Systemic effects of salbutamol and salmeterol in patients with asthma

The Acute Effects of the Use of Salbutamol and Ipratropium on the Heart Rates of Patients With Obstructive Airway Disease

Background The cornerstone of pharmaceutical therapy for obstructive airway illnesses involves inhalation of bronchodilators, such as ipratropium bromide (IP) and salbutamol (SB). The heart rate regulation may be changed by β-2 agonists and anticholinergic medications. Investigating the impact of inhaled SB and IP on the heart rate was the goal of this study. Methods A total of 304 patients were enrolled in this investigation. Baseline demographic characteristics, medical history, and adverse events were documented. Their heart rates were monitored before and after bronchodilator administration. SB and IP were selected based on historical usage. Blood pressure readings were also taken before and after each session. Results There was a significant increase in heart rates after SB from a mean of 106.69 to 117.20. Similarly, the heart rate of the patients in the IP group increased to a mean of 106.95 from 93.44, with a statistically significant p-value. Moreover, tremors were the most common adverse effect, accounting for 85.3% of the patients in the IP group and 75% in the SB group. In contrast, palpitation was more common in the SB group 25% vs. 14.7% with a significant p-value. Conclusion Frequently administered dosages of SB and IP caused a considerable increase in heart rates, as well as tremors and palpitation.

Asthma and COPD: A Focus on β-Agonists - Past, Present and Future

Asthma has been recognised as a respiratory disorder for millennia and the focus of targeted drug development for the last 120 years. Asthma is one of the most common chronic non-communicable diseases worldwide. Chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide, is caused by exposure to tobacco smoke and other noxious particles and exerts a substantial economic and social burden. This chapter reviews the development of the treatments of asthma and COPD particularly focussing on the β-agonists, from the isolation of adrenaline, through the development of generations of short- and long-acting β-agonists. It reviews asthma death epidemics, considers the intrinsic efficacy of clinical compounds, and charts the improvement in selectivity and duration of action that has led to our current medications. Important β2-agonist compounds no longer used are considered, including some with additional properties, and how the different pharmacological properties of current β2-agonists underpin their different places in treatment guidelines. Finally, it concludes with a look forward to future developments that could improve the β-agonists still further, including extending their availability to areas of the world with less readily accessible healthcare.

Electrochemical Discrimination of Salbutamol from Its Excipients in VentolinTM at Nanoporous Gold Microdisc Arrays

The emergence of specific drug–device combination products in the inhalable pharmaceutical industry demands more sophistication of device functionality in the form of an embedded sensing platform to increase patient safety and extend patent coverage. Controlling the nebuliser function at a miniaturised, integrated electrochemical sensing platform with rapid response time and supporting novel algorithms could deliver such a technology offering. Development of a nanoporous gold (NPG) electrochemical sensor capable of creating a unique fingerprint signal generated by inhalable pharmaceuticals provided the impetus for our study of the electrooxidation of salbutamol, which is the active bronchodilatory ingredient in Ventolin^TM formulations. It was demonstrated that, at NPG-modified microdisc electrode arrays, salbutamol is distinguishable from the chloride excipient present at 0.0154 M using linear sweep voltammetry and can be detected amperometrically. In contrast, bare gold microdisc electrode arrays cannot afford such discrimination, as the potential for salbutamol oxidation and chloride adsorption reactions overlap. The discriminative power of NPG originates from the nanoconfinement effect for chloride in the internal pores of NPG, which selectively enhances the electron transfer kinetics of this more sluggish reaction relative to that of the faster, diffusion-controlled salbutamol oxidation. Sensing was performed at a fully integrated three-electrode cell-on-chip using Pt as a quasi-reference electrode.

Regular treatment with formoterol and an inhaled corticosteroid versus regular treatment with salmeterol and an inhaled corticosteroid for chronic asthma: serious adverse events

BACKGROUND

Asthma is characterised by chronic inflammation of the airways and recurrent exacerbations with wheezing, chest tightness, and cough. Treatment with inhaled steroids and bronchodilators can result in good control of symptoms, prevention of further morbidity, and improved quality of life. However, an increase in serious adverse events with the use of both regular formoterol and regular salmeterol (long-acting beta₂-agonists) compared with placebo for chronic asthma has been demonstrated in previous Cochrane Reviews. This increase was statistically significant in trials that did not randomise participants to an inhaled corticosteroid, but not when formoterol or salmeterol was combined with an inhaled corticosteroid. The confidence intervals were found to be too wide to ensure that the addition of an inhaled corticosteroid renders regular long-acting beta₂-agonists completely safe; few participants and insufficient serious adverse events in these trials precluded a definitive decision about the safety of combination treatments.

OBJECTIVES

To assess risks of mortality and non-fatal serious adverse events in trials that have randomised patients with chronic asthma to regular formoterol and an inhaled corticosteroid versus regular salmeterol and an inhaled corticosteroid.

SEARCH METHODS

We searched the Cochrane Airways Register of Trials, CENTRAL, MEDLINE, Embase, and two trial registries to identify reports of randomised trials for inclusion. We checked manufacturers' websites and clinical trial registers for unpublished trial data, as well as Food and Drug Administration (FDA) submissions in relation to formoterol and salmeterol. The date of the most recent search was  24 February 2021.

SELECTION CRITERIA

We included controlled clinical trials with a parallel design, recruiting patients of any age and severity of asthma, if they randomised patients to treatment with regular formoterol versus regular salmeterol (each with a randomised inhaled corticosteroid) and were of at least 12 weeks' duration.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion in the review, extracted outcome data from published papers and trial registries, and applied GRADE rating for the results. We sought unpublished data on mortality and serious adverse events from study sponsors and authors. The primary outcomes were all cause mortality and non-fatal serious adverse events. We chose not to calculate an average result from all the formulations of formoterol and inhaled steroid, as the doses and delivery devices are too diverse to assume a single class effect.

MAIN RESULTS

Twenty-one studies in 11,572 adults and adolescents and two studies in 723 children met the eligibility criteria of the review. No data were available for two studies; therefore these were not included in the analysis. Among adult and adolescent studies, seven compared formoterol and budesonide to salmeterol and fluticasone (N = 7764), six compared formoterol and beclomethasone to salmeterol and fluticasone (N = 1923), two compared formoterol and mometasone to salmeterol and fluticasone (N = 1126), two compared formoterol and fluticasone to salmeterol and fluticasone (N = 790), and one compared formoterol and budesonide to salmeterol and budesonide (N = 229). In total, five deaths were reported among adults, none of which was thought to be related to asthma. The certainty of evidence for all-cause mortality was low, as there were not enough deaths to permit any precise conclusions regarding the risk of mortality on combination formoterol versus combination salmeterol. In all, 201 adults reported non-fatal serious adverse events. In studies comparing formoterol and budesonide to salmeterol and fluticasone, there were 77 in the formoterol arm and 68 in the salmeterol arm (Peto odds ratio (OR) 1.14, 95% confidence interval (CI) 0.82 to 1.59; 5935 participants, 7 studies; moderate-certainty evidence). In the formoterol and beclomethasone studies, there were 12 adults in the formoterol arm and 13 in the salmeterol arm with events (Peto OR 0.94, 95% CI 0.43 to 2.08; 1941 participants, 6 studies; moderate-certainty evidence). In the formoterol and mometasone studies, there were 18 in the formoterol arm and 11 in the salmeterol arm (Peto OR 1.02, 95% CI 0.47 to 2.20; 1126 participants, 2 studies; moderate-certainty evidence). One adult in the formoterol and fluticasone studies in the salmeterol arm experienced an event (Peto OR 0.05, 95% CI 0.00 to 3.10; 293 participants, 2 studies; low-certainty evidence). Another adult in the formoterol and budesonide compared to salmeterol and budesonide study in the formoterol arm had an event (Peto OR 7.45, 95% CI 0.15 to 375.68; 229 participants, 1 study; low-certainty evidence). Only 46 adults were reported to have experienced asthma-related serious adverse events. The certainty of the evidence was low to very low due to the small number of events and the absence of independent assessment of causation. The two studies in children compared formoterol and fluticasone to salmeterol and fluticasone. No deaths and no asthma-related serious adverse events were reported in these studies. Four all-cause serious adverse events were reported: three in the formoterol arm, and one in the salmeterol arm (Peto OR 2.72, 95% CI 0.38 to 19.46; 548 participants, 2 studies; low-certainty evidence).

AUTHORS' CONCLUSIONS

Overall, for both adults and children, evidence is insufficient to show whether regular formoterol in combination with budesonide, beclomethasone, fluticasone, or mometasone has a different safety profile from salmeterol in combination with fluticasone or budesonide. Five deaths of any cause were reported across all studies and no deaths from asthma; this information is insufficient to permit any firm conclusions about the relative risks of mortality on combination formoterol in comparison to combination salmeterol inhalers. Evidence on all-cause non-fatal serious adverse events indicates that there is probably little to no difference between formoterol/budesonide and salmeterol/fluticasone inhalers. However events for the other formoterol combination inhalers were too few to allow conclusions. Only 46 non-fatal serious adverse events were thought to be asthma related; this small number in addition to the absence of independent outcome assessment means that we have very low confidence for this outcome. We found no evidence of safety issues that would affect the choice between salmeterol and formoterol combination inhalers used for regular maintenance therapy by adults and children with asthma.

iPSC- and mesenchymoangioblast-derived mesenchymal stem cells provide greater protection against experimental chronic allergic airways disease compared with a clinically used corticosteroid

The airway remodeling (AWR) associated with chronic allergic airways disease (AAD)/asthma contributes to irreversible airway obstruction. This study compared and combined the antiremodeling and other effects of induced pluripotent stem cell and mesenchymoangioblast-derived mesenchymal stem cells (MCA-MSCs) with the corticosteroid dexamethasone (Dex) in experimental chronic AAD/asthma. Female BALB/c mice subjected to 11 wk of ovalbumin (Ova)-induced chronic AAD were intranasally administered MCA-MSCs (1 × 10⁶ cells/mouse; once weekly on wk 10 and 11), Dex (0.5 mg/ml; once daily for 2 wk), or both combined. MCA-MSC detection and changes in airway inflammation (AI), AWR, and airway hyperresponsiveness (AHR) were measured at the end of wk 11. Mice with chronic AAD had significant AI, goblet cell metaplasia, epithelial damage/thickening, aberrant TGF-β1 levels, subepithelial myofibroblast accumulation, airway/lung fibrosis, and AHR (all P < 0.001 vs. healthy controls). MCA-MSCs were detected in the lungs up to 5-7 d postadministration and demonstrated modest anti-inflammatory but striking antifibrotic effects against Ova-induced AAD, effectively decreasing AHR by 70-75% (all P < 0.05 vs. Ova alone). In comparison, Dex predominantly demonstrated anti-inflammatory effects, decreasing AHR by ∼30%. Combining MCA-MSCs with Dex provided equivalent protection to that offered by either therapy alone. MCA-MSCs reduce chronic AAD-induced AWR and AHR to a greater extent than Dex and may act as a suitable adjunct therapy to corticosteroid treatment of asthma.-Royce, S. G., Mao, W., Lim, R., Kelly, K., Samuel, C. S. iPSC- and mesenchymoangioblast-derived mesenchymal stem cells provide greater protection against experimental chronic allergic airways disease compared with a clinically used corticosteroid.

