Safety of formoterol by Turbuhaler as reliever medication compared with terbutaline in moderate asthma

Inhaled Reliever Therapies for Asthma: A Systematic Review and Meta-Analysis

Importance

The optimal inhaled reliever therapy for asthma remains unclear.

Objective

To compare short-acting β agonists (SABA) alone with SABA combined with inhaled corticosteroids (ICS) and with the fast-onset, long-acting β agonist formoterol combined with ICS for asthma.

Data Sources

The MEDLINE, Embase, and CENTRAL databases were searched from January 1, 2020, to September 27, 2024, without language restrictions.

Study Selection

Pairs of reviewers independently selected randomized clinical trials evaluating (1) SABA alone, (2) ICS with formoterol, and (3) ICS with SABA (combined or separate inhalers).

Data Extraction and Synthesis

Two reviewers independently extracted data and assessed risk of bias. Random-effects meta-analyses synthesized outcomes. GRADE (Grading of Recommendations Assessment, Development, and Evaluation) was used to evaluate the certainty of evidence.

Main Outcomes and Measures

Asthma symptom control (5-item Asthma Control Questionnaire; range, 0-6, lower scores indicate better asthma control; minimum important difference [MID], 0.5 points), asthma-related quality of life (Asthma Quality of Life Questionnaire; range, 1-7, higher scores indicate better quality of life; MID, 0.5 points), risk of severe exacerbations, and risk of serious adverse events.

Results

A total of 27 randomized clinical trials (N = 50 496 adult and pediatric patients; mean age, 41.0 years; 20 288 male [40%]) were included. Compared with SABA alone, both ICS-containing relievers were associated with fewer severe exacerbations (ICS-formoterol risk ratio [RR], 0.65 [95% CI, 0.60-0.72]; risk difference [RD], -10.3% [95% CI, -11.8% to -8.3%]; ICS-SABA RR, 0.84 [95% CI, 0.73-0.95]; RD, -4.7% [95% CI, -8.0% to -1.5%]) with high certainty. Compared with SABA alone, both ICS-containing relievers were associated with improved asthma control (ICS-formoterol RR improvement [MID] in total score, 1.07 [95% CI, 1.04-1.10]; RD, 4.1% [95% CI, 2.3%-5.9%]; ICS-SABA RR, 1.09 [95% CI, 1.03-1.15]; RD, 5.4% [95% CI, 1.8%-8.5%]) with high certainty. In an indirect comparison with ICS-SABA, ICS-formoterol was associated with fewer severe exacerbations (RR, 0.78 [95% CI, 0.66-0.92]; RD, -5.5% [95% CI, -8.4% to -2.0%]) with moderate certainty. Compared with SABA alone, ICS-formoterol (RD, -0.6% [95% CI, -1.3% to 0%]) was not associated with increased risk of serious adverse events (high certainty) and ICS-SABA (RD, 0% [95% CI, -1.1% to 1.2%]) was not associated with increased risk of serious adverse events (moderate certainty).

Conclusions and Relevance

In this network meta-analysis of patients with asthma, ICS combined with formoterol and ICS combined with SABA were each associated with reduced asthma exacerbations and improved asthma control compared with SABA alone.

Self-titration of inhaled corticosteroid and β2-agonist in response to symptoms in mild asthma: a pre-specified analysis from the PRACTICAL randomised controlled trial

INTRODUCTION

In mild asthma, as-needed budesonide-formoterol is superior or noninferior to maintenance budesonide plus as-needed short-acting β₂-agonist in reducing severe exacerbations. In this pre-specified analysis, we investigated patterns of inhaled corticosteroid (ICS) and β₂-agonist use in PRACTICAL, a randomised controlled trial.

METHODS

Participants were randomised 1:1 to as-needed budesonide-formoterol (200/6 μg Turbuhaler, one actuation) or maintenance budesonide (200 μg Turbuhaler, one actuation twice a day) with as-needed terbutaline (250 μg, two actuations) for 52 weeks. 110 participants had electronic monitors attached to their study inhalers which captured the time and date of every actuation. Key outcome measures were patterns of ICS and β₂-agonist use. One actuation of budesonide-formoterol was considered to be an equivalent bronchodilator dose as two actuations of terbutaline.

RESULTS

Participants randomised to as-needed budesonide-formoterol had more days with no ICS use compared with maintenance budesonide (median total days of no use 156 versus 22 days, respectively), lower median daily budesonide dose (164 versus 328 μg, respectively) and a greater median number of days of ≥4 budesonide actuations (4 versus 1 days, respectively). Participants randomised to as-needed budesonide-formoterol took higher equivalent doses of β₂-agonist both overall (median number of actuations 0.8 versus 0.3 per day, respectively) and in response to worsening asthma (total number of "overuse days" of >8 or >16 actuations of budesonide-formoterol or terbutaline 33 versus 10 days, respectively).

CONCLUSIONS

The timing of ICS dose when self-titrated to β₂-agonist use is more important than total ICS dose in reducing severe exacerbation risk in mild asthma, when associated with greater overall use of as-needed β₂-agonist.

Formoterol as reliever medication in asthma: a post-hoc analysis of the subgroup of the RELIEF study in East Asia

Background

As-needed formoterol can effectively relieve asthma symptoms. Since budesonide/formoterol is available as maintenance and reliever therapy in Asia, formoterol is now being used as-needed, but always with concomitant inhaled corticosteroids. The objective of this analysis was to assess the safety and efficacy of formoterol therapy in patients in East Asia (China, Indonesia, Korea, the Philippines and Singapore) with asthma.

Methods

Post-hoc analyses of data from the East Asian population of the RELIEF (REal LIfe EFfectiveness of Oxis® Turbuhaler® as-needed in asthmatic patients; study identification code: SD-037-0699) study were performed.

Results

This sub-group comprised 2834 randomised patients (formoterol n = 1418; salbutamol n = 1416) with mean age 35 years; 50.7 % were male. 2678 patients completed the study. There was no significant difference in the total number of adverse events (AEs) reported in the formoterol and salbutamol groups (21.3 % vs 20.9 % of patients; p = 0.813), nor in the total number of serious AEs and/or discontinuations due to AEs (4.6 % vs 5.5 %, respectively; p = 0.323). Compared with salbutamol, formoterol was associated with a significantly longer time to first exacerbation (hazard ratio 0.86; p = 0.023) and a 14 % reduction in the risk of any exacerbation (p < 0.05). Relative to salbutamol, mean adjusted reliever medication use throughout the study was significantly lower in the formoterol group (p = 0.017) and the risk of increased asthma medication use was 20 % lower with formoterol (p = 0.005).

Conclusions

Among patients with asthma in East Asia, as-needed formoterol and salbutamol had similar safety profiles but, compared with salbutamol, formoterol reduced the risk of exacerbations, increased the time to first exacerbation and reduced the need for reliever medication.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0166-0) contains supplementary material, which is available to authorized users.

[A new fixed dose combination of fluticasone and formoterol in a pressurised metered-dose inhaler for the treatment of asthma]

The combination of an inhaled corticosteroid and a long acting beta-2 agonist is indicated for the regular treatment of persistent moderate-to-severe asthmatics whose asthma is not controlled by inhaled corticosteroids and the occasional use of a short acting beta-2 agonist. The aim of this review is to give an overview of the rationale of combining formoterol and fluticasone and to analyze the clinical data concerning a new fixed combination of fluticasone and formoterol in a pressurised metered-dose inhaler with a dose counter (Flutiform(®)) that was approved for the treatment of asthma in France in 2013. The clinical studies provide evidence that combined fluticasone/formoterol is more efficacious than fluticasone or formoterol given alone, and provides similar improvements in lung function to fluticasone (Flixotide(®)) and formoterol (Foradil(®)) administered concurrently. The combination of fluticasone/formoterol gave a more rapid bronchodilatation than the combination fluticasone/salmeterol. As a whole, the combination of fluticasone/formoterol had similar efficacy and tolerability profiles to the combinations of either budesonide/formoterol or fluticasone/salmeterol.

Combination formoterol and budesonide as maintenance and reliever therapy versus current best practice (including inhaled steroid maintenance), for chronic asthma in adults and children

BACKGROUND

Traditionally inhaled treatment for asthma has used separate preventer and reliever therapies. The combination of formoterol and budesonide in one inhaler has made possible a single inhaler for both prevention and relief of symptoms (single inhaler therapy or SiT).

OBJECTIVES

To assess the efficacy and safety of budesonide and formoterol in a single inhaler for maintenance and reliever therapy in asthma compared with maintenance with inhaled corticosteroids (ICS) (alone or as part of current best practice) and any reliever therapy.

