Concluding remarks: can we explain the association of beta-agonists with asthma mortality? A hypothesis

Should all asthma patients be switched to single maintenance and reliever therapy?

ABSTRACT

Recent data indicate that overuse of short-acting beta2-agonists (SABAs) results in an increased risk of asthma exacerbations and mortality. The use of inhaled corticosteroid-formoterol as both maintenance and reliever therapy has become a preferred regimen for asthma management. Clinicians should be aware of the pharmacology, dosing, and prescribing considerations regarding the use of budesonide-formoterol as the available combination in the United States.

Diagnosis and treatment of adult asthma patients in Serbia: a 2022 experts group position statement

INTRODUCTION

Asthma is the most common non-communicable chronic lung condition across all ages. Epidemiological data indicate that many asthma patients in Serbia remain undiagnosed and untreated. The implementation of recent global advances in asthma management is limited due to the lack of a systematic approach, drug availability and regulatory affairs. In addition, the global coronavirus disease pandemic has posed a significant challenge, particularly in resource-limited settings.

AREAS COVERED

In this paper, we propose an algorithm for treating adult asthma patients in Serbia. We performed PubMed database search on published asthma clinical trials and guidelines from 1 January 2015 to 10 March 2020. The consensus process incorporated a modified Delphi method that included two rounds of e-mail questionnaires and three rounds of national asthma expert meetings. We focus on 1) objective diagnosis of asthma, 2) the implementation of up-to-date therapeutic options, and 3) the identification and referral of severe asthma patients to newly established severe asthma centers.

EXPERT OPINION

Regional specificities and variations in healthcare systems require the adaptation of evidence-based knowledge. Practical, clinically oriented algorithms designed to overcome local barriers in healthcare delivery may facilitate timely and adequate asthma diagnosis and the local implementation of current advances in asthma management.

Short-Acting Beta-2-Agonist Exposure and Severe Asthma Exacerbations: SABINA Findings From Europe and North America

BACKGROUND

Expert national/global asthma management recommendations raise the issue whether a safe threshold of short-acting beta-2 agonist (SABA) use without concomitant inhaled corticosteroids (ICS) exists.

OBJECTIVE

To examine SABA and maintenance therapy associations with severe asthma exacerbations across North America and Europe.

METHODS

Observational analyses of 10 SABa use IN Asthma (SABINA) datasets involving 1,033,564 patients (≥12 y) from Canada, France, the Netherlands, Poland, Spain, the United Kingdom, and the United States. Negative binomial models (incidence rate ratio [IRR] [95% CI adjusted for prespecified-covariates]) evaluated associations between SABA and exacerbations.

RESULTS

Across severities, 40.2% of patients were prescribed/possessed 3 or more SABA canisters/y. Per the Global Initiative for Asthma (GINA) 2018 definitions, steps 3 to 5-treated patients prescribed/possessing 3 or more versus 1 or 2 SABAs experienced more severe exacerbations (IRR 1.08 [95% CI 1.04‒1.13], U.S. Medicare; IRR 2.11 [95% CI 1.96‒2.27], Poland). This association was not observed in all step 1 or 2-treated patients (the Netherlands, IRR 1.25 [95% CI 0.91‒1.71]; U.S. commercial, IRR 0.92 [95% CI 0.91‒0.93]; U.S. Medicare, IRR 0.74 [95% CI 0.71‒0.76]). We hypothesize that this inverse association between SABA and severe exacerbations in the U.S. datasets was attributable to the large patient population possessing fewer than 3 SABA and no maintenance therapy and receiving oral corticosteroid bursts without face-to-face health care provider encounters. In U.S. SABA monotherapy-treated patients, 3 or more SABAs were associated with more emergency/outpatient visits and hospitalizations (IRR 1.31 [95% CI 1.29‒1.34]). Most GINA 2 to 5-treated study patients (60.6%) did not have maintenance therapy for up to 50% of the time; however, the association of 3 or more SABAs and severe exacerbations persisted (IRR 1.32 [95% CI 1.18‒1.49]) after excluding these patients and the independent effect was further confirmed when U.K. SABA data were analyzed as a continuous variable in patients with up to 100% annual coverage for ICS-containing medications.