Inhaled steroids with and without regular salmeterol for asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between use of beta₂-agonists and increased asthma mortality. Much debate has surrounded possible causal links for this association, and whether regular (daily) long-acting beta₂-agonists (LABAs) are safe, particularly when used in combination with inhaled corticosteroids (ICSs). This is an update of a Cochrane Review that now includes data from two large trials including 11,679 adults and 6208 children; both were mandated by the US Food and Drug Administration (FDA).  OBJECTIVES: To assess risks of mortality and non-fatal serious adverse events (SAEs) in trials that randomised participants with chronic asthma to regular salmeterol and ICS versus the same dose of ICS.

SEARCH METHODS

We identified randomised trials using the Cochrane Airways Group Specialised Register of trials. We checked websites of clinical trials registers for unpublished trial data. We also checked FDA submissions in relation to salmeterol. The date of the most recent search was 10 October 2018.

SELECTION CRITERIA

We included parallel-design randomised trials involving adults, children, or both with asthma of any severity who were randomised to treatment with regular salmeterol and ICS (in separate or combined inhalers) versus the same dose of ICS of at least 12 weeks in duration.

DATA COLLECTION AND ANALYSIS

We conducted the review according to standard procedures expected by Cochrane. We obtained unpublished data on mortality and SAEs from the sponsors, from ClinicalTrials.gov, and from FDA submissions. We assessed our confidence in the evidence according to current GRADE recommendations.

MAIN RESULTS

We have included in this review 41 studies (27,951 participants) in adults and adolescents, along with eight studies (8453 participants) in children. We judged that the overall risk of bias was low for all-cause events, and we obtained data on SAEs from all study authors. All except 542 adults (and none of the children) were given salmeterol and fluticasone in the same (combination) inhaler.DeathsEleven of a total of 14,233 adults taking regular salmeterol and ICS died, as did 13 of 13,718 taking regular ICS at the same dose. The pooled Peto odds ratio (OR) was 0.80 (95% confidence interval (CI) 0.36 to 1.78; participants = 27,951; studies = 41; I² = 0%; moderate-certainty evidence). In other words, for every 1000 adults treated for 25 weeks, one death occurred among those on ICS alone, and the corresponding risk among those taking salmeterol and ICS was also one death (95% CI 0 to 2 deaths).No children died, and no adults or children died of asthma, so we remain uncertain about mortality in children and about asthma mortality in any age group.Non-fatal serious adverse eventsA total of 332 adults receiving regular salmeterol with ICS experienced a non-fatal SAE of any cause, compared to 282 adults receiving regular ICS. The pooled Peto OR was 1.14 (95% CI 0.97 to 1.33; participants = 27,951; studies = 41; I² = 0%; moderate-certainty evidence). For every 1000 adults treated for 25 weeks, 21 adults on ICS alone had an SAE, and the corresponding risk for those on salmeterol and ICS was 23 adults (95% CI 20 to 27).Sixty-five of 4229 children given regular salmeterol with ICS suffered an SAE of any cause, compared to 62 of 4224 children given regular ICS. The pooled Peto OR was 1.04 (95% CI 0.73 to 1.48; participants = 8453; studies = 8; I² = 0%; moderate-certainty evidence). For every 1000 children treated for 23 weeks, 15 children on ICS alone had an SAE, and the corresponding risk for those on salmeterol and ICS was 15 children (95% CI 11 to 22).Asthma-related serious adverse eventsEighty and 67 adults in each group, respectively, experienced an asthma-related non-fatal SAE. The pooled Peto OR was 1.15 (95% CI 0.83 to 1.59; participants = 27,951; studies = 41; I² = 0%; low-certainty evidence). For every 1000 adults treated for 25 weeks, five receiving ICS alone had an asthma-related SAE, and the corresponding risk among those on salmeterol and ICS was six adults (95% CI 4 to 8).Twenty-nine children taking salmeterol and ICS and 23 children taking ICS alone reported asthma-related events. The pooled Peto OR was 1.25 (95% CI 0.72 to 2.16; participants = 8453; studies = 8; I² = 0%; moderate-certainty evidence). For every 1000 children treated for 23 weeks, five receiving an ICS alone had an asthma-related SAE, and the corresponding risk among those receiving salmeterol and ICS was seven children (95% CI 4 to 12).

AUTHORS' CONCLUSIONS

We did not find a difference in the risk of death or serious adverse events in either adults or children. However, trial authors reported no asthma deaths among 27,951 adults or 8453 children randomised to regular salmeterol and ICS or ICS alone over an average of six months. Therefore, the risk of dying from asthma on either treatment was very low, but we remain uncertain about whether the risk of dying from asthma is altered by adding salmeterol to ICS.Inclusion of new trials has increased the precision of the estimates for non-fatal SAEs of any cause. We can now say that the worst-case estimate is that at least 152 adults and 139 children must be treated with combination salmeterol and ICS for six months for one additional person to be admitted to the hospital (compared to treatment with ICS alone). These possible risks still have to be weighed against the benefits experienced by people who take combination treatment.However more than 90% of prescribed treatment was taken in the new trials, so the effects observed may be different from those seen with salmeterol in combination with ICS in daily practice.

An electrochemical MIP sensor for selective detection of salbutamol based on a graphene/PEDOT:PSS modified screen printed carbon electrode

The first MIP sensor on an inkjet-printed graphene nanocomposite modified screen-printed carbon electrode was developed.

Effect of Ventolin on QTc in children with respiratory distress

INTRODUCTION

β2-agonists are first election drugs for the treatment of respiratory disease that may alter cardiac autonomic modulation. The aim of this study was to evaluate the effects of nebulized Ventolin on electrocardiogram, particularly QTc interval to assess the potential arrhythmogenic risks.

METHODS

A total of 192 patients between 2 months and 15 years which received nebulized Ventolin were enrolled in this study. Patients were divided into two groups. Electrocardiograms of patients before and after nebulized Ventolin were taken. Differences between two groups were assessed using a paired student's t test.

RESULTS

There was statistically significant differences in QTc before and after Ventolin in each groups (P<0.005).Ventolin effect on QTc interval in both groups did not differ. In first group, there was statistically significant differences between heart rate before and after Ventolin taken (P=0.009) but in second group there was not statistically significant differences between heart rate (P=0.345).

CONCLUSION

Although Ventolin can cause changes in QTc, Ventolin with 0.15 mg/kg/dose in comparison with 0.1 mg/kg/dose does not cause significant changes in QTc.

The effects of salbutamol on epithelial ion channels depend on the etiology of acute respiratory distress syndrome but not the route of administration

Introduction

We investigated the effects of intravenous and intratracheal administration of salbutamol on lung morphology and function, expression of ion channels, aquaporin, and markers of inflammation, apoptosis, and alveolar epithelial/endothelial cell damage in experimental pulmonary (p) and extrapulmonary (exp) mild acute respiratory distress syndrome (ARDS).

Methods

In this prospective randomized controlled experimental study, 56 male Wistar rats were randomly assigned to mild ARDS induced by either intratracheal (n = 28, ARDSp) or intraperitoneal (n = 28, ARDSexp) administration of E. coli lipopolysaccharide. Four animals with no lung injury served as controls (NI). After 24 hours, animals were anesthetized, mechanically ventilated in pressure-controlled mode with low tidal volume (6 mL/kg), and randomly assigned to receive salbutamol (SALB) or saline 0.9% (CTRL), intravenously (i.v., 10 μg/kg/h) or intratracheally (bolus, 25 μg). Salbutamol doses were targeted at an increase of ≈ 20% in heart rate. Hemodynamics, lung mechanics, and arterial blood gases were measured before and after (at 30 and 60 min) salbutamol administration. At the end of the experiment, lungs were extracted for analysis of lung histology and molecular biology analysis. Values are expressed as mean ± standard deviation, and fold changes relative to NI, CTRL vs. SALB.

Results

The gene expression of ion channels and aquaporin was increased in mild ARDSp, but not ARDSexp. In ARDSp, intravenous salbutamol resulted in higher gene expression of alveolar epithelial sodium channel (0.20 ± 0.07 vs. 0.68 ± 0.24, p < 0.001), aquaporin-1 (0.44 ± 0.09 vs. 0.96 ± 0.12, p < 0.001) aquaporin-3 (0.31 ± 0.12 vs. 0.93 ± 0.20, p < 0.001), and Na-K-ATPase-α (0.39 ± 0.08 vs. 0.92 ± 0.12, p < 0.001), whereas intratracheal salbutamol increased the gene expression of aquaporin-1 (0.46 ± 0.11 vs. 0.92 ± 0.06, p < 0.001) and Na-K-ATPase-α (0.32 ± 0.07 vs. 0.58 ± 0.15, p < 0.001). In ARDSexp, the gene expression of ion channels and aquaporin was not influenced by salbutamol. Morphological and functional variables and edema formation were not affected by salbutamol in any of the ARDS groups, regardless of the route of administration.

Conclusion

Salbutamol administration increased the expression of alveolar epithelial ion channels and aquaporin in mild ARDSp, but not ARDSexp, with no effects on lung morphology and function or edema formation. These results may contribute to explain the negative effects of β2-agonists on clinical outcome in ARDS.

Regular treatment with formoterol and inhaled steroids for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta2-agonists and increases in asthma mortality. Much debate has surrounded possible causal links for this association and whether regular (daily) long-acting beta2-agonists are safe when used alone or in conjunction with inhaled corticosteroids. This is an updated Cochrane Review.

OBJECTIVES

To assess the risk of fatal and non-fatal serious adverse events in people with chronic asthma given regular formoterol with inhaled corticosteroids versus the same dose of inhaled corticosteroids alone.

SEARCH METHODS

Trials were identified using the Cochrane Airways Group Specialised Register of trials. Web sites of clinical trial registers were checked for unpublished trial data; Food and Drug Administration (FDA) submissions in relation to formoterol were also checked. The date of the most recent search was August 2012.

SELECTION CRITERIA

Controlled clinical trials with a parallel design were included if they randomly allocated people of any age and severity of asthma to treatment with regular formoterol and inhaled corticosteroids for at least 12 weeks.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Unpublished data on mortality and serious adverse events were obtained from the sponsors. We assessed the quality of evidence using GRADE recommendations.

MAIN RESULTS

Following the 2012 update, we have included 20 studies on 10,578 adults and adolescents and seven studies on 2788 children and adolescents. We found data on all-cause fatal and non-fatal serious adverse events for all studies, and we judged the overall risk of bias to be low.Six deaths occurred in participants taking regular formoterol with inhaled corticosteroids, and one in a participant administered regular inhaled corticosteroids alone. The difference was not statistically significant (Peto odds ratio (OR) 3.56, 95% confidence interval (CI) 0.79 to 16.03, low-quality evidence). All deaths were reported in adults, and one was believed to be asthma-related.Non-fatal serious adverse events of any cause were very similar for each treatment in adults (Peto OR 0.98, 95% CI 0.76 to 1.27, moderate-quality evidence), and weak evidence suggested an increase in events in children on regular formoterol (Peto OR 1.62, 95% CI 0.80 to 3.28, moderate-quality evidence).In contrast with all-cause serious adverse events, the addition of new trial data means that asthma-related serious adverse events associated with formoterol are now significantly fewer in adults taking regular formoterol with inhaled corticosteroids (Peto OR 0.49, 95% CI 0.28 to 0.88, moderate-quality evidence). Although a greater number of asthma-related events were reported in children receiving regular formoterol, this finding was not statistically significant (Peto OR 1.49, 95% CI 0.48 to 4.61, low-quality evidence).

