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

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 We checked manufacturers' websites and clinical trial registers for unpublished trial data, as well as Food and Drug Administration (FDA) submissions in relation to formoterol and salmeterol.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.

The impact of Cochrane Reviews: a mixed-methods evaluation of outputs from Cochrane Review Groups supported by the National Institute for Health Research

BACKGROUND

The last few decades have seen a growing emphasis on evidence-informed decision-making in health care. Systematic reviews, such as those produced by Cochrane, have been a key component of this movement. The National Institute for Health Research (NIHR) Systematic Review Programme currently supports 20 Cochrane Review Groups (CRGs) in the UK and it is important that this funding represents value for money.

AIMS AND OBJECTIVES

The overall aim was to identify the impacts and likely impacts on health care, patient outcomes and value for money of Cochrane Reviews published by 20 NIHR-funded CRGs during the years 2007-11.

DESIGN

We sent questionnaires to CRGs and review authors, undertook interviews with guideline developers (GDs) and used bibliometrics and documentary review to get an overview of CRG impact and to evaluate the impact of a sample of 60 Cochrane Reviews. The evaluation was guided by a framework with four categories (knowledge production, research targeting, informing policy development and impact on practice/services).

RESULTS

A total of 3187 new and updated reviews were published on the Cochrane Database of Systematic Reviews between 2007 and 2011, 1502 (47%) of which were produced by the 20 CRGs funded by the NIHR. We found 40 examples where reviews appeared to have influenced primary research and reviews had contributed to the creation of new knowledge and stimulated debate. Twenty-seven of the 60 reviews had 100 or more citations in Google Scholar™ (Google, CA, USA). Overall, 483 systematic reviews had been cited in 247 sets of guidance. This included 62 sets of international guidance, 175 sets of national guidance (87 from the UK) and 10 examples of local guidance. Evidence from the interviews suggested that Cochrane Reviews often play an instrumental role in informing guidance, although reviews being a poor fit with guideline scope or methods, reviews being out of date and a lack of communication between CRGs and GDs were barriers to their use. Cochrane Reviews appeared to have led to a number of benefits to the health service including safer or more appropriate use of medication or other health technologies or the identification of new effective drugs or treatments. However, whether or not these changes were directly as a result of the Cochrane Review and not the result of subsequent clinical guidance was difficult to judge. Potential benefits of Cochrane Reviews included economic benefits through budget savings or the release of funds, improvements in clinical quality, the reduction in the use of unproven or unnecessary procedures and improvements in patient and carer experiences.

CONCLUSIONS

This study identified a number of impacts and likely impacts of Cochrane Reviews. The clearest impacts of Cochrane Reviews are on research targeting and health-care policy, with less evidence of a direct impact on clinical practice and the organisation and delivery of NHS services. Although it is important for researchers to consider how they might increase the influence of their work, such impacts are difficult to measure. More work is required to develop suitable methods for defining and quantifying the impact of research.

FUNDING

The NIHR Health Technology Assessment programme.

Safety of regular formoterol or salmeterol in adults with asthma: an overview of Cochrane reviews

BACKGROUND

For adults with asthma that is poorly controlled on inhaled corticosteroids (ICS), guidelines suggest adding a long-acting beta2-agonist (LABA). The LABA can be taken together with ICS in a single (combination) inhaler. Improved symptom control can be assessed in the individual; however, the long-term risk of hospital admission or death requires evidence from randomised controlled trials. Clinical trials record these safety outcomes as non-fatal and fatal serious adverse events (SAEs), respectively.

OBJECTIVES

To assess the risk of serious adverse events in adults with asthma treated with regular maintenance formoterol or salmeterol compared with placebo, or when randomly assigned in combination with regular ICS, compared with the same dose of ICS.

METHODS

We included Cochrane reviews on the safety of regular formoterol and salmeterol from a June 2013 search of the Cochrane Database of Systematic Reviews. We carried out a search for additional trials in September 2013 and incorporated the new data. All reviews were independently assessed for inclusion and for quality (using the AMSTAR tool). We extracted from each review data from trials recruiting adults (participants older than 12 or 18 years of age).We combined the results from reviews on formoterol and salmeterol to assess the safety of twice-daily regular LABA as a class effect, both as monotherapy versus placebo and as combination therapy versus the same dose of ICS.We did not combine the results of direct and indirect comparisons of formoterol and salmeterol, or carry out a network meta-analysis, because of concerns over transitivity assumptions that posed a threat to the validity of indirect comparisons.

