthma only versus those with concomitant COPD.

Our results provide insights into how clinicians apply treatment guidelines for initiating add-on LAMA and biologic therapies in moderate-to-severe asthma patients and highlight patients who have an unmet treatment need after discontinuation.

Development of novel fluorescent histamine H1-receptor antagonists to study ligand-binding kinetics in living cells

The histamine H1-receptor (H1R) is an important mediator of allergy and inflammation. H1R antagonists have particular clinical utility in allergic rhinitis and urticaria. Here we have developed six novel fluorescent probes for this receptor that are very effective for high resolution confocal imaging, alongside bioluminescence resonance energy transfer approaches to monitor H1R ligand binding kinetics in living cells. The latter technology exploits the opportunities provided by the recently described bright bioluminescent protein NanoLuc when it is fused to the N-terminus of a receptor. Two different pharmacophores (mepyramine or the fragment VUF13816) were used to generate fluorescent H1R antagonists conjugated via peptide linkers to the fluorophore BODIPY630/650. Kinetic properties of the probes showed wide variation, with the VUF13816 analogues having much longer H1R residence times relative to their mepyramine-based counterparts. The kinetics of these fluorescent ligands could also be monitored in membrane preparations providing new opportunities for future drug discovery applications.

Xanthines and Phosphodiesterase Inhibitors

Theophylline is an orally acting xanthine that has been used since 1937 for the treatment of respiratory diseases including asthma and chronic obstructive pulmonary disease (COPD). However, in most treatment guidelines, xanthines have now been consigned to third-line therapy because of their narrow therapeutic window and propensity for drug-drug interactions. However, lower than conventional doses of theophylline considered to be bronchodilator are now known to have anti-inflammatory actions of relevance to the treatment of respiratory disease. The molecular mechanism(s) of action of theophylline are not well understood, but several potential targets have been suggested including non-selective inhibition of phosphodiesterases (PDE), inhibition of phosphoinositide 3-kinase, adenosine receptor antagonism and increased activity of certain histone deacetylases. Although theophylline has a narrow therapeutic window, other xanthines are in clinical use that are claimed to have a better tolerability such as doxofylline and bamifylline. Nonetheless, xanthines still play an important role in the treatment of asthma and COPD as they can show clinical benefit in patients who are refractory to glucocorticosteroid therapy, and withdrawal of xanthines from patients causes worsening of disease, even in patients taking concomitant glucocorticosteroids.More recently the orally active selective PDE4 inhibitor, roflumilast, has been introduced into clinical practice for the treatment of severe COPD on top of gold standard treatment. This drug has been shown to improve lung function in patients with severe COPD and to reduce exacerbations, but is dose limited by a range side effect, particularly gastrointestinal side effects.

Pharmacotherapy in the management of asthma in the elderly: a review of clinical studies

Asthma in the elderly is a disease with emerging concern. Despite some recent advances in our understanding of epidemiology and pathophysiology, there is a considerable lack of clinical evidence specific to elderly patients. Currently available high quality clinical evidence has been mostly obtained from younger adults, but rarely from elderly patients. Under-representation of elderly patients in previous randomized trials may have been due to being, old age, or having comorbidities. Thus, a question may be raised whether current clinical evidence could be well generalized into elderly patients. Further clinical trials should address clinical issues raised in elderly population. In this review, we aimed to overview the efficacy and safety of pharmacological management, and also to summarize the literature relevant to elderly asthma.

Long-acting muscarinic antagonists (LAMA) added to inhaled corticosteroids (ICS) versus higher dose ICS for adults with asthma

BACKGROUND

Long-acting muscarinic antagonists (LAMA), a class of drugs with proven effectiveness in chronic obstructive pulmonary disease (COPD), are being considered as an add-on option for adults with asthma whose condition is uncontrolled on inhaled corticosteroids (ICS). It is important to assess the safety and efficacy of LAMA add-on as an alternative to the prolonged use of higher doses of ICS, which are known to cause undesirable side effects in some people.

OBJECTIVES

To compare the effects of adding a LAMA to any dose of ICS versus increasing the dose of ICS, for uncontrolled asthma in adults.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register (CAGR) from its inception in 1995 to April 2015, imposing no restriction on language of publication. We also handsearched trial registries, reference lists of primary studies and existing reviews, as well as manufacturers' websites.