AUTHORS' CONCLUSIONS

From the evidence in this review, it is not possible to reassure people with asthma that regular use of inhaled corticosteroids with formoterol carries no risk of increasing mortality in comparison with use of inhaled corticosteroids alone. On the other hand, we have found no conclusive evidence of serious harm, and only one asthma-related death was registered during more than 4200 patient-years of observation with formoterol.In adults, no significant difference in all-cause non-fatal serious adverse events was noted with regular formoterol with inhaled corticosteroids, but a significant reduction in asthma-related serious adverse events was observed in comparison with inhaled corticosteroids alone.In children the number of events was too small, and consequently the results too imprecise, to allow determination of whether the increased risk of all-cause non-fatal serious adverse events found in a previous meta-analysis on regular formoterol alone is abolished by the additional use of inhaled corticosteroids.We await the results of large ongoing surveillance studies mandated by the Food and Drug Administration (FDA) for more information. Clinical decisions and information provided to patients regarding regular use of formoterol have to take into account the balance between known symptomatic benefits of formoterol and the degree of uncertainty associated with its potential harmful effects.

Regular treatment with salmeterol and inhaled steroids for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta2-agonists and increased asthma mortality. There has been much debate about possible causal links for this association, and whether regular (daily) long-acting beta2-agonists are safe. This is an updated systematic review.

OBJECTIVES

To assess the risk of mortality and non-fatal serious adverse events in trials which randomised patients with chronic asthma to regular salmeterol and inhaled corticosteroids in comparison to the same dose of inhaled corticosteroids.

SEARCH METHODS

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

SELECTION CRITERIA

We included parallel design controlled clinical trials on patients of any age and severity of asthma if they randomised patients to treatment with regular salmeterol and inhaled corticosteroids (in separate or combined inhalers), and were of at least 12 weeks duration.

DATA COLLECTION AND ANALYSIS

We conducted the review according to standard procedures expected by the Cochrane Collaboration. We obtained unpublished data on mortality and serious adverse events from the sponsors, and from FDA submissions. We assessed the quality of evidence according to GRADE recommendations.

MAIN RESULTS

We have included 35 studies (13,447 participants) in adults and adolescents, and 5 studies (1862 participants) in children in this review. We judged that the overall risk of bias was low, and we obtained data on serious adverse events from all studies. All except 542 adults (and none of the children) who were randomised to salmeterol were given fluticasone in the same (combination) inhaler.Seven deaths occurred in 6986 adults on regular salmeterol with inhaled corticosteroids (ICS), and seven deaths in 6461 adults on regular inhaled corticosteroids at the same dose. The difference was not statistically significant (Peto odds ratio (OR) 0.90; 95% confidence interval (CI) 0.31 to 2.60, moderate quality evidence). The risk of dying from any cause in adults on ICS was 10 per 10,000, and on salmeterol and ICS we would expect between 3 and 26 deaths per 10,000. No deaths were reported in 1862 children, and no deaths were reported to be asthma-related in adults or children.Non-fatal serious adverse events of any cause were reported in 167 adults on regular salmeterol with ICS, compared to 135 adults on regular ICS; again this was not a statistically significant increase (Peto OR 1.15; 95% CI 0.91 to 1.44, moderate quality evidence). The frequency of serious adverse events was 21 per 1000 in the adults treated with ICS and 24 per 1000 in those treated with salmeterol and ICS. The absolute difference in the risk of non-fatal serious adverse events was an increase of 3 per 1000, that was not statistically significant (risk difference (RD) 0.003; 95% CI -0.002 to 0.008).There were 6 of 930 children with serious adverse events on regular salmeterol with ICS, compared to 5 out of 932 on regular ICS: there was no significant difference between treatments (Peto OR 1.20; 95% CI 0.37 to 3.91, moderate quality evidence).Asthma-related serious adverse events were reported in 29 and 23 adults in each group respectively, a non-significant difference (Peto OR 1.12; 95% CI 0.65 to 1.94, moderate quality evidence), and only 1 asthma-related event was reported in children in each treatment group.

AUTHORS' CONCLUSIONS

We found no statistically significant differences in fatal or non-fatal serious adverse events in trials in which regular salmeterol was randomly allocated with ICS, in comparison to ICS alone at the same dose. Although 13,447 adults and 1862 children have now been included in trials, the frequency of adverse events is too low and the results are too imprecise to confidently rule out a relative increase in all cause mortality or non-fatal adverse events with salmeterol used in conjunction with ICS. However, the absolute difference between groups in the risk of serious adverse events was very small. We could not determine whether the increase in all cause non-fatal serious adverse events reported in the previous meta-analysis on regular salmeterol alone is abolished by the additional use of regular ICS. We await the results of large ongoing surveillance studies mandated by the FDA to provide more information. There were no asthma-related deaths and few asthma-related serious adverse events. Clinical decisions and information for patients regarding regular use of salmeterol have to take into account the balance between known symptomatic benefits of salmeterol and the degree of uncertainty and concern associated with its potential harmful effects.

Asthma vital signs at triage: home or admission (ASTHmA)

OBJECTIVES

Commonly used acute asthma scoring systems assess severity of symptoms, whereas other clinical models aim to predict hospitalization; all rely on a measure of response to treatment and use the same criteria across age ranges. This may not reflect a child's changing physiology and response to illness as he or she grows older.This study aimed to find age-specific objective predictors of hospitalization readily known at triage. The goal is to identify rapidly those who will likely need admission regardless of treatment administered or response to aggressive treatment in the emergency department (ED).

METHODS

Children between 1 and 18 years of age with a final primary ED International Classification of Diseases, Ninth Revision, diagnosis of asthma or asthma-related spectrum of disease were studied using data from the National Hospital Ambulatory Medical Care Survey. The primary outcome was hospital admission (observation unit, ward, monitored, or pediatric intensive care unit).Triage vital signs, mode of arrival, recent visits, emergency severity index score, as well as demographic and socioeconomic factors were incorporated into age-specific forward-selection multiple logistic regression models.

RESULTS

In 2,454,983 ED visits for asthma or reactive airway disease among children 1 to 18 years of age, patterns of vital sign predictors for admission varied by age group. Across all ages, diastolic hypotension at triage was an early, consistent, independent predictor of admission, especially in 1- to 3-year-olds (odds ratio, 6.27; 95% confidence interval, 6.01-6.54) and 3- to 6-year-olds (odds ratio, 17.95; 95% confidence interval, 16.80-19.17).

CONCLUSIONS

Age-specific assessment is important in the evaluation of acute asthma or reactive airway exacerbation. Diastolic hypotension may serve as an early warning indicator of severity of disease and need for hospitalization. Variability by age group in vital sign predictor for admission calls for further development or refinement of age-specific asthma assessment tools.

Short-term safety and tolerability of double-dose salmeterol/fluticasone propionate in adult asthmatic patients

INTRODUCTION

The incidence of asthma exacerbations in patients receiving salmeterol/fluticasone propionate (Seretidetrade mark or Advair((R))) is low. However, when asthma control deteriorates, clinicians may instruct patients to double the dose of their inhaled corticosteroid medication for a short period. The purpose of this study was to demonstrate that doubling the dose of Seretidetrade mark for a period of 2 weeks in subjects with persistent asthma is safe and well tolerated.

METHODS

This randomised, double-blind, parallel-group study was conducted in primary-care centres. Adults with a post-bronchodilator forced expiratory volume in 1 second (FEV(1)) of >/=70% predicted were stratified to receive a single dose of Seretidetrade mark 50mug/100mug, 50mug/250mug or 50mug/500mug twice daily from a Diskustrade mark inhaler for a 4-week run-in period, dependent on the dose of inhaled corticosteroid on entry. Subjects were then randomised to receive either an extra inhalation of the same dose of Seretidetrade mark received during the run-in (double dose) or an inhalation of matching placebo (single dose) for 14 days in a 2 : 1 ratio. Subjects were asked to record any adverse events, morning and evening heart rate (HR), peak flow and relief medication use in daily record cards. The primary endpoint was tremor as perceived by the subject. Clinic evaluations included HR, 12-lead ECG, and potassium and glucose levels.

RESULTS

110 and 208 subjects received single- and double-dose Seretidetrade mark, respectively. Only one subject experienced tremor. This was classified as mild and occurred in a subject receiving double-dose Seretidetrade mark (50mug/100mug). There was no difference between the treatment groups in the incidence of tremor (difference <1%; 95% CI -6, 8). Other salmeterol-related adverse events (palpitations, muscle cramps and headache) and fluticasone propionate-related events (oral candidiasis and hoarseness) occurred in a similar percentage of subjects in each treatment group. The treatment differences for morning and evening HR measurements showed small differences between the two groups (<2 beats/min). The adjusted mean treatment difference (double dose - single dose) in morning HR was 1.1 beats/min (95% CI 0.2, 2.0) and evening HR was 0.9 beats/min (95% CI 0.1, 1.7). Seven percent of subjects receiving single-dose Seretidetrade mark and 8% receiving double-dose Seretidetrade mark had a QTc change from baseline in the interval 30-59 msec. No increases above 59 msec were seen in either group. There were no clinically significant changes from baseline for potassium levels. Two percent of subjects in the single dose and <1% in the double-dose group had a change from a non-clinically significant baseline blood glucose assessment to a clinically significant abnormality at the end of treatment.

CONCLUSION

In circumstances in which a physician may be considering doubling the dose of Seretidetrade mark for a short period of time in adult asthmatics, this study demonstrates that doubling the dose for a period of 2 weeks is safe and well tolerated.

Regular treatment with formoterol for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta(2)-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 formoterol versus placebo or regular short-acting beta(2)-agonists.

SEARCH METHODS

We identified trials using the Cochrane Airways Group Specialised Register of trials. We checked websites of clinical trial registers for unpublished trial data and Food and Drug Administration (FDA) submissions in relation to formoterol. 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 severity of asthma if they randomised patients to treatment with regular formoterol 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. One author extracted outcome data and the second author checked them. We sought unpublished data on mortality and serious adverse events.

MAIN RESULTS

The review includes 22 studies (8032 participants) comparing regular formoterol to placebo and salbutamol. Non-fatal serious adverse event data could be obtained for all participants from published studies comparing formoterol and placebo but only 80% of those comparing formoterol with salbutamol or terbutaline.Three deaths occurred on regular formoterol and none on placebo; this difference was not statistically significant. It was not possible to assess disease-specific mortality in view of the small number of deaths. Non-fatal serious adverse events were significantly increased when regular formoterol was compared with placebo (Peto odds ratio (OR) 1.57; 95% CI 1.06 to 2.31). One extra serious adverse event occurred over 16 weeks for every 149 people treated with regular formoterol (95% CI 66 to 1407 people). The increase was larger in children than in adults, but the impact of age was not statistically significant. Data submitted to the FDA indicate that the increase in asthma-related serious adverse events remained significant in patients taking regular formoterol who were also on inhaled corticosteroids.No significant increase in fatal or non-fatal serious adverse events was found when regular formoterol was compared with regular salbutamol or terbutaline.

