Case-control study of salmeterol and near-fatal attacks of asthma

Boxed Warnings and Off-Label Use of Allergy Medications: Risks, Benefits, and Shared Decision Making

The Food and Drug Administration is tasked with evaluating the efficacy and safety of a drug. Despite having a regimented appraisal process in place, safety evidence can emerge during clinical trials as well as from observations and studies conducted after the drug has been on the market, which might require a boxed warning. The boxed warning is the most severe warning that the Food and Drug Administration can give to an approved drug. It is commonly referred to as a Black Box Warning because it is outlined in the package insert by a thick black box to garner the attention of prescribers and patients. There are currently more than 400 medications that have boxed warnings, and the information addressing major risks associated with a particular drug may, appropriately or inappropriately, influence patient and clinician decision making. Health care professionals must use the best evidence and clinical judgment in determining whether to prescribe medications with these warnings. Use of an approved drug at dosages or for indications other than what it was originally licensed for is referred to as "off-label" and is legal, commonplace, and may be evidence-based. All drugs may expose patients to possible harm, so prescribers have an obligation to discuss the best available evidence regarding benefits and harms so that patients can participate in shared decision making.

Paradoxical bronchoconstriction caused by β2-adrenoceptor agonists

Introduction

Salbutamol and terbutaline are short-acting β₂ adrenergic agonists that produce bronchial smooth muscle relaxation and are widely used in obstructive pulmonary diseases. Nevertheless, their use has been the cause of a paradoxical bronchoconstriction, which is a rare and potentially serious adverse reaction. The aim of this study is to report a case of paradoxical bronchoconstriction caused by β₂ adrenergic agonists.

Methods

This case is about a 50-year-old asthmatic patient who describes a history of repeated acute asthma attacks after salbutamol inhalation or terbutaline nebulization. A double-blind crossover study was performed over 3 days, in order to compare the effects of each bronchodilator. Forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), and maximal expiratory flow 25-75 (MEF25-75) were measured.

Results

On the first day, a bronchoconstriction caused by deep and repeated inhalations was eliminated. On the second day, an airway obstruction was confirmed by a decrease in FEV₁ at 40% from baseline values after nebulization of a standard dose of terbutaline. On the third day, a spirometry was performed before and after nebulization of a standard dose of ipratropium bromide, and there were no significant changes in the spirometric parameters. Finally the patient was discharged with a written warning mentioning the danger of salbutamol and terbutaline use.

Conclusion

Salbutamol and terbutaline are generally well-tolerated β₂ adrenergic agonists. Nevertheless, in rare cases, these substances can cause a paradoxical bronchoconstriction. Doctors must therefore remain vigilant about its side effect and possibly investigate each case.

Interest of pharmacoepidemiology for the study of inhaled drugs

Pharmacoepidemiology studies are of particular interest in the respiratory field and especially for inhaled drugs. In real-life, excessive use of rescue medications and under- or inappropriate-prescribing of preventer medications has been shown. In asthma and chronic obstructive pulmonary disease (COPD), the poor use of inhalation device is associated with uncontrolled diseases and occurrence of exacerbations. Inhalation treatments are directly delivered within the lung and are generally considered as safe. However, systemic adverse drug reactions that were not evidenced in clinical trials may be observed after a long-term treatment.

IL-1β: a key modulator in asthmatic airway smooth muscle hyper-reactivity

Asthma is a chronic inflammatory disorder of the airway. It is characterized by airway hyper-reactivity, which can be attributed to the chronically inflamed airway. However, the molecular mechanism is still under investigation. In this article, we have shown that IL-1β is a key molecule that can orchestrate both Toll-like receptor and muscarinic receptor pathways, and that antagonizing the function of IL-1β has a promising future as a potential drug target for asthma treatment. IL-1β can activate NF-κB pathways via Toll-like receptors, and NF-κB will eventually transactivate the genes of cytokines, chemokines, proteins of the complement system, adhesion molecules and immune receptors involved in inflammation. IL-1β can activate eosinophils, which can release major basic protein (MBP) to antagonize the M2 receptors leading to excessive acetylcholine release. Acetylcholine has an effect on M3 receptors, which are related to airway smooth muscle contraction and mucus production. IL-1β is reported to activate COX-2 resulting in heterologous desensitization of adenylate cyclase and impairs relaxation of the ASM. IL-1β is involved in mediation of neutrophilic inflammation. Identification of the prominent role of IL-1β in asthma could lead to successful use of anti-IL1β agents.