SELECTION CRITERIA

We looked for parallel or cross-over randomised controlled trials lasting at least 12 weeks, in which adults whose asthma was not well controlled on ICS alone were randomised to treatment with LAMA add-on to ICS or with an increased dose of ICS. Trials were excluded if patients were taking long-acting beta2-agonists during the study period.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the searches and extracted data from studies meeting all the inclusion criteria. We used Covidence to manage duplicate screening, data extraction and risk of bias judgements, and to form a consensus where discrepancies arose. We used standard methods expected by The Cochrane Collaboration.The pre-specified primary outcomes were exacerbations requiring a course of oral corticosteroids (OCS), effects on quality of life and serious adverse events.

MAIN RESULTS

One cross-over randomised controlled trial met the inclusion criteria. The trial was performed in 210 patients with moderate to severe asthma and compared the use of the LAMA tiotropium bromide with double dose beclomethasone (an ICS) using a cross-over design and 14-week treatment periods.Compared with people taking a double dose of ICS, fewer people taking a LAMA add-on had an exacerbation requiring treatment with OCS (odds ratio (OR) 0.57, 95% confidence interval (CI) 0.22 to 1.43) or an exacerbation resulting in emergency department admission (OR 0.49, 95% CI 0.09 to 2.77), but the confidence intervals for both outcomes did not exclude the possibility that double dose ICS was more effective. Serious adverse events and exacerbations requiring hospitalisation occurred in similarly low numbers of people taking each treatment, but confidence intervals were too wide to suggest that the two treatment options were equivalent.Asthma-related quality of life was similar in both treatment groups (mean difference (MD) in change from baseline 0.10, 95% CI - 0.07 to 0.27). Those taking LAMA add-on scored slightly better on a scale measuring asthma control than those increasing their ICS dose (MD in change from baseline - 0.18, 95% CI - 0.34 to - 0.02), although the difference was clinically small. Evidence was deemed low quality for both quality of life and asthma control.There was moderate-quality evidence that participants' trough forced expiratory volume in one second (FEV1) was 100 mL better when taking LAMA add-on than with increased ICS dose (MD in change from baseline 0.10, 95% CI 0.03 to 0.17).

AUTHORS' CONCLUSIONS

Only one randomised trial was found, comparing tiotropium add-on to increased dose beclomethasone. Differences between the treatments were too small or imprecise to understand whether adding a LAMA to ICS is safer or more effective than increasing the dose of ICS, and there is a possibility of carry-over effects due to the study's cross-over design. LAMA add-on may lead to more improvement in lung function (FEV1) than an increased dose of ICS.The results of this review, alongside pending results from related reviews assessing the use of LAMA against other treatments, will help to define the role of these drugs in asthma management, and this review should be updated as results from future trials emerge. Studies assessing the role of LAMA add-on should be longer and include a double-ICS treatment arm so that the results can be interpreted in the context of the guideline-recommended treatment options that are available to physicians.

Long-acting muscarinic antagonists (LAMA) added to inhaled corticosteroids (ICS) versus addition of long-acting beta2-agonists (LABA) for adults with asthma

BACKGROUND

Poorly controlled asthma and preventable exacerbations place a significant strain on healthcare, often requiring additional medications, hospital stays or treatment in the emergency department.Long-acting beta2-agonists (LABA) are the preferred add-on treatment for adults with asthma whose symptoms are not well controlled on inhaled corticosteroids (ICS), but have important safety concerns in asthma. Long-acting muscarinic antagonists (LAMA) have confirmed efficacy in chronic obstructive pulmonary disease and are now being considered as an alternative add-on therapy for people with uncontrolled asthma.

OBJECTIVES

To assess the efficacy and safety of adding a LAMA to ICS compared with adding a LABA for adults whose asthma is not well controlled on ICS alone.

SEARCH METHODS

We searched the Cochrane Airways Group's Specialised Register (CAGR) from inception to April 2015, and imposed no restriction on language of publication. We searched additional resources to pick up unpublished studies, including ClinicalTrials.gov, World Health Organization trials portal, reference lists of primary studies and existing reviews, and manufacturers' trial registries. The most recent search was conducted in April 2015.

