Has the change to beta-agonists combined with oral theophylline increased cases of fatal asthma?

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

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

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.

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

BACKGROUND

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Cardiotoxic Effects in Rats and Rabbits Treated with Terbutaline Alone and in Combination with Aminophylline

Studies were conducted to determine the myocardial effects of a selective beta-adrenoceptor agonist, terbutaline, administered alone and in combination with aminophylline in the 4-to 5-month-old, 500-600 g (heavy) rat and the rabbit, using electrocardiographic and histopathological methods. Terbutaline given at high (5.0 mg/kg) and low (0.1 mg/kg) doses was not arrhythmogenic in the heavy rat; however, dose-dependent myocardial lesions were observed. Terbutaline given at the same doses to heavy rats pretreated with aminophylline was arrhythmogenic and produced severe cardiac lesions. Rats administered aminophylline at a dose of 18.75 mg/kg had plasma theophylline levels of 15-22 μg/ml; these concentrations are similar to the recommended human therapeutic levels, i.e., 10-20 μg/ml. The administration of terbutaline in conjunction with aminophylline did not seem to affect the plasma levels of theophylline. No arrythmias were detected in rabbits given terbutaline alone or in combination with aminophylline and no deaths occurred.

Severity Stratification in Life-threatening Asthma

Severity differences may in part explain the large varia tions in asthma mortality that occur in different coun tries. This study examines the use of APACHE II for measuring asthma severity in 118 adult asthma admis sions at one intensive care unit in New Zealand during 1987-1988. Most admissions were hypercapnic (72%), and 61 % had an altered level of consciousness. Mean APACHE II score was 20 in the emergency department and 12 upon ICU admission. We summarize the extent of physiological derangement using four acute physiol ogy score (APS) ranges. Each APS range stratified admis sions into groups with differing clinical course, therapy, and outcome. These results document a high level of asthma severity among patients treated in New Zealand, the country with the world's highest asthma mortality. APACHE II provides a valid and reproducible measure of asthma severity and should be useful for describing and comparing international differences in asthma severity and as a case-mix control in studies of asthma therapy.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Regular treatment with formoterol for chronic asthma: serious adverse events

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Two authors independently selected trials for inclusion in the review. One author extracted outcome data and the second author checked them. We sought unpublished data on mortality and serious adverse events.

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Beta-Adrenergic Agonists

Inhaled β₂-adrenoceptor (β₂-AR) agonists are considered essential bronchodilator drugs in the treatment of bronchial asthma, both as symptoms-relievers and, in combination with inhaled corticosteroids, as disease-controllers. In this article, we first review the basic mechanisms by which the β₂-adrenergic system contributes to the control of airway smooth muscle tone. Then, we go on describing the structural characteristics of β₂-AR and the molecular basis of G-protein-coupled receptor signaling and mechanisms of its desensitization/ dysfunction. In particular, phosphorylation mediated by protein kinase A and β-adrenergic receptor kinase are examined in detail. Finally, we discuss the pivotal role of inhaled β₂-AR agonists in the treatment of asthma and the concerns about their safety that have been recently raised.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVES

The aim of this review is to assess the risk of fatal and non-fatal serious adverse events in trials that randomised patients with chronic asthma to regular salmeterol with inhaled corticosteroids versus the same dose of inhaled corticosteroids alone.

SEARCH STRATEGY

Trials were identified using the Cochrane Airways Group Specialised Register of trials. Web sites of clinical trial registers were checked for unpublished trial data and Food and Drug Administration (FDA) submissions in relation to salmeterol were also checked. The date of the most recent search was October 2008.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Drug utilization and morbidity statistics for the evaluation of drug safety in Sweden

For a continuous monitoring and evaluation of drug safety problems in Sweden, the Department of Drugs of the National Board of Health and Welfare has access to a number of computerised patient-, drug-, and disease-oriented registers. The usefulness and limitations of these registers are presented by examples. A recent increase in asthma deaths is presently being analysed by comparing information from death certificates and case records with drug sales and prescription data. A recent analysis of the cancer register showed no increased risk of malignant thyroid tumors after diagnostic or therapeutic doses of I 131. Similarly no increased risk of malformations after occupational exposure to hexachlorophene could be detected by analysing the malformation and medical birth-record registers in relation to hospital hexachlorophene use. The register of patient discharge diagnoses has been repeatedly used to analyse the incidence and pattern of drug induced blood dyscrasias and thromboembolism associated with oral contraceptives (OC). These analyses have resulted i.a. in the withdrawal of dipyrone and tenalidine and a decrease of the estrogen-content of OCs. At the same time about 1/3 of these serious adverse drug reactions (ADR) was found to have been reported to the ADR-register. By combining sales and prescription data with ADR-reports the risk of inducing lactic acidosis was found to be significantly higher for phenformin than for metformin. Also the incidence of tardive dyskinesia from longterm use of metoclopramide was found to be much higher than hitherto recognized. By use of these registers it is possible to obtain valuable information about the safety of drugs. The raw data must, however, be interpreted with care and often be supplemented with in depth studies of the various problems.