AUTHORS' CONCLUSIONS

In comparison with placebo, we have found an increased risk of serious adverse events with regular formoterol, and this does not appear to be abolished in patients taking inhaled corticosteroids. The effect on serious adverse events of regular formoterol in children was greater than the effect in adults, but the difference between age groups was not significant.Data on all-cause serious adverse events should be more fully reported in journal articles, and not combined with all severities of adverse events or limited to those events that are thought by the investigator to be drug-related.

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.

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.

A novel breath-actuated integrated vortex spacer device increases relative lung bioavailability of fluticasone/salmeterol in combination

BACKGROUND

Spacer devices facilitate respirable drug delivery. A novel breath-actuated antistatic spacer with integrated vortex chamber (Synchro-Breathe) device has been developed, which is compact,portable and user friendly as compared to conventional spacers which are bulky and cumbersome. The relative bioavailability to the lung of inhaled fluticasone and salmeterol combination is primarily dependent on respirable dose delivery and can be reliably quantified using adrenal suppression and early fall in serum potassium (marker of systemic beta-2 adrenoreceptor response) as surrogate markers for delivered lung dose.

AIMS AND OBJECTIVES

To compare the in vivo relative bioavailability to the lung of Hydrofluoroalkane(HFA) Seretide delivered via Synchro-Breathe (SB); an optimally prepared 750 ml large volume plastic spacer, Volumatic (VM); and conventional Evohaler pMDI (EH).

METHODS

Nineteen healthy volunteers completed the study using a randomised double blind, double dummy crossover design. Single doses of placebo or Seretide HFA 250 (total dose ex-valve: fluticasone 2000 mcg/salmeterol 200 mcg) were administered via SB, VM and EH. Overnight urinary cortisol creatinine (OUCC) and serum potassium (K) were measured at baseline and after each dose as systemic surrogates of relative respirable dose delivery for the fluticasone and salmeterol moieties, respectively.

RESULTS

Significant suppression of OUCC and K occurred from baseline with SB and VM but not EH devices(geometric mean fold suppression, 95% CI, p and arithmetic mean fall mmol/L, 95% CI, respectively); EH:1.51(0.43-1.01), p 1/4 0.06; VM: 2.52(1.57-4.04), p < 0.001; SB: 2.66(1.57-4.49), p < 0.001(equating to 33.8%,60.2% and 62.3% falls, respectively). For K, the falls for EH were 0.09(0.25 to 0.07), p 1/4 0.69; VM: 0.27(0.46 to 0.08), p 1/4 0.003; SB: 0.32(0.53 to 0.11), p 1/4 0.002 (equating to 2.2%, 6.8%, and 8.06% fall,respectively). There were no significant differences between SB and VM.

CONCLUSION

The breath-actuated Synchro-Breathe device was comparable to an optimally prepared Volumatic spacer, and resulted in commensurate improvement in relative lung bioavailability for both fluticasone and salmeterol moieties compared to pMDI.

Regular treatment with salmeterol and inhaled steroids for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta(2)-agonists and increased 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 with inhaled corticosteroids versus the same dose of inhaled corticosteroids alone.

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 Food and Drug Administration (FDA) submissions in relation to salmeterol were also checked. The date of the most recent search was October 2008.

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 inhaled corticosteroids (in separate or combined inhalers), and were of at least 12 weeks duration.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review. Outcome data were independently extracted by two authors. Unpublished data on mortality and serious adverse events were obtained from the sponsors, and from FDA submissions.

MAIN RESULTS

The review included 30 studies (10,873 participants) in adults and adolescents, and three studies (1,173 participants) in children. The overall risk of bias was low and data on serious adverse events were obtained from all studies.Six deaths occurred in 5,710 adults on regular salmeterol with inhaled corticosteroids, and five deaths in 5,163 adults on regular inhaled corticosteroids at the same dose. The difference was not statistically significant (Peto OR 1.05; 95% CI 0.32 to 3.47) and the absolute difference between groups in risk of death of any cause was 0.00005 (95% CI -0.002 to 0.002). No deaths were reported in 1,173 children, and no deaths were reported to be asthma-related.Non-fatal serious adverse events of any cause were reported in 134 adults on regular salmeterol with inhaled corticosteroids, compared to 103 adults on regular inhaled corticosteroids; again this was not a significant increase (Peto OR 1.17; 95% CI 0.90 to 1.52). The absolute difference in the risk of non-fatal serious adverse events was 0.003 (95% CI -0.002 to 0.009).There were three of 586 children with serious adverse events on regular salmeterol with inhaled corticosteroids, compared to four out of 587 on regular inhaled corticosteroids: there was no significant difference between treatments (Peto OR 0.75; 95% CI 0.17 to 3.31).Asthma-related serious adverse events were reported in 23 and 21 adults in each group respectively, a non-significant difference (Peto OR 0.95; 95% CI 0.52 to 1.73), and only one event was reported in children.

AUTHORS' CONCLUSIONS

No significant differences have been found in fatal or non-fatal serious adverse events in trials in which regular salmeterol has been randomly allocated with inhaled corticosteroids, in comparison to inhaled corticosteroids at the same dose. Although 10,873 adults and 1,173 children have been included in trials, the number of patients suffering adverse events is too small, and the results are too imprecise to confidently rule out a relative increase in all-cause mortality or non-fatal adverse events. It is therefore not possible to determine whether the increase in all-cause non-fatal serious adverse events reported in the previous meta-analysis on regular salmeterol alone is abolished by the additional use of regular inhaled corticosteroids. The absolute difference between groups in the risk of serious adverse events was small. There were no asthma-related deaths and few asthma-related serious adverse events. Clinical decisions and information for patients regarding regular use of salmeterol have to take into account the balance between known symptomatic benefits of salmeterol and the degree of uncertainty and concern associated with its potential harmful effects.

Regular treatment with formoterol and inhaled steroids for chronic asthma: serious adverse events

BACKGROUND

Epidemiological evidence has suggested a link between beta(2)-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 when used alone or in conjunction with inhaled corticosteroids.

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 formoterol with inhaled corticosteroids versus the same dose of inhaled corticosteroids alone.

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 Food and Drug Administration (FDA) submissions in relation to formoterol were also checked. The date of the most recent search was October 2008.

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 and inhaled corticosteroids, and were of at least 12 weeks duration.

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review. Outcome data were independently extracted by two authors. Unpublished data on mortality and serious adverse events were obtained from the sponsors.

MAIN RESULTS

The review included 14 studies on adults and adolescents (8,028 participants) and seven studies on children and adolescents (2,788 participants). Data on all cause fatal and non-fatal serious adverse events were found for all studies, and the overall risk of bias was low.Four deaths occurred on regular formoterol with inhaled corticosteroids, and none on regular inhaled corticosteroids alone. All the deaths were in adults, and one was reported to be asthma-related. The difference was not statistically significant.Non-fatal serious adverse events of any cause were very similar in adults [Peto Odds Ratio 0.99 (95% CI 0.74 to 1.33)], and an increase in events in children on regular formoterol was not statistically significant [Peto Odds Ratio 1.62 (95% CI 0.80 to 3.28)].Asthma related serious adverse events on formoterol were lower in adults [Peto Odds Ratio 0.53 (95% CI 0.28 to 1.00)] and although they were higher in children [Peto Odds Ratio 1.49 (95% CI 0.48 to 4.61)], this was not statistically significant.

AUTHORS' CONCLUSIONS

It is not possible, from the data in this review, to reassure people with asthma that inhaled corticosteroids with regular formoterol carries no risk of increasing mortality in comparison to inhaled corticosteroids alone as all four deaths occurred among 6,594 people using inhaled corticosteroids with formoterol. On the other hand, we have found no conclusive evidence of harm and there was only one asthma related death registered during over 3,000 patient year observation on formoterol. In adults, the decrease in asthma-related serious adverse events on regular formoterol with inhaled corticosteroids was not accompanied by a decrease in all cause serious adverse events. In children the number of events was too small, and consequently the results too imprecise, to determine whether the increase in all cause non-fatal serious adverse events found in the previous meta-analysis on regular formoterol alone is abolished by the additional use of inhaled corticosteroids. Clinical decisions and information for patients regarding regular use of formoterol have to take into account the balance between known symptomatic benefits of formoterol and the degree of uncertainty and concern associated with its potential harmful effects.

Indacaterol, A Novel Once Daily Inhaled beta2-Adrenoreceptor Agonist

In this article we will review the role of long acting β2-adrenoreceptor agonists and long-acting muscarinic agents in the management of airflow obstruction. We will then focus our attention on indacaterol, one of the new once daily inhaled β2-adrenoreceptor agonists. Pharmacologically this drug is a nearly full β2-agonist without loss of efficacy after prolonged administration. We will also discuss its dosing, safety and tolerability.

Regular treatment with formoterol 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 formoterol 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 Food and Drug Administration (FDA) submissions in relation to formoterol were also checked. The date of the most recent search was July 2008.

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 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 were extracted by one author and checked by the second author. Unpublished data on mortality and serious adverse events were sought.

MAIN RESULTS

The review includes 22 studies (8,032 participants) comparing regular formoterol to placebo and salbutamol. Non-fatal serious adverse event data could be obtained for all participants from published studies comparing formoterol and placebo but only 80% of those comparing formoterol with salbutamol or terbutaline.Three deaths occurred on regular formoterol and none on placebo; this difference was not statistically significant. It was not possible to assess disease specific mortality in view of the small number of deaths. Non-fatal serious adverse events were significantly increased when regular formoterol was compared with placebo (Odds Ratio 1.57 [95% CI: 1.05 to 2.37]). One extra serious adverse event occurred over 16 weeks for every 179 people treated with regular formoterol [95% CI: 75 to 2022]. The increase was larger in children than in adults, but the impact of age was not statistically significant. Data submitted to the FDA indicates that the increase in asthma-related serious adverse events remained significant in patients taking regular formoterol who were also on inhaled corticosteroids.No significant increase in fatal or non-fatal serious adverse events was found when regular formoterol was compared with regular salbutamol or terbutaline.

AUTHORS' CONCLUSIONS

In comparison with placebo, we have found an increased risk of serious adverse events with regular formoterol, and this does not appear to be abolished in patients taking inhaled corticosteroids. The effect on serious adverse events of regular formoterol in children was greater than the effect in adults, but the difference between age-groups was not significant.Data on all-cause serious adverse events should be more fully reported in journal articles, and not combined with all adverse events or limited to those events that are thought by the investigator to be drug-related.