SEARCH METHODS

We searched the Cochrane Airways Group trials register in February 2013.

SELECTION CRITERIA

Parallel, randomised controlled trials of 12 weeks or longer in adults and children with chronic asthma. Studies had to assess the combination of formoterol and budesonide as SiT, against a control group that received inhaled steroids and a separate reliever inhaler.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included 13 trials involving 13,152 adults and one of the trials also involved 224 children (which have been separately reported). All studies were sponsored by the manufacturer of the SiT inhaler. We considered the nine studies assessing SiT against best practice to be at a low risk of selection bias, but a high risk of detection bias as they were unblinded.In adults whose asthma was not well-controlled on ICS, the reduction in hospital admission with SiT did not reach statistical significance (Peto odds ratio (OR) 0.81; 95% confidence interval (CI) 0.45 to 1.44, eight trials, N = 8841, low quality evidence due to risk of detection bias in open studies and imprecision). The rates of hospital admission were low; for every 1000 people treated with current best practice six would experience a hospital admission over six months compared with between three and eight treated with SiT. The odds of experiencing exacerbations needing treatment with oral steroids were lower with SiT compared with control (OR 0.83; 95% CI 0.70 to 0.98, eight trials, N = 8841, moderate quality evidence due to risk of detection bias). For every 100 adults treated with current best practice over six months, seven required a course of oral steroids, whilst for SiT there would be six (95% CI 5 to 7). The small reduction in time to first severe exacerbation needing medical intervention was not statistically significant (hazard ratio (HR) 0.94; 95% CI 0.85 to 1.04, five trials, N = 7355). Most trials demonstrated a reduction in the mean total daily dose of ICS with SiT (mean reduction was based on self-reported data from patient diaries and ranged from 107 to 385 µg/day). Withdrawals due to adverse events were more common in people treated with SiT (OR 2.85; 95% CI 1.89 to 4.30, moderate quality evidence due to risk of detection bias).Three studies including 4209 adults compared SiT with higher dose budesonide maintenance and terbutaline for symptom relief. The studies were considered as low risk of bias. The run-in for these studies involved withdrawal of LABA, and patients were recruited who were symptomatic during run-in. The reduction in the odds of hospitalisation with SiT compared with higher dose ICS did not reach statistical significance (Peto OR; 0.56; 95% CI 0.28 to 1.09, moderate quality evidence due to imprecision). Fewer patients on SiT needed a course of oral corticosteroids (OR 0.54; 95% CI 0.45 to 0.64, high quality evidence). For every 100 adults treated with ICS over 11 months, 18 required a course of oral steroids, whilst for SiT there would be 11 (95% CI 9 to 12). Withdrawals due to adverse events were more common in people treated with SiT (OR 0.57; 95% CI 0.35 to 0.93, high quality evidence).One study included children (N = 224), in which SiT was compared with higher dose budesonide. There was a significant reduction in participants who needed an increase in their inhaled steroids with SiT, but there were only two hospitalisations for asthma and no separate data on courses of oral corticosteroids. Less inhaled and oral corticosteroids were used in the SiT group and the annual height gain was also 1 cm greater in the SiT group, (95% CI 0.3 cm to 1.7 cm).The results for fatal serious adverse events were too rare to rule out either treatment being harmful. There was no significant difference found in non-fatal serious adverse events for any of the comparisons.

AUTHORS' CONCLUSIONS

Single inhaler therapy has now been demonstrated to reduce exacerbations requiring oral corticosteroids against current best practice strategies and against a fixed higher dose of inhaled steroids. The strength of evidence that SiT reduces hospitalisation against these same treatments is weak. There were more discontinuations due to adverse events on SiT compared to current best practice, but no significant differences in serious adverse events. Our confidence in these conclusions is limited by the open-label design of the trials, and by the unknown adherence to treatment in the current best practice arms of the trials.Single inhaler therapy can reduce the risk of asthma exacerbations needing oral corticosteroids in comparison with fixed dose maintenance ICS and separate relief medication. The reduced odds of exacerbations with SiT compared with higher dose ICS should be viewed in the context of the possible impact of LABA withdrawal during study run-in. This may have made the study populations more likely to respond to SiT.Single inhaler therapy is not currently licensed for children under 18 years of age in the United Kingdom and there is currently very little research evidence for this approach in children or adolescents.

Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults

BACKGROUND

Daily inhaled corticosteroids (ICS) are the recommended mainstay of treatment in children and adults with persistent asthma. However, often, ICS are used intermittently by patients or recommended by physicians to be used only at the onset of exacerbations.

OBJECTIVES

The aim of this review was to compare the efficacy and safety of intermittent versus daily ICS in the management of children and adults with persistent asthma and preschool-aged children suspected of persistent asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov web site up to October 2012.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intermittent ICS versus daily ICS in children and adults with persistent asthma. No co-interventions were permitted other than rescue relievers and oral corticosteroids used during exacerbations.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data. The primary efficacy outcome was the number of patients with one or more exacerbations requiring oral corticosteroids and the primary safety outcome was the number of patients with serious adverse health events. Secondary outcomes included exacerbations, lung function tests, asthma control, adverse effects, withdrawal rates and inflammatory markers. Equivalence was assumed if the risk ratio (RR) estimate and its 95% confidence interval (CI) were between 0.9 and 1.1. Quality of the evidence was assessed using GRADE.

MAIN RESULTS

Six trials (including one trial testing two relevant protocols) met the inclusion criteria for a total of seven group comparisons. The four paediatric trials (two involving preschool children and two school-aged children) and two adult parallel-group trials, lasting 12 to 52 weeks, were of high methodological quality. A total of 1211 patients with confirmed, or suspected, persistent asthma contributed to the meta-analyses. There was no statistically significant group difference in the risk of patients experiencing one or more exacerbations requiring oral corticosteroids (1204 patients; RR 1.07; 95% CI 0.87 to 1.32; the large confidence interval translates into a risk of exacerbations in the intermittent ICS group varying between 17% and 25%, assuming a 19% risk with daily ICS). Age, severity of airway obstruction, step-up protocol used during exacerbations and trial duration did not significantly influence the primary efficacy outcome. No group difference was observed in the risk of patients with serious adverse health events (1055 patients; RR 0.82; 95% CI 0.33 to 2.03). Compared to the daily ICS group, the intermittent ICS group displayed a smaller improvement in change from baseline peak expiratory flow rate (PEFR) by 2.56% (95% CI -4.49% to -0.63%), fewer symptom-free days (standardised mean difference (SMD) -0.15 (95% CI -0.28 to -0.03), fewer asthma control days -9% (95% CI -14% to -4%), more use of rescue β2-agonists by 0.12 puffs/day (95% CI 0 to 0.23) and a greater increase from baseline in exhaled nitric oxide of 16.80 parts per billion (95% CI 11.95 to 21.64). There was no significant group difference in forced expiratory volume in one second (FEV1), quality of life, airway hyper-reactivity, adverse effects, hospitalisations, emergency department visits or withdrawals. In paediatric trials, intermittent ICS (budesonide and beclomethasone) were associated with greater growth by 0.41 cm change from baseline (532 children; 95% CI 0.13 to 0.69) compared to daily treatment.

AUTHORS' CONCLUSIONS

In children and adults with persistent asthma and in preschool children suspected of persistent asthma, there was low quality evidence that intermittent and daily ICS strategies were similarly effective in the use of rescue oral corticosteroids and the rate of severe adverse health events. The strength of the evidence means that we cannot currently assume equivalence between the two options.. Daily ICS was superior to intermittent ICS in several indicators of lung function, airway inflammation, asthma control and reliever use. Both treatments appeared safe, but a modest growth suppression was associated with daily, compared to intermittent, inhaled budesonide and beclomethasone. Clinicians should carefully weigh the potential benefits and harm of each treatment option, taking into account the unknown long-term (> one year) impact of intermittent therapy on lung growth and lung function decline.

Intermittent versus daily inhaled corticosteroids for persistent asthma in children and adults

BACKGROUND

Daily inhaled corticosteroids (ICS) are the recommended mainstay of treatment in children and adults with persistent asthma. Yet often, ICS are used intermittently by patients or recommended by physicians to be used only at the onset of exacerbations.