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

BACKGROUND

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

OBJECTIVES

The aim of this review is to assess the risk of fatal and non-fatal serious adverse events in trials that randomised patients with chronic asthma to regular formoterol with inhaled corticosteroids versus the same dose of inhaled corticosteroids alone.

SEARCH STRATEGY

Trials were identified using the Cochrane Airways Group Specialised Register of trials. Web sites of clinical trial registers were checked for unpublished trial data and Food and Drug Administration (FDA) submissions in relation to formoterol were also checked. The date of the most recent search was October 2008.

SELECTION CRITERIA

Controlled parallel design clinical trials on patients of any age and severity of asthma were included if they randomised patients to treatment with regular formoterol and inhaled corticosteroids, and were of at least 12 weeks duration.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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.

Regular treatment with salmeterol for chronic asthma: serious adverse events

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Forensic Lung Pathology

Sudden and unexpected natural deaths and nonnatural deaths may result from various pulmonary conditions. Additionally, several nonpulmonary conditions of forensic significance may be complicated by the development of respiratory lesions. Certain situations with pulmonary pathology are particularly likely to be critically scrutinized and may form the basis of allegations of medical negligence, other personal injury liability, or wrongful death.1

Clinical features of fatal asthma

To characterize the clinical features of fatal asthma, we retrospectively analyzed the clinical characteristics of patients who died of an acute asthma attack in our hospital during a 15-year period from 1989 to 2003. Twelve patients had fatal asthma during this period, including eight who were dead on arrival in the emergency room (ER) and three who died within 1 hour of admission to the ER. Patients were categorized into three groups according to the clinical presentations during the fatal attack: (1) rapid (< 3 hours) decompensation in four patients; (2) gradual development of respiratory failure over several days in two patients; and (3) acute deterioration after unstable asthma lasting several days in six patients. All patients in groups 1 and 2 had reported previous near-fatal attacks. The proportion of young patients was highest in group 3, with half of them (3/6) younger than 35 years of age. Only one patient in group 3 had had a previous near-fatal attack. Five of the seven patients, with previous near-fatal attacks, had a pattern of decompensation during their fatal attack that was similar to their previous attacks. In conclusion, nearly all patients with fatal asthma in this study died outside of the hospital or within 1 hour after admission to the ER. Patients had patterns of decompensation during the fatal attack that were similar to those of their previous attacks. Early detection of warning signs, early admission to the ER, adequate treatment, and extremely close observation of patients, especially within 1 hour after ER arrival, may prevent or decrease the incidence of fatal asthmatic attack.

Perception of exercise induced asthma by children and their parents

BACKGROUND

Exercise induced asthma (EIA) plays an important role in clinical evaluation. There has been little previous work validating EIA as reported directly by children and indirectly by their parents.

AIMS

(1) To determine the strength of the association between children's symptoms of EIA and their physiological response to exercise in a laboratory setting. (2) To compare parents' perception of EIA with that of their children. (3) To seek factors influencing the perception of EIA.

METHODS

Forty three asthmatic children and their parents answered a questionnaire, which included measures of symptom perception in EIA using visual analogue (VAS) and Likert scales. The children underwent a standardised treadmill exercise challenge, using spirometry to measure the physiological outcome, after which they and their parents independently completed the symptom scores. Twenty four subjects agreed to return for a second visit, in order to assess repeatability.

RESULTS

The VAS and Likert scales were highly correlated. Children's symptom perception as measured by change in VAS scores related weakly to change in FEV(1) after exercise, and was unaffected by confounding factors such as age, gender, medication, and habitual exercise. Parents' perception of symptoms was unrelated to any physiological measure. There was no significant relation between parent and child VAS scores after exercise, and there was poor agreement between the Likert scale scores after exercise. The repeatability of the perception of change in FEV(1) after exercise was poor for both parents and children.

CONCLUSION

Physicians should obtain reports of EIA from children rather than parents, but be aware of their limited accuracy and repeatability.

Characterization of airway plugging in fatal asthma

PURPOSE

Case reports suggest that deaths due to asthma can occur without airway plugging. In this study, we examined the hypothesis that obstruction of the airway lumen by an exudate containing mucus and cells is a key feature of fatal asthma attacks.