MAIN RESULTS

We identified six high-quality, up-to-date Cochrane reviews. Of these, four reviews (89 trials with 61,366 adults) related to the safety of regular formoterol or salmeterol as monotherapy or combination therapy. Two reviews assessed safety from trials in which adults were randomly assigned to formoterol versus salmeterol. These included three trials with 1116 participants given monotherapy (all prescribed background ICS) and 10 trials with 8498 adults receiving combination therapy. An additional search for trials in September 2013 identified five new included studies contributing data from 693 adults with asthma treated with combination formoterol/fluticasone in comparison with the same dose of inhaled fluticasone, as well as from 447 adults for whom formoterol monotherapy was compared with placebo.No trials reported separate results in adolescents. Overall, risks of bias for the primary outcomes were assessed as low. Death of any causeNone of the reviews found a significant increase in death of any cause from direct comparisons; however, none of the reviews could exclude the possibility of a two-fold increase in mortality on regular formoterol or salmeterol (as monotherapy vs placebo or as combination therapy versus ICS) in adults with asthma. Pooled mortality results from direct comparisons were as follows: formoterol monotherapy (odds ratio (OR) 4.49, 95% confidence interval (CI) 0.24 to 84.80, 13 trials, N = 4824), salmeterol monotherapy (OR 1.33, 95% CI 0.85 to 2.08, 10 trials, N = 29,128), formoterol combination (OR 3.56, 95% CI 0.79 to 16.03, 25 trials, N = 11,271) and salmeterol combination (OR 0.90, 95% CI 0.31 to 2.6, 35 trials, N = 13,447). In each case, we did not detect heterogeneity, and the quality of evidence was rated as moderate. Absolute differences in mortality were very small, translating into an increase of 7 per 10,000 over 26 weeks on any monotherapy (95% CI 2 less to 23 more) and 3 per 10,000 over 32 weeks on any combination therapy (95% CI 3 less to 17 more).Very few deaths were reported in the combination therapy trials, and combination therapy trial designs were different from those of monotherapy trials. Therefore we could not use indirect evidence to assess whether regular combination therapy was safer than regular monotherapy.Only one death occurred in the monotherapy trials comparing formoterol versus salmeterol, so evidence was insufficient to compare mortality. Non-fatal serious adverse events of any causeDirect evidence showed that non-fatal serious adverse events were increased in adults receiving salmeterol monotherapy (OR 1.14, 95% 1.01 to 1.28, I(2) = 0%,13 trials, N = 30,196) but were not significantly increased in any of the other reviews: formoterol monotherapy (OR 1.26, 95% CI 0.78 to 2.04, I(2) = 15%, 17 trials, N = 5758), formoterol combination (OR 0.99, 95% CI 0.77 to 1.27, I(2) = 0%, 25 trials, N = 11,271) and salmeterol combination (OR 1.15, 95% CI 0.91 to 1.44, I(2) = 0%, 35 trials, N = 13,447). This represents an absolute increase on any monotherapy of 43 per 10,000 over 26 weeks (95% CI 6 more to 85 more) and 16 per 10,000 over 32 weeks (95% CI 22 less to 60 more) on any combination therapy.Direct comparisons of formoterol and salmeterol detected no significant differences between risks of all non-fatal events in adults (as monotherapy or as combination therapy).

AUTHORS' CONCLUSIONS

Available evidence from the reviews of randomised trials cannot definitively rule out an increased risk of fatal serious adverse events when regular formoterol or salmeterol was added to an inhaled corticosteroid (as background or as randomly assigned treatment) in adults or adolescents with asthma.An increase in non-fatal serious adverse events of any cause was found with salmeterol monotherapy, and the same increase cannot be ruled out when formoterol or salmeterol was used in combination with an inhaled corticosteroid, although possible increases are small in absolute terms.However, if the addition of formoterol or salmeterol to an inhaled corticosteroid is found to improve symptomatic control, it is safer to give formoterol or salmeterol in the form of a combination inhaler (as recommended by the US Food and Drug Administration (FDA)). This prevents the substitution of LABA for an inhaled corticosteroid if symptom control is improved on LABA.The results of three large ongoing trials in adults and adolescents are awaited; these will provide more information on the safety of combination therapy under less supervised conditions and will report separate results for the adolescents included.

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.

Safety of regular formoterol or salmeterol in children with asthma: an overview of Cochrane reviews

BACKGROUND

Two large surveillance studies in adults with asthma have found an increased risk of asthma-related mortality in those who took regular salmeterol as monotherapy in comparison to placebo or regular salbutamol. No similar sized surveillance studies have been carried out in children with asthma, and we remain uncertain about the comparative safety of regular combination therapy with either formoterol or salmeterol in children with asthma.