SELECTION CRITERIA

We searched for parallel and cross-over RCTs in which adults whose asthma was not well controlled with ICS alone were randomised to receive LAMA add-on or LABA add-on for at least 12 weeks.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the electronic and additional searches and extracted data from study reports. We used Covidence for duplicate screening, extraction of study characteristics and numerical data, and risk of bias ratings.The pre-specified primary outcomes were exacerbations requiring oral corticosteroids (OCS), quality of life and serious adverse events.

MAIN RESULTS

We included eight studies meeting the inclusion criteria, but four double-blind, double-dummy studies of around 2000 people dominated the analyses. These four trials were between 14 and 24 weeks long, all comparing tiotropium (usually Respimat) with salmeterol on top of medium doses of ICS.Studies reporting exacerbations requiring OCS showed no difference between the two add-ons, but our confidence in the effect was low due to inconsistency between studies and because the confidence intervals (CI) included significant benefit of either treatment (odds ratio (OR) 1.05, 95% CI 0.50 to 2.18; 1753 participants; 3 studies); three more people per 1000 might have an exacerbation on LAMA, but the CIs ranged from 29 fewer to 61 more. Imprecision was also an issue for serious adverse events and exacerbations requiring hospital admission, rated low (serious adverse events) and very low quality (exacerbations requiring hospital admission), because there were so few events in the analyses.People taking LAMA scored slightly worse on two scales measuring quality of life (Asthma Quality of Life Questionnaire; AQLQ) and asthma control (Asthma Control Questionnaire; ACQ); the evidence was rated high quality but the effects were small and unlikely to be clinically significant (AQLQ: mean difference (MD) -0.12, 95% CI -0.18 to -0.05; 1745 participants; 1745; 4 studies; ACQ: MD 0.06, 95% CI 0.00 to 0.13; 1483 participants; 3 studies).There was some evidence to support small benefits of LAMA over LABA on lung function, including on our pre-specified preferred measure trough forced expiratory volume in one second (FEV1) (MD 0.05 L, 95% CI 0.01 to 0.09; 1745 participants, 4 studies). However, the effects on other measures varied, and it is not clear whether the magnitude of the differences were clinically significant.More people had adverse events on LAMA but the difference with LABA was not statistically significant.

AUTHORS' CONCLUSIONS

Direct evidence of LAMA versus LABA as add-on therapy is currently limited to studies of less than six months comparing tiotropium (Respimat) to salmeterol, and we do not know how they compare in terms of exacerbations and serious adverse events. There was moderate quality evidence that LAMAs show small benefits over LABA on some measures of lung function, and high quality evidence that LABAs are slightly better for quality of life, but the differences were all small. Given the much larger evidence base for LABA versus placebo for people whose asthma is not well controlled on ICS, the current evidence is not strong enough to say that LAMA can be substituted for LABA as add-on therapy.The results of this review, alongside pending results from related reviews assessing the use of LAMA in other clinical scenarios, will help to define the role of these drugs in asthma and it is important that they be updated as results from ongoing and planned trials emerge.

Addition to inhaled corticosteroids of leukotriene receptor antagonists versus theophylline for symptomatic asthma: a meta-analysis

BACKGROUND

Inhaled corticosteroids (ICSs) are widely used in combination with second controller medications in the management of asthma in adults and children. There lacks a systematic comparison between addition of leukotriene receptor antagonists (LTRAs) and theophylline to ICS. The purpose of this meta-analysis was to evaluate the difference of the efficacy and safety profile of adding either LTRAs or theophylline to ICS in adults and children with symptomatic asthma.

METHODS

Randomised controlled trials (RCTs) published prior to November 2014 were acquired through systematically searching and selected based on the established inclusion criteria for publications. The data extracted from the included studies were further analyzed by a meta-analysis.