METHODS

We quantified airway narrowing and lumenal content in 275 airways from 93 patients with fatal asthma aged 10 to 49 years (59 white subjects and 34 Polynesian subjects, including 19 children), compared with airways from control patients who died suddenly without pulmonary diseases.

RESULTS

The severity of lumenal occlusion ranged from 4% to 100% in these cases, but only five airways showed less than 20% occlusion. Compared with controls, patients with asthma had more lumenal occlusion (mean [+/- SD] open lumen, 42% +/- 23% vs. 93% +/- 8%), greater mucus occlusion (28% +/- 13% vs. 5% +/- 6%), and more occlusion by cells (30% +/- 17% vs. 3% +/- 2%, all P<0.0001). Airway narrowing was greater in larger airways (P<0.0001) and older patients (P = 0.009). Greater lumen content was associated with a higher proportion of cells (P = 0.003), and cells made up a higher proportion of the exudate in the small airways (P<0.0001). Lumenal mucus was greater in younger patients with asthma (P = 0.0007) and in Polynesian patients with asthma (P = 0.04).

CONCLUSION

Airway lumenal obstruction by an exudate composed of mucus and cells is a major contributing cause of fatal asthma in most patients.

Demographic characteristics of patients experiencing near-fatal and fatal asthma: results of a regional survey of 400 asthma specialists [see comment]

BACKGROUND

Case-control studies now describe a growing number of younger patients with varying levels of asthma severity who experience near-fatal or fatal asthma unexpectedly at home, en route to the hospital, or in public places.

OBJECTIVE

To collect case reports and analyze the demographic characteristics and patient profiles that may help identify predisposing factors which trigger near-fatal and fatal asthma episodes.

METHODS

In order to gather case reports and analyze the demographics and clinical characteristics of patients experiencing near-fatal and fatal asthma, a questionnaire on near-fatal and fatal asthma was distributed to 400 regional asthma specialists.

RESULTS

Forty physicians reported 25 cases of near-fatal asthma and 20 cases of fatal asthma. Twenty-five patients (13 males and 12 females) with a mean age of 29.4 years experienced near-fatal asthma. The time of onset of the near-fatal event was sudden (less than 3 hours) in 60% of cases and 76% of the episodes occurred at home or en route to the hospital. All 25 patients were using short acting inhaled beta agonists and 88% were reportedly using inhaled corticosteroids on a daily basis. Good to excellent compliance was noted in 60% of patients. Six patients were using a peak flow meter prior to their near-fatal attack. Predisposing psychosocial factors for life threatening asthma were noted in 44% of patients. Twenty patients, (4 males and 16 females) with a mean age of 21.7 years experienced fatal asthma. The time of onset of the fatal event was sudden (less than 3 hours) in 80% of cases and all but one patient died at home, en route to the hospital, or in a public place. All 20 patients were using short acting inhaled beta agonists, 80% were reportedly on daily inhaled corticosteroids and six patients were on oral corticosteroids. Good to excellent compliance was noted in 60% of patients. Only two patients were using a peak flow meter immediately prior to their fatal attack. Predisposing psychosocial factors for life threatening asthma were noted in 45% of decedent patients. Risk factors for fatal asthma included running in cold weather, over relying on home nebulizers, and a delay in seeking care on long holiday weekends.

CONCLUSIONS

While approximately 50% of the patients in this survey had moderate to severe asthma tainted by adverse psychosocial factors, nearly half of near-fatal and fatal attacks occurred suddenly and unexpectedly, outside the hospital in stable, younger, atopic, reportedly compliant patients utilizing inhaled corticosteroids on a daily basis. This regional survey supports the need for additional studies and the establishment of a national case registry to collect case reports and analyze the demographics and clinical characteristics of patients experiencing near-fatal and fatal asthma in order to further define the risk factors and develop preventative protocols for patients at risk for near-fatal or fatal asthma.

Hypokalemia and salbutamol therapy in asthma

Hypokalemia is a common side effect in adult asthmatic patients on beta 2 adrenergic therapy. There is limited information in regard to hypokalemia and its relation to the clinical responses following administration of beta 2 agonist therapy in children with asthma. We observed that salbutamol inhalation significantly improved asthmatic symptoms as demonstrated by increases in peak expiratory flow (PEF: 122.37+/-75.38 vs. 152.59+/-80.29; P < 0.001) and venous oxygen tension (Pv,O2: 33.24+/-4.95 vs. 58.16+/-2.31; P < 0.001), and decreases in respiratory rate (RR: 36.39+/-3.78 vs. 28.62+/-3.12; P< 0.01), clinical scores (CS: 3.59+/-1.28 vs. 1.59+/-0.71), and venous PCO2 tensions (Pv,CO2: 40.84+/-2.67 vs. 34.75+/-2.31; P < 0.001). Salbutamol-induced hypokalemia was correlated with a decrease in RR, and an increase of Pv,O2 and PEF. These findings suggest that the same mechanism is involved in eliciting hypokalemia and bronchodilatation.