Treating Chronic Fatigue states as a disease of the regulation of energy metabolism

Chronic Fatigue Syndrome is a physiological state in which the patient feels high levels of fatigue without an obvious organic cause, which affects around 1 in 400 people in the developed world. A wide range of causes have been suggested, including immune or hormonal dysfunction, viral or bacterial infection, and psychological somatization. It is likely that several causes are needed to trigger the disease, and that the triggers are different from the mechanisms that maintain fatigue over months or years. Many treatments have been tested for CFS, with very limited success - a programme of combined CBT and graded exercise shows the most effect. I suggest that patients with CFS have a reduced ability to increase mitochondrial energy production when exertion requires it, with fewer mitochondria that are each more efficient, and hence nearer to their maximum energy output, than normal. A range of indirect evidence suggests that the renin-angiotensin system stimulates mitochondrial responsiveness and reduces mitochondrial efficiency: chronic under-stimulation of this system could contribute to CFS aetiology. If correct, this means that CFS can be successfully treated with RAS agonists (eg angiotensin mimetics), or adrenergic agonists. It also suggests that there will be a positive link between the use of adrenergic- and RAS-blocking drugs and CFS incidence, and a negative link between adrenergic agonist use and CFS.

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.

Systemic and bronchodilator effects of inhaled rac-formoterol in subjects with chronic obstructive pulmonary disease: a dose-response study

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The long-acting inhaled beta(2)-agonist formoterol has systemic effects when taken in high doses. It can be used as relief medication in asthma and there is interest in this approach in chronic obstructive pulmonary disease (COPD). Relief medication can involve high doses, and in subjects with COPD who have limited ability to bronchodilate the adverse effects can outweigh the benefits. There are concerns with the overall safety of high-dose beta(2)-agonists in subjects with COPD, and this study looks at the balance of beneficial and adverse effects of a range of doses of inhaled formoterol.

WHAT THIS STUDY ADDS

Among subjects with COPD, high-dose inhaled formoterol produced a dose-related increase in forced expiratory volume in 1 s without a corresponding reduction in dyspnoea or increase in walk distance. Systemic effects were modest, however, and high doses did not appear to reduce patient satisfaction. Although further safety data are needed, inhaled formoterol may have a role as relief medication in COPD. AIMS Rac-formoterol is effective as maintenance treatment for both asthma and chronic obstructive pulmonary disease (COPD) and is now used as relief therapy in asthma. Using rac-formoterol for relief and maintenance treatment could involve inhalation of high doses, and whether this is of benefit in COPD is uncertain. Our aim was to determine whether higher doses of inhaled rac-formoterol produce systemic adverse effects that outweigh the limited bronchodilator benefit seen in subjects with COPD.

METHODS

We examined airway and systemic effects of 6, 12, 24 and 48 microg rac-formoterol and placebo on separate days in 20 subjects with symptomatic COPD [forced expiratory volume in 1 s (FEV(1)) 47% predicted]. FEV(1), oxygen saturation, dyspnoea, 6-min walk distance, patient satisfaction and systemic effects were measured and treatment was assessed against placebo and for dose-response effects.

RESULTS

FEV(1)[area under the time-response curve (AUC)] and satisfaction scores increased with all formoterol doses compared with placebo, as did AUC tremor with the 24- and 48-microg doses and AUC heart rate with the 48-microg dose. A dose-response relationship was seen with FEV(1) and tremor, but not with satisfaction scores. There was no difference between placebo and rac-formoterol for other variables.

CONCLUSIONS

Our results show that in patients with COPD rac-formoterol improves FEV(1) and patient satisfaction without a corresponding reduction in dyspnoea. Since the systemic effects from a relatively high dose were minimal, its use as relief medication in COPD merits further evaluation.

Cardiac safety profile of nebulized formoterol in adults with COPD: a 12-week, multicenter, randomized, double- blind, double-dummy, placebo- and active-controlled trial

BACKGROUND

Recently, there have been concerns about the tolerability of long-acting (2)-agonists, including possible adverse cardiovascular effects-a particular concern in patients with chronic obstructive pulmonary disease (COPD), who are at elevated risk for cardiovascular disease.

OBJECTIVE

The aim of this study was to assess the cardiac safety profile of nebulized formoterol fumarate inhalation solution.

METHODS

Cardiac safety was assessed as part of a 12-week, randomized, double-blind, double-dummy, placebo- and active-controlled trial that was conducted at 38 centers across the United States. Male and female patients aged >/=40 years with COPD and without other significant disease were enrolled. After a 4- to 14-day, single-blind placebo run-in period, patients with COPD were randomly assigned to receive formoterol fumarate inhalation solution 20 microg BID via nebulizer (FFIS group), formoterol fumarate 12 microg BID via dry powder inhaler (FA group), or placebo. Cardiac effects-measured by changes in heart rate (HR) and ventricular premature beats; incidence of proarrhythmic events; change in corrected QT (QTc) interval; and incidence of maximum mean change in QTc >/=60 ms-were assessed using 24-hour Holter monitoring at baseline and 12 weeks; 12-lead electrocardiography at screening and weeks 4, 8, and 12; and patient diary cards.

RESULTS

A total of 351 patients with COPD were randomized (mean age, 62.8 years; 56.1% male; mean postbronchodilator forced expiratory volume in 1 second, 1.5 L). Holter monitoring found no clinically meaningful effects of FFIS or FA treatment on mean or maximum HR, ventricular premature beats, or inci dence of arrhythmic events compared with placebo. At week 12, mean (SD) changes from baseline in mean HR were -0.6 (10.9), +0.1 (11.6), and -1.4 (9.4) bpm in the FFIS, FA, and placebo groups, respectively. The incidence of mean maximum changes in QTc >/=60 ms at any time during the 12-week treatment period were 1.6%, 1.8%, and 1.8% with FFIS, FA, and placebo, respectively. Treatment-emergent cardiac adverse events (AEs) occurred in 4.1%, 3.5%, and 4.4% of patients in the FFIS, FA, and placebo groups; withdrawals due to possible cardiac AEs occurred in 1 patient per treatment group. No deaths or serious cardiac AEs occurred during the treatment period.

CONCLUSION

In this COPD population, no clinically significant cardiac effects were found with twicedaily treatment with nebulized formoterol fumarate inhalation solution.

Safety and tolerability of indacaterol in asthma: a randomized, placebo-controlled 28-day study

The safety and tolerability of indacaterol, a novel once-daily beta(2)-agonist bronchodilator with a fast onset of action, were assessed in 156 asthma patients in a multicentre, randomized, double-blind, placebo-controlled study. Patients received indacaterol 200, 400 or 600 microg or placebo once daily for 28 days. Adverse events (AEs), laboratory assessments, vital signs, electrocardiograms, spirometry and physical examinations were monitored. Indacaterol pharmacokinetics were assessed. There was no evidence of dose-related increases in AE incidence or clinically significant hypokalaemia or hyperglycaemia in indacaterol-treated patients. Mean pulse rate changes were minor in any group, with maximum 1-h post-dose changes from baseline of -3.7, -3.3 and -2.2 bpm for indacaterol 200, 400 and 600 microg, respectively, and -2.9 bpm for placebo. Mean QTc interval was similar between groups; change from baseline >60 ms occurred in only two patients. Mean FEV(1) increased after the first indacaterol dose; baseline-adjusted pre-dose (trough) values remained >or=166 mL higher than placebo at all subsequent visits, supporting a 24-h bronchodilator effect. Pre-dose (but not post-dose) serum indacaterol concentrations indicated a slight trend for accumulation. Once-daily indacaterol 200-600 microg has a favourable therapeutic index. It is well tolerated, and is not associated with any adverse cardiac or metabolic effects, while providing effective 24-h bronchodilation.

Use of short-acting beta2-agonists during pregnancy and the risk of pregnancy-induced hypertension

BACKGROUND

The effect of inhaled short-acting beta(2)-agonists (SABAs) on pregnancy outcome, especially hypertensive complications, is not well documented. After the finding of a possible protective association of inhaled SABAs with pregnancy-induced hypertension (PIH) in a previous study, we decided to further investigate their effect on this condition.

OBJECTIVE

We sought to determine the effect of inhaled SABA use during pregnancy on the risk of PIH (gestational hypertension, preeclampsia, or eclampsia) in asthmatic women.

METHODS

Three of Quebec's administrative databases were linked to constitute a cohort of asthmatic women who had at least 1 delivery between 1990 and 2000. A nested case-control study was performed using up to 10 control subjects matched to each case patient for the year of conception and gestational age. Statistical analyses considered 22 confounders.

RESULTS

The cohort was composed of 3505 asthmatic women who had a total of 4593 pregnancies. Three hundred two patients with PIH and 3013 control subjects were identified. Compared with nonuse, inhaled SABA use during pregnancy was significantly associated with a reduced risk of PIH (adjusted rate ratios: >0-3 doses/week, 0.62 (95% CI, 0.44-0.87); > 3-10 doses/week, 0.51 (95% CI, 0.34-0.79); and >10 doses/week, 0.48 (95% CI, 0.30-0.75)).

CONCLUSIONS

To our knowledge, this is the first study reporting that inhaled SABA use during pregnancy is associated with a reduced risk of PIH. Potential explanations include pharmacologic and physiological effects or residual confounding.

CLINICAL IMPLICATIONS

These results increase the evidence about the safety of inhaled SABAs in this population, although they should not undervalue the importance of maintaining good control of asthma symptoms.

Safety, tolerability and efficacy of indacaterol, a novel once-daily beta(2)-agonist, in patients with COPD: a 28-day randomised, placebo controlled clinical trial

In patients with chronic obstructive pulmonary disease (COPD) classified as moderate onwards, Global Initiative for Chronic Obstructive Lung Disease (GOLD) Guidelines recommend regular treatment with one or more long-acting bronchodilators, such as beta(2)-agonists or anticholinergics. In contrast to currently available long-acting beta(2)-agonists, which have a duration of action of 12 h, indacaterol has demonstrated effective 24-h bronchodilation on once-daily dosing. A double-blind, randomised, placebo-controlled study was conducted to compare the safety, tolerability and efficacy of indacaterol with that of placebo, over a 28-day period, in patients with moderate COPD (as defined by GOLD 2001 criteria; equivalent to moderate-to-severe COPD in the GOLD 2005 criteria). Patients were randomised 2:2:1 to receive indacaterol 400 microg or 800 microg or placebo once-daily (between 07:00 and 11:00 h) via a single-dose dry-powder inhaler for 28 days. Assessments included monitoring of adverse events (AEs), blood chemistry (including serum potassium and blood glucose), vital signs (blood pressure and heart rate), electrocardiograms and spirometry. One hundred and sixty-three patients were randomised, with 155 (95%) completing the study. There were no statistically significant differences between treatment groups in the overall incidence of AEs, with AEs reported by 35%, 51% and 25% of patients in the indacaterol 400 microg, 800 microg and placebo groups, respectively. The majority of AEs were mild or moderate in severity, and there were no study-drug related serious AEs. There were no statistically significant differences between indacaterol groups and placebo in mean pulse rate and QTc interval, and isolated statistically significant (p<0.05) treatment-placebo differences in mean blood pressure, blood glucose and serum potassium. There was a statistically significant improvement in FEV(1) vs placebo at all post-baseline timepoints for both indacaterol treatment groups; 30 min post-dose, adjusted mean+/-SE FEV(1) indacaterol-placebo differences were: Day 1, 220+/-36 ml and 210+/-36 ml; Day 14, 320+/-50 ml and 270+/-50 ml; Day 28, 260+/-61 ml and 200+/-61 ml for 400 and 800 microg, respectively (all p<0.01 vs placebo). Bronchodilation was still apparent after 24h, with pre-dose (i.e. trough) adjusted mean+/-SE FEV(1) indacaterol-placebo differences of: Day 14, 230+/-44 ml and 210+/-44 ml; Day 28, 220+/-49 ml and 210+/-49 ml for indacaterol 400 and 800 microg, respectively (all p<0.0001 vs placebo). Once-daily indacaterol was well tolerated at doses up to 800 microg with a good overall safety profile. There was no statistical difference at any dose between the safety of indacaterol and placebo. Furthermore, this study supports the previously demonstrated 24-h bronchodilator efficacy of indacaterol.