Prescription patterns in asthma patients initiating salmeterol in UK general practice: a retrospective cohort study using the General Practice Research Database (GPRD)

BACKGROUND

An association between salmeterol, a long-acting β(2)-agonist (LABA), use and rare serious asthma events or asthma mortality was observed in two large clinical trials. This has resulted in heightened scrutiny of LABAs and comprehensive reviews by regulatory agencies.

OBJECTIVE

The aim of this retrospective observational cohort study was to better characterize salmeterol medication use patterns in the UK. We describe asthma prescription patterns in a cohort of patients (n =17,745) in the General Practice Research Database who initiated treatment with salmeterol-containing prescriptions between 2003 and 2006, including salmeterol and salmeterol/fluticasone propionate in a single device.

METHODS

Prescriptions patterns by medication class, including concurrent prescription of salmeterol with inhaled corticosteroids (ICS), were described using 6-month intervals in the 1-year period before and after the salmeterol-containing index prescription.

RESULTS

In the 0- to 6-month and 7- to 12-month periods prior to initiation of the salmeterol-containing prescription, the cohort experienced worsening of asthma, measured by an increase in the proportion of patients with prescriptions for short-acting β-agonists [SABA] (73-89%), ICS (70-81%) and systemic corticosteroids (14-28%). Nearly all patients prescribed salmeterol were concurrently prescribed ICS (≥95% within 90 days). In the 12 months following initiation of the salmeterol-containing prescription, a decrease in asthma prescriptions was observed.

DISCUSSION

These results support the appropriate prescribing of salmeterol-containing medications, as per recommendations in asthma treatment guidelines in the UK.

CONCLUSION

Salmeterol was consistently prescribed as an add-on asthma-controller with an ICS for most patients, and was associated with improvements in asthma control, as indicated by decreases in SABA and systemic corticosteroid prescriptions following salmeterol introduction.

Ecologic analysis of asthma-related events and dispensing of inhaled corticosteroid- and salmeterol-containing products

BACKGROUND

An association between salmeterol use and serious asthma episodes or asthma-related mortality has been noted in 2 clinical trials; however, a causal relationship has not been established. To date, observational studies have not replicated this finding.

OBJECTIVE

To examine the relationship between number of prescriptions dispensed of salmeterol-containing products and inhaled corticosteroid (ICS)-containing products and the rates of asthma-related hospitalizations and mortality in the United States.

METHODS

In this ecologic study, annual age-adjusted rates of asthma-related hospitalization and asthma-related mortality from US population-based sources were graphed alongside annual number of prescriptions dispensed of salmeterol- and ICS-containing products by year from 1991 to 2004. We computed the Spearman rank correlations between number of prescriptions dispensed and serious events (asthma-related hospitalization rate, number of hospitalizations, asthma-related mortality rate, and number of asthma deaths).

RESULTS

During more than 14 years, while number of prescriptions dispensed of salmeterol-containing and ICS-containing products increased, age-adjusted asthma-related mortality rates declined and asthma-related hospitalization rates remained relatively stable. The number of asthma-related deaths has decreased steadily since the mid-1990s.

CONCLUSION

This study provides population-level evidence that asthma-related death rates declined and asthma-related hospitalization rates remained relatively constant for more than 14 years during a period of improvements in asthma management per treatment guidelines, including increased use of maintenance medications, such as ICSs and salmeterol.

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.