Case discussions on the pathophysiology and clinical features of near-fatal asthma episodes

This article reviews the definition of near-fatal asthma. The slow-onset, late arrival group and the sudden-onset groups of near-fatal asthma patients are discussed. Risk factors for near-fatal asthma and the pathologic differences between the two groups are elucidated.

The decline in asthma hospitalisations in persons aged 0-34 years in New Zealand

AIMS

Hospitalisation rates for asthma for the 0-14 year and five-34 year age ranges have been examined from 1969 to 1993 to determine whether the rise observed between the 1960s and 1980s has continued into the 1990s.

RESULTS

In the 0-14 age range, hospitalisations peaked in 1986 then fell by 18.7% by 1993. There was a corresponding rise in hospitalisation rates for acute bronchitis/bronchiolitis and it is possible that the fall in asthma hospitalisations in this age range is at least partly explained by diagnostic transfer. On the other hand, the trends in the five-34 age range appear unlikely to be explained by diagnostic transfer. The rate peaked in 1986 and fell by 34.7% by 1993, with most of the decline occurring after 1989. This in part parallels the trends in mortality in this age range, which saw a sudden fall in the death rate in 1989.

CONCLUSIONS

New Zealand is not only benefiting from a marked fall in asthma deaths, but is also benefiting from a marked decline in asthma hospitalisations in young adults, and probably also in children.

Possible serotonin syndrome associated with tramadol and sertraline coadministration

OBJECTIVE

To report a possible case of serotonin syndrome associated with coadministration of tramadol hydrochloride and sertraline hydrochloride.

CASE SUMMARY

A 42-year-old woman developed atypical chest pain, sinus tachycardia, confusion, psychosis, sundowning, agitation, diaphoresis, and tremor. She was taking multiple medications, including tramadol and sertraline. The tramadol dosage had recently been increased, resulting in what was believed to be serotonergic syndrome.

DISCUSSION

Serotonin syndrome is a toxic hyperserotonergic state that develops soon after initiation or dosage increments of the offending agent. Patients may differ in their susceptibility to the development of serotonin syndrome. The (+) enantiomer of tramadol inhibits serotonin uptake. Tramadol is metabolized to an active metabolite, M1, by the CYP2D6 enzyme. If this metabolite has less serotonergic activity than tramadol, inhibition of CYP2D6 by sertraline could have been a factor in the interaction.

CONCLUSIONS

Clinicians should be aware of the potential for serotonin syndrome with concomitant administration of sertraline and tramadol.

Deaths from asthma in Italy (1974-1988): is there a relationship with changing pharmacological approaches?

In this article we consider the relationship between asthma mortality rates, obtained from the Italian National Institute of Statistics (ISTAT), and the doses of all antiasthmatic drugs except systemic steroids sold in Italy in the years 1974-1988. The total asthma mortality rate showed three different trends: it decreased slowly until 1978 (period A); increased 10-fold from 1979 to 1985, rising from 0.30 to 4.17/100,000 (period B); and remained stable until 1988 (period C). More than half of the deaths in 1988 occurred in people 75 years of age or more. Men died more in the older age groups, while the mortality of women prevailed in the 35- to 54-year age group. In the 5- to 34-year age group the rate rose from 0.01 in 1978 to 0.21 /100,000 in 1986. Coding changes due to the 9th revision of the International Classification of Disease, adopted in Italy in 1979, probably increased the number of deaths being attributed to asthma in case of contemporary mention of bronchitis, a common diagnosis in older men, which showed the greatest increase in mortality. Increased prevalence and awareness of asthma may also have played a role. Although international comparisons strongly suggest undertreatment of asthma in Italy, the doses of anti-asthma drugs sold in Italy grew from 276 to 1,080 million from 1974 to 1985. During period B xanthine sales rose sevenfold and grew from 6.5 to 23.3% of the total doses, along with a twofold increase in beta 2-agonist and cromolyn sales. Period C was characterized by stable total doses (1155 million in 1988), with increases only in antiinflammatory and preventive drug sales. The increase in asthma deaths in Italy has been striking despite the contemporary rise in sales of all antiasthma drugs, particularly of beta 2-agonist metered aerosols and xanthine tablets. The increase in antiinflammatory and preventive drug sales may have contributed to the stabilization of asthma deaths during period C.