OBJECTIVES

The aim of this review was to compare the efficacy and safety of intermittent versus daily ICS in the management of children and adults with persistent asthma and preschool-aged children suspected of persistent asthma.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials (CAGR) and the ClinicalTrials.gov website up to December 2011.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared intermittent ICS versus daily ICS in children and adults with persistent asthma. No co-interventions were permitted other than rescue relievers and oral corticosteroids used during exacerbations.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, methodological quality and extracted data. The primary efficacy outcome was the number of patients with one or more exacerbations requiring oral corticosteroids and the primary safety outcome was the number of patients with serious adverse health events. Secondary outcomes included exacerbations, lung function tests, asthma control, adverse effects, withdrawal rates and inflammatory markers. Equivalence was assumed if the risk ratio (RR) estimate and its 95% confidence interval (CI) were between 0.9 and 1.1.

MAIN RESULTS

Six trials (including one trial testing two relevant protocols) met the inclusion criteria for a total of seven group comparisons. The four paediatric trials (two involving preschool children and two school-aged children) and two adult parallel-group trials, lasting 12 to 52 weeks, were of high methodological quality. A total of 1211 patients with confirmed, or suspected, persistent asthma contributed to the meta-analyses. There was no statistically significant group difference in the risk of patients experiencing one or more exacerbations requiring oral corticosteroids (1204 patients; RR 1.07; 95% CI 0.87 to 1.32). The patients' age, severity of airway obstruction, step-up protocol used during exacerbations and trial duration did not significantly influence the primary efficacy outcome. No group difference was observed in the risk of patients with serious adverse health events (1055 patients; RR 0.82; 95% CI 0.33 to 2.03). Compared to the daily ICS group, the intermittent ICS group displayed a smaller improvement in change from baseline peak expiratory flow rate (PEFR) by 2.56% (95% CI -4.49% to -0.63%), fewer symptom-free days (standardised mean difference (SMD) -0.15 (95% CI -0.28 to -0.03), fewer asthma control days -9% (95% CI -14% to -4%), more use of rescue β(2)-agonists by 0.12 puffs/day (95% CI 0 to 0.23) and a greater increase from baseline in exhaled nitric oxide of 16.80 parts per billion (95% CI 11.95 to 21.64). There was no significant group difference in forced expiratory volume in one second (FEV(1)), quality of life, airway hyper-reactivity, adverse effects, hospitalisations, emergency department visits or withdrawals. In paediatric trials, intermittent ICS (budesonide and beclomethasone) were associated with greater growth by 0.41 cm change from baseline (532 children; 95% CI 0.13 to 0.69) compared to daily treatment.

AUTHORS' CONCLUSIONS

In children and adults with persistent asthma and in preschool children suspected of persistent asthma, intermittent and daily ICS strategies did not significantly differ in the use of rescue oral corticosteroids and the rate of severe adverse health events, neither did they reach equivalence. Daily ICS was superior to intermittent ICS in several indicators of lung function, airway inflammation, asthma control and reliever use. Both treatments appeared safe, but a modest growth suppression was associated with daily, compared to intermittent, inhaled budesonide and beclomethasone. The clinician should carefully weigh the potential benefits and harm of each treatment option, taking into account the unknown long-term (> one year) impact of intermittent therapy on lung growth and lung function decline.

Use of metered-dose inhaler electronic monitoring in a real-world asthma randomized controlled trial

BACKGROUND

Electronic monitoring of inhaled asthma medications is one method to measure medication adherence and patterns of use. Information on the performance of monitors in a randomized controlled trial allows researchers and clinicians to understand their utility and limitations. The Smartinhaler Tracker is an electronic monitor for metered-dose inhalers (MDIs) that records the date, time, and number of actuations.

OBJECTIVE

To determine the performance of the Smartinhaler monitors used in a 24-week randomized controlled trial of 303 patients with asthma in a real-world setting.

METHODS

Prestudy use checks involved 2 actuations of the MDI, with a further 2 performed 2 hours later. Within-study monitor checks, performed before dispensing at clinic visits 2 to 4, included a computerized check of monitor clock function, actuation accuracy, and battery life. Within-study data checks involved computerized checks of monitor clock function before data upload.

RESULTS

Two thousand six hundred seventy-eight of 2728 monitors (98.2%) passed prestudy use checks. Seventy-six of 2642 monitors (2.9%) dispensed to participants failed within-study monitor checks. Fifty-one of 2642 monitors (1.9%) malfunctioned before data upload, mostly as a result of fluid immersion. Ninety-three of 2642 monitors (3.5%) were lost or thrown away by participants. Complete data was available from 2498 of 2642 dispensed monitors (94.5%) and 2498 of 2549 returned monitors (98.0%).

CONCLUSIONS

The Smartinhaler Tracker is a reliable monitor for measuring MDI use in a real-world setting. Use of extensive monitor and data-checking protocols reduces data loss. In a research or clinical setting, the use of a validated and reliable electronic monitor represents the reference standard for assessing patterns of medication use.

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.

Formoterol versus short-acting beta-agonists as relief medication for adults and children with asthma

BACKGROUND

Formoterol is a long-acting beta(2)-agonist but because it has a fast onset of action it can also be used as a relief medication.

OBJECTIVES

To asses the efficacy and safety of formoterol as reliever therapy in comparison to short-acting beta(2)-agonists in adults and children with asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register and websites of clinical trial registers (for unpublished trial data), and we checked the Food and Drug Administration (FDA) submissions in relation to formoterol. The date of the most recent search was February 2010.

SELECTION CRITERIA

Randomised, parallel-arm trials of at least 12 weeks duration in patients of any age and severity of asthma. Studies randomised patients to any dose of as-needed formoterol versus short-acting beta(2)-agonist. Concomitant use of inhaled corticosteroids or other maintenance medication 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. We sought unpublished data on primary outcomes.

MAIN RESULTS

This review includes eight studies conducted in 22,604 participants (mostly adults). Six studies compared formoterol as-needed to terbutaline whilst two studies compared formoterol with salbutamol as-needed. Background maintenance therapy varied across the trials. Asthma exacerbations and serious adverse events showed a direction of treatment effect favouring formoterol, of which one outcome reached statistical significance (exacerbations requiring a course of oral corticosteroids). In patients on short-acting beta(2)-agonists, 117 people out of 1000 had exacerbations requiring oral corticosteroids over 30 weeks, compared to 101 (95% CI 93 to 108) out of 1000 for patients on formoterol as-needed. In patients on maintenance inhaled corticosteroids there were also significantly fewer exacerbations requiring a course of oral corticosteroids on formoterol as-needed (Peto OR 0.75; 95% CI 0.62 to 0.91). There was one death per 1000 people on formoterol or on short-acting beta(2)-agonists.

AUTHORS' CONCLUSIONS

In adults, formoterol was similar to short-acting beta(2)-agonists when used as a reliever, and showed a reduction in the number of exacerbations requiring a course of oral corticosteroids. Clinicians should weigh the relatively modest benefits of formoterol as-needed against the benefits of single inhaler therapy and the potential danger of long-term use of long-acting beta(2)-agonists in some patients. We did not find evidence to recommend changes to guidelines that suggest that long-acting beta(2)-agonists should be given only to patients already taking inhaled corticosteroids.There was insufficient information reported from children in the included trials to come to any conclusion on the safety or efficacy of formoterol as relief medication for children with asthma.

Addition of long-acting beta2-agonists to inhaled corticosteroids versus same dose inhaled corticosteroids for chronic asthma in adults and children

BACKGROUND

Long-acting inhaled ss(2)-adrenergic agonists (LABAs) are recommended as 'add-on' medication to inhaled corticosteroids (ICS) in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of LABAs to ICS in patients insufficiently controlled on ICS alone.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

We included RCTs if they compared the addition of inhaled LABAs versus placebo to the same dose of ICS in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the relative risk (RR) of asthma exacerbations requiring rescue oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), rescue beta2-agonist use, symptoms, withdrawals and adverse events.