Use of salmeterol with and without concurrent use of inhaled corticosteroids and the risk of asthma-related hospitalization among patients with asthma

RATIONALE

Studies evaluating the safety of salmeterol are inconclusive, which might be the result from not taking into account the impact of concomitant inhaled corticosteroids (ICS).

OBJECTIVE

To study whether salmeterol use with and without concomitant ICS, respectively, was associated with an increased risk of asthma-related hospitalizations among patients with asthma.

METHODS

A case-control study nested within a cohort of patients with asthma, identified in the year 2000, over a 2-year period was conducted. Cases were subjects who had a first-time hospitalization for asthma in the year 2001, and were matched with up to five controls by age (+/- 5 years), sex, and number of asthma-related outpatient visits.

MEASUREMENTS

Hospitalizations and medication use were extracted from the MEDSTAT's MarketScan database.

MAIN RESULTS

There were 333 cases of asthma-related hospitalizations and 1607 matched control subjects. Any use of salmeterol with concomitant ICS use during the prior year was associated with a 32% risk reduction for being hospitalized due to asthma (OR = 0.68; 95% CI = 0.48, 0.96). In the presence of concomitant ICS use, patients who either used salmeterol currently or used seven or more canisters of salmeterol during the prior year had 46% (OR = 0.54, 95% CI = 0.32, 0.92), and 59% (OR = 0.41, 95% CI = 0.21, 0.79) reductions in the risk of hospital admissions for asthma, respectively.

LIMITATIONS

Though indirect measure of asthma severity was adjusted during the analyses, the lack of information on lung function might result in a selection bias. Additionally, only a small sample size of patients was found to use salmeterol without concomitant ICS use, and this introduced the issue of lack of power.

CONCLUSIONS

Use of salmeterol in conjunction with ICS is associated with a decreased risk of hospital admission for asthma.

Acute severe asthma

Acute severe asthma remains a major economic and health burden. The natural history of acute decompensations is one of resolution and only about 0.4% of patients succumb overall. Mortality in medical intensive care units is higher but is less than 3% of hospital admissions. "Near-fatal" episodes may be more frequent, but precise figures are lacking. However, about 30% of medical intensive care unit admissions require intubation and mechanical ventilation with mortality of 8%. Morbidity and mortality increase with socioeconomic deprivation and ethnicity. Seventy to 80% of patients in emergency departments clear within 2 hours with standardized care. The relapse rate varies between 7 and 15%, depending on how aggressively the patient is treated. The airway obstruction in the 20-30% of people resistant to adrenergic agonists in the emergency department slowly reverses over 36-48 hours but requires intense treatment to do so. Current therapeutic options for this group consist of ipratropium and corticosteroids in combination with beta2 selective drugs. Even so, such regimens are not optimal and better approaches are needed. The long-term prognosis after a near-fatal episode is poor and mortality may approach 10%.