CONCLUSIONS

Increasing SABA exposure is associated with severe exacerbation risk, independent of maintenance therapy. As addressed by GINA, based on studies across asthma severities where as-needed fast-acting bronchodilators with concomitant ICS decrease severe exacerbations compared with SABA, our findings highlight the importance of avoiding a rescue/reliever paradigm utilizing SABA monotherapy.

Is Overreliance on SABA Associated with Health Risks in the Older Asthma Population?

Recent Global Initiative for Asthma (GINA) recommendations reduce the role of short-acting β₂-agonist (SABA) premised on the associated exacerbation risk. The widely accepted SABA risk profile is based on limited data described 30 years ago. This GINA paradigm shift demands an examination of SABA risks in a modern therapeutic era. Recent studies confirm that SABA overuse is common and associated with adverse outcomes. This study aimed to determine associations between SABA use, all-cause mortality and asthma exacerbations in an older North American asthma population.

In this population-based cohort study, individuals with prevalent asthma (2006–2015) aged ≥65 years, eligible for provincial drug coverage, were included. Annual SABA canisters filled (0, 1–2, 3–5, ≥6) was the primary exposure. Hazard ratios (HRs) with 95% CIs were estimated using Cox proportional hazard regression, adjusted for confounders.

There were 59 533 asthma individuals; 14% overused SABA (≥3 canisters annually). Compared to those who used <3 canisters, the adjusted HRs of death for those who used 3–5 and ≥6 canisters were 1.11 (95% CI: 1.02–1.22, p=0.0157) and 1.56 (95% CI: 1.41–1.71, p<0.0001), respectively. Severe asthma exacerbation rates for ≥3 and <3 canisters/year were 7.5% and 2.1%, respectively. The adjusted HRs of severe asthma exacerbations were 1.59 (95% CI: 1.40–1.82, p<0.0001) and 2.26 (95% CI: 1.96–2.60, p<0.0001) in those who used 3–5 and ≥6 SABA canisters per year, respectively.

In Canada, 1 in 7 individuals with asthma overused SABA associated with increased risks of severe asthma exacerbations and death. The adverse impacts of SABA overuse continue 30 years after early publications.

These results in older people with asthma add strength to previously documented associations of SABA use, severe asthma exacerbations and death. Clinicians may consider these safety results when prescribing and assessing new therapeutic recommendations.https://bit.ly/34Gr56P

Demographics, Treatment Patterns, and Morbidity in Patients with Exercise-Induced Bronchoconstriction: An Administrative Claims Data Analysis

PURPOSE

Exercise-induced bronchoconstriction (EIB) is generally treated with short-acting β2-agonists (SABA) before exercising, to prevent symptoms. Real-world data on treatments and outcomes for patients with EIB alone (EIBalone), or with asthma (EIBasthma), in the USA are limited. This study compared demographics, treatment patterns, morbidity, and costs of treating EIB between these two groups of patients.

PATIENTS AND METHODS

Administrative claims from US IBM® MarketScan® Research databases were analyzed retrospectively. Patients aged ≥4 years filling a SABA claim between 1/1/2011 and 12/31/2016 were evaluated. Patients were indexed on a random SABA claim and required to have 12 months' continuous eligibility pre- and post-index, ≥1 maintenance medication and/or SABA fill post-index, and were designated EIBalone or EIBasthma according to diagnostic codes (EIB only or EIB plus asthma, respectively). Descriptive statistics were used.

RESULTS

In total, 13,480 patients had EIBalone and 14,862 had EIBasthma. Compared with EIBasthma, the EIBalone group was older (mean[SD] 20.4[13.6] vs 17.8[13.6] years), had more females (60.7% vs 54.7%), and filled fewer SABA claims (1.9[1.4] vs 2.5[2.2]) (all p<0.001). A smaller proportion of patients in the EIBalone than EIBasthma group had maintenance therapy claims (79.9% vs 90.6%, p<0.001). The EIBalone group also had a lower proportion of patients with oral or injectable corticosteroid claims (29.4% vs 32.0%) and asthma and/or EIB-related emergency department (1.0% vs 13.0%) or outpatient visits (65.1% vs 72.3%; all p<0.0001). Annual days' supply of oral corticosteroids was similar between groups (mean[SD] EIBalone: 20.7[30.8] vs EIBasthma: 19.8[28] days).