RESULTS

We included eight RCTs, of which six recruited adults and two recruited children aged 5 to 14 years. The primary outcomes were changes in lung function from baseline, including forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF). Overall, addition of LTRAs led to significantly better morning PEF {mean difference (MD) 16.94 [95% confidence interval (CI): 11.49-22.39] L/min, P<0.01} and FEV1 [MD 0.09 (95% CI: 0.03-0.15) L, P=0.005] as compared to addition of theophylline. There were no differences between the two treatments in terms of evening PEF, adverse events, rescue medication use and asthma exacerbation.

CONCLUSIONS

The combination of LTRA and ICS leads to modestly greater improvement in lung function than the combination of theophylline and ICS in the treatment of symptomatic asthma. Long-term trials are required to assess the efficacy and safety of these two therapies.

Interventions for managing asthma in pregnancy

BACKGROUND

Asthma is the most common respiratory disorder complicating pregnancy, and is associated with a range of adverse maternal and perinatal outcomes. There is strong evidence however, that the adequate control of asthma can improve health outcomes for mothers and their babies. Despite known risks of poorly controlled asthma during pregnancy, a large proportion of women have sub-optimal asthma control, due to concerns surrounding risks of pharmacological agents, and uncertainties regarding the effectiveness and safety of different management strategies.

OBJECTIVES

To assess the effects of interventions (pharmacologic and non-pharmacologic) for managing women's asthma in pregnancy on maternal and fetal/infant outcomes.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (2 June 2014) and the Cochrane Airways Group's Trials Register (4 June 2014).

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing any intervention used to manage asthma in pregnancy, with placebo, no intervention, or an alternative intervention. We included pharmacological and non-pharmacological interventions (including combined interventions). Cluster-randomised trials were eligible for inclusion (but none were identified). Cross-over trials were not eligible for inclusion.We included multi-armed trials along with two-armed trials. We also included studies published as abstracts only.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed trial eligibility and quality and extracted data. Data were checked for accuracy.

MAIN RESULTS

We included eight trials in this review, involving 1181 women and their babies. Overall we judged two trials to be at low risk of bias, two to be of unclear risk of bias, and four to be at moderate risk of bias.Five trials assessed pharmacological agents, including inhaled corticosteroids (beclomethasone or budesonide), inhaled magnesium sulphate, intravenous theophylline, and inhaled beclomethasone verus oral theophylline. Three trials assessed non-pharmacological interventions, including a fractional exhaled nitric oxide (FENO)-based algorithm versus a clinical guideline-based algorithm to adjust inhaled corticosteroid therapy, a pharmacist-led multi-disciplinary approach to management versus standard care, and progressive muscle relaxation (PMR) versus sham training.The eight included trials were assessed under seven separate comparisons. Pharmacological interventionsPrimary outcomes: one trial suggested that inhaled magnesium sulphate in addition to usual treatment could reduce exacerbation frequency in acute asthma (mean difference (MD) -2.80; 95% confidence interval (CI) -3.21 to -2.39; 60 women). One trial assessing the addition of intravenous theophylline to standard care in acute asthma did not report on exacerbations (65 women). No clear difference was shown in the risk of exacerbations with the use of inhaled beclomethasone in addition to usual treatment for maintenance therapy in one trial (risk ratio (RR) 0.36; 95% CI 0.13 to 1.05; 60 women); a second trial also showed no difference, however data were not clearly reported to allow inclusion in a meta-analysis. No difference was shown when inhaled beclomethasone was compared with oral theophylline for maintenance therapy (RR 0.88; 95% CI 0.59 to 1.33; one trial, 385 women). None of these trials reported on neonatal intensive care admissions.

SECONDARY OUTCOMES

inhaled magnesium sulphate in acute asthma was shown to improve lung function measures (one trial, 60 women); intravenous theophylline in acute asthma was not associated with benefits (one trial, 65 women). No clear differences were seen with the addition of inhaled corticosteroids to routine treatment in three trials (374 women). While inhaled beclomethasone, compared with oral theophylline, significantly reduced treatment discontinuation due to adverse effects in one trial (384 women), no other differences were observed, except for higher treatment adherence with theophylline. Four of the five trials did not report on adverse effects. Non-pharmacological interventionsPrimary outcomes: in one trial, the use of a FENO-based algorithm was shown to significantly reduce asthma exacerbations (RR 0.61; 95% CI 0.41 to 0.90; 220 women); and a trend towards fewer neonatal hospitalisations was observed (RR 0.46; 95% CI 0.21 to 1.02; 214 infants). No exacerbations occurred in one trial assessing pharmacist-led management; this approach did not reduce neonatal intensive care admissions (RR 1.50; 95% CI 0.27 to 8.32; 58 infants). One trial (64 women) assessing PMR did not report on exacerbations or neonatal intensive care admissions.