Hypokalemia after normal doses of neubulized albuterol (salbutamol)

The cases of two asthmatic patients who became hypokalemic after inhalation of normal doses of albuterol are presented. One patient was symptomatic and the other had only electrocardiographic changes. Both were treated successfully with oral potassium. Albuterol-induced hypokalemia and its potential cardiac toxicity are discussed briefly.

Major reduction in asthma morbidity and continued reduction in asthma mortality in New Zealand: what lessons have been learned?

Increasing financial barriers to primary health care against a background of social and economic decline are likely to have contributed to asthma morbidity and mortality in New Zealand. Although there would not have been a sufficient increase in asthma prevalence to have accounted for the threefold increase in mortality rates, whether or not there was an increase in asthma severity in the late 1970s remains open to debate. Misuse or poor use of newly available and potent bronchodilator medications by those with the most severe asthma may simply have contributed to further delays in obtaining appropriate care and therefore to an increase in frequency of severe attacks in the community. Despite substantial increases in the use of bronchodilator therapy in New Zealand, there was no immediate improvement in indices of either asthma morbidity or mortality. The initial reduction in mortality rates in the 1980s happened at a time when first admissions for asthma were still increasing and seems to be best explained by an improvement in utilisation of hospital services (which were free until 1992) rather than a reduction in asthma severity. However, the recent reductions in all measures of asthma morbidity and further reduction in asthma mortality since 1989 does now suggest a reduction in asthma severity and would be best explained by the substantial increase in medium and high dose inhaled corticosteroid use, and to the endorsement of the current management strategies for asthma which are being promoted internationally and which were given considerable publicity in New Zealand in 1989 and 1990. Whilst sales of inhaled beta agonists were higher in 1991 than 1989, this may not reflect their pattern of use by individual patients since the need for an increase in inhaled beta agonist treatment has been accepted as indicating a lack of control and the need for either starting or increasing the dose of inhaled steroid treatment.

End of the New Zealand asthma mortality epidemic

In 1989, a case-control study reported that inhaled fenoterol was associated with the epidemic of asthma deaths that had affected New Zealand since 1976. The New Zealand Department of Health issued warnings about the safety of fenoterol and restricted its availability. The associated time trends are consistent with the hypothesis that fenoterol was the main factor in the New Zealand asthma mortality epidemic. The epidemic commenced when fenoterol was introduced in 1976, and the New Zealand death rate remained the highest in the world for more than a decade. After publication of the case-control study, the death rate fell by half and has now remained low for a further 3 years (1990-92). Time-trend data do not suggest a class effect of inhaled beta-agonists in the epidemic: there was no association between beta-agonist sales and the start of the epidemic, and total sales of inhaled beta-agonists actually increased slightly during 1989-90 when the epidemic came to an end. Time-trend data are also inconsistent with the hypothesis that the epidemic may have occurred because of underprescribing of inhaled corticosteroids. Similarly, time-trend data is incosistent with hypotheses postulating a major role of social factors such as unemployment. Data on time trends should be assessed with caution, because time trends in asthma deaths can be affected by many factors. Nevertheless, the New Zealand time trends are consistent with fenoterol being the main cause of the New Zealand asthma mortality epidemic and are inconsistent with a significant role for other suggested causes.

The beta 2-agonist controversy. Observations, explanations and relationship to asthma epidemiology

Links between frequent use of inhaled beta 2-agonists and morbidity and mortality from asthma appear probable. Two mortality epidemics followed the marketing of potent inhaled adrenergic agents. Case-control studies in New Zealand linked mortality with prescription of fenoterol, especially in severe asthma. A Saskatchewan case-control study confirmed an association of mortality with fenoterol, and also with frequent use of salbutamol (albuterol). Cardiac effects of beta 2-agonists do not cause mortality, but frequent use of these agents may increase the chronic severity of asthma, hence increasing the number of asthmatic patients at risk of death in an acute attack. Frequent use of beta 2-agonists may reduce lung function, increasing airway responsiveness, and impair control of asthma, despite use of inhaled corticosteroids. Mechanisms for this effect may include tachyphylaxis to nonbronchodilator effects, increased responsiveness to allergen, interaction with corticosteroid receptors, altered mucociliary function, differential effects of enantiomers, and masking of symptoms by beta 2-agonist use. The withdrawal of fenoterol from New Zealand in 1990 was associated with a substantial decline in morbidity and mortality. Overall, the evidence suggests that frequent use of inhaled beta 2-agonists has a deleterious effect on the control of asthma. Epidemics of mortality are explained by an increase in chronic severity of asthma following introduction of more potent beta 2-agonists. While beta 2-agonists remain essential for relief of breakthrough symptoms, long term use, particularly with high doses of potent agents, appears to be detrimental.