CONCLUSION

Individuals with EIBalone or EIBasthma demonstrate considerable morbidity. New treatment paradigms may be needed to optimize outcomes for both patient groups.

Recent Advances in β2-Agonists for Treatment of Chronic Respiratory Diseases and Heart Failure

β₂-Adrenoceptor (β₂-AR) agonists are widely used as bronchodilators. The emerge of ultralong acting β₂-agonists is an important breakthrough in pulmonary medicine. In this review, we will provide mechanistic insights into the application of β₂-agonists in asthma, chronic obstructive pulmonary disease (COPD), and heart failure (HF). Recent studies in β-AR signal transduction have revealed opposing functions of the β₁-AR and the β₂-AR on cardiomyocyte survival. Thus, β₂-agonists and β-blockers in combination may represent a novel strategy for HF management. Allosteric modulation and biased agonism at the β₂-AR also provide a theoretical basis for developing drugs with novel mechanisms of action and pharmacological profiles. Overlap of COPD and HF presents a substantial clinical challenge but also a unique opportunity for evaluation of the cardiovascular safety of β₂-agonists. Further basic and clinical research along these lines can help us develop better drugs and innovative strategies for the management of these difficult-to-treat diseases.

Long-term safety and efficacy studies of epinephrine HFA metered-dose inhaler (Primatene® Mist): a two-stage randomized controlled trial

Objective: A new epinephrine hydrofluoroalkane (HFA) asthma metered-dose inhaler (MDI) was reformulated to replace the previously marketed epinephrine chlorofluorocarbon (CFC) MDI. In addition to the HFA propellant change, several enhanced modifications (i.e. changed from solution to suspension, 43% dose reduction, etc.) were made to the formulation of epinephrine HFA MDI. This study evaluates the 6-month long-term safety and efficacy profile of the new epinephrine HFA MDI.Method: The long-term safety study consists of two 3-month, multi-center, double- or evaluator-blinded, parallel-group, placebo, and active controlled stages. In each stage, subjects aged ≥12 years with intermittent or mild-to-moderate persistent asthma were randomized to receive epinephrine HFA (2 × 125 mcg/inhalation), placebo HFA, or epinephrine CFC (2 × 220 mcg/inhalation). Bronchodilator efficacy was assessed in Stage 1 and was determined primarily by the change in the forced expiratory volume in 1 s (ΔFEV1) at Week 12, relative to the same day baseline.Results: The primary efficacy endpoint (AUC_0-6hrs of %ΔFEV1 at Week 12) for epinephrine HFA (47.3 ± 54.2) closely paralleled those for the active control, epinephrine CFC (41.0 ± 43.4). Both groups were found to be overall comparable in bronchodilator efficacy. Both also showed low incidence rates of AEs with tremor being most commonly reported for epinephrine HFA. All AEs found were non-serious and non-significant. The observed changes in vital signs, ECG, serum glucose, and potassium were minimal and not clinically relevant.Conclusion: This study demonstrated that the new epinephrine HFA is overall comparable, in both safety and efficacy, to the previous epinephrine CFC.

A multinational observational study identifying primary care patients at risk of overestimation of asthma control