MAIN RESULTS

Seventy-seven studies met the entry criteria and randomised 21,248 participants (4625 children and 16,623 adults). Participants were generally symptomatic at baseline with moderate airway obstruction despite their current ICS regimen. Formoterol or salmeterol were most frequently added to low-dose ICS (200 to 400 microg/day of beclomethasone (BDP) or equivalent) in 49% of the studies. The addition of a daily LABA to ICS reduced the risk of exacerbations requiring oral steroids by 23% from 15% to 11% (RR 0.77, 95% CI 0.68 to 0.87, 28 studies, 6808 participants). The number needed to treat with the addition of LABA to prevent one use of rescue oral corticosteroids is 41 (29, 72), although the event rates in the ICS groups varied between 0% and 38%. Studies recruiting adults dominated the analysis (6203 adult participants versus 605 children). The subgroup estimate for paediatric studies was not statistically significant (RR 0.89, 95% CI 0.58 to 1.39) and includes the possibility of the superiority of ICS alone in children.Higher than usual dose of LABA was associated with significantly less benefit. The difference in the relative risk of serious adverse events with LABA was not statistically significant from that of ICS alone (RR 1.06, 95% CI 0.87 to 1.30). The addition of LABA led to a significantly greater improvement in FEV(1) (0.11 litres, 95% 0.09 to 0.13) and in the proportion of symptom-free days (11.88%, 95% CI 8.25 to 15.50) compared to ICS monotherapy. It was also associated with a reduction in the use of rescue short-acting ss(2)-agonists (-0.58 puffs/day, 95% CI -0.80 to -0.35), fewer withdrawals due to poor asthma control (RR 0.50, 95% CI 0.41 to 0.61), and fewer withdrawals due to any reason (RR 0.80, 95% CI 0.75 to 0.87). There was no statistically significant group difference in the risk of overall adverse effects (RR 1.00, 95% 0.97 to 1.04), withdrawals due to adverse health events (RR 1.04, 95% CI 0.86 to 1.26) or any of the specific adverse health events.

AUTHORS' CONCLUSIONS

In adults who are symptomatic on low to high doses of ICS monotherapy, the addition of a LABA at licensed doses reduces the rate of exacerbations requiring oral steroids, improves lung function and symptoms and modestly decreases use of rescue short-acting ss(2)-agonists. In children, the effects of this treatment option are much more uncertain. The absence of group difference in serious adverse health events and withdrawal rates in both groups provides some indirect evidence of the safety of LABAs at usual doses as add-on therapy to ICS in adults, although the width of the confidence interval precludes total reassurance.

Addition of long-acting beta2-agonists to inhaled steroids versus higher dose inhaled steroids in adults and children with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled ss2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine the effect of the combination of long-acting ss(2) agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the risk of asthma exacerbations, pulmonary function and on other measures of asthma control, and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs, clinical trial registries and correspondence with manufacturers until May 2008.

SELECTION CRITERIA

RCTs that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed methodological quality and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was the number of patients experiencing one or more asthma exacerbations requiring oral corticosteroids.

MAIN RESULTS

This review included 48 studies (15,155 participants including 1155 children and 14,000 adults). Participants were inadequately controlled on their current ICS regimen, experiencing ongoing symptoms and with generally moderate (FEV1 60% to 79% of predicted) airway obstruction. The studies tested the combination of salmeterol or formoterol with a median dose of 400 mcg/day of beclomethasone or equivalent (BDP-eq) compared to a median of 1000 mcg/day of BDP-eq, usually for 24 weeks or less. There was a statistically significantly lower risk of exacerbations requiring systemic corticosteroids in patients treated with LABA and ICS (RR 0.88, 95% CI 0.78 to 0.98, 27 studies, N = 10,578) from 11.45% to 10%, with a number needed to treat of 73 (median study duration: 12 weeks). The study results were dominated by adult studies; trial data from three paediatric studies showed a trend towards increased risk of rescue oral steroids (RR 1.24, 95% CI 0.58 to 2.66) and hospital admission (RR 2.21, 95% CI 0.74 to 6.64) associated with combination therapy. Overall, there was no statistically significant difference in the risk ratios for either hospital admission (RR 1.02, 95% CI 0.67 to 1.56) or serious adverse events (RR 1.12, 95% CI 0.91 to 1.37). The combination of LABA and ICS resulted in significantly greater but modest improvement from baseline in lung function, symptoms and rescue medication use than with higher ICS dose. Despite no significant group difference in the risk of overall adverse events (RR 0.99, 95% CI 0.95 to 1.03), there was an increase in the risk of tremor (RR 1.84, 95% CI 1.20 to 2.82) and a lower risk of oral thrush (RR 0.58, 95% CI 0.40 to 0.86)) in the LABA and ICS compared to the higher ICS group. There was no significant difference in hoarseness or headache between the treatment groups. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS (RR 0.65, 95% CI 0.51 to 0.83).

AUTHORS' CONCLUSIONS

In adolescents and adults with sub-optimal control on low dose ICS monotherapy, the combination of LABA and ICS is modestly more effective in reducing the risk of exacerbations requiring oral corticosteroids than a higher dose of ICS. Combination therapy also led to modestly greater improvement in lung function, symptoms and use of rescue ss(2) agonists and to fewer withdrawals due to poor asthma control than with a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor and less oral candidiasis with combination therapy, the two options appear relatively safe in adults although adverse effects associated with long-term ICS treatment were seldom monitored. In children, combination therapy did not lead to a significant reduction, but rather a trend towards an increased risk, of oral steroid-treated exacerbations and hospital admissions. These trends raised concern about the safety of combination therapy in view of modest improvement in children under the age of 12 years.

A randomized, comparative study of formoterol and terbutaline dry powder inhalers in the treatment of mild to moderate asthma exacerbations in the pediatric acute care setting

BACKGROUND

Formoterol is a fast-acting, long-acting beta-agonist. Its on-demand use by outpatients has been beneficial in controlling asthma.

OBJECTIVE

To evaluate the efficacy of formoterol as rescue medication for pediatric asthma exacerbation.

METHODS

A randomized, double-blind study was conducted on parallel groups involving 79 pediatric patients (mean [SD] age, 9.92 [2.5] years) with mild to moderate asthma exacerbations. They were treated with up to 3 doses of formoterol aerolizer, 12 microg, or terbutaline Turbuhaler, 0.5 mg (dry powder inhalers). Respiratory rate, clinical score, pulse oximetry, and spirometry were analyzed at baseline and 15 minutes after administration of each bronchodilator dose. All the patients received oral prednisolone, 1 mg/kg, at study entry, followed by a single daily dose for 4 days. Forty-one patients were treated with formoterol and 38 with terbutaline. The groups were comparable in age and in severity of asthma exacerbation.

RESULTS

Both treatments resulted in similar clinical and functional improvement; 37 patients (47%) required 1 bronchodilator dose. Increases of 19.5% and 15.3% occurred in forced expiratory volume in 1 second in the formoterol and terbutaline groups, respectively. Therapeutic failures occurred in 2 patients. No adverse effects were observed. At 1-week follow-up, patients were stable, with pulmonary function close to normal.

CONCLUSION

Formoterol therapy was at least as effective as terbutaline therapy in children and adolescents with mild and moderate asthma exacerbations.

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults and children

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled ss2-agonists (LABA) only in asthmatic patients who are inadequately controlled on inhaled corticosteroids (ICS). It is not uncommon for some patients to be commenced on ICS and LABA together as initial therapy.

OBJECTIVES

To compare the efficacy of combining inhaled corticosteroids with long-acting ss2-agonists (ICS+LABA) with inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma. We assessed two protocols: (1) LABA + ICS versus a similar dose of ICS (comparison 1) and (2) LABA + ICS versus a higher dose of ICS (comparison 2).

SEARCH STRATEGY

We identified randomised controlled trials through electronic database searches (May 2008).

SELECTION CRITERIA

Randomised trials comparing ICS + LABA with ICS alone in children and adults with asthma who had no inhaled corticosteroids in the preceding 28 days prior to enrolment.

DATA COLLECTION AND ANALYSIS

Each author assessed studies independently for risk of bias and extracted data. We obtained confirmation from the trialists when possible. The primary endpoint was rate of patients with one or more asthma exacerbations requiring rescue systemic corticosteroids. Results are expressed as relative risks (RR) for dichotomous data and as mean differences (MD) or standardised mean differences (SMD) for continuous data.