Effects of salmeterol in patients with persistent asthma receiving inhaled corticosteroid plus theophylline

BACKGROUND

Patients with severe asthma require multiple therapies to improve lung function and reduce symptoms. The use of long-acting inhaled beta(2)-agonists plus theophylline in addition to high doses of inhaled corticosteroids (ICSs) for the treatment of severe asthma has not been extensively studied.

OBJECTIVE

The purpose of this study was to investigate the efficacy and safety of salmeterol combined with high-dose ICSs plus theophylline in severe asthma.

METHODS

We undertook a randomized, placebo-controlled, crossover study to compare the effect of a single dose of inhaled salmeterol (50 microg) or a placebo in patients with severe asthma whose conditions were not being adequately controlled by therapies with high-dose ICSs plus oral theophylline with or without leukotriene receptor antagonists.

RESULTS

Twenty patients took part in the trial. Compared with the placebo, the inhalation of salmeterol significantly increased the FEV(1). Even in the 9 patients treated with high-dose ICSs plus theophylline plus a leukotriene receptor antagonist, the FEV(1) increased significantly more after salmeterol than after the placebo.

CONCLUSION

Patients with severe asthma receiving high-dose ICSs plus theophylline may benefit from the addition of salmeterol.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

In Vitro and in Vivo Pharmacological Characterization of 5-[(R)-2-(5,6-Diethyl-indan-2-ylamino)-1-hydroxy-ethyl]-8-hydroxy-1H-quinolin-2-one (Indacaterol), a Novel Inhaled β2 Adrenoceptor Agonist with a 24-h Duration of Action

Here, we describe the preclinical pharmacological profile of 5-[(R)-2-(5,6-diethyl-indan-2-ylamino)-1-hydroxy-ethyl]-8-hydroxy-1H-quinolin-2-one (indacaterol), a novel, chirally pure inhaled beta(2) adrenoceptor agonist, in comparison with marketed drugs. Indacaterol is close to a full agonist at the human beta(2) adrenoceptor (E(max) = 73 +/- 1% of the maximal effect of isoprenaline; pEC(50) = 8.06 +/- 0.02), whereas salmeterol displays only partial efficacy (38 +/- 1%). The functional selectivity profile of indacaterol over beta(1) human adrenoceptors is similar to that of formoterol, whereas its beta(3) adrenoceptor selectivity profile is similar to that of formoterol and salbutamol. In isolated superfused guinea pig trachea, indacaterol has a fast onset of action (30 +/- 4 min) similar to formoterol and salbutamol, and a long duration of action (529 +/- 99 min) comparable with salmeterol. In the conscious guinea pig, when given intratracheally as a dry powder, indacaterol inhibits 5-hydroxytryptamine-induced bronchoconstriction for at least 24 h, whereas salmeterol, formoterol, and salbutamol have durations of action of 12, 4, and 2 h, respectively. When given via nebulization to anesthetized rhesus monkeys, all of the compounds dose-dependently inhibit methacholine-induced bronchoconstriction, although indacaterol produces the most prolonged bronchoprotective effect and induces the lowest increase in heart rate for a similar degree of antibronchoconstrictor activity. In conclusion, the preclinical profile of indacaterol suggests that this compound has a superior duration of action compatible with once-daily dosing in human, together with a fast onset of action and an improved cardiovascular safety profile over marketed inhaled beta(2) adrenoceptor agonists.

Long-acting beta2-agonists: comparative pharmacology and clinical outcomes

Salmeterol and formoterol are both long-acting beta(2)-adrenoceptor agonists (beta(2)-agonists). They both provide excellent bronchodilating and bronchoprotective effects in patients with asthma but their are some differences between these two long-acting beta(2)-agonists in vitro and in vivo. Formoterol has a greater potency and intrinsic activity than salmeterol, which can become especially apparent at higher doses than that clinically recommended, and in contracted bronchi. Long-term use of long-acting beta(2)-agonists can induce tolerance, which can be partially reversed with corticosteroids. Long-acting beta(2)-agonists have some anti-inflammatory effects in vitro, but data in vivo are less convincing. Compared with doubling the dose of inhaled corticosteroids, the addition of inhaled long-acting beta(2)-agonists to inhaled corticosteroids improves symptom control in patients with asthma and reduces both the exacerbation rate of asthma and hospital admission rate. No enhanced airway responsiveness or loss of perception of dyspnea has been observed with the use of inhaled long-acting beta(2)-agonists. Monotherapy with long-acting beta(2)-agonists is not recommended.

A benefit-risk assessment of inhaled long-acting beta2-agonists in the management of obstructive pulmonary disease

The two inhaled long-acting beta2-adrenoceptor agonists, salmeterol and formoterol, have been studied extensively since their introduction in the early 1990s. In this review we consider the evidence for their efficacy and safety in adults with asthma and chronic obstructive pulmonary disease (COPD), by reviewing long-term prospective studies in which these drugs have been compared with placebo or an alternative bronchodilator. We have also assessed safety, including data from postmarketing surveillance studies and case-control studies using large databases. In patients with asthma, salmeterol and formoterol increase lung function, reduce asthmatic symptoms and improve quality of life when compared with placebo. Both drugs protect against exercise-induced asthma, although some tolerance develops with regular use. Tolerance to the bronchodilator effects of formoterol has also been seen, although this is small and most of the beneficial effects are maintained long-term. Both drugs have been shown to reduce asthma exacerbations but only in studies in which most patients were taking an inhaled corticosteroid. Adding a long-acting beta2-agonist provided better control than increasing the dose of inhaled corticosteroid in several studies. Long-acting beta2-agonists also provide better asthma control than use of regular short-acting beta2-agonists and theophylline. Their relative efficacy compared with leukotriene antagonists is uncertain as yet. Formoterol appears to be at least as safe and effective as a short-acting beta2-agonist when used on an 'as required' basis. In patients with COPD, both salmeterol and formoterol offer improved lung function and reduced COPD symptoms compared with placebo, and quality of life has been improved in some studies. Some tolerance to the bronchodilating effect of salmeterol was seen in one study. Most studies have not found a significant reduction in exacerbations in COPD. Both drugs have provided greater benefit than ipratropium bromide or theophylline; there are limited data on tiotropium bromide. The long-acting beta2-agonists cause predictable adverse effects including headache, tremor, palpitations, muscle cramps and a fall in serum potassium concentration. Salmeterol can also cause paradoxical bronchospasm. There is some evidence that serious adverse events including dysrhythmias and life-threatening asthma episodes can occur; however, the incidence of such events is very low but may be increased in patients not taking an inhaled corticosteroid. Salmeterol 50 microg twice daily and formoterol 12 microg twice daily are effective and safe in treating patients with asthma and COPD. Higher doses cause more adverse effects, although serious adverse events are rare.

Cardiovascular safety of beta(2)-adrenoceptor agonist use in patients with obstructive airway disease: a systematic review

BACKGROUND

beta(2)-Adrenoceptor agonists have been used as bronchodilators in the management of asthma and chronic obstructive pulmonary disease (COPD); however, there is evidence suggesting that beta(2)-adrenoceptor agonist use may increase morbidity and mortality.

METHODS

A systematic review of case-control studies and randomised controlled trials was performed to evaluate the cardiovascular safety of beta(2)-adrenoceptor agonist use in patients with obstructive airway disease, defined as asthma or COPD.

RESULTS

Case-control studies have shown that beta(2)-adrenoceptor agonist use is associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. The degree of risk appears to be dose-dependent, and may be highest for new users and those with concomitant cardiac conditions. Pooled data from randomised placebo-controlled trials indicate that beta(2)-adrenoceptor agonist use increases the risk of adverse cardiovascular events by more than 2-fold compared with placebo, thus providing evidence that the association seen in case-control studies is a causal one. Single doses of beta(2)-adrenoceptor agonists significantly increase heart rate and decrease potassium concentrations compared with placebo.

CONCLUSIONS

Initiation of beta(2)-adrenoceptor agonist treatment increases heart rate and decreases potassium concentrations, while continued use may increase the risk of adverse cardiovascular events. It could be through these effects of beta-adrenergic stimulation that beta(2)-adrenoceptor agonists may induce ischaemia, congestive heart failure, arrhythmias and sudden cardiac death. In addition to increasing adverse cardiovascular events, beta(2)-adrenoceptor agonist use may induce respiratory tolerance and increase the risk of asthma attacks. It is not clear whether beta(2)-adrenoceptor agonists should be used regularly in the treatment of obstructive airway disease, with or without concomitant cardiovascular disease.

Cardiovascular Effects of β-Agonists in Patients With Asthma and COPD

BACKGROUND

beta-Adrenergic agonists exert physiologic effects that are the opposite of those of beta-blockers. beta-Blockers are known to reduce morbidity and mortality in patients with cardiac disease. beta(2)-Agonist use in patients with obstructive airway disease has been associated with an increased risk for myocardial infarction, congestive heart failure, cardiac arrest, and acute cardiac death.

OBJECTIVES

To assess the cardiovascular safety of beta(2)-agonist use in patients with obstructive airway disease, defined as asthma or COPD.

METHODS

A meta-analysis of randomized placebo-controlled trials of beta(2)-agonist treatment in patients with obstructive airway disease was performed, to evaluate the short-term effect on heart rate and potassium concentrations, and the long-term effect on adverse cardiovascular events. Longer duration trials were included in the analysis if they reported at least one adverse event. Adverse events included sinus and ventricular tachycardia, syncope, atrial fibrillation, congestive heart failure, myocardial infarction, cardiac arrest, or sudden death.

RESULTS

Thirteen single-dose trials and 20 longer duration trials were included in the study. A single dose of beta(2)-agonist increased the heart rate by 9.12 beats/min (95% confidence interval [CI], 5.32 to 12.92) and reduced the potassium concentration by 0.36 mmol/L (95% CI, 0.18 to 0.54), compared to placebo. For trials lasting from 3 days to 1 year, beta(2)-agonist treatment significantly increased the risk for a cardiovascular event (relative risk [RR], 2.54; 95% CI, 1.59 to 4.05) compared to placebo. The RR for sinus tachycardia alone was 3.06 (95% CI, 1.70 to 5.50), and for all other events it was 1.66 (95% CI, 0.76 to 3.6).