Factors related to the discrepancy between patient-perceived and actual disease control remain unclear. Identifying patients at risk of overestimation of asthma control remains elusive. This study aimed to (i) investigate the relationship between patient-reported and actual level of asthma control (ii), compare the characteristics between patients who believe their asthma is well controlled that accurately report ‘well-controlled’ asthma with those that do not, and (iii) identify factors associated with inaccurately reported ‘well-controlled’ asthma. A historical, multinational, cross-sectional study using data from the iHARP (initiative Helping Asthma in Real-life Patients) review service for adults with asthma prescribed fixed-dose combination therapy. Data from 4274 patients were analysed. A major discrepancy between patient-reported and Global Initiative for Asthma defined asthma control was detected; 71.1% of patients who reported ‘well-controlled’ asthma were inaccurate in their perception despite receiving regular maintenance therapy. Significant differences were noted in age, gender, body mass index, education level, medication use, side effects, attitudes to preventer inhaler use, inhaler technique review and respiratory specialist review between patients who accurately reported ‘well-controlled’ asthma and those who did not. Independent risk factors associated with inaccurately reported ‘well-controlled’ asthma were: having taken a maximum of 5–12 puffs or more of reliever inhaler on at least one day within the previous 4 weeks; being female; having seen a respiratory specialist more than a year ago (rather than in the previous year); and having required oral corticosteroids for worsening asthma in the previous year. The study highlighted the significant hidden burden associated with under-recognition of poor asthma control, on the part of the patient and the need for targeted interventions designed to address the continuing discrepancy between perceived and actual disease control.

Long-Acting β2-Agonists in Asthma: Enantioselective Safety Studies are Needed

Long-acting β2-agonists (LABAs) such as formoterol and salmeterol are used for prolonged bronchodilatation in asthma, usually in combination with inhaled corticosteroids (ICSs). Unexplained paradoxical asthma exacerbations and deaths have been associated with LABAs, particularly when used without ICS. LABAs clearly demonstrate effective bronchodilatation and steroid-sparing activity, but long-term treatment can lead to tolerance of their bronchodilator effects. There are also concerns with regard to the effects of LABAs on bronchial hyperresponsiveness (BHR), where long-term use is associated with increased BHR and loss of bronchoprotection. A complicating factor is that formoterol and salmeterol are both chiral compounds, usually administered as 50:50 racemic (rac-) mixtures of two enantiomers. The chiral nature of these compounds has been largely forgotten in the debate regarding LABA safety and effects on BHR, particularly that (S)-enantiomers of β2-agonists may be deleterious to asthma control. LABAs display enantioselective pharmacokinetics and pharmacodynamics. Biological plausibility of the deleterious effects of β2-agonists (S)-enantiomers is provided by in vitro and in vivo studies from the short-acting β2-agonist (SABA) salbutamol. Supportive clinical findings include the fact that patients in emergency departments who demonstrate a blunted response to salbutamol are more likely to benefit from (R)-salbutamol than rac-salbutamol, and resistance to salbutamol appears to be a contributory mechanism in rapid asthma deaths. More effort should therefore be applied to investigating potential enantiospecific effects of LABAs on safety, specifically bronchoprotection. Safety studies directly assessing the effects of LABA (S)-enantiomers on BHR are long overdue.

Risks associated with managing asthma without a preventer: urgent healthcare, poor asthma control and over-the-counter reliever use in a cross-sectional population survey

OBJECTIVES

Overuse of asthma relievers, particularly without anti-inflammatory preventers, increases asthma risks. This study aimed to identify how many reliever-only users have urgent healthcare, explore their attitudes and beliefs about asthma and its treatment, and investigate whether purchasing over-the-counter relievers was associated with worse asthma outcomes than by prescription.

DESIGN AND SETTING

Cross-sectional population-based Internet survey in Australia.

PARTICIPANTS

Of 2686 participants ≥16 years with current asthma randomly drawn from a web-based panel, 1038 (50.7% male) used only reliever medication.

MAIN OUTCOME MEASURES

Urgent asthma-related healthcare; Asthma Control Test (ACT); patient attitudes about asthma and medications; reliever purchase (with/without prescription).

RESULTS

Of 1038 reliever-only participants, 23.3% had required urgent healthcare for asthma in the previous year, and only 36.0% had a non-urgent asthma review. Those needing urgent healthcare were more likely than those without such events to be male (56.5% vs 49.0%, p=0.003) and current smokers (29.4% vs 23.3%, p=0.009). Only 30.6% had well-controlled asthma (ACT ≥20) compared with 71.0% of those with no urgent healthcare (p<0.0001), and 20.8% used relievers regularly to prevent asthma symptoms (vs 5.5% of those without urgent healthcare). Those with urgent healthcare were more frustrated by their asthma and less happy with how they managed it, and they were less confident about their ability to manage worsening asthma, but just as likely as those without urgent healthcare to manage worsening asthma themselves rather than visit a doctor. Reliever-only users purchasing over-the-counter relievers were no more likely than those purchasing relievers by prescription to have uncontrolled asthma (35.9% vs 40.6%, p=0.23) but were less likely to have had a non-urgent asthma review.