Asthma deaths among coloured and white South Africans: 1962 to 1988

To determine whether death rates from asthma have been rising in South Africa, asthma mortality rates among coloured and white South Africans were calculated from official figures for the years 1962-1988. Sharp increases in the 1960s were noted in both groups. Since the early 1970s whites rates have generally shown a downward trend. In contrast, coloured rates have remained high, with a marked excess of male deaths. In the age stratum 5-34 years, there has been considerable fluctuation, with the long-term trend being slightly downward. Some increase in death rates occurred among the young in the early 1980s, but coloureds in this age group have shown falling rates in the most recent years. Coloured death rates in the younger age stratum have, however, continued to exceed whites rates, although by a decreasing margin, and have been high by international comparison. These group disparities are unlikely to be due to differences in certification or in coding. Variation in prevalence or severity of asthma may explain some of the disparity. However, these group differences, taken with well-known inequalities in medical care, suggest that preventable determinants of asthma deaths related to access to and quality of medical care may be important and accordingly a target for preventive strategies.

Mortality from airways disorders in Alberta, 1927-1987: an expanding epidemic of COPD, but asthma shows little change

Mortality from asthma has been reported to be increasing in recent years in many countries, including Canada. Alberta, and the prairie provinces generally, appear to have an excess of deaths from asthma compared to other provinces. We studied mortality from asthma and from chronic obstructive pulmonary disease (COPD) generally in Alberta between 1927 and 1987 using a data set compiled and recorded from Alberta Vital Statistics to describe birth cohorts' age-specific mortality rates. We also present the distribution of deaths in the years since 1987. There was a clear and sustained increase in mortality from COPD since 1950 after age 40 but no evidence to support the proposition that deaths from asthma were increasing in recent years; more recent data from Alberta Vital Statistics show no sustained increase since 1987, either. There was great variability from year to year and sporadically increased rates in a given year that were not sustained. These transient increases were observed particularly among females aged 10-14, 15-19, and 25-29 and among males aged 15-19, 25-29, and 80-84; however, there were also comparable decreases in asthma mortality of similar magnitude during the same time period in different age groups or in the other sex in the age group 10-14. We conclude that there is no excess of deaths from asthma over those expected by historical trends in Alberta at the present time but that the smoking-related epidemic of deaths from COPD continues unabated. The "smoothness" and consistency of the mortality trends suggest that physicians certifying deaths from these causes are using implicit diagnostic criteria that have not changed abruptly.

Determinants of near fatality in acute severe asthma

PURPOSE

The data extrapolated from cases of acute severe asthma that narrowly miss being fatal may prove valuable in the identification of the factors implicated in mortality. The purpose of this study was, therefore, to identify determinants of near fatality in patients with acute severe asthma.

PATIENTS AND METHODS

We studied 81 patients with acute severe asthma in whom mechanical ventilation was required. Near fatality was defined as the occurrence of respiratory arrest and/or coma necessitating emergency tracheal intubation and resuscitation. In the cases that were not regarded as near fatal, tracheal intubation was performed electively because of deteriorating arterial blood gas values and/or the anticipation of exhaustion. Various continuous and categorical variables were compared in these two groups of patients. Patients with a hyperacute attack (period from onset of attack to mechanical ventilation less than 3 hours) were specifically sought and studied to determine the impact of such a course on near fatality.

RESULTS

The "attack duration" (period from onset of attack to mechanical ventilation) was an important determinant of near fatality and of the subsequent clinical course. It was shorter in the group with a near-fatal episode (p < 0.03), and hyperacute attacks were uniformly near fatal. The attack duration correlated positively with the duration of the requirement for mechanical ventilation (p < 0.01). A longer attack duration was associated with an increased likelihood of the occurrence of major atelectasis (p < 0.01). There was no evidence of a relationship between near fatality and the side effects of bronchodilators as regards hypokalemia, arrhythmias, or cardiotoxicity. There was evidence of considerable under-treatment in the patient population as a whole, particularly in regard to the use of corticosteroids.