MAIN RESULTS

Twenty-eight study comparisons drawn from 27 trials (22 adult; five paediatric) met the review entry criteria (8050 participants). Baseline data from the studies indicated that trial populations had moderate or mild airway obstruction (FEV1>/=65% predicted), and that they were symptomatic prior to randomisation. In comparison 1, the combination of ICS and LABA was not associated with a significantly lower risk of patients with exacerbations requiring oral corticosteroids (RR 1.04; 95% confidence interval (CI) 0.73 to 1.47) or requiring hospital admissions (RR 0.38; 95% CI 0.09 to 1.65) compared to a similar dose of ICS alone. The combination of LABA and ICS led to a significantly greater improvement from baseline in FEV1 (0.12 L/sec; 95% CI 0.07 to 0.17), in symptoms (SMD -0.26; 95% CI -0.37 to -0.14) and in rescue ss2-agonist use (-0.41 puffs/day; 95% CI -0.73 to -0.09) compared with a similar dose of ICS alone. There was no significant group difference in the risk of serious adverse events (RR 1.15; 95% CI 0.64 to 2.09), any adverse events (RR 1.02; 95% CI 0.96 to 1.09), study withdrawals (RR 0.95; 95% CI 0.82 to 1.11), or withdrawals due to poor asthma control (RR 0.94; 95% CI 0.63 to 1.41).In comparison 2, the combination of LABA and ICS was associated with a higher risk of patients requiring oral corticosteroids (RR 1.24; 95% CI 1 to 1.53) and study withdrawal (RR 1.31; 95% CI 1.07 to 1.59) than a higher dose of ICS alone. For every 100 patients treated over 43 weeks, nine patients using a higher dose ICS compared to 11 (95% CI 9 to 14) on LABA and ICS suffered one or more exacerbations requiring rescue oral corticosteroids. There was a high level of statistical heterogeneity for FEV1 and morning peak flow. There was no statistically significant group difference in the risk of serious adverse events. Due to insufficient data we could not aggregate results for hospital admission, symptoms and other outcomes.

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the combination of ICS and LABA does not significantly reduce the risk of patients with exacerbations requiring rescue oral corticosteroids over that achieved with a similar dose of ICS alone. However, it significantly improves lung function, reduces symptoms and marginally decreases rescue ss2-agonist use. Initiation of a higher dose of ICS is more effective at reducing the risk of exacerbations requiring rescue systemic corticosteroids, and of withdrawals, than combination therapy. Although children appeared to respond similarly to adults, no firm conclusions can be drawn regarding combination therapy in steroid-naive children, given the small number of children contributing data.

Effects of formoterol on contraction and Ca2+ signaling of mouse airway smooth muscle cells

Formoterol, a long-acting beta(2)-receptor agonist, is used to relieve bronchial constriction. However, formoterol is often a racemic formulation, and contains both (R,R)- and (S,S)-enantiomers. Because the activity of each isomer is poorly defined, the mechanisms by which formoterol relaxes smooth muscle cells (SMCs) of intrapulmonary airways are not well understood. Consequently, we compared the effects of (S,S)-, (R,R)-, and racemic formoterol, as well as (R)-albuterol, on the contraction and Ca(2+) signaling of airway SMCs in mouse lung slices with phase-contrast and confocal microscopy. Small airways were contracted with methacholine and the associated SMCs displayed sustained Ca(2+) oscillations and an increase in Ca(2+) sensitivity. These contracted airways displayed a substantial, concentration-dependent relaxation in response to (R,R)-formoterol. Racemic formoterol had a similar potency as (R,R)-formoterol for relaxing airways. By contrast, (S,S)-formoterol only induced a small relaxation. In conjunction with relaxation, (R,R)- and racemic formoterol stopped and decreased the methacholine-induced Ca(2+) oscillations and Ca(2+) sensitivity of the SMCs, respectively, whereas (S,S)-formoterol only decreased the Ca(2+) sensitivity. In these studies, (R,R)- and racemic formoterol had a similar, but much greater, potency than (R)-albuterol for relaxing mice airways. This action was quickly initiated at high concentrations by decreasing the frequency of Ca(2+) oscillations, but was more usually mediated at lower concentrations by decreasing the Ca(2+) sensitivity of the SMCs.

Combination formoterol and budesonide as maintenance and reliever therapy versus inhaled steroid maintenance for chronic asthma in adults and children

BACKGROUND

Traditionally inhaled treatment for asthma has been considered as preventer and reliever therapy. The combination of formoterol and budesonide in a single inhaler introduces the possibility of using a single inhaler for both prevention and relief of symptoms (single inhaler therapy).

OBJECTIVES

The aim of this review is to compare formoterol and corticosteroid in single inhaler for maintenance and relief of symptoms with inhaled corticosteroids for maintenance and a separate reliever inhaler.

SEARCH STRATEGY

We last searched the Cochrane Airways Group trials register in September 2008.

SELECTION CRITERIA

Randomised controlled trials in adults and children with chronic asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and extracted the characteristics and results of each study. Authors or manufacturers were asked to supply unpublished data in relation to primary outcomes.

MAIN RESULTS

Five studies on 5,378 adults compared single inhaler therapy with current best practice, and did not show a significant reduction in participants with exacerbations causing hospitalisation (Peto OR 0.59; 95% CI 0.24 to 1.45) or treated with oral steroids (OR 0.83; 95% CI 0.66 to 1.03). Three of these studies on 4281 adults did not show a significant reduction in time to first severe exacerbation needing medical intervention (HR 0.96; 95% CI 0.85 to 1.07). These trials demonstrated a reduction in the mean total daily dose of inhaled corticosteroids with single inhaler therapy (mean reduction ranged from 107 to 267 micrograms/day, but the trial results were not combined due to heterogeneity). The full results from four further studies on 4,600 adults comparing single inhaler therapy with current best practice are awaited.Three studies including 4,209 adults compared single inhaler therapy with higher dose budesonide maintenance and terbutaline for symptom relief. No significant reduction was found with single inhaler therapy in the risk of patients suffering an asthma exacerbation leading to hospitalisation (Peto OR 0.56; 95% CI 0.28 to 1.09), but fewer patients on single inhaler therapy needed a course of oral corticosteroids (OR 0.54; 95% CI 0.45 to 0.64). These results translate into an eleven month number needed to treat of 14 (95% CI 12 to 18), to prevent one patient being treated with oral corticosteroids for an exacerbation. The run-in for these studies involved withdrawal of long-acting beta(2)-agonists, and patients were recruited who were symptomatic during run-in.One study included children (N = 224), in which single inhaler therapy was compared to higher dose budesonide. There was a significant reduction in participants who needed an increase in their inhaled steroids with single inhaler therapy, but there were only two hospitalisations for asthma and no separate data on courses of oral corticosteroids. Less inhaled and oral corticosteroids were used in the single inhaler therapy group and the annual height gain was also 1 cm greater in the single inhaler therapy group, [95% CI 0.3 to 1.7 cm].There was no significant difference found in fatal or non-fatal serious adverse events for any of the comparisons.

AUTHORS' CONCLUSIONS

Single inhaler therapy can reduce the risk of asthma exacerbations needing oral corticosteroids in comparison with fixed dose maintenance inhaled corticosteroids. Guidelines and common best practice suggest the addition of regular long-acting beta(2)-agonist to inhaled corticosteroids for uncontrolled asthma, and single inhaler therapy has not been demonstrated to significantly reduce exacerbations in comparison with current best practice, although results of five large trials are awaiting full publication. Single inhaler therapy is not currently licensed for children under 18 years of age in the United Kingdom.

Combination formoterol and inhaled steroid versus beta2-agonist as relief medication for chronic asthma in adults and children

BACKGROUND

Formoterol has a fast onset of action and can therefore be used to relieve symptoms of asthma. A combination inhaler can deliver formoterol with different doses of inhaled corticosteroid; when used as a reliever both drugs will be delivered more frequently when asthma symptoms increase. This has the potential to treat both bronchoconstriction and inflammation in the early stages of exacerbations.

OBJECTIVES

To assess the efficacy and safety of combined inhalers containing both formoterol and an inhaled corticosteroid when used for reliever therapy in adults and children with chronic asthma.

SEARCH STRATEGY

We last searched the Cochrane Airways Group trials register in April 2008.

SELECTION CRITERIA

Randomised trials in adults and children with chronic asthma, where a combination inhaler containing formoterol and inhaled corticosteroid is compared with fast-acting beta2-agonist alone for the relief of asthma symptoms. This should be the only planned difference between the trial arms.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the characteristics and results of each study. Authors or manufacturers were asked to supply unpublished data in relation to primary outcomes.

MAIN RESULTS

Three trials involving 5905 participants were included. In patients with mild asthma who do not need maintenance treatment, no clinically important advantages of budesonide/formoterol as reliever were found in comparison to formoterol as reliever.Two studies enrolled patients with more severe asthma who were not controlled on high doses of inhaled corticosteroids (around 700 mcg/day in adults), and had suffered a clinically important asthma exacerbation in the past year. Hospitalisations related to asthma in the two studies comparing budesonide/formoterol for maintenance and relief with the same dose of budesonide/formoterol for maintenance with terbutaline for relief yielded an odds ratio of 0.68 (95% CI 0.40 to 1.16), which was not a statistically significant reduction. One adult study found a reduction in exacerbations requiring oral corticosteroids compared to terbutaline, odds ratio 0.56 (95% CI 0.42 to 0.74) and the study in children found less serious adverse events with budesonide/formoterol used for maintenance and relief. There was no significant difference in annual growth in children using budesonide/formoterol reliever in comparison to terbutaline.