CONCLUSIONS

One-quarter of the reliever-only population had needed urgent asthma healthcare in the previous year, demonstrating the importance of identifying such patients. Their attitudes and beliefs suggest opportunities for targeting this population in the community.

Rebound effect of modern drugs: serious adverse event unknown by health professionals

OBJECTIVE

Supported in the Hippocratic aphorism primum non nocere, the bioethical principle of non-maleficence pray that the medical act cause the least damage or injury to the health of the patient, leaving it to the doctor to assess the risks of a particular therapy through knowledge of possible adverse events of drugs. Among these, the rebound effect represents a common side effect to numerous classes of modern drugs, may cause serious and fatal disorders in patients. This review aims to clarify the health professionals on clinical and epidemiological aspects of rebound phenomenon.

METHODS

A qualitative, exploratory and bibliographic review was held in the PubMed database using the keywords 'rebound', 'withdrawal', 'paradoxical', 'acetylsalicylic acid', 'anti-inflammatory', 'bronchodilator', 'antidepressant', 'statin', 'proton pump inhibitor' and 'bisphosphonate'.

RESULTS

The rebound effect occurs after discontinuation of numerous classes of drugs that act contrary to the disease disorders, exacerbating them at levels above those prior to treatment. Regardless of the disease, the drug and duration of treatment, the phenomenon manifests itself in a small proportion of susceptible individuals. However, it may cause serious and fatal adverse events should be considered a public health problem in view of the enormous consumption of drugs by population.

CONCLUSION

Bringing together a growing and unquestionable body of evidence, the physician needs to have knowledge of the consequences of the rebound effect and how to minimize it, increasing safety in the management of modern drugs. On the other hand, this rebound can be used in a curative way, broadening the spectrum of the modern therapeutics.

Regular treatment with formoterol versus regular treatment with salmeterol for chronic asthma: serious adverse events

BACKGROUND

An increase in serious adverse events with both regular formoterol and regular salmeterol in chronic asthma has been demonstrated in previous Cochrane reviews.

OBJECTIVES

We set out to compare the risks of mortality and non-fatal serious adverse events in trials which have randomised patients with chronic asthma to regular formoterol versus regular salmeterol.

SEARCH METHODS

We identified trials using the Cochrane Airways Group Specialised Register of trials. We checked manufacturers' websites of clinical trial registers for unpublished trial data and also checked Food and Drug Administration (FDA) submissions in relation to formoterol and salmeterol. The date of the most recent search was January 2012.

SELECTION CRITERIA

We included controlled, parallel-design clinical trials on patients of any age and with any severity of asthma if they randomised patients to treatment with regular formoterol versus regular salmeterol (without randomised inhaled corticosteroids), and were of at least 12 weeks' duration.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review and extracted outcome data. We sought unpublished data on mortality and serious adverse events from the sponsors and authors.

MAIN RESULTS

The review included four studies (involving 1116 adults and 156 children). All studies were open label and recruited patients who were already taking inhaled corticosteroids for their asthma, and all studies contributed data on serious adverse events. All studies compared formoterol 12 μg versus salmeterol 50 μg twice daily. The adult studies were all comparing Foradil Aerolizer with Serevent Diskus, and the children's study compared Oxis Turbohaler to Serevent Accuhaler. There was only one death in an adult (which was unrelated to asthma) and none in children, and there were no significant differences in non-fatal serious adverse events comparing formoterol to salmeterol in adults (Peto odds ratio (OR) 0.77; 95% confidence interval (CI) 0.46 to 1.28), or children (Peto OR 0.95; 95% CI 0.06 to 15.33). Over a six-month period, in studies involving adults that contributed to this analysis, the percentages with serious adverse events were 5.1% for formoterol and 6.4% for salmeterol; and over a three-month period the percentages of children with serious adverse events were 1.3% for formoterol and 1.3% for salmeterol.