CONCLUSIONS

A short attack duration is associated with an increased risk of near fatality in acute severe asthma. This is particularly evident in hyperacute attacks. Hyperacute attacks resolve rapidly once bronchodilator therapy has been instituted, suggesting that smooth muscle spasm is the predominant pathogenetic mechanism. The importance of routine anti-inflammatory therapy in mild to moderate asthma requires re-emphasis but, in addition, all patients should be provided with, and educated in the use of, bronchodilator rescue therapy, which should be available at all times. Despite current trends, the use of regular, prophylactic bronchodilator therapy in strict conjunction with anti-inflammatory agents may still be indicated. There is little evidence in the present data obtained from near-fatal cases to support the concept that cardiotoxicity related to bronchodilators contributes significantly to mortality from asthma.

Interaction between corticosteroid and beta-agonist drugs. Biochemical and cardiovascular effects in normal subjects

The aim of this study was to investigate whether the administration of prednisone potentiates any of the acute biochemical and cardiovascular effects of high-dose inhaled beta-agonist drugs. These agents are known to cause dose-related changes in plasma potassium and glucose, as well as ECG changes in heart rate, corrected QT interval (QTc), T wave, and U wave. On theoretical grounds, the concomitant use of systemic corticosteroids might enhance these actions. Twenty-four healthy subjects were randomized to receive one of three treatments: salbutamol 5 mg or fenoterol 5 mg or normal saline solution. Each drug was administered twice, 30 min apart by nebulizer, and the procedure was repeated after each subject had received prednisone 30 mg daily for one week. Plasma potassium and glucose levels were measured, and ECGs were obtained after each treatment, together with 12-h Holter monitoring for arrhythmias. Changes in plasma potassium and glucose following nebulized beta-agonist were significantly greater after treatment with prednisone. Baseline potassium level fell from 3.75 mmol/L (95 percent CI 3.61, 3.89) to 3.50 mmol/L (95 percent CI 3.36, 3.64), and thereafter all values were significantly lower at each time point (p = 0.003). The lowest mean plasma potassium was obtained 90 min after fenoterol administration with prednisone pretreatment: 2.78 mmol/L (95 percent CI 2.44, 3.13). Increases in heart rate and QTc interval following both beta-agonist drugs were significant, but T-wave amplitude reductions did not reach significance. Prednisone treatment did not significantly alter the cardiovascular responses. Supraventricular and ventricular ectopic activity was related to beta-agonist use, but no potentiating effect was noted following steroid treatment. We conclude that the acute biochemical effects of beta-agonist administration are augmented by prior treatment with prednisone, but this is not the case for ECG effects. However, the degree of hypokalemia noted as a result of this drug interaction may be of clinical significance in the hypoxic conditions of acute airways obstruction.

Can fatal asthma be prevented?--a personal view

An increase in the mortality rate from asthma in several countries has been observed in recent years, notwithstanding the great improvement in pathophysiological findings and the introduction of new effective therapeutic agents. The phenomenon is difficult to explain but the causes of death and identification of high-risk patients have been widely studied. It is suggested that the most vital aim for physicians is the avoidance of those factors which may contribute to death from asthma. These are particularly: inadequate assessment of its severity by patients, general practitioners and hospital doctors, and inadequate and inappropriate treatment. From the diagnostic point of view, the measurement of airflow rates is necessary to establish the diagnosis in terms of reversibility, quantify the severity and assess the response to therapy. The different entity of reversibility of bronchial obstruction is due to the various mechanisms intervening in different patients. After adequate treatment, according to our observations, the reversibility is more complete in young people and when the duration of the disease is less than 2 years. Trigger factors must also be considered. From the therapeutic point of view, considering that the most important alteration in asthma is the inflammation of bronchial structures with intervention of several inflammatory cells and of numerous different chemical mediators, physicians have to apply treatment aimed at reducing inflammation rather than relying on symptomatic bronchodilator remedies. Treatment should be divided into three phases, according to symptoms: induction, consolidation and maintenance. Finally, on the basis of data here presented and of clinical experience, the essential measures for the prevention of asthma mortality are reported. If general practitioners take them into account, deaths from asthma will be reduced to a minimum.

Electrophysiologic Study of the Effects of Aminophylline and Metaproterenol on Canine Myocardium