SECONDARY OUTCOMES

the use of a FENO-based algorithm to adjust therapy led to some improvements in quality of life scores, as well as more frequent use of inhaled corticosteroids and long-acting β-agonists, and less frequent use of short-acting β-agonists (one trial, 220 women). The FENO-based algorithm was associated with fewer infants with recurrent episodes of bronchiolitis in their first year of life, and a trend towards fewer episodes of croup for infants. Pharmacist-led management improved asthma control scores at six months (one trial, 60 women); PMR improved lung function and quality of life measures (one trial, 64 women). No other differences between comparisons were observed.

AUTHORS' CONCLUSIONS

Based on eight included trials, of moderate quality overall, no firm conclusions about optimal interventions for managing asthma in pregnancy can be made. Five trials assessing pharmacological interventions did not provide clear evidence of benefits or harms to support or refute current practice. While inhaled magnesium sulphate for acute asthma was shown to reduce exacerbations, this was in one small trial of unclear quality, and thus this finding should be interpreted with caution. Three trials assessing non-pharmacological interventions provided some support for the use of such strategies, however were not powered to detect differences in important maternal and infant outcomes. While a FENO-based algorithm reduced exacerbations, the effects on perinatal outcomes were less certain, and thus widespread implementation is not yet appropriate. Similarly, though positive effects on asthma control were shown with PMR and pharmacist-led management, the evidence to date is insufficient to draw definitive conclusions.In view of the limited evidence base, further randomised trials are required to determine the most effective and safe interventions for asthma in pregnancy. Future trials must be sufficiently powered, and well-designed, to allow differences in important outcomes for mothers and babies to be detected. The impact on health services requires evaluation. Any further trials assessing pharmacological interventions should assess novel agents or those used in current practice. Encouragingly, at least five trials have been identified as planned or underway.

Comparative effectiveness of long term drug treatment strategies to prevent asthma exacerbations: network meta-analysis

OBJECTIVE

To determine the comparative effectiveness and safety of current maintenance strategies in preventing exacerbations of asthma.

DESIGN

Systematic review and network meta-analysis using Bayesian statistics.

DATA SOURCES

Cochrane systematic reviews on chronic asthma, complemented by an updated search when appropriate. ELIGIBILITY CRITERIA TRIALS OF Adults with asthma randomised to maintenance treatments of at least 24 weeks duration and that reported on asthma exacerbations in full text. Low dose inhaled corticosteroid treatment was the comparator strategy. The primary effectiveness outcome was the rate of severe exacerbations. The secondary outcome was the composite of moderate or severe exacerbations. The rate of withdrawal was analysed as a safety outcome.

RESULTS

64 trials with 59,622 patient years of follow-up comparing 15 strategies and placebo were included. For prevention of severe exacerbations, combined inhaled corticosteroids and long acting β agonists as maintenance and reliever treatment and combined inhaled corticosteroids and long acting β agonists in a fixed daily dose performed equally well and were ranked first for effectiveness. The rate ratios compared with low dose inhaled corticosteroids were 0.44 (95% credible interval 0.29 to 0.66) and 0.51 (0.35 to 0.77), respectively. Other combined strategies were not superior to inhaled corticosteroids and all single drug treatments were inferior to single low dose inhaled corticosteroids. Safety was best for conventional best (guideline based) practice and combined maintenance and reliever therapy.

CONCLUSIONS

Strategies with combined inhaled corticosteroids and long acting β agonists are most effective and safe in preventing severe exacerbations of asthma, although some heterogeneity was observed in this network meta-analysis of full text reports.