AUTHORS' CONCLUSIONS

In mild asthma it is not yet known whether patients who use a budesonide/formoterol inhaler for relief of asthma symptoms derive any clinically important benefits. In more severe asthma, one study that enrolled patients who were not controlled on quite high doses of inhaled corticosteroids, and had suffered an exacerbation in the previous year, demonstrated a reduction in the risk of exacerbations that require oral corticosteroids with budesonide/formoterol for maintenance and relief in comparison with budesonide/formoterol for maintenance and terbutaline or formoterol for relief. The incidence of serious adverse events in children was also less using budesonide/formoterol for maintenance and relief in one study, which similarly enrolled children who were not controlled on medium to high doses of inhaled corticosteroids, and compared to terbutaline relief with an explorative maintenance dose of budesonide/formoterol that is not approved for treatment.

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.

Poor adherence with inhaled corticosteroids for asthma: can using a single inhaler containing budesonide and formoterol help?

BACKGROUND

Poor adherence with inhaled corticosteroids is an important problem in asthma management. Previous approaches to improving adherence have had limited success.

AIM

To determine whether treatment with a single inhaler containing a long-acting beta(2)-agonist and a corticosteroid for maintenance treatment and symptom relief can overcome the problem of poor adherence with inhaled corticosteroids.

DESIGN OF STUDY

Randomised, parallel group, open-label trial.

SETTING

Forty-four general practices in Nottinghamshire.

METHOD

Participants who used less than 70% of their prescribed dose of inhaled corticosteroid and had poorly controlled asthma were randomised to budesonide 200 microg one puff twice daily plus their own short-acting beta(2)-agonist as required (control group), or budesonide/formoterol 200/6 microg one puff once daily and as required (active group) for 6 months. The primary outcome was inhaled corticosteroid dose.

RESULTS

Seventy-one participants (35 control, 36 active group) were randomised. Adherence with budesonide in the control group was approximately 60% of the prescribed dose. Participants in the active group used approximately 80% more budesonide than participants in the control group (448 versus 252 microg/day, mean difference 196 mug, 95% confidence interval 113 to 279; P<0.001) and were less likely to withdraw from the study (3 versus 13; P<0.01). No safety issues were identified.

CONCLUSION

Using a single inhaler for both maintenance treatment and symptom relief approximately doubled the dose of inhaled corticosteroid taken, suggesting this could be a useful strategy to overcome the problems related to poor adherence with inhaled corticosteroids.

Tolerability of high cumulative doses of the HFA modulite beclomethasone dipropionate/formoterol combination inhaler in asthmatic patients

The corticosteroid beclomethasone dipropionate (BDP) has been formulated with the long acting beta agonist formoterol (BDP/formoterol 100 microg/6 microg, Foster) in a single inhaler using Modulite technology. We have investigated the acute tolerability of high, cumulative doses of BDP/formoterol compared to formoterol alone and placebo. This was a double blind, 3-way cross-over comparison of 10 puffs of BDP/formoterol 100 microg/6 microg or formoterol 6 microg or placebo during maintenance treatment with BDP/formoterol two puffs per day. Pharmacokinetics over 12h during maintenance treatment was measured on day 7. High cumulative doses were then administered on three separated days. Eighteen patients with asthma were recruited (mean FEV(1) 65% predicted). The primary endpoint was serum potassium over the 12h period after high doses. QTc, blood pressure and heart rate over 12h, and plasma lactate and glucose over 3h following dosing were assessed. Formoterol caused a significantly greater decrease in serum potassium than BDP/formoterol or placebo (difference in mean minimum concentrations; 0.11 and -0.15 mmol/l, respectively, p<0.05 for both comparisons). No significant differences in serum potassium parameters were found between BDP/formoterol and placebo. QTc, plasma lactate and vital signs values observed with the combination were not statistically different from those with formoterol alone. For glucose, the mean maximum increase after formoterol treatment was 0.4 mmol/l (p<0.01 compared to placebo), while BDP/formoterol treatment caused a maximum increase of 0.7 mmol/l (p<0.01 compared to formoterol and placebo). The active metabolite of BDP is beclomethasone-17-monopropriate (B17MP), which reached Cmax at 0.25 h, with an elimination half-life of 3.7 h. Formoterol also reached Cmax at 0.25 h, and concentrations were measurable up to 12 h. High doses of BDP/formoterol did not significantly reduce serum potassium, while formoterol alone did to a greater extent. The BDP/formoterol combination was well tolerated, and exhibited a safety profile generally similar to formoterol alone when administered in high doses to stable asthmatic patients.

Peak inspiratory flow rate after methacholine challenge in asthmatic patients and its impact on the effect of formoterol via different inhalers

The goal of the present study was to investigate the bronchodilating effects of 6 and 12 microg formoterol delivered by the Turbuhaler, in comparison to salbutamol 200 microg (metered dose inhaler) and to controls without treatment. After inducing acute and severe bronchial obstruction by means of methacholine challenge, peak inspiratory mouth flow (PIMF) was measured through a stenosis, simulating the internal resistance of the Turbuhaler, with the in-check device. In addition the relationship was studied between PIMF and clinical response in the 3 treatment groups. In the 176 patients methacholine caused a mean fall in FEV(1) of 37.1 +/- 6.9% compared to baseline. Ten minutes after bronchodilator inhalation, FEV(1) improved significantly in all three treatment groups. At 30 minutes after bronchodilator administration, only the salbutamol 200 microg and the formoterol 12 microg groups had a significantly greater increase in FEV1 than controls (0.69 +/- 0.43 l and 0.66 +/- 0.37 l vs 0.38 +/- 0.32 l, p < 0.0005), whereas the formoterol 6 microg group showed no significant improvement (0.41 +/- 0.38 l, p = 0.74). Thirteen patients (7.4%) did not reach a minimal PIMF of 30 l/min through the in-check device after challenge. In the four patients in the formoterol 6 microg group with a PIMF below 30 l/min inhalation did not cause bronchodilation. In conclusion, the results demonstrate that 6 microg formoterol via Turbuhaler leads to less and slower onset of bronchodilation compared to the other groups in our setting. If patients fail to generate a PIMF of 30 l/min, 6 microg formoterol via Turbuhaler may provide inadequate relief in a severe asthma attack.

The use of inhaled formoterol in the treatment of asthma

OBJECTIVE

To discuss the clinical efficacy and safety of formoterol when used to relieve symptoms of asthma and prevent exercise-induced bronchoconstriction (EIB).

DATA SOURCES

A PubMed search was performed for articles published between 1997 and 2005 with the keywords formoterol, asthma, and long-acting beta2-adrenergic agonist, with cross-referencing to identify peer-reviewed journal articles.

STUDY SELECTION

Published articles on the clinical use of formoterol for asthma or EIB were included as well as articles detailing the pharmacologic properties of the drug. To present a thorough review of the literature, published studies based on patient number, study design, or other measures of study quality were not excluded.

RESULTS

Formoterol is the only long-acting beta2-adrenergic agonist that combines a rapid onset of action (within 3 minutes) with a long duration of effect (approximately 12 hours). Clinically, as recommended by asthma treatment guidelines, formoterol in conjunction with inhaled corticosteroids (ICSs) is a preferred treatment for moderate to severe persistent asthma. Significant clinical data support the use of formoterol in combination with ICSs for the treatment of asthma, with studies demonstrating improved pulmonary function and symptom scores and decreased need for maintenance ICSs and short-acting beta2-adrenergic agonists (SABAs) as relief medication. Recent studies also demonstrate that use of formoterol as needed as relief medication is associated with a prolonged time to exacerbation, improved pulmonary function, and decreased asthma symptoms. When used as monotherapy, formoterol provides protection against EIB. Clinical data also demonstrate that formoterol is safe and well tolerated even in high doses, with an adverse event profile similar to that of SABAs.

CONCLUSION

Overall, formoterol is safe and effective as adjunct controller therapy for moderate and severe persistent asthma and as monotherapy for EIB.