OBJECTIVES

We have used the paediatric trial results from Cochrane systematic reviews to assess the safety of regular formoterol or salmeterol, either as monotherapy or as combination therapy, in children with asthma.

METHODS

We included Cochrane reviews relating to the safety of regular formoterol and salmeterol from a search of the Cochrane Database of Systematic Reviews conducted in May 2012, and ran updated searches for each of the reviews. These were independently assessed. All the reviews were assessed for quality using the AMSTAR tool. We extracted the data relating to children from each review and from new trials found in the updated searches (including risks of bias, study characteristics, serious adverse event outcomes, and control arm event rates).The safety of regular formoterol and salmeterol were assessed directly from the paediatric trials in the Cochrane reviews of monotherapy and combination therapy with each product. Then monotherapy was indirectly compared to combination therapy by looking at the differences between the pooled trial results for monotherapy and the pooled results for combination therapy. The comparative safety of formoterol and salmeterol was assessed using direct evidence from trials that randomised children to each treatment; this was combined with the result of an indirect comparison of the combination therapy trials, which represents the difference between the pooled results of each product when randomised against inhaled corticosteroids alone.

MAIN RESULTS

We identified six high quality, up to date Cochrane reviews. Four of these related to the safety of regular formoterol or salmeterol (as monotherapy or combination therapy) and these included 19 studies in children. We added data from two recent studies on salmeterol combination therapy in 689 children which were published after the relevant Cochrane review had been completed, making a total of 21 trials on 7474 children (from four to 17 years of age). The two remaining reviews compared the safety of formoterol with salmeterol from trials randomising participants to one or other treatment, but the reviews only included a single trial in children in which there were 156 participants.Only one child died across all the trials, so impact on mortality could not be assessed.We found a statistically significant increase in the odds of suffering a non-fatal serious adverse event of any cause in children on formoterol monotherapy (Peto odds ratio (OR) 2.48; 95% confidence interval (CI) 1.27 to 4.83, I(2) = 0%, 5 trials, N = 1335, high quality) and smaller increases in odds which were not statistically significant for salmeterol monotherapy (Peto OR 1.30; 95% CI 0.82 to 2.05, I(2) = 17%, 5 trials, N = 1333, moderate quality), formoterol combination therapy (Peto OR 1.60; 95% CI 0.80 to 3.28, I(2) = 32%, 7 trials, N = 2788, moderate quality) and salmeterol combination therapy (Peto OR 1.20; 95% CI 0.37 to 2.91, I(2) = 0%, 5 trials, N = 1862, moderate quality).We compared the pooled results of the monotherapy and combination therapy trials. There was no significant difference between the pooled ORs of children with a serious adverse event (SAE) from long-acting beta(2)-agonist beta agonist (LABA) monotherapy (Peto OR 1.60; 95% CI 1.10 to 2.33, 10 trials, N = 2668) and combination trials (Peto OR 1.50; 95% CI 0.82 to 2.75, 12 trials, N = 4,650). However, there were fewer children with an SAE in the regular inhaled corticosteroid (ICS) control group (0.7%) than in the placebo control group (3.6%). As a result, there was an absolute increase of an additional 21 children (95% CI 4 to 45) suffering such an SAE of any cause for every 1000 children treated over six months with either regular formoterol or salmeterol monotherapy, whilst for combination therapy the increased risk was an additional three children (95% CI 1 fewer to 12 more) per 1000 over three months.We only found a single trial in 156 children comparing the safety of regular salmeterol to regular formoterol monotherapy, and even with the additional evidence from indirect comparisons between the combination formoterol and salmeterol trials, the CI around the effect on SAEs is too wide to tell whether there is a difference in the comparative safety of formoterol and salmeterol (OR 1.26; 95% CI 0.37 to 4.32).

AUTHORS' CONCLUSIONS

We do not know if regular combination therapy with formoterol or salmeterol in children alters the risk of dying from asthma.Regular combination therapy is likely to be less risky than monotherapy in children with asthma, but we cannot say that combination therapy is risk free. There are probably an additional three children per 1000 who suffer a non-fatal serious adverse event on combination therapy in comparison to ICS over three months. This is currently our best estimate of the risk of using LABA combination therapy in children and has to be balanced against the symptomatic benefit obtained for each child. We await the results of large on-going surveillance studies to further clarify the risks of combination therapy in children and adolescents with asthma.The relative safety of formoterol in comparison to salmeterol remains unclear, even when all currently available direct and indirect trial evidence is combined.