Overcoming gaps in the management of asthma in older patients: new insights

Asthma is under-recognised and undertreated in older populations. This is not surprising, given that one-third of older people experience significant breathlessness. The differential diagnosis commonly includes asthma, chronic obstructive pulmonary disease (COPD), heart failure, malignancy, aspiration and infections. Because symptoms and signs of several cardiorespiratory diseases are nonspecific in older people and diseases commonly co-exist, investigations are important. A simple strategy for the investigation of breathlessness in older people should include a full blood count, chest radiograph, ECG, peak flow diary and/or spirometry with reversibility as a minimum. If there are major abnormalities on the ECG, an echocardiogram should also be performed. Diurnal variability in peak flow readings >or=20% or >or=15% reversibility in forced expiratory volume in 1 second, spontaneously or with treatment, support a diagnosis of asthma. Distinguishing asthma from COPD is important to allow appropriate management of disease based on aetiology, accurate prediction of treatment response, correct prognosis and appropriate management of the chest condition and co-morbidities. The two conditions are usually readily differentiated by clinical features, particularly age at onset, variability of symptoms and nocturnal symptoms in asthma, supported by the results of reversibility testing. Full lung function tests may not necessarily help in differentiating the two entities, although gas transfer factor is characteristically reduced in COPD and usually normal or high in asthma. Methacholine challenge tests previously mainly used in research are now also used widely and safely to confirm asthma in clinical settings. Interest in exhaled nitric oxide as a biomarker of airways inflammation is increasing as a noninvasive tool in the diagnosis and monitoring of asthma. Regular inhaled corticosteroids (ICS) are the mainstay of treatment of asthma. Even in mild disease in older adults, regular preventive treatment should be considered, given the poor perception of bronchoconstriction by older asthmatic patients. If symptoms persist despite ICS, addition of long-acting beta(2)-adrenoceptor agonists (LABA) should be considered. Addition of LABA to ICS improves asthma control and allows reduction in ICS dose. However, older people have been grossly under-represented in trials of LABA, many trials having excluded those >or=65 years of age. On meta-analysis, beta(2)-adrenoceptor agonists (both short acting and long acting) are associated with increased cardiovascular mortality and morbidity in asthma and COPD. While the evidence for excess cardiovascular mortality is stronger for short-acting beta(2)-adrenoceptor agonists, it would be prudent to exercise particular care in using beta(2)-adrenoceptor agonists (long acting and short acting) in those at risk of adverse cardiovascular outcomes, including older people. Regular review of cardiovascular status (and monitoring of serum potassium concentration) in patients taking beta(2)-adrenoceptor agonists is crucial. The response to LABA should be carefully monitored and alternative 'add-on' therapy such as leukotriene receptor antagonists (LRA) should be considered. LRA have fewer adverse effects and in individual cases may be more effective and appropriate than LABA. Long-term trials evaluating beta(2)-adrenoceptor agonists and other bronchodilator strategies are needed particularly in the elderly and in patients with cardiovascular co-morbidities. There is no evidence that addition of anticholinergics improves control of asthma further, although the role of long-acting anticholinergics in the prevention of disease progression is currently being researched. Older patients need to be taught good inhaler technique to improve delivery of medications to lungs, minimise adverse effects and reduce the need for oral corticosteroids. Nurse-led education programmes that include a written asthma self-management plan have the potential to improve outcomes.

The Salmeterol Multicenter Asthma Research Trial: a comparison of usual pharmacotherapy for asthma or usual pharmacotherapy plus salmeterol

STUDY OBJECTIVE

To compare the safety of salmeterol xinafoate or placebo added to usual asthma care.

DESIGN

A 28-week, randomized, double-blind, placebo-controlled, observational study.

SETTING

Study subjects were seen once in the study physician's office for screening and were provided all blinded study medication for the entire study period. Follow-up by telephone was scheduled every 4 weeks.

PARTICIPANTS

Subjects (> 12 years old) with asthma as judged by the study physician were eligible. Individuals with a history of long-acting beta2-agonist use were excluded.

INTERVENTIONS

Salmeterol, 42 mug bid via metered-dose inhaler (MDI), and placebo bid via MDI.

MEASUREMENTS AND RESULTS

Following an interim analysis in 26,355 subjects, the study was terminated due to findings in African Americans and difficulties in enrollment. The occurrence of the primary outcome, respiratory-related deaths, or life-threatening experiences was low and not significantly different for salmeterol vs placebo (50 vs 36; relative risk [RR] = 1.40; 95% confidence interval [CI], 0.91 to 2.14). There was a small, significant increase in respiratory-related deaths (24 vs 11; RR, 2.16; 95% CI, 1.06 to 4.41) and asthma-related deaths (13 vs 3; RR, 4.37; 95% CI, 1.25 to 15.34), and in combined asthma-related deaths or life-threatening experiences (37 vs 22; RR, 1.71; 95% CI, 1.01 to 2.89) in subjects receiving salmeterol vs placebo. The imbalance occurred largely in the African-American subpopulation: respiratory-related deaths or life-threatening experiences (20 vs 5; RR, 4.10; 95% CI, 1.54 to 10.90) and combined asthma-related deaths or life-threatening experiences (19 vs 4; RR, 4.92; 95% CI, 1.68 to 14.45) in subjects receiving salmeterol vs placebo.

CONCLUSIONS

For the primary end point in the total population, there were no significant differences between treatments. There were small, but statistically significant increases in respiratory-related and asthma-related deaths and combined asthma-related deaths or life-threatening experiences in the total population receiving salmeterol. Subgroup analyses suggest the risk may be greater in African Americans compared with Caucasian subjects. Whether this risk is due to factors including but not limited to a physiologic treatment effect, genetic factors, or patient behaviors leading to poor outcomes remains unknown.

Asthma treatment in the 21st century: what's next?

Asthma treatment is evolving as we enter the 21st century. This review focuses on several different areas of asthma treatment now in evolution. These include: (1) the proper role of various asthma controllers--either already approved or under investigation--besides inhaled corticosteriods in asthma therapy; (2) the potential role for immune and cytokine modulation for asthma therapy; (3) the potential role for pharmacogenetics in asthma therapy; and (4) whether single-inhaler therapy with a combination of an inhaled corticosteriod and a long-acted beta-agonist could be used for both maintenance and rescue in patients with asthma.

Bronchodilator treatment and deaths from asthma: case-control study

OBJECTIVE

To investigate the association between bronchodilator treatment and death from asthma.

DESIGN

Case-control study.

SETTING

33 health authorities or health boards in Great Britain.

PARTICIPANTS

532 patients under age 65 who died from asthma and 532 controls with a hospital admission for asthma matched for period, age, and area.

MAIN OUTCOME MEASURES

Odds ratios for deaths from asthma associated with prescription of bronchodilators and other treatment, with sensitivity analyses adjusting for age at onset, previous hospital admissions, associated chronic obstructive lung disease, and number of other drug categories.

RESULTS

After full adjustment, there were no significant associations with drugs prescribed in the 4-12 months before the index date. For prescriptions in the 1-5 years before, mortality was positively associated with inhaled short acting beta2 agonists (odds ratio 2.05, 95% confidence interval 1.26 to 3.33) and inversely associated with antibiotics (0.59, 0.39 to 0.89). The former association seemed to be confined to those aged 45-64, and the association with antibiotics was more pronounced in those under 45. Significant age interactions across all periods suggested inverse associations with oral steroids confined to the under 45 age group. An inverse association with long acting beta2 agonists and a positive association with methylxanthines in the 1-5 year period were non-significant.

CONCLUSION

There was no evidence of adverse effects on mortality with medium to long term use of inhaled long acting beta2 agonist drugs. The association with short acting beta(2) agonists has several explanations, only one of which may be a direct adverse effect.

The relationship between the quality of prescribing and practice appointment rates with asthma management data in those admitted to hospital due to an acute exacerbation

Specific targeting of patients with a previous asthma hospitalisation could be more focused if predictors could be identified. This study was an observational retrospective analysis using ridge and linear multivariate regression analysis. Patient asthma management data were extracted from the hospital and general practice notes of those that had been admitted with an acute exacerbation of their asthma over a 5-year period. From the prescribing data, the annual doses of preventer (P) and reliever (R) medication were converted to defined daily doses then divided to give a P:R ratio. Preliminary statistical analysis was used to identify any association between either the P:R ratio or for the number of general practitioner (GP) practice appointments (PA) and their asthma management data. Multivariate regression analysis was applied to the P:R ratio and to PA to determine a model between each of these and asthma management data/events. GPs gave consent to access the data of 115 (out of 440) asthmatics, age >5 years, admitted to a district general hospital for asthma exacerbations between 1994 and 1998. The multivariate analysis revealed that PA was associated with oral prednisolone rescue courses (PRCs) and age whilst the P:R ratio was associated to PRCs and more reliever usage but not preventers. Patients with low preventer usage with respect to their reliever medication should be targeted for medication review as these were the patients prescribed more prednisolone courses and their increased PAs reflect this. This could decrease visits to the doctor and acute exacerbations.

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

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

Sequential evaluation of the national medical expenditures for asthma care in Japan

BACKGROUND: It has been reported that the prevalence of asthma is on the rise in various countries; but studies on its effects on national medical expenditures are scarce.

METHODS: From the outcome of the “Estimates of National Medical Care Expenditures” and “Patient Survey” compiled by the Statistics and Information Department, Minister’s secretariat, the Ministry of Health, Labour, and Welfare of Japan, medical expenditures on asthmatic patients in Japan were sequentially examined.

RESULTS: It was found that the percentage of asthmatic patients to the general medical care expenditures has been on the steady increase. A closer examination revealed that the percentage of asthmatic outpatients receiving care increased while those receiving care as inpatients decreased.

CONCLUSION: The relationships between the percentage of the number of asthmatic patients utilizing medical services and the expenditures for their care differed between inpatients and outpatients.

Risk factors of emergency care and admissions in COPD patients with high consumption of health resources

This study is a case-control study looking to identify factors associated with frequent use of hospital services (emergency care and admissions) in COPD patients. Data from 64 patients with moderate-severe COPD (FEV1/FVC < or = 70, FEV1 < or = 50%) were prospectively collected, 32 cases with high consumption of health resources (COPD-HC) and 32 controls. COPD-HC was defined as a patient diagnosed of COPD requiring during one year: (1) two or more hospitalizations; (2) three or more emergency visits; or (3) one admission and two emergency visits. Patients with COPD and a similar age, FEV1 and PaO2 who required no hospital care during the study year (1998) were randomly selected as controls. Demographic, clinical and socioeconomic data were collected from each subject, and evaluations were made of anxiety, health-related quality of life [measured with the St. George's Respiratory Questionnaire (SGRQ)], nutritional parameters, and different therapeutic aspects. Forced spirometry, resting arterial blood gases, maximal respiratory muscle pressures and a 6-min walking test were measured in all cases. After applying a logistic regression model, the variables that finally proved to be independent predictors of frequent use of hospital services were: treatment with salmeterol, the presence of cardiac arrhythmias, and increased SGRQ scores. The administration of inhaled salmeterol multiplied the risk of having COPD-HC criteria by 27.4 (95%CI: 2.4-308.1), while the presence of arrhythmias multiplied the probability of meeting high consumption criteria by 24.3 (95%CI: 1.7-340.1). For each point of worsened quality of life, the risk of hospital care increased 1.06-fold (95%CI: 1.01-1.10). Although a severity bias related to the presence of long-acting beta2-agonists in the final regression equation cannot be ruled out, the variables associated in our sample to an increased utilization of hospital services are the regular use of inhaled salmeterol, the presence of cardiac arrhythmias, and an impaired health-related quality of life. The use of specific strategies aimed at modulating these aspects could, at least in theory, reduce the number of exacerbations requiring hospital care, with the resultant individual and collective benefits derived.

Adverse effects of beta-agonists: are they clinically relevant?

Inhaled beta(2)-adrenoceptor agonists (beta(2)-agonists) are the most commonly used asthma medications in many Western countries. Minor adverse effects such as palpitations, tremor, headache and metabolic effects are predictable and dose related. Time series studies suggested an association between the relatively nonselective beta-agonist fenoterol and asthma deaths. Three case-control studies confirmed that among patients prescribed fenoterol, the risk of death was significantly elevated even after controlling for the severity of asthma. The Saskatchewan study not only found an increased risk of death among patients dispensed fenoterol, but also suggested this might be a class effect of beta(2)-agonists. However, in subsequent studies, the long-acting beta(2)-agonist salmeterol was not associated with increased asthma mortality. In a case-control study blood albuterol (salbutamol) concentrations were found to be 2.5 times higher among patients who died of asthma compared with controls. It is speculated that such toxic concentrations could cause tachyarrhythmias under conditions of hypoxia and hypokalemia. The risk of asthma exacerbations and near-fatal attacks may also be increased among patients dispensed fenoterol, but this association may be largely due to confounding by severity. Although salmeterol does not appear to increase the risk of near-fatal attacks, there is a consistent association with the use of nebulized beta(2)-agonists. Nebulized and oral beta(2)-agonists are also associated with an increased risk of cardiovascular death, ischemic heart disease and cardiac failure. Caution should be exercised when first prescribing a beta-agonist for patients with cardiovascular disease. A potential mechanism for adverse effects with regular use of beta(2)-agonists is tachyphylaxis. Tachyphylaxis to the bronchodilator effects of long-acting beta(2)-agonists can occur, but has been consistently demonstrated only for formoterol (eformoterol) a full agonist, rather than salmeterol, a partial agonist. Tachyphylaxis to protection against induced bronchospasm occurs with both full and partial beta(2)-agonists, and probably within a matter of days at most. Underlying airway responsiveness to directly acting bronchoconstricting agents is not increased when the bronchodilator effect of the regular beta(2)-agonist has been allowed to wear off, although there may be an increase in responsiveness to indirectly acting agents. While there has been speculation that underlying airway inflammation in asthma may be made worse by regular use of short-acting beta(2)-agonists, in contradistinction, a number of studies have shown that long-acting beta(2)-agonists have positive anti-inflammatory effects. An Australian Cochrane Airways Group systematic review of the randomized, controlled trials of short-acting beta-agonists found only minimal and clinically unimportant differences between regular use and use as needed. Regular short-acting treatment was better than placebo. However, a subsequent systematic review has found that regular use of long-acting beta-agonists had significant advantages over regular use of short-acting beta-agonists. More studies and data are needed on the regular use of beta(2)-agonists in patients not taking inhaled corticosteroids, and in potentially vulnerable groups, such as the elderly and those with particular genotypes for the beta-receptor, who might be more prone to adverse effects.

A case-control study of asthma death and life-threatening attack: their possible relationship with prescribed drug therapy in Japan

Sales of inhaled beta2-agonist bronchodilators may be related to the increase in asthma deaths. The aim of this study is to find whether prescribed drug therapy was associated with the increased risk of death from asthma and life-threatening attacks (LTA). The "case" group comprised those under 35 years of age who expired or experienced LTA from January 1994 through December 1996. For each case, an age and sex matched control was selected from asthma patients. Hospital records were reviewed to obtain information on the prescribed drug therapy and clinical asthma severity for the cases and controls. Bivariate analysis with conditional logistic regression models for matched data sets were used to estimate the severity-adjusted odds ratios for each asthma medication. Twenty-four fatal cases and 54 LTA cases were observed. The crude odds ratio of clinical severity (OR=9.33, 95%CI:2.84-30.7) was larger than unity and with statistical significance. After adjusting for clinical severity, the odds ratios computed for all beta2-agonists delivered by metered dose inhaler (MDI) increased (OR=2.08, 95%CI:0.78-5.50) from that of crude analysis. Among those subjects under 20 years of age, the clinical severity-adjusted odds ratio for the use of all beta2-agonists by MDI (OR=3.67, 95%CI:0.77-17.5) was higher than that of all subjects. The prescription of B2-agonists by MDI increased the risk of asthma death after taking clinical severity into account. Although not statistically significant, our results suggested that beta2-agonists administered by a MDI might have increased the risk of asthma death and LTA in Japan because the magnitude of the effect was similar to that reported in other countries.

Long-acting beta-agonist treatment in patients with persistent asthma already receiving inhaled corticosteroids

International guidelines recommend that long-acting beta-agonists should be considered in patients who are symptomatic despite moderate doses of inhaled corticosteroids. When combined with inhaled corticosteroids they improve asthma symptoms and lung function and reduce exacerbations. The evidence suggests that they are well tolerated. However, they are less effective than inhaled corticosteroids as monotherapy and should not be used alone, although the addition of a long-acting beta-agonist may permit a small reduction in the corticosteroid dose. Both salmeterol and formoterol appear equally effective in improving asthma control. Formoterol, however, has a rapid onset of action and is now being promoted for the relief of acute asthma symptoms. Both drugs provide prolonged protection against exercise-induced bronchospasm. However, this effect rapidly diminishes with continuous therapy and if this is the main aim of treatment, intermittent use may be preferable. When compared with alternative treatments, inhaled long-acting beta-agonists are more effective in controlling asthma symptoms than either theophylline or antileukotriene agents. Bambuterol, an oral prodrug of terbutaline, appears to be as effective as the inhaled long-acting beta-agonists and has the advantage of once daily oral administration. However, the inhaled long-acting beta-agonists are less likely to have systemic adverse effects. There are theoretical concerns that regular beta-agonist treatment may lead to tolerance and a failure to respond to emergency asthma treatment. While there is no doubt that tolerance occurs, there is currently little evidence that this is a clinical problem. Insights into pharmacological as well as therapeutic interactions between inhaled corticosteroids and beta-agonists are providing justification for their use in combination. Guidelines for the management of patients with chronic persistent asthma are likely to require modification to reflect these developments.

Acute asthma

OBJECTIVE: Asthma is the most common medical emergency in children. It is associated with significant morbidity and mortality rates and poses a tremendous societal burden worldwide. Management of the acute attack involves a stepwise approach that includes beta-agonist and steroid therapy, the mainstay of emergency treatment. Most patients will respond to this regime and can be discharged from the emergency department. Failure to respond to treatment necessitates hospital admission and sometimes admission to the intensive care unit (ICU). Management in the ICU involves intensification of pharmacologic therapy, including nonstandard therapies, in an attempt to avoid intubation and ventilation. When needed, mechanical ventilatory support can be rendered fairly safe with little morbidity if the likely cardiorespiratory physiologic derangements are appreciated and if appropriate ventilatory strategies are used. In the past two decades, the availability of newer potent medications and changes in approach to monitoring and ventilatory strategies have resulted in a decrease in ICU morbidity and mortality rates. Research endeavors are presently underway to further characterize the underlying mechanisms of the disease and are likely to lead to novel therapies. This article reviews the approach to management of acute severe asthma.

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.

[What is new in pediatric pneumology?]

Have been selected for this review: 1) the recent and impressive development of high-resolution and spiral CT scan in pediatric thoracic imaging; 2) the emerging of new and promising therapies for asthma (long acting inhaled beta 2-agonists, leukotriene antagonists, anti-IgE monoclonal antibodies); 3) the multifactorial origin of asthma in childhood; 4) the development of thoracoscopic surgery, a minimal-invasive approach beneficial in numerous circumstances.

Risk of emergency care, hospitalization, and ICU stays for acute asthma among recipients of salmeterol

We used automated health insurance claims records of a New England insurer to assess the relation between salmeterol and severe nonfatal asthma. We identified 61,712 members who received a beta-agonist from January 1, 1993 to August 31, 1995, including 2, 708 recipients of salmeterol. Compared with recipients of other beta-agonists, future salmeterol recipients had higher rates of asthma hospitalization and dispensings of asthma medications during the year before they received salmeterol. We selected as a comparison group 3,825 recipients of sustained-release theophylline. We defined a baseline period as the year before the start of the follow-up period, and we characterized patients according to age, sex, calendar period, presence of baseline hospitalizations for asthma, presence of chronic obstructive pulmonary disease (COPD), and baseline dispensings of asthma medications. After adjusting for baseline factors, incidence rates of severe asthma in the salmeterol group were not elevated for emergency care (rate ratio estimate [RR] = 0.69, 95% confidence intervals [CI] = 0.42, 1.11), hospitalization (RR = 1.09, 95% CI = 0.60, 1.98), or intensive care unit (ICU) stays (RR = 0.81, 95% CI = 0.25, 2.62). We conclude that salmeterol was prescribed preferentially to high-risk patients and, after adjusting for baseline risk, salmeterol recipients did not have a greater risk than theophylline recipients of severe nonfatal asthma.