Progress in the management of childhood asthma

Asthma has become the most common chronic disease in childhood. Significant advances in epidemiological research as well as in therapy of pediatric asthma have been made over the past 2 decades. In this review, we look at certain aspects therapy of childhood asthma, both in the past and present. Literature review on allergen avoidance (including mites, cockroach and cat), intensive therapy with β(2)-agonists in acute asthma (administering via continuous nebulization and intravenous routes), a revisit of theophylline use and its action, the use of inhaled corticosteroids in various phases of childhood asthma and sublingual immunotherapy in asthma are examined. Recent facts and dilemmas of these treatments are identified along with expression of our opinions, particularly on points of childhood asthma in the Asia-Pacific, are made in this review.

Achieving symptom control in patients with moderate asthma

Disease severity in asthma can be classified as mild, moderate or severe based upon the frequency of symptoms or the severity of airflow obstruction. This review will focus on the treatment of youths greater than 12 years of age and adults with moderate persistent asthma. Moderate asthmatics may have daily symptoms that cause some limitation with normal daily activities and require use of a rescue inhaled short-acting beta(2)-agonist inhaler or experience nocturnal awakenings secondary to asthma that occur more than once per week. Furthermore, spirometry may reveal airflow obstruction with a reduction in FEV(1) to between 60% and 80% of predicted. Although inhaled corticosteroids (ICS) are the primary controller medication used to modify symptoms in moderate asthmatics, additional controller medications, such as inhaled long-acting beta(2)-agonists (LABA), leukotriene receptor antagonists (LTRA) or theophylline, are often needed to obtain optimal disease control. While the addition of an inhaled LABA to an ICS is very effective at improving disease control in moderate asthma, concerns have arisen over the safety of LABAs, in particular the risk of asthma-related death. Therefore, consideration may be given to initially adding a LTRA, rather than a LABA, to ICS when asthma symptoms are not adequately controlled by ICS alone. Furthermore, individualization of medication regimens, treatment of co-morbid conditions, and patient education are crucial to optimizing compliance with therapy, improving disease control, and reducing the risk of exacerbations. Lastly, the development of new asthma treatments, perhaps based upon personalized medicine, may revolutionize the future treatment of moderate asthma.

Revisiting an Old Therapy

The use of theophylline for the treatment of asthma has decreased significantly over the past few decades. Nonetheless, clinicians may still encounter patients with theophylline-based asthma regimens. While theophylline’s exact mechanism of action is not defined, new theories infer that the benefit of theophylline is due to its anti-inflammatory, rather than bronchodilatory, effects. Clinical trials have explored the combination of theophylline with lower doses of corticosteroids as a steroid-sparing strategy. Complex pharmacokinetics, significant adverse effects, and interpatient variability have contributed to the decreased use of this medication for asthma. Clinicians should be cognizant of the appropriate initial dosing, variety of formulations, and timing of theophylline levels to reduce toxicity and better control asthma symptoms. This review summarizes literature supporting the use of low-dose theophylline as an adjunct to corticosteroids in asthma, as well as pharmacokinetics, drug interactions, and adverse effects associated with its traditional dosing strategy.

Endotyping asthma: new insights into key pathogenic mechanisms in a complex, heterogeneous disease

Clinical asthma is very widely assumed to be the net result of excessive inflammation driven by aberrant T-helper-2 (Th2) immunity that leads to inflamed, remodelled airways and then functional derangement that, in turn, causes symptoms. This notion of disease is actually poorly supported by data, and there are substantial discrepancies and very poor correlation between inflammation, damage, functional impairment, and degree of symptoms. Furthermore, this problem is compounded by the poor understanding of the heterogeneity of clinical disease. Failure to recognise and discover the underlying mechanisms of these major variants or endotypes of asthma is, arguably, the major intellectual limitation to progress at present. Fortunately, both clinical research and animal models are very well suited to dissecting the cellular and molecular basis of disease endotypes. This approach is already suggesting entirely novel pathways to disease-eg, alternative macrophage specification, steroid refractory innate immunity, the interleukin-17-regulatory T-cell axis, epidermal growth factor receptor co-amplification, and Th2-mimicking but non-T-cell, interleukins 18 and 33 dependent processes that can offer unexpected therapeutic opportunities for specific patient endotypes.