Aminophylline and beta-adrenergic agonists are widely used in the treatment of obstructive lung diseases. It has been suggested that combined aminophylline and beta-agonist therapy may promote the development of atrial and ventricular arrhythmias. The effects of these agents in combination on myocardial conduction and tissue refractoriness have not been documented. We evaluated the electrophysiologic effects of intravenous aminophylline and inhaled metaproterenol on canine myocardium. Aminophylline produced significant decreases from baseline in the AH interval (85 +/- 6.5 [SD] to 63 +/- 4.1 ms [p less than 0.02]), Wenckebach cycle length (WCL) (226 +/- 8.7 to 182 +/- 5.8 ms [p less than 0.02]), and ventricular effective refractory period (VERP) (166 +/- 6.0 to 148 +/- 4.9 ms [p less than 0.01]). Metaproterenol produced similar results, except metaproterenol significantly decreased the atrial effective refractory period (AERP) from 152 +/- 6.6 to 130 +/- 3.2 ms (p less than 0.02), an effect not seen with aminophylline alone. Metaproterenol also produced significantly greater reductions in AH interval and WCL, as well as a greater increase in heart rate than aminophylline did. When compared with aminophylline alone, combined metaproterenol and aminophylline therapy produced significantly greater reductions in the AH interval (63 +/- 4.1 versus 48 +/- 1.2 ms for combined therapy [p less than 0.01]), HV interval (32 +/- 1.2 versus 28 +/- 2.0 ms for combined therapy [p less than 0.02]), WCL (182 +/- 5.8 versus 150 +/- 7.1 ms for combined therapy [p less than 0.02]), and VERP (148 +/- 4.9 versus 132 +/- 2.0 ms for combined therapy [p less than 0.02]). We conclude that both aminophylline and metaproterenol significantly enhance AV nodal and His-Purkinje conduction. Metaproterenol produced significant changes in both atrial and ventricular tissue refractoriness. Metaproterenol produced significantly greater changes than aminophylline alone, and inhaled metaproterenol combined with intravenous aminophylline produced greater changes in AV nodal and His-Purkinje conduction and ventricular refractoriness than did aminophylline alone in a canine model.

Asthma deaths

Deaths from asthma seem to be increasing in spite of considerable improvements in drug treatment and management plans. There are many hypotheses to explain this, but little emphasis has been placed on the possibility that confidence in better drug treatments may modify patients' behavior so as to place them at greater risk of illness. It is well recognized that excessive confidence in bronchodilator inhalers and nebulizers can make patients stay away from hospitals too long during acute attacks. It is also very possible that prevention of symptoms by use of antiasthma drugs could allow patients to spend more time in environments containing antigens or other agents that provoke asthma, resulting in more serious and long-lasting bronchial inflammation and reactivity.

Respiratory arrest in near-fatal asthma

BACKGROUND AND METHODS

The majority of asthma-related deaths occur outside the hospital, and therefore the exact factors leading to the terminal event are difficult to ascertain. To examine the mechanisms by which patients might die during acute exacerbations of asthma, we studied 10 such patients who arrived at the hospital in respiratory arrest or in whom it developed soon (within 20 minutes) after admission.

RESULTS

The characteristics of the group were similar to those associated in the literature with a high risk of death from asthma, including a long history of the disease in young to middle-aged patients, previous life-threatening attacks or hospitalizations, delay in obtaining medical aid, and sudden onset of a rapidly progressive crisis. Extreme hypercapnia (mean [+/- SD] partial pressure of arterial carbon dioxide, 97.1 +/- 31.1 mm Hg) and acidosis (mean [+/- SD] pH, 7.01 +/- 0.11) were found before mechanical ventilation was begun, and four patients had hypokalemia on admission. Despite the severe respiratory acidosis, no patient had a serious cardiac arrhythmia during the resuscitation maneuvers or during hospitalization. We observed systemic hypertension and sinus tachycardia in eight patients, atrial fibrillation in one, and sinus bradycardia in another. In both patients with arrhythmia the heart reverted to sinus rhythm immediately after manual ventilation with 100 percent oxygen was begun. The median duration of mechanical ventilation was 12 hours, and all patients had normocapnia on discharge from the hospital.

CONCLUSIONS

We conclude that at least in this group of patients, the near-fatal nature of the exacerbations was the result of severe asphyxia rather than cardiac arrhythmias. These results suggest that undertreatment rather than overtreatment may contribute to an increase in mortality from asthma.

Longitudinal study of near fatal asthma

The effect of careful follow-up and treatment modification for 45 patients with an admission for NFA has been studied. In 24 of 45, inciting events were recognized. BDP was used by 14 patients pre-NFA. In the mean follow-up of 863 days, there have been no deaths and seven patients have been readmitted with asthma. Six of the 45 patients have attained normal FEV1 and PC20H. Blunted perception of breathlessness, change in VAS ratio/change in FEV1, was found when first measured, but normalized to be no different than that of other asthmatic subjects as airway responsiveness became milder. The CO2 ventilatory responses did not differentiate individual NFA patients from non-NFA asthmatic or normal subjects. Comparison of the NFA cohort with the 1985 asthma admission cohort showed that an asthma admission within the last five years was a risk factor for a NFA episode.