AUTHORS' CONCLUSIONS

We identified four studies comparing regular formoterol to regular salmeterol (without randomised inhaled corticosteroids, but all participants were on regular background inhaled corticosteroids). The events were infrequent and consequently too few patients have been studied to allow any firm conclusions to be drawn about the relative safety of formoterol and salmeterol. Asthma-related serious adverse events were rare and there were no reported asthma-related deaths.

β₂ AR agonists in treatment of chronic heart failure: long path to translation

The main clinical manifestations of advanced chronic heart failure (CHF), e.g. in dilated cardiomyopathy (DCM), are reduced systolic and diastolic functions, increased arterial elastance and arterio-ventricular uncoupling, accompanied and exacerbated by an excessive sympathetic activation and extensive abnormalities in the βAR signaling. Loss of cardiomyocytes due to apoptosis is one mechanism that undoubtedly contributes to cardiac remodeling and functional deterioration associated with dilated cardiomyopathy (DCM). Research during the last decade on the single cardiomyocyte level strongly suggested that selective stimulation of β(1) AR activates the proapoptotic signaling pathways, while selective stimulation of β(2) AR is antiapoptotic, but its precise mechanisms remain to be elucidated. Extensive research in the rat model of DCM following induction of myocardial infarction (MI) showed that prolonged treatment with of β(2) AR agonist, fenoterol, in combination with a β(1) AR blocker, metoprolol, is more effective than β(1) AR blocker alone and as effective as β(1) AR blocker with ACE inhibitor with respect to survival and cardiac remodeling. This combined regimen of β(2) AR agonists and a β(1) AR blocker might be considered for clinical testing as alternative or adjunct therapy to currently acceptable CHF arsenal. This article is part of a special issue entitled "Key Signaling Molecules in Hypertrophy and Heart Failure."

Regular treatment with formoterol versus regular treatment with salmeterol for chronic asthma: serious adverse events

BACKGROUND

An increase in serious adverse events with both regular formoterol and regular salmeterol in chronic asthma has been demonstrated in previous Cochrane reviews.

OBJECTIVES

We set out to compare the risks of mortality and non-fatal serious adverse events in trials which have randomised patients with chronic asthma to regular formoterol versus regular salmeterol.

SEARCH STRATEGY

Trials were identified using the Cochrane Airways Group Specialised Register of trials. Manufacturers' web sites of clinical trial registers were checked for unpublished trial data and Food and Drug Administration (FDA) submissions in relation to formoterol and salmeterol were also checked. The date of the most recent search was January 2009.

SELECTION CRITERIA

Controlled parallel design clinical trials on patients of any age and severity of asthma were included if they randomised patients to treatment with regular formoterol versus regular salmeterol (without randomised inhaled corticosteroids), and were of at least 12 weeks duration.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review and extracted outcome data. Unpublished data on mortality and serious adverse events were sought from the sponsors and authors.

MAIN RESULTS

Four studies were included in the review (involving 1116 adults and 156 children). All studies were open label and recruited patients who were already taking inhaled corticosteroids for their asthma, and all studies contributed data on serious adverse events. All studies compared formoterol 12 mug versus salmeterol 50 mug twice daily. The adult studies were all comparing Foradil Aerolizer with Serevent Diskus, and the children's study compared Oxis Turbohaler to Serevent Accuhaler. There was only one death in an adult (which was unrelated to asthma), and none in children, and there were no significant differences in non-fatal serious adverse events comparing formoterol to salmeterol in adults (Peto OR 0.77; 95% CI 0.46 to 1.28), or children (Peto OR 0.95; 95% CI 0.06 to 15.33). Over a six month period in studies involving adults that contributed to this analysis the percentage with serious adverse events were 5.1% for formoterol and 6.4% for salmeterol; and over a 3 month period the percentage of children with serious adverse events were 1.3% for formoterol, and 1.3% for salmeterol.