Pharmacological management of mild or moderate persistent asthma

Patients with mild persistent asthma rarely see their doctor with symptoms of the disease. Partly as a result of this situation, mild asthma is generally undertreated. Findings of several large randomised clinical trials have shown benefits for this population of regular treatment with low doses of inhaled corticosteroids. Additional drugs are rarely needed, and although leukotriene modifiers are effective, they are less so than inhaled corticosteroids. People with moderate persistent asthma are not well controlled on low doses of inhaled corticosteroids. A combination of this drug and long-acting inhaled beta2 agonists provides improved control compared with doubling of the maintenance dose of inhaled corticosteroids. The combination of budesonide and formoterol has been assessed as both maintenance and reliever treatment. This approach further reduces the risk for severe exacerbations. With these strategies, most individuals can achieve good control of their asthma. For patients who do not achieve asthma control despite taking drugs, measurement of the inflammatory response in the airway in induced sputum could provide further information to guide treatment.

Long-acting beta2-agonists versus placebo in addition to inhaled corticosteroids in children and adults with chronic asthma

BACKGROUND

Long-acting inhaled beta2-adrenergic agonists are recommended as 'add-on' medication to inhaled corticosteroids in the maintenance therapy of asthmatic adults and children aged two years and above.

OBJECTIVES

To quantify in asthmatic patients the safety and efficacy of the addition of long-acting beta2-agonists to inhaled corticosteroids on the incidence of asthma exacerbations, pulmonary function and other measures of asthma control.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (the Cochrane Airways Group Specialised Register, MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers, until April 2004.

SELECTION CRITERIA

RCTs were included that compared the addition of inhaled long-acting beta2-agonists to corticosteroids with inhaled corticosteroids alone for asthma therapy in children aged two years and above and in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by two review authors for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of asthma exacerbations requiring systemic corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptom scores, adverse events and withdrawal rates.

MAIN RESULTS

Of 594 identified citations, 49 trials met the inclusion criteria: 27 full-text publications, one unpublished full-text report and 21 abstracts. Twenty-three citations (21 abstracts and two full-text publications) provided data in insufficient detail, 26 trials contributed to this systematic review. All but three trials were of high methodological quality. Most interventions (N = 26) were of four-month duration or less. Eight trials focused on children and 18 on adults, with participants generally symptomatic with moderate airway obstruction despite their current inhaled steroid regimen. If a trial had more than one intervention or control group, additional control to intervention comparisons were considered separately. Formoterol (N = 17) or salmeterol (N = 14) were most frequently added to low-dose inhaled corticosteroids (200 to 400 microg/day of beclomethasone (BDP) or equivalent). The addition of a daily long-acting beta2-agonist (LABA) reduced the risk of exacerbations requiring systemic steroids by 19% (relative risk (RR) 0.81, 95% CI 0.73 to 0.90). The number needed to treat for one extra patient to be free from exacerbation for one year was 18 (95% CI 13 to 33). The addition of LABA significantly improved FEV1 (weighted mean difference (WMD) 170 mL, 95% CI 110 to 240) using a random-effects model, increased the proportion of symptom-free days (WMD 17%, 95% CI 12 to 22, N = 6 trials) and rescue-free days (WMD 19%, 95% CI 12 to 26, N = 2 trials). The group treated with LABA plus inhaled corticosteroid showed a reduction in the use of rescue short-acting beta2-agonists (WMD -0.7 puffs/day, 95% CI -1.2 to -0.2), experienced less withdrawals due to poor asthma control (RR 0.5, 95% CI 0.4 to 0.7) and less withdrawals due to any reason (RR 0.9, 95% CI 0.8 to 0.98), using a random-effects model. There was no group difference in risk of overall adverse effects (RR 0.98, 95% CI 0.92 to 1.05), withdrawals due to adverse health events (RR 1.29, 95% CI 0.96 to 1.75) or specific adverse health events.

AUTHORS' CONCLUSIONS

In patients who are symptomatic on low to high doses of inhaled corticosteroids, the addition of a long-acting beta2-agonist reduces the rate of exacerbations requiring systemic steroids, improves lung function, symptoms and use of rescue short-acting beta2-agonists. The similar number of serious adverse events and withdrawal rates in both groups provides some indirect evidence of the safety of long-acting beta2-agonists as add-on therapy to inhaled corticosteroids.

Combination of inhaled long-acting beta2-agonists and inhaled steroids versus higher dose of inhaled steroids in children and adults with persistent asthma

BACKGROUND

In asthmatic patients inadequately controlled on inhaled corticosteroids and/or those with moderate persistent asthma, two main options are recommended: the combination of a long-acting inhaled beta2 agonist (LABA) with inhaled corticosteroids (ICS) or use of a higher dose of inhaled corticosteroids.

OBJECTIVES

To determine, in asthmatic patients, the effect of the combination of long-acting beta2 agonists and inhaled corticosteroids compared to a higher dose of inhaled corticosteroids on the incidence of asthma exacerbations, on pulmonary function and on other measures of asthma control and to look for characteristics associated with greater benefit for either treatment option.

SEARCH STRATEGY

We identified randomized controlled trials (RCTs) through electronic database searches (MEDLINE, EMBASE and CINAHL), bibliographies of RCTs and correspondence with manufacturers until April 2004.

SELECTION CRITERIA

RCTs were included that compared the combination of inhaled LABA and ICS to a higher dose of inhaled corticosteroids, in children aged 2 years and older, and in adults with asthma.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by two authors for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of patients experiencing one or more asthma exacerbations requiring oral corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptoms, use of rescue beta2 agonists, adverse events and withdrawal rates. The meta-analysis was done with RevMan Analyses and the meta-regression, with Stata.

MAIN RESULTS

Of 593 citations identified, 30 (three pediatric; 27 adult) trials were analysed recruiting 9509 participants, including one study providing two control-intervention comparisons. Only one trial included corticosteroid-naive patients. Participants were symptomatic, generally (N=20 trials) presenting with moderate (FEV1 60-79% of predicted) rather than mild airway obstruction. Trials tested the combination of salmeterol (N=22) or formoterol (N=8) with a median of 400 mcg of beclomethasone or equivalent (BDP-eq) compared to a median of 800 to 1000 mcg/day of BDP-eq. Trial duration was 24 weeks or less in all but four trials. There was no significant group difference in the rate of patients with exacerbations requiring systemic corticosteroids [N=15, RR=0.88 (95% CI: 0.77, 1.02)]. The combination of LABA and ICS resulted in greater improvement from baseline in FEV1 [N=7, WMD=0.10 L (95% CI: 0.07, 0.12)], in symptom-free days [N=8 , WMD=11.90% (95% CI:7.37, 16.44), random effects model], and in the daytime use of rescue beta2 agonists than a higher dose of ICS [N=4, WMD= -0.99 puffs/day (95% CI: -1.41, -0.58), random effects model]. There was no significant group difference in the rate of overall adverse events [N=15, RR=0.93 (95% CI: 0.84, 1.03), random effects model], or specific side effects, with the exception of a three-fold increase rate of tremor in the LABA group [N= 10, RR=2.96 (95%CI: 1.60, 5.45)]. The rate of withdrawals due to poor asthma control favoured the combination of LABA and ICS [N=20, RR=0.69 (95%CI: 0.52, 0.93)].

AUTHORS' CONCLUSIONS

In adult asthmatics, there was no significant difference between the combination of LABA and ICS and a higher dose of ICS for the prevention of exacerbations requiring systemic corticosteroids. Overall, the combination therapy led to greater improvement in lung function, symptoms and use of rescue beta2 agonists, (although most of the results are from trials of up to 24 weeks duration). There were less withdrawals due to poor asthma control in this group than when using a higher dose of inhaled corticosteroids. Apart from an increased rate of tremor, the two options appear safe although adverse effects associated with long-term ICS treatment were seldom monitored.

A randomized, double-blind, double-dummy, safety crossover trial comparing cumulative doses up to 96 microg of formoterol delivered via an HFA-134a-propelled pMDI vs. same cumulative doses of formoterol DPI and placebo in asthmatic patients

BACKGROUND

Formoterol's effects on the cardiovascular system are well known, but whether these effects are altered by the reformulation of inhalers to replace CFC propellants with HFA propellants is not.

OBJECTIVES

To evaluate the effect of cumulative doses up to 96 microg of formoterol delivered via an HFA-134a-propelled pMDI, on cardiac safety and the QTc interval, compared the same cumulative doses delivered via a DPI, in adult patients with moderate-to-severe asthma.

METHODS

This study was a multicenter, double-blind, double-dummy, placebo-controlled, three-period, crossover trial in which 22 patients with moderate-to-severe asthma received cumulative doses up to 96 microg of formoterol (12 + 12 + 24 + 48 microg) delivered via a pMDI or a dry power inhaler (DPI). Vital signs and fourteen 12-lead ECG measurements were taken at each clinic visit and at 5-10 days after the final drug administration.