CONCLUSION

beta(2)-Agonist use in patients with obstructive airway disease increases the risk for adverse cardiovascular events. The initiation of treatment increases heart rate and reduces potassium concentrations compared to placebo. It could be through these mechanisms, and other effects of beta-adrenergic stimulation, that beta(2)-agonists may precipitate ischemia, congestive heart failure, arrhythmias, and sudden death.

Electrophysiologic Effects of Salbutamol, a β 2 ‐Selective Agonist

INTRODUCTION

A positive chronotropic effect of beta2 stimulation is well known. Case reports of ventricular arrhythmias during beta2-inhalation therapy have been published. The aim of this study was to asses the overall electrophysiologic effects of the beta2-agonist salbutamol.

METHODS AND RESULTS

Electrophysiologic and hemodynamic variables were measured in 10 healthy volunteers during atrial pacing at baseline and during infusion of salbutamol at two different rates (0.1 and 0.2 microg/kg/min). To characterize beta2-agonist effects, a comparison was made with the beta1-selective agonist dobutamine. Salbutamol infusion produced significant changes in electrophysiologic properties in both myocardial and nodal tissues, with significantly greater effects on nodal properties. The proportional decreases in AV nodal parameters were more pronounced than in the sinus node (P < 0.001). An interesting result was a significant increase in the duration of the QS interval, which in the presence of an unchanged His-Purkinje conduction (HV) represents slower depolarization of the ventricle. QT dispersion also increased.

CONCLUSION

Infusion of salbutamol results in significant electrophysiologic effects on most heart structures, proportionally most pronounced in the AV node. Discordant effects on ventricular conduction, which slowed, and the refractoriness of the ventricular myocardium, which shortened, were seen. QT dispersion was increased.

Effects of bronchodilator particle size in asthmatic patients using monodisperse aerosols

Aerosol particle size influences airway drug deposition. Current inhaler devices are inefficient, delivering a heterodisperse distribution of drug particle sizes where, at best, 20% reaches the lungs. Monodisperse aerosols are the appropriate research tools to investigate basic aerosol science concepts within the human airways. We hypothesized that engineering such aerosols of albuterol would identify the ideal bronchodilator particle size, thereby optimizing inhaled therapeutic drug delivery. Eighteen stable mildly to moderately asthmatic patients [mean forced expiratory volume in 1 s (FEV1) 74.3% of predicted] participated in a randomized, double-blind, crossover study design. A spinning-top aerosol generator was used to produce monodisperse albuterol aerosols that were 1.5, 3, and 6 microm in size, and also a placebo, which were inhaled at cumulative doses of 10, 20, 40, and 100 microg. Lung function changes and tolerability effects were determined. The larger particles, 6 and 3 microm, were significantly more potent bronchodilators than the 1.5-microm and placebo aerosols for FEV1 and for the forced expiratory flow between exhalation of 25 and 75% of forced vital capacity. A 20-microg dose of the 6- and 3-microm aerosols produced FEV1 bronchodilation comparable to that produced by 200 microg from a metered-dose inhaler. No adverse effects were observed in heart rate and plasma potassium. The data suggest that in mildly to moderately asthmatic patients there is more than one optimal beta2-agonist bronchodilator particle size and that these are larger particles in the higher part of the respirable range. Aerosols delivered in monodisperse form can enable large reductions of the inhaled dose without loss of clinical efficacy.

Effect of salmeterol xinafoate on lung mucociliary clearance in patients with asthma

Lung mucociliary clearance is impaired in stable asthma. The long-acting beta2-agonist salmeterol has been shown in vitro to cause a significant increase in ciliary beat frequency. It seemed possible therefore that salmeterol may also have a favourable effect on lung mucociliary transport in asthmatic patients. Fourteen patients with asthma participated in a double-blind, placebo-controlled, crossover study to assess the effect of 2 weeks of treatment with salmeterol MDI (50 microg b.d.) on lung mucociliary clearance. The 11 patients who completed the study (seven males, four females) had a mean +/- SE age of 50 +/- 4 years, % predicted FEV1 of 74 +/- 8% and a tobacco consumption history of 13 +/- 7 pack-years (seven non-smokers, four exsmokers). Lung mucociliary transport was measured by a radioaerosol technique. Pulmonary function indices (FEV1, FVC, and PEF) were significantly improved on salmeterol relative to placebo. The main radioaerosol finding was a significant increase in the penetration of radioaerosol into the lung with 24-h radioaerosol rising from 40 +/- 5% on placebo to 49 +/- 4% (P < 0.01) on salmeterol. Despite this increased penetration, a slight favourable change occurred in tracheobronchial aerosol clearance. This study demonstrates that 2 weeks salmeterol treatment influences deposition of particles within the lung by increasing airway patency and indicates a beneficial effect of MDI salmeterol on lung mucociliary clearance.

Alternative mechanisms for long-acting beta(2)-adrenergic agonists in COPD

beta(2)-Adrenergic agonists are commonly used as bronchodilators to treat patients with COPD. In addition to prolonged bronchodilation, long-acting beta(2)-agonists (LABAs) exert other effects that may be of clinical relevance. These include inhibition of airway smooth-muscle cell proliferation and inflammatory mediator release, as well as nonsmooth-muscle effects, such as stimulation of mucociliary transport, cytoprotection of the respiratory mucosa, and attenuation of neutrophil recruitment and activation. This review details the possible alternative mechanisms of action of the LABAs, salmeterol and formoterol, in COPD.

Advair: combination treatment with fluticasone propionate/salmeterol in the treatment of asthma

Several classes of medications are available for the treatment of asthma, and often they must be taken concurrently to achieve asthma control. Based on the understanding of asthma as an inflammatory disease, the National Heart Lung and Blood Institute guidelines provide a stepwise approach to pharmacologic therapy. Corticosteroid therapy, principally inhaled corticosteroid (ICS) therapy, is considered the most effective anti-inflammatory treatment. In cases of moderate-to-severe persistent asthma, the addition of a second long-term control medication to ICS therapy is one recommended treatment option. A combination-product inhaler (Advair, Seretide) was developed to treat both the inflammatory and bronchoconstrictive components of asthma by delivering a dose of the ICS, fluticasone propionate, and a dose of the long-acting beta2-adrenergic (LABA) bronchodilator, salmeterol. The Advair Diskus is available in 3 strengths of fluticasone propionate (100, 250, and 500 microg) and a fixed dose (50 microg) of salmeterol. Combination treatment with both ICS and LABA provides greater asthma control than increasing the ICS dose alone, while at the same time reducing the frequency and perhaps the severity of exacerbations. Furthermore, salmeterol added to ICS therapy provides superior asthma control compared with the addition of leukotriene modifiers or theophylline. The superior control is likely a consequence of the complementary actions of the drugs when taken together, including the activation of the glucocorticoid receptor by salmeterol. By combining anti-inflammatory treatment with a long-acting beta2-agonist in a single inhaler (1 inhalation twice daily), physicians can provide coverage for both the inflammatory and bronchoconstrictive aspects of asthma without introducing any new or unexpected adverse consequences. The most common drug-related adverse events were those known to be attributable to the constituent medications (ICS therapy and/or LABA therapy). Although the benefits of combined ICS plus LABA therapy can be achieved with separate inhalers, the convenience of the combination product may improve patient adherence and may therefore reduce the morbidity of asthma.

Systemic effects of formoterol and salmeterol: a dose-response comparison in healthy subjects

BACKGROUND

The main adverse effects of inhaled long acting beta(2) agonists relate to their systemic activity. The systemic effects seen over eight hours after inhalation of three doses of salmeterol and formoterol were therefore compared in normal subjects.

METHODS

A double blind, randomised, crossover study was carried out in 16 healthy subjects who inhaled formoterol 24, 48 and 96 microg (via Turbuhaler((R))), salmeterol 100, 200 and 400 microg (via Diskhaler((R))), or placebo on separate days. Heart rate, systolic and diastolic blood pressure, and plasma potassium and glucose concentrations were measured for eight hours following each drug and mean values were used to plot the time course of change after each dose. Mean maximum (or minimum) absolute values were used to construct dose-response curves to calculate the relative dose potency of the two drugs. Lunch was taken after the four hour readings and, since this caused additional changes to the main outcome measures, data from the first four hours are also presented in a post hoc analysis.

RESULTS

Both salmeterol and formoterol caused an early dose dependent increase in heart rate and glucose concentrations and a fall in diastolic blood pressure and plasma potassium concentration; formoterol also caused an early increase in systolic blood pressure. The cardiovascular effects occurred more rapidly than the metabolic effects and the response to formoterol was faster than that of salmeterol, apart from the glycaemic response. The effects of salmeterol were slightly more prolonged than those of formoterol, although some dose related effects were apparent at eight hours with both drugs. The relative dose potency for formoterol compared with salmeterol at four and eight hours for the different end points excluding systolic blood pressure ranged from 1.6 to 7.0 after adjusting for baseline values. Relative dose potencies (95% CI) for maximum heart rate and plasma potassium concentrations were 4.1 (3.0 to 5.6) and 5.8 (4.1 to 8.6) over four hours and 2.4 (1.2 to 3.8) and 3.0 (1.2 to 5.7) over eight hours.

CONCLUSIONS

Formoterol and salmeterol cause dose related changes in heart rate, diastolic blood pressure, and plasma glucose and potassium concentrations. Formoterol has a more rapid onset for most end points whereas salmeterol has slightly more prolonged activity. Both drugs have a relatively modest therapeutic window. The relative dose potencies of the two drugs for the main end points were similar to the fourfold difference in recommended doses. Some differences in the pharmacological profile of the two drugs emerged and are as yet unexplained.

Pharmacokinetics and pharmacodynamics of cumulative single doses of inhaled salbutamol enantiomers in asthmatic subjects

Objectives of this study were to compare the pharmacokinetics, pharmacodynamics and safety of single cumulative doses of active (R)-salbutamol given either as the single enantiomer or racemic mixture by inhalation to subjects with mild to moderate asthma. This was a double-blind, crossover, cumulative-dose, randomized study where all subjects received either four doses of 1.25 mg of (R)-salbutamol or 2.5 mg of racemic (RS-) salbutamol by nebulization. The pharmacokinetic parameters were determined by noncompartmental analysis and model-fitting. Changes in FEV(1), plasma potassium, plasma glucose, heart rate, and QTc interval were measured. The potassium and glucose data were fitted to indirect response pharmacodynamic models. The heart rate and QTc data were evaluated using data descriptors. No significant differences in pharmacokinetics of (R)-salbutamol given as either (R)- or (RS)-salbutamol were found with AUC values of 11.90 +/- 4.37 and 11. 47 +/- 2.88 ng.h/ml. The t(max)of about 2 h reflected serial dosing rather than delayed absorption. The t(1/2)averaged about 3.5 h. The (S)-salbutamol showed AUC of 48.46 +/- 12.11 ng.h/ml with a t(1/2)of about 5 h. The changes in FEV(1)reached a plateau after an initial increase and did not return to pre-drug values for 10 h. All pharmacodynamic parameters were similar whether (R)- or (RS)-salbutamol was given. The exposure to (R)-salbutamol was identical after inhalation of (R) -and (RS)-salbutamol by subjects with asthma. Several pharmacological responses including FEV(1)were also similar and there were no unique safety concerns with either treatment.

Salbutamol inhalation has no effect on myocardial ischaemia, arrhythmias and heart-rate variability in patients with coronary artery disease plus asthma or chronic obstructive pulmonary disease

OBJECTIVES

Inhaled beta-2 agonists raise heart rate, systolic blood pressure and contractility, all of which cause an increase in oxygen consumption of the heart. We performed a study on the influence of inhaled salbutamol on myocardial ischaemia, rhythm, and heart rate variability as assessed by Holter monitoring of 24 patients with coronary artery disease (CAD) and clinically stable asthma or chronic obstructive pulmonary disease (COPD).

DESIGN

In hospital the patients received 0.2 mg (hour 1), 0.4 mg (hour 6), 0.8 mg (hour 13) of salbutamol with a metered-dose inhaler and a spacer, and 5 mg (hour 25) with a nebulizer; symptoms, peak expiratory flow (PEF), 30-h Holter monitoring, and blood pressure (BP) were recorded. The study parameters were compared for the hour preceding and following each dose of salbutamol.

RESULTS

No cardiac symptoms were associated with salbutamol inhalation. PEF increased after all doses (P < 0.005). A dose of 0.2 mg salbutamol induced no changes in heart rate, whereas dose of 0.4 mg increased heart rate from a mean of 75 +/- 13 to 79 +/- 14 beats min-1 (P < 0.005), and a dose of 0.8 mg from 76 +/- 14 to 78 +/- 15 beats min-1 (P < 0.05). No changes in systolic BP appeared after any dose of salbutamol. The diastolic BP was lowered after 0.8 mg of salbutamol from 86 +/- 12 to 82 +/- 10 mmHg (P < 0.05). The 5 mg of nebulized drug provoked no significant changes in heart rate or BP. Myocardial ischaemia, heart rate variability and ventricular arrhythmias remained unaltered with all doses.

CONCLUSIONS

The commonly used doses of inhaled or nebulized salbutamol induced no acute myocardial ischaemia, arrhythmias or changes in heart rate variability in patients with CAD and clinically stable asthma or COPD.

Effects of inhaled salmeterol and salbutamol (albuterol) on morning dips compared in intensive care patients recovering from an acute severe asthma attack

OBJECTIVE

To assess the effect of a long-acting inhaled beta 2-agonist, salmeterol (SM), compared to a short-acting inhaled beta 2-agonist, salbutamol (or albuterol, SB) on the occurrence of morning dip (MD) in patients recovering from an acute severe asthma attack (ASA).

DESIGN

Prospective study.

SETTING

18-bed, medical intensive care unit (ICU) in a university hospital.

PATIENTS

19 patients suffering from an ASA.

INTERVENTIONS

Serial measurements of the peak expiratory flow rate (PEFR), arterial blood gases, vital capacity and forced expiratory volume in one second (FEV1) were performed from admission. All patients were first treated with i.v. methyl prednisolone and i.v. SB. Once the PEFR was stable and > 35% of predicted value, i.v. SB was stopped while i.v. steroids were maintained, and patients were randomised to either inhaled SB (9 patients, 400 micrograms every 4 h) or inhaled SM (10 patients, 100 micrograms every 12 h).

RESULTS

The mean admission PEFR was 26.1 +/- 11.7% of the predicted value and was not different between the two groups. MD was more frequent with SB (6/9 patients) than with SM (4/10). The severity of MD, expressed in l/min fall in PEFR, was higher in SB than in SM (106 +/- 25 vs 55 +/- 37; p < 0.05).

DISCUSSION

MD is frequent in ASA. In ASA, SM appears to reduce the frequency and the severity of MD more than SB. The clinical implications of this observation, particularly a lowering of mortality and a shortening of the ICU stay, remain to be investigated.

Partial pulmonary sympathetic denervation by thoracoscopic D2-D3 sympathicolysis for essential hyperhidrosis: effect on the pulmonary diffusion capacity

In patients with essential hyperhidrosis (EH), a pathological condition characterized by increased activity of the upper dorsal sympathetic ganglia D2-D3, anatomical interruption at the D2-D3 level by thoracoscopic sympathicolysis (TS) is a safe and effective treatment. The D2 and D3 ganglia, however, are also in the pathway of sympathetic lung innervation, which may influence the pulmonary diffusion capacity for carbon monoxide (expressed as transfer factor for CO:TLCO, and as transfer coefficient for CO:KCO). We therefore studied the effect of TS on TLCO and KCO in 50 EH patients: compared with pre-operative values, both TLCO (-6.7%, P < 0.001) and KCO (-4.2%, P = 0.002) were significantly decreased at 6 weeks after bilateral TS, an effect which was independent of the smoking status of the patients. In order to explain this phenomenon, the following pharmacological interventions were studied: (1) oral beta 1 + 2-adrenoreceptor blockade with propranolol caused a comparable decrease of TLCO (-6.3%) and KCO (-7.5%) in matched normal subjects, but had no effect on TLCO and KCO in EH patients prior to TS; and (2) subsequent inhalation of the beta 2-adrenoreceptor agonist salbutamol in a dosage suspected to cause alveolar beta-receptor stimulation had no effect on TLCO and KCO, neither in the normal subjects, nor in EH patients (before and after TS). Although the exact mechanism of the TS-induced decrease in TLCO and KCO remains speculative, these findings suggest that they may be related to a beta 1-adrenoreceptor-mediated change in pulmonary capillary membrane permeability, although TS-induced changes in pulmonary blood flow or an interplay of both mechanisms cannot be excluded.

Time course and relative dose potency of systemic effects from salmeterol and salbutamol in healthy subjects

BACKGROUND

The main adverse effects of beta 1 agonists relate to their systemic activity. The time course and dose response relations of the systemic effects of salmeterol compared with salbutamol were investigated.

METHODS

A double blind, randomised, crossover study was carried out in 14 healthy subjects who attended on seven days. Heart rate, QTc interval, blood pressure, plasma potassium and glucose concentrations were measured for four hours following inhaled placebo, salmeterol 100, 200 and 400 micrograms and salbutamol 600, 1200 and 2400 micrograms given by metered dose inhaler. Maximum changes from baseline and maximum absolute values following each dose of treatment were used to construct log dose response curves and calculate relative dose potency.

RESULTS

Both salmeterol and salbutamol caused dose dependent changes in heart rate, QTc interval, and plasma potassium and glucose concentrations. The onset of cardiac effects was rapid following both drugs, whereas changes in glucose and potassium concentrations occurred more gradually with salmeterol. The increase in heart rate and fall in potassium level were sustained over the four hours whereas glucose levels gradually returned towards baseline. The relative dose potency of salmeterol compared with salbutamol for changes from baseline was 7.1 (95% CI 3.9 to 14.4) for the QTc interval and 8.2 (95% CI 5.7 to 12.6) for plasma potassium concentration. Salmeterol caused steeper dose response curves for heart rate and plasma glucose concentration than salbutamol so relative dose potency values could not be calculated.

CONCLUSIONS

These findings support previous data that salmeterol 100 micrograms is broadly equivalent to salbutamol 800 micrograms for systemic effects. The greater systemic effects of salmeterol are most likely to be due to greater potency relative to dose, although it may also have greater systemic bioavailability. The steeper dose response curve for heart rate with salmeterol indicates that it has a narrower therapeutic window than salbutamol and thus should be prescribed at the lowest effective dose.

Dose-response of inhaled drugs in asthma. An update

The demographic characteristics of patients used in clinical trials (such as the severity of airway obstruction) can significantly influence the results of dose-response studies, emphasising the need to evaluate effects on the steep part of the dose-response curve. Differences in inhaler devices can also influence study outcomes, as for inhaled drugs both airway efficacy and adverse effect profiles are primarily determined by lung deposition and hence bioavailability. Dose-response studies with short- and long-acting beta 2-agonists show an excellent therapeutic ratio at conventional doses used in everyday clinical practice (i.e. 2 to 4 puffs). Dose-related systemic effects of beta 2-agonist occur at higher doses, for salbutamol (albuterol) > 500 micrograms. Fenoterol is a beta 2-agonists with higher intrinsic activity than salbutamol and produces greater systemic effects at higher than conventional doses on a microgram equivalent basis, although even at 4000 micrograms such differences are unlikely to be clinically relevant. No differences between fenoterol and salbutamol have been shown in terms of bronchodilator potency on a microgram equivalent basis. The long-acting beta 2-agonist salmeterol, as a partial agonist, has the potential to attenuate the acute bronchodilator response to a higher activity beta 2-agonist such as salbutamol or fenoterol, although there is no evidence to date on whether this is relevant in the setting of acute asthma. When comparing inhaled corticosteroids, attention should be focused on their respective risk-benefit ratios for antiasthmatic versus systemic activity. In terms of detecting systemic activity, it is important to use sensitive measures, such as urinary cortisol excretion, rather than insensitive parameters, such as a single morning plasma cortisol measurement between 0800h and 1000h. For fluticasone, a greater in vitro potency results in only marginal differences in antiasthmatic efficacy, particularly on the flatter part of the dose-response curve above 1000 micrograms/day in adults and 400 micrograms/day in children. However, the same enhanced potency translates directly into commensurate differences in systemic adverse effects on the steep part of the systemic dose-response curve above 1000 micrograms/day in adults and 400 micrograms/day in children, respectively. Furthermore, with repeated twice-daily administration, a longer elimination half-life and prolonged systemic tissue retention due to enhanced lipophilicity will result in greater systemic activity observed at steady-state in long term administration studies. This dissociation of airway and systemic dose-response curves results in a J-shaped curve for benefit: risk ratio, with a watershed area above 1000 microgram/day in adults. This fall in the benefit: risk ratio is likely to be greater for fluticasone than for budesonide or beclomethasone. Further studies are needed to clearly define the dose-response relationships of higher potency steroids such as fluticasone, particularly on the steep part of the curve (for clinical efficacy), using the appropriate back-titration design along with sensitive measures of antiasthmatic and systemic activity.

Airway effects of salmeterol in healthy individuals

The long-acting beta 2-agonist salmeterol has been shown in several in vitro studies to produce non-beta-mediated relaxant effects. The aim of the present study was to investigate whether these effects have any relevance in humans in vivo. Thirteen healthy individuals were studied in a randomized, double-blind, cross-over study on five separate days. The subjects were pre-treated orally with either propranolol 400 mg in order to block beta-adrenoceptor mediated effects or placebo. Two hours after drug intake, three increasing doses of salmeterol (25 + 50 + 100 micrograms), salbutamol (100 + 200 + 400 micrograms) or placebo were given from matched meter dose inhalers at 1-h intervals between doses. Specific airway conductance (sGAW) was measured in a body plethysmograph at the beginning of the experiment and 30 and 60 min after each inhaled dose of the beta-agonists. Salmeterol and salbutamol produced the same maximal increase in sGAW and had the same area under the dose-response curves. Pre-treatment with propranolol totally inhibited the effect of both drugs. In conclusion, salmeterol at clinically used doses did not produce any non-beta-mediated bronchodilating effect in normal individuals, measured as sGAW. Salmeterol and salbutamol showed the same efficacy but salmeterol was four times more potent than salbutamol.