AUTHORS' CONCLUSIONS

Four studies have been identified comparing regular formoterol to regular salmeterol (without randomised inhaled corticosteroids, but all subjects were on regular background inhaled corticosteroids). The events were infrequent and consequently too few patients have been studied to allow any firm conclusions to be drawn about the relative safety of formoterol and salmeterol. Asthma-related serious adverse events were rare, and there were no reported asthma-related deaths.

Whither autoimmunity: the lessons of anti-CCP and B cell depletion

The most difficult component to understand in autoimmune disease has been the issue of causation. In contrast, there have been enormous gains in improved diagnostics as well as improved therapy. Indeed, the use of biologics have changed the profile of numerous autoimmune diseases. In this issue, we discuss two such aspects. Firstly, we place in perspective the use of anti-citrullinated protein antibodies in rheumatoid arthritis. Second, we discuss the increasing use of B cell depletion in the treatment of autoimmunity. Clinical Reviews in Allergy and Immunology is a unique venue for these themes because it covers the spectrum of allergy through autoimmunity. Indeed, we also present a special paper on the relationships of the hepatitis B virus and autoimmunity. Although the Th1 to Th2 dichotomy is well known to both murine and human immunologists, it is really in the study of specific inflammatory responses that they are correctly placed in the perspective of the continuum of immunopathology.

Regular treatment with salmeterol for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta-agonists and increases in asthma mortality. There has been much debate about possible causal links for this association, and whether regular (daily) long-acting beta(2)-agonists are safe.

OBJECTIVES

The aim of this review is to assess the risk of fatal and non-fatal serious adverse events in trials that randomised patients with chronic asthma to regular salmeterol versus placebo or regular short-acting beta(2)-agonists.

SEARCH STRATEGY

Trials were identified using the Cochrane Airways Group Specialised Register of trials. Web sites of clinical trial registers were checked for unpublished trial data and FDA submissions in relation to salmeterol were also checked. The date of the most recent search was October 2007.

SELECTION CRITERIA

Controlled parallel design clinical trials on patients of any age and severity of asthma were included if they randomised patients to treatment with regular salmeterol and were of at least 12 weeks duration. Concomitant use of inhaled corticosteroids was allowed, as long as this was not part of the randomised treatment regimen.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review. Outcome data was extracted by one author and checked by the second author. Unpublished data on mortality and serious adverse events was sought.

MAIN RESULTS

The review includes 26 trials comparing salmeterol to placebo and 8 trials comparing with salbutamol. These included 62,630 participants with asthma (including 2,380 children). In 6 trials (2,766 patients), no serious adverse event data could be obtained. All cause mortality was higher with regular salmeterol than placebo but the increase was not significant, Odds Ratio 1.33 [95% CI: 0.85, 2.10]. Non-fatal serious adverse events were significantly increased when regular salmeterol was compared with placebo, Odds Ratio 1.14 [95% CI: 1.01, 1.28]. One extra serious adverse event occurred over 28 weeks for every 188 people treated with regular salmeterol [95% CI: 95 to 2606]. There is insufficient evidence to assess whether the risk in children is higher or lower than in adults. No significant increase in fatal or non-fatal serious adverse events was found when regular salmeterol was compared with regular salbutamol. Individual patient data from the SNS study have been combined with the results of the SMART study; in patients who were not taking inhaled corticosteroids, compared to regular salbutamol or placebo, there was a significant increase in risk of asthma-related death with regular salmeterol, Odds Ratio 9.52 [95% CI: 1.24, 73.09]. The confidence interval for patients taking inhaled corticosteroids is too wide to rule out an increase in asthma mortality in this group.

AUTHORS' CONCLUSIONS

In comparison with placebo, we have found an increased risk of serious adverse events with regular salmeterol. There is also a clear increase in risk of asthma-related mortality in patients not using inhaled corticosteroids in the two large surveillance studies. Although the increase in asthma-related mortality was smaller in patients taking inhaled corticosteroids at baseline, the confidence interval is wide, so it cannot be concluded that the inhaled corticosteroids abolish the risks of regular salmeterol. The adverse effects of regular salmeterol in children remain uncertain due to the small number of children studied.