RESULTS

An increase from baseline in QTc interval was observed with all formoterol treatment arms in a dose-dependent manner. The maximum increases were 56.3, 62.6 and 25.0 ms for the formoterol pMDI, formoterol DPI and placebo treatments, respectively. Heart rate was increased by 10.7, 14.9 and 6.5 bpm in the pMDI, DPI and placebo groups, respectively. Both formoterol treatments were also associated with a decrease in diastolic blood pressure compared with placebo.

CONCLUSIONS

With respect to cardiovascular safety parameters, the administration of formoterol via a pMDI device is comparable to its delivery via a DPI.

Addition of inhaled long-acting beta2-agonists to inhaled steroids as first line therapy for persistent asthma in steroid-naive adults

BACKGROUND

Consensus statements recommend the addition of long-acting inhaled beta2-agonists only in asthmatic patients who are inadequately controlled on inhaled corticosteroids.

OBJECTIVES

To compare the efficacy of initiating anti-inflammatory therapy using the combination of inhaled corticosteroids and long-acting beta2-agonists (ICS+LABA) as compared to inhaled corticosteroids alone (ICS alone) in steroid-naive children and adults with persistent asthma.

SEARCH STRATEGY

We identified randomised controlled trials (RCTs) through electronic database searches (Cochrane Airways Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and CINAHL) until April 2004, bibliographies of identified RCTs and correspondence with manufacturers.

SELECTION CRITERIA

RCTs comparing the combination of inhaled corticosteroids and long-acting beta2-agonists (ICS + LABA) to inhaled corticosteroids (ICS) alone in steroid-naive children and adults with asthma.

DATA COLLECTION AND ANALYSIS

Studies were assessed independently by each reviewer for methodological quality and data extraction. Confirmation was obtained from the trialists when possible. The primary endpoint was rate of asthma exacerbations requiring systemic corticosteroids. Secondary endpoints included pulmonary function tests (PFTs), symptoms, use of other measures of asthma control, adverse events, and withdrawal rates.

MAIN RESULTS

Eighteen trials met the inclusion criteria; nine (totaling 1061 adults) contributed sufficient data to be analysed. Baseline forced expiratory volume in one minute (FEV1) was less than 80% predicted value in four trials and equal to or greater than 80% in five trials. The long-acting beta2-agonists (LABA) formoterol (N=2) or salmeterol (N=7) were added to a dose of at least 800 microg/day of beclomethasone dipropionate (BDP) equivalent of inhaled corticosteroids (ICS) in three trials and to at least 400 microg/day in the six remaining trials. Treatment with ICS plus LABA was not associated with a lower risk of exacerbations requiring oral corticosteroids than ICS alone (relative risk (RR) 1.2; 95% confidence interval (CI) 0.8 to 1.9). FEV1 improved significantly with LABA (weighted mean difference (WMD) 210 ml; 95% CI 120 to 300), as did symptom-free days (WMD 10.74%; 95% CI 1.86 to 19.62), but the change in use of rescue fast-acting beta2-agonists was not significantly different between the groups (WMD -0.4 puff/day, 95% CI -0.9 to 0.1). There was no significant group difference in adverse events (RR 1.1; 95% CI 0.8 to 1.5), withdrawals (RR 0.9; 95% CI 0.6 to 1.2), or withdrawals due to poor asthma control (RR 1.3; 95% CI 0.5 to 3.4).

AUTHORS' CONCLUSIONS

In steroid-naive patients with mild to moderate airway obstruction, the initiation of inhaled corticosteroids in combination with long-acting beta2-agonists does not significantly reduce the rate of exacerbations over that achieved with inhaled corticosteroids alone; it does improve lung function and symptom-free days but does not reduce rescue beta2-agonist use as compared to inhaled steroids alone. Both options appear safe. There is insufficient evidence at present to recommend use of combination therapy rather than ICS alone as a first-line treatment.

Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline

OBJECTIVES

To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children.

METHODS

Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxis) 4.5 microg (F4.5) or terbutaline (Bricanyl) 500 microg (T500) were inhaled cumulatively via a dry powder inhaler (Turbuhaler) over 1 h (three patients) or 2.5 h (17 patients) and compared to a day of no treatment, in a randomised, double-blind (active treatments only), crossover trial. Blood pressure (BP), ECG, plasma potassium, glucose, lactate, and adverse events were monitored up to 10 h to assess tolerability and relative systemic dose potency.

RESULTS

Formoterol and terbutaline had significant beta2-adrenergic effects on most outcomes. Apart from the effect on systolic BP, QRS duration and PR interval, the systemic effects were significantly more pronounced with terbutaline than with formoterol. Thus, mean minimum plasma potassium, was suppressed from 3.56 (95% confidence interval, CI: 3.48-3.65) mmol l(-1) on the day of no treatment to 2.98 (CI: 2.90-3.08) after 10 x F4.5 and 2.70 (CI: 2.61-2.78) mmol l(-1) after 10 x T500, and maximum Q-Tc (heart rate corrected Q-T interval [Bazett's formula]) was prolonged from 429 (CI: 422-435) ms on the day of no treatment, to 455 (CI: 448-462) ms after 10 x F4.5 and 470 (CI: 463-476) ms after 10 x T500. Estimates of relative dose potency indicated that F4.5 microg had the same systemic activity as the clinically less effective dose of 250 microg terbutaline. The duration of systemic effects differed marginally between treatments. Spontaneously reported adverse events (most frequently tremor) were fewer with formoterol (78% of the children) than with terbutaline (95%). A serious adverse event occurred after inhalation of 45 microg formoterol over the 1 h dosing time, that prompted the extension of dosing time to 2.5 h.

CONCLUSIONS

Multiple inhalations over 2.5 h of formoterol (4.5 microg) via Turbuhaler) are at least as safe as and associated with less systemic effects than multiple inhalations of the clinically equipotent dose of terbutaline (500 microg) in children with asthma.

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.

Tolerability of short-term, high-dose formoterol in healthy volunteers and patients with asthma

BACKGROUND

Formoterol is a long-acting (>or=12 hours) beta(2)-receptor agonist with a rapid onset of action (1-3 minutes). It is approved in the United States, delivered via a single-dose dry-powder inhaler (DPI), for use in combination with anti-inflammatory therapy for the maintenance treatment of asthma and for the prevention of exercise-induced bronchospasm. Potential exposure of patients to higher doses than are currently approved is an important consideration in assessing the safety profile of formoterol.

OBJECTIVE

This article reviews data from clinical trials investigating the effects of short-term use (4-48 hours) of high doses of formoterol (maximum, 228 microg).

METHODS

Comparative and noncomparative studies of the effects of short-term, high-dose formoterol, inhaled via metered-dose inhaler (MDI) or single-dose DPI, were identified through searches of the literature indexed on MEDLINE, EMBASE, Current Contents, and Science Citation Index from their inception through August 15, 2003.

RESULTS

This review included 1 open-label noncomparative study of high-dose formoterol in 12 healthy volunteers (mean age, 29 years), 1 placebo-controlled dose-escalation study of formoterol in 20 patients with asthma (mean age, 30 years), and 3 comparative studies of formoterol and short-acting beta(2)-agonists. The latter included a dose-escalation study in 13 patients with asthma (mean age, 47.2 years), a high-dose study in 12 healthy volunteers (mean age, 27 years), and a dose-escalation study in 9 children with asthma (mean age, 10 years). In the study in healthy volunteers, the metabolic and cardiovascular effects of high single doses of formoterol (maximum, 120 microg) were small and had no clinical consequences. In the placebo-controlled dose-escalation study in patients with asthma, however, the metabolic effects of formoterol at doses from 24 to 96 microg and the cardiovascular effects of formoterol at doses from 48 to 96 microg differed significantly from those of placebo (P < 0.05 to P <0.001) but were unlikely to result in clinically significant adverse effects. In the studies comparing formoterol with short-acting beta(2)-agonists in patients with stable asthma, the cardiovascular and metabolic effects of short-term, high-dose formoterol (cumulative dose, up to 228 microg) were comparable to those of high-dose albuterol (salbutamol) (cumulative dose, up to 3800 microg). Studies of high-dose formoterol delivered via multidose DPI (not available in the United States) have reported a safety profile similar to those of high-dose terbutaline and albuterol.

CONCLUSION

In studies of the short-term use of high-dose formoterol delivered via an MDI or single-dose DPI, this agent had a safety profile comparable to that of short-acting beta(2)-agonists.