Effect of prednisone and beclomethasone dipropionate on airway responsiveness in asthma: a comparative study

The effects of oral corticosteroids on lung function, type-2 biomarkers and patient-reported outcomes in stable asthma: A systematic review and meta-analysis

BACKGROUND

Several studies have investigated the physiological effect of OCS in stable asthma, however these have included heterogeneous populations and outcomes. This paper is the first to combine their results.

METHODS

We searched Medline, Embase and Web of Science databases for studies reporting the impact of OCS on FEV₁, FVC, blood eosinophils, fractional exhaled nitric oxide (FeNO), Asthma Control Questionnaire (ACQ) score or Asthma Quality Of Life Questionnaire (AQLQ) score in stable asthma. We extracted data on the correlates of OCS response.

RESULTS

61 studies, comprising 1608 patients, were included. FEV₁ was improved by 9% (95% CI: 7, 11). There were stronger increases in FEV₁ among those with a mean baseline FEV₁<60% predicted (19%, 95% CI: 13, 24). Despite these improvements, substantial residual impairment remained after treatment. Blood eosinophils were reduced by 76% (95% CI: 63, 88) with larger decreases in studies of corticosteroid-naïve patients (93%, 95% CI: 73,100). Sputum eosinophils were reduced by 89% (95% CI: 79, 98) while FeNO was decreased by 35% (95% CI: 28, 41). ACQ scores were reduced by 20% (95% CI: 11, 29). Patients with higher baseline lung function impairment, sputum eosinophils, blood eosinophils and FeNO had improved OCS response.

INTERPRETATION

OCS consistently improves lung function, reduces markers of type-2 inflammation, and alleviates asthma symptoms. However, substantial residual impairment remained following treatment and mean improvements were below the minimally important clinically difference. Patients with increased markers of type-2 inflammation are more responsive to treatment, suggesting these should be used to better target OCS use.

Repurposing drugs as inhaled therapies in asthma

For the first 40 years of the 20th century treatment for asthma occurred in response to an asthma attack. The treatments were given by injection or orally and included the adrenergic agonists adrenalin/epinephrine and ephedrine and a phosphodiesterase inhibitor theophylline. Epinephrine became available as an aerosol in 1930. After 1945, isoprenaline, a non-selective beta agonist, became available for oral use but it was most widely used by inhalation. Isoprenaline was short-acting with unwanted cardiac effects. More selective beta agonists, with a longer duration of action and fewer side-effects became available, including orciprenaline in 1967, salbutamol in 1969 and terbutaline in 1970. The inhaled steroid beclomethasone was available by 1972 and budesonide by 1982. Spirometry alone and in response to exercise was used to assess efficacy and duration of action of these drugs for the acute benefits of beta₂ agonists and the chronic benefits of corticosteroids. Early studies comparing oral and aerosol beta₂ agonists found equivalence in bronchodilator effect but the aerosol treatment was superior in preventing exercise-induced bronchoconstriction. Inhaled drugs are now widely used including the long-acting beta₂ agonists, salmeterol and formoterol, and the corticosteroids, fluticasone, ciclesonide, mometasone and triamcinolone, that act locally and have low systemic bio-availability. Repurposing drugs as inhaled therapies permitted direct delivery of low doses of drug to the site of action reducing the incidence of unwanted side-effects and permitting the prophylactic treatment of asthma.

Epimedium flavonoids counteract the side effects of glucocorticoids on hypothalamic-pituitary-adrenal axis

Our previous studies demonstrated that the epimedium herb, when simultaneously used with GCs, counteracted suppressive effects of GCs on the HPA axis without adverse influence on the therapeutic action of GCs. Here, total flavones were extracted from the epimedium flavonoids (EFs) and then used to investigate whether EFs provide protective effects on the HPA axis. We found that GCs induced a significant decrease in body weight gain, adrenal gland weight gain, and plasma adrenocorticotropin (ACTH) and corticosterone levels. After treatment with EFs, body weight gain, adrenal gland weight gain, and plasma corticosterone level were significantly restored, whilst plasma ACTH level was partially elevated. EFs were also shown to promote cell proliferation in the outer layer of adrenal cortex and to enhance the migration of newly divided cells toward the inner layer. To elucidate the underlying mechanisms, the mRNA expression of insulin-like growth factor II (IGF-II) was measured, and EFs significantly upregulated IGF-II expression. Our results indicated that EFs counteract the suppression of the HPA axis induced by GCs. This may involve both the ACTH and IGF-II pathways and thereby promote regeneration of the adrenal cortex suggesting a potential clinical application of EFs against the suppressive effects of GCs on the HPA axis.

Corticosteroids in respiratory diseases in children

We review recent advances in the use of corticosteroids (CS) in pediatric lung disease. CS are frequently used, systemically or by inhalation. Their mechanisms of action in pulmonary diseases are ill defined. CS exert direct inhibitory effects on many inflammatory cells through genomic mechanisms. There is a time lag before clinical response, and the washout of effects is also prolonged. Prompt relief in some conditions, such as croup, may be related to airway mucosal vasoconstriction through a nongenomic mechanism. CS have proven beneficial roles in the treatment of asthma, croup, allergic bronchopulmonary aspergillosis, and subglottic hemangioma. In some conditions, such as bronchiolitis, cystic fibrosis, and bronchopulmonary dysplasia, their use is controversial and is not recommended routinely. In other conditions, such as tuberculosis, interstitial lung disease, acute lung aspiration, and acute respiratory distress syndrome, CS are often used empirically despite the lack of clear evidence of their benefit. New drug regimens, including the more flexible use of inhaled corticosteroids and long-acting β-agonists in asthma, the lack of efficacy of oral corticosteroids in preschool children with acute wheeze, the severe complications of systemic dexamethasone used to prevent bronchopulmonary dysplasia and thus more restricted use, and the beneficial effect of pulse high-dose intravenous methylprednisolone in patients with allergic bronchopulmonary aspergillosis or cystic fibrosis are among the major recent developments. There is concern about adverse effects, especially growth and adrenal suppression, induced by systemic CS in children. These have been reduced, but not eliminated, with the use of the inhaled route. The benefits must be weighed against the potential detrimental effects.

Similar efficacy of ciclesonide versus prednisolone to treat asthma worsening after steroid tapering

RATIONALE

Oral corticosteroids effectively treat asthma exacerbations but are associated with well-described side effects.

OBJECTIVE

This study compared the efficacy and safety of a high dose of an inhaled corticosteroid with oral prednisolone in patients with worsening of their asthma after medication withdrawal.

METHODS

Patients tapered off their inhaled corticosteroids until they reached predefined criteria of "worsening asthma". Randomized patients (n=130) were treated double blind with either ciclesonide 800mug twice daily (starting with 800mug hourly for 3h after randomization) or prednisolone 40mg once daily for 2 weeks. Spirometry, daily asthma symptoms, morning and evening peak expiratory flow and blood parameters were assessed in all, methacholine challenge and inflammatory measures were determined in induced sputum in a subset of patients.

RESULTS

Ciclesonide was as effective as prednisolone in improving forced expiratory flow in 1s, morning peak expiratory flow and symptoms, the latter improving more rapidly with ciclesonide. No differences were found in methacholine responsiveness or inflammatory measures in sputum or blood. Ciclesonide caused significantly less reduction in morning plasma cortisol levels (p<0.0001).

CONCLUSION

This study shows that inhaled ciclesonide (800mug twice daily) has comparable efficacy to oral prednisolone (40mg once daily) to regain asthma control in patients with asthma worsening. The more rapid onset and smaller effect on cortisol suppression suggest a better safety profile of ciclesonide.

Increased glycosaminoglycans in the urine of asthmatic children on inhaled corticosteroids

Increased extracellular matrix (ECM) deposition in the airway wall contributes to the airway remodeling in asthmatics. Glycosaminoglycans (GAGs) are polysaccharides attached to a protein core in order to form proteoglycans, a component of the ECM. In this study, we investigated the possible influence of long-term treatment with inhaled corticosteroids (ICS) on urinary GAGs levels of asthmatic children. Seventy asthmatic children (41 boys), aged 6.8-12.5 yr, participated in the study. About 44 were treated with inhaled budesonide via turbuhaler for 2-35 months (median 12 months) and 26 were on relief medications. About 30 healthy controls were also studied. GAGs were precipitated from early morning urine samples, collected, isolated and quantified using uronic acid-carbazole reaction and expressed as uronic acid (UA) in microg/g/Cr(u)/m2. Urinary GAGs values did not differ significantly between controls and asthmatics but significant differences were found between children on ICS and asthmatics on relief medications (p < 0.001). There was a positive correlation between the daily dose of inhaled budesonide and the urinary GAGs values (r = 0.32, p = 0.037) whereas a threshold distinguishing 'low' vs. 'high' doses of ICS was found to be at 300 microg/m2 per day with a significant difference in urinary GAGs secretion (p = 0.006). Our data show that urinary GAGs secretion is reduced in asthmatic children that used only relief medication but it is increased in those on long-term treatment with ICS. A dose dependent effect of ICS was also detected.

Exhaled markers in the monitoring of airways inflammation and its response to steroid's treatment in mild persistent asthma

The measure of inflammatory cytokines in the exhaled breath condensate has been recently proposed for use in monitoring asthma and the therapeutic response to steroids. The aim of the present study was to investigate the usefulness of measuring exhaled IL-6, IL-4 and pH in mild persistent asthma. Furthermore the effects on these markers of inhaled steroids were assessed. The study enrolled 28 asthmatic (15 males, 38+/-12 years) and 15 healthy subjects (5 males, 35+/-6 years). IL-6, IL-4 and pH were measured in the exhaled breath condensate of the subjects studied. Significantly higher concentrations of IL-6 and IL-4 were observed in the breath condensate of asthmatic patients (7.1+/-1.1 and 64.4+/-8.3 pg/ml) compared to controls (2.7+/-0.6 and 31.7+/-3.5 pg/ml), p<0.001. Furthermore, exhaled IL-4 fell significantly after treatment with inhaled steroids for 6 months (47.9+/-3.2 pg/ml, p<0.001) while exhaled IL-6 did not (6.4+/-1.0 pg/ml, p=0.8). The exhaled pH turned out to be lower in asthmatic subjects than in controls (7.39+/-0.11 vs. 7.85+/-0.14; P<0.001) but trended towards control levels after steroid treatment (7.65+/-0.16, P<0.001). We conclude that the measurement of exhaled IL-4 and pH in mild asthmatic subjects could be a useful way of monitoring their airway inflammation as well as their response to the treatment.

Increase in airway neutrophils after oral but not inhaled corticosteroid therapy in mild asthma

BACKGROUND

Neutrophils, in addition to eosinophils, are prominent in the airways of patients with severe asthma who are usually on long-term oral and inhaled corticosteroid treatment. We determined whether inhaled or oral corticosteroid therapy can induce airway neutrophilia.

METHODS

We performed two separate placebo-controlled studies in which patients with mild asthma were treated with either prednisolone (30mg per day for 7 days; n = 9) or placebo tablets (n = 8), or with either inhaled budesonide (800 microg twice daily for 4 weeks; n = 6) or inhaled placebo (n = 6). Fiberoptic bronchoscopy was performed before treatment and at day 7 of oral treatment, and at day 28 of inhaled therapy. Bronchial sections were immunostained with an antibody to major basic protein for eosinophils, and with an antibody to neutrophil elastase for neutrophils. Induced sputum was obtained in the prednisolone study.

RESULTS

Neutrophils in airway submucosa increased after prednisolone from median 76 to 140/mm2 (P = 0.05); this change was higher than that after placebo (P = 0.04). Eosinophils decreased from 24 to 9/mm2 (P = 0.03), but this was not significantly different from placebo. Eosinophils and neutrophils, and levels of IL-8 and myeloperoxidase in induced sputum did not change after prednisolone. There was no change in neutrophil counts after budesonide, but the reduction in eosinophils was greater than placebo (P = 0.05). Budesonide improved bronchial responsiveness, but prednisolone did not.

CONCLUSION

Corticosteroid therapy by the oral but not inhaled route can induce neutrophil recruitment into the airways of patients with mild asthma. This could explain the increase in airway neutrophils observed in severe asthmatics treated with oral corticosteroids.

Time course of action of two inhaled corticosteroids, fluticasone propionate and budesonide

BACKGROUND

It is important to be able to compare the efficacy and systemic effects of inhaled corticosteroids but their slow onset of action makes it difficult to measure the maximum response to a given dose. Submaximal responses could be compared if the time course of action of the inhaled corticosteroids being compared was similar. We have compared the time course of action of fluticasone and budesonide, measuring response as change in the provocative dose of adenosine monophosphate causing a 20% fall in forced expiratory volume in 1 second (PD20AMP).

METHODS

Eighteen subjects with mild asthma, aged 18-65, took part in a three way randomised crossover study. Subjects took fluticasone (1500 microg/day), budesonide (1600 microg/day), and placebo each for 4 weeks with a washout period of at least 2 weeks between treatments; PD20AMP and forced expiratory volume in 1 second (FEV1) were measured during and after treatment. The time taken to achieve 50% of the maximum response (T50%) was compared as a measure of onset of action.

RESULTS

There was a progressive increase in PD20AMP during the 4 weeks of treatment with both fluticasone and budesonide but not placebo; the increase after 1 and 4 weeks was 2.28 and 4.50 doubling doses (DD) for fluticasone and 2.49 and 3.65 DD for budesonide. T50% was 9.3 days for fluticasone and 7.5 days for budesonide with a median difference between fluticasone and budesonide of 0.1 days (95% CI -1.4 to 2.65). There was a wide range of response to both inhaled corticosteroids but good correlation between the response to fluticasone and budesonide within subjects. FEV1 and morning peak expiratory flow rate (PEFR) increased during the first week of both active treatments and were stable thereafter. There was a small progressive improvement in nocturnal symptoms with both active treatments.

CONCLUSION

PD20AMP was a more sensitive marker of response to inhaled corticosteroid therapy than FEV1 and PEFR. The time course of action of fluticasone and budesonide on PD20AMP is similar, suggesting that comparative studies of their efficacy using 1 or 2 week treatment periods are valid. When a new inhaled corticosteroid becomes available, a pilot study comparing its time course of action with that of an established corticosteroid should allow comparative studies to be performed more efficiently.

Inhaled corticosteroids for asthma: common clinical quandaries

This narrative review provides evidence-based explanations to some of the common clinical concerns regarding inhaled corticosteroids. Inhaled corticosteroids are the treatment of choice for a newly diagnosed asthmatic patient. Better results are obtained when treatment is initiated as soon as the diagnosis is made. Asthma control can be achieved and maintained in most patients with a low or moderate dose of inhaled corticosteroid administered in two daily doses. Longer duration of treatment provides more sustained benefits than treatment that is intermittent and for short periods of time. The clinical benefits can be observed within 24 hours of commencing treatment and may be more pronounced in patients with an eosinophilic bronchitis. Inhaled corticosteroids provide additional benefit when used in conjunction with prednisone in acute severe asthma. Low doses do not have clinically deleterious side effects on the bones, growth, eye, or hypothalamo-pituitary-adrenal-axis. However, they do not normalize lung function and prevent structural changes in the airway wall in all asthmatic patients.

Pharmacotherapy and airway remodelling in asthma?

Over the last few decades attention has largely focused on airway inflammation in asthma, but more recently it has been appreciated that there are important structural airway changes which have been grouped together under the term "airway remodelling". It is only now that questions have been asked about the impact of treatment on these structural changes. This review examines the nature of these structural airway changes, the mechanisms of their generation, their potential consequences, and what is known about the ability of anti-asthma treatments to modulate these changes.

Diurnal variability of peak expiratory flow

Diurnal variation in peak expiratory flow (PEFvar) has been suggested as a surrogate for bronchial hyperreactivity, and may be a useful tool in the management of bronchial asthma. Several indices have been postulated to measure PEFvar; however, the number of daily measurements and the timing of recordings are not clearly established. Although several investigators have defined ranges for PEFvar in healthy individuals, clear cutoff values that differentiate asthmatics from others are not available. Despite this shortcoming, PEFvar is an important measurement in screening and diagnosis of asthma in population-based studies, as well as for assessing disease severity and prognosis. Treatment of asthma with either inhaled corticosteroids or bronchodilators may influence the magnitude of PEFvar in a complex fashion. Therefore, PEFvar should only be interpreted in conjunction with other clinical and laboratory information.

The effects of inhaled fluticasone on airway inflammation in chronic obstructive pulmonary disease: a double-blind, placebo-controlled biopsy study

Inhaled corticosteroids (ICS) are effective in the treatment of asthma and markedly reduce the numbers of inflammatory cells in bronchial biopsies. However, the effect of ICS on the inflammatory profile of biopsies in smokers with chronic obstructive pulmonary disease (COPD) is unknown. We have performed a double-blind, placebo-controlled, randomized study to compare fluticasone propionate (FP) 500 microg twice daily via a dry powder inhaler and placebo (P) over a 3-month period in subjects with COPD. Fiberoptic bronchoscopy and bronchial biopsy was carried out at baseline and after the 3 months of treatment. Thirty-one subjects completed the trial and 30 paired biopsies were available for analysis. Compared with P (n = 14), subjects on inhaled FP (n = 16) had no significant reductions in the primary endpoints: CD8+, CD68+ cells, or neutrophils, considered to be of importance in COPD. However, there was a reduction in the CD8:CD4 ratio in the epithelium and of the numbers of subepithelial mast cells in the FP group. CD4+ cells were significantly raised in the P group in both subepithelium and epithelium. Symptoms significantly improved, and there were significantly fewer exacerbations in subjects on FP, compared to subjects on P. The data indicate that inhaled fluticasone does affect selected aspects of airway inflammation in COPD, and this may explain, in part, the decrease in exacerbations seen in long-term studies with fluticasone propionate.

Step one for asthma treatment: Beta2-agonists or inhaled corticosteroids?

Inhaled corticosteroids have proven effectiveness in chronic persistent asthma and are now recommended as first-line therapy in this condition. In contrast, long term preventative therapy is not currently considered necessary for patients with disease that is only mild and episodic. Recently, there has been growing interest in the possible benefits of using inhaled corticosteroids at an earlier stage in asthma, as soon as the condition is diagnosed. The concept of early intervention is supported by the recognition that airway inflammation is common to all grades of asthma, including early and mild disease. A number of studies have suggested that delayed introduction of inhaled corticosteroids in asthma can result in a poorer clinical response. The precise reason for this is unknown, although it may result from persistent uncontrolled inflammation leading to airway remodelling associated with airflow obstruction that is relatively resistant to therapy. There have also been suggestions that early intervention may alter the natural history of the disease, either to induce sustained remission or to prevent long term decline in lung function, but these effects have yet to be clearly established. On the basis of present knowledge, early intervention remains controversial, particularly in children. The Steroid Treatment As Regular Therapy (START) trial is a large, placebo-controlled, multicentre study that is currently comparing early and delayed use of inhaled corticosteroids in adults and children with newly diagnosed asthma. It is hoped that this study will resolve some of the present uncertainties, and lead to a better understanding of whether an early intervention strategy in asthma can be justified.

Anti-remodelling drugs for the treatment of asthma: requirement for animal models of airway wall remodelling

1. Airway wall remodelling (AWR), the structural change induced by acute and chronic inflammation in the airways, may be one of the most significant and difficult to reverse components of progressive asthma. 2. The mechanisms underlying the development of AWR are not known. Studies of only the most superficial wall structures of large airways can be conducted in living humans because of the degree of invasiveness required to measure airway structural changes. These studies reveal that currently available agents do not fully prevent or reverse AWR. Thus, animal models of asthma pathology may be used to assess the contribution of particular mediators and cells to the development of remodelling and may also prove to be useful in the initial screening of potential anti-remodelling agents. 3. Airway hyperresponsiveness and AWR stimulated by chronic antigen challenge in previously disease-free animals is the most popular of the currently used models of remodelling. Other animal models include the use of specially bred strains with intrinsic airway hyperresponsiveness or animals that have a naturally occurring asthma-like disease, such as cats with feline asthma or horses with heaves. The further development of animal models of AWR will facilitate the development of novel anti-asthma therapies.

Predictive markers of asthma exacerbation during stepwise dose reduction of inhaled corticosteroids

To determine predictors for failed reduction of inhaled corticosteroids (ICS), in 50 subjects with well-controlled asthma (age 43.7 [18-69]; 22 males) taking a median dose of 1,000 microg ICS/d (100-3,600 microg/d), ICS were halved every 8 wk. Airway hyperresponsiveness (AHR) to a bronchial provocation test (BPT) with histamine was measured at baseline. AHR to BPT with mannitol, spirometry, exhaled nitric oxide (eNO), and, in 31 subjects, sputum inflammatory cells were measured at baseline and at monthly intervals. Thirty-nine subjects suffered an asthma exacerbation. Seven subjects were successfully weaned off ICS. Using a Kaplan- Meier survival analysis, the significant predictors of a failure of ICS reduction were being hyperresponsive to both histamine and mannitol at baseline (p = 0.039), and being hyperresponsive to mannitol during the dose-reduction phase of the study (p = 0.02). Subjects older than 40 yr of age tended to be at greater risk of ICS reduction failure (p = 0.059). Response to mannitol and percentage sputum eosinophils were significantly greater before a failed ICS reduction than before the last successful ICS reduction, whereas there were no significant differences in symptoms, spirometry, or eNO. These findings suggest that documentation of patient's AHR or sputum eosinophils may be useful in guiding the reduction of ICS doses.

Prednisolone hastens recovery from histamine-induced bronchospasm in asthmatics

Short-term treatment with oral steroids is very effective in control ling symptoms and improving lung function in asthma but has not been shown unequivocally to reduce bronchial hyperresponsiveness. Recently it has been shown to increase the activities of sodium-potassium and calcium adenosine triphosphatases, enzymes that regulate intracellular calcium levels. This action may be expected to promote recovery of cells from an excitatory stimulus. The present study was carried out to determine how prednisolone modulates airway response to histamine, including recovery from induced bronchospasm in asthmatics. Spirometry and measurement of bronchial responsiveness (forced expiratory volume in 1 sec [FEV1] and concentration of histamine causing a 20% reduction FEV1 [PD20 FEV1]) to inhaled histamine were carried out in 10 clinically stable asthmatics. Subsequently, all of the patients were prescribed oral prednisolone, 0.6-0.75 mg/kg body weight for 1 week. At the end of 1 week, spirometry was repeated and bronchial reactivity was measured again. Comparison of PD20 FEV1 values before and after treatment (geometric means 0.66 and 0.81 mg/mL, respectively) for the whole group did not show any significant change. The mean +/- SD time for 95% recovery from histamine-induced bronchospasm was 33.00 +/- 19.47 min before treatment and decreased significantly to 18.00 +/- 7.88 min after treatment. It was concluded that short-term benefits from oral prednisolone do not result from changes in bronchial responsiveness. These benefits may be related to effects on mechanisms that lead to recovery from an excitatory stimulus.

Equivalent asthma control after dose reduction with HFA-134a beclomethasone solution aerosol. Comparative Inhaled Steroid Investigation Group (CISIG)

AIM

The replacement of chlorofluorocarbon (CFC) by hydrofluoroalkane has the potential to improve airway deposition of BDP. We investigated whether HFA-BDP extra-fine solution aerosol 400 microg day(-1) is as effective as CFC-BDP 1000 micro day(-1) in patients with stable, moderate asthma, having persistent bronchial hyperresponsiveness.

PATIENTS AND METHODS

One hundred and fifty patients with moderate asthma from 20 centres, on inhaled steroids for < or = 3 months, entered a 4-week run-in period with 1000 microg day(-1) CFC-BDP. Patients were then allocated to a 10-week study phase, receiving CFC-BDP 1000 microg day(-1) or HFA-BDP 400 microg day(-1). Symptom score and PEF were measured daily and recorded as biweekly means. Spirometry, PC20FEV1, blood eosinophils and serum ECP were determined on days 15, 29, 43 and 71, and compared to the last visit of the run-in period. All group members were trained in a quality control centre.

RESULTS

Treating the population of the HFA-BDP group (n = 72) and the CFC-BDP group (n = 78) did not show significant differences in terms of symptoms, lung function, airway hyperresponsiveness and serum markers of inflammation at the end of the run-in period and the end of the study phase.

CONCLUSION

Using HFA instead of a CFC metered dose inhaler, containing less than half the daily dose of BDP, allows control of symptoms and lung function parameters, without changes in bronchial hyperresponsiveness.

Inhaled vs oral steroids for adults with chronic asthma

OBJECTIVES

To determine therapeutically equivalent doses of inhaled versus oral steroids for adults with chronic asthma.

SEARCH STRATEGY

The Cochrane Airways Group trials register was searched using the terms: (drug delivery systems OR ((nebuli* OR inhal* OR MDI) AND oral*)) AND ( steroid* OR corticosteroid* OR glucocorticoid* OR beclomethasone OR betamethasone OR fluticasone OR cortisone OR dexamethasone OR hydrocortisone OR prednisolone OR prednisone OR triamcinolone).

SELECTION CRITERIA

Randomised controlled trials were selected of at least 4 weeks duration and included patients over the age of 15 years with chronic asthma. Trials compared inhaled steroids and oral prednisolone or prednisone; where the maximum dose for inhaled steroids was 2000 mcg/day and prednisolone 60 mg (on alternate days).

DATA COLLECTION AND ANALYSIS

Two independent reviewers screened 1285 titles and abstracts from the electronic search, bibliography searches and other contacts. Of these, 10 trials met previously defined inclusion criteria. Two reviewers independently extracted study characteristics, and outcome measures.

MAIN RESULTS

All trials were small and no data could be pooled. Carry-over effects were present in at least one cross-over trial. Data from six trials produced the same pattern, in which prednisolone 7.5-12 mg/day appeared to be as effective as inhaled steroid 300-2000 mcg/day. In two trials, inhaled steroid 300-400 mcg/day was more effective than prednisolone 5 mg/day. All doses of inhaled steroid appeared to be more effective than alternate day doses of prednisolone up to 60 mg on alternate days. Side-effect data were reported too variably to permit comparisons. A 30% incidence was reported in one study in patients receiving prednisolone 5 mg/day, none were reported in patients on inhaled steroids.

REVIEWER'S CONCLUSIONS

A daily dose of prednisolone 7.5-10 mg/day appears to be equivalent to moderate-high dose inhaled corticosteroids. Side-effects may be present on low doses, so if there is no alternative to oral steroids, the lowest effective dose should be prescribed.

Effects of inhaled fluticasone and oral prednisolone on clinical and inflammatory parameters in patients with asthma

BACKGROUND

Guidelines state that oral and inhaled corticosteroids are the cornerstone of asthma treatment. The effect of both types of treatment can be assessed by measuring lung and systemic parameters. Treatment for two weeks with either oral prednisolone (30 mg/day), high dose fluticasone propionate (2000 microg/day, FP2000), or lower dose FP (500 microg/day, FP500), both given by a dry powder inhaler, were compared.

METHODS

One hundred and twenty patients with asthma were treated for two weeks in a double blind parallel group design. Lung function, asthma symptoms, airway hyperresponsiveness (PC(20) methacholine and adenosine-5'-monophosphate), sputum eosinophil and eosinophilic cationic protein (ECP) levels were measured as lung parameters. In addition, morning serum blood cortisol, blood eosinophil, and serum ECP levels were measured as systemic parameters.

RESULTS

PC(20) methacholine and adenosine-5'-monophosphate showed significantly greater improvement with FP2000 (1.99 and 4.04 doubling concentrations (DC), respectively) than prednisolone (0.90 DC, p = 0.02; 2.15 DC, p = 0. 05) and marginally more than with FP500 (1.69 and 3.54 DC). Changes in sputum eosinophil and ECP concentrations showed similar trends; the decrease in ECP was significantly greater with FP2000 than with FP500. In contrast, the systemic parameters of steroid activity (cortisol, peripheral blood eosinophils, and serum ECP) decreased to a similar extent with FP2000 and prednisolone but significantly less with FP500.

CONCLUSIONS

Oral prednisolone (30 mg/day) was inferior to FP2000 in improving airway hyperresponsiveness to both methacholine and AMP, with similar trends in forced expiratory volume in one second (FEV(1)), sputum eosinophil and ECP concentrations. Systemic effects were similar with prednisolone and FP2000 and less with FP500.

Early treatment of asthma

The early treatment of asthma was not greatly studied before the 1990s. Subjects included in intervention trials have usually had persistent asthma with a long duration of symptoms. Only a few studies have been done on early intervention. It has also become obvious that eosinophilic airway inflammation is common and does not always significantly affect lung function. If patients do not fulfill the functional criteria for asthma, they may not receive specific diagnosis and effective treatment. I have suggested the term "asthma-like inflammation" to describe the disorder of such patients. Bronchial obstruction and increased bronchial responsiveness are outcomes of the inflammatory process, and it may be argued that detection of eosinophilic inflammation is always late at the time asthma is diagnosed. The diagnosis of asthma is often severely delayed, a fact which influences the prognosis and efficacy of therapeutic interventions. The benefits of early treatment of symptomatic asthma have been shown, and several international guidelines recommend anti-inflammatory medication, preferably with inhaled steroids as first-line treatment to gain control of the disease as fast as possible. Very few studies, however, have addressed the long-term influence of various therapeutic approaches. Usually, the beneficial effects gradually disappear when treatment is withdrawn. There is no convincing evidence that any of the current pharmacologic therapies can change the natural course of asthma. Nevertheless, inhaled steroids seem to have a disease-modifying effect if started early enough, and there is a consensus that steroids abolish symptoms, improve lung function, and decrease the need for hospitalization and probably the mortality rate. In future, various combinations of immunologic and pharmacologic treatments may offer more permanent results in asthma therapy.

Early effects of inhaled steroids on airway hyperreactivity and pulmonary function in asthma

While inhaled steroids (IS) are increasingly recognized as having a more rapid onset of action than was once thought, little is known about the early changes in objective measures of respiratory function that follow the inhalation of repeated doses. These early effects were examined in a randomized, double-blind, placebo-controlled, crossover study of 20 children aged 10-16 years with stable mild asthma. Beclomethasone dipropionate (BDP) 2,000 mcg, fluticasone propionate (FP) 400 mcg, and placebo were given twice daily for three doses. Airway hyperreactivity (AHR) to methacholine (PC20), pulmonary function tests (PFT: FVC, FEV1, FEF25-75%), and the rate of recovery from methacholine-induced bronchospasm following administration of salbutamol were determined at 8 h (after 1 dose) and at 32 h (after three doses). At 8 h, minor improvements in AHR were demonstrated, averaging 0.32 doubling doses in PC20. At 32 h, significant improvements in AHR and PFTs were present, averaging 0.92 doubling doses in PC20, 3.96% of predicted values in FEV1, and 7.74% of predicted values in FEF25-75%. No significant changes occurred in FVC. There were no significant differences between the effects of BDP and FP. Inhaled steroids were associated with a slower response to salbutamol following methacholine challenge testing at 32 h. We conclude that IS, given in repeated high doses, result in significant improvements within 32 h in both AHR and PFTs, along with changes in response to beta2 agonists. These effects are likely to be the result of the topical activity of IS.

Efficacy of inhaled steroids (beclomethasone dipropionate) for treatment of mild to moderately severe asthma in the emergency department: a randomized clinical trial

STUDY OBJECTIVE

To examine the efficacy of an inhaled steroid, when added to a standard regimen of beta-agonist therapy, in the treatment of patients with mild to moderately severe asthma in the emergency department.

METHODS

A convenience sample of adult patients with asthma (FEV1 % predicted 40% to 69%) presenting to the ED was randomly assigned in a double-blind fashion into 2 treatment groups. The first group received 2.5 mg nebulized salbutamol plus 1 mg (4 puffs) of beclomethasone dipropionate (BDP) at baseline, 30 minutes, and at 1, 2, and 4 hours, delivered by a metered-dose inhaler (MDI) attached to a spacer device (Vent-AH-aler, Glaxo). The second group was given the same salbutamol regimen plus MDI placebo through the Vent-AH-aler. The primary endpoint was improvement in FEV1 %predicted at 6 hours.

RESULTS

Of 54 patients enrolled, 28 were assigned to the BDP group and 26 to the placebo group. Spirometry improved significantly in both groups over the 6 hours compared with baseline (ANOVA, P <.001). At 6 hours, the mean absolute improvement in FEV1 % predicted for BDP was 18% versus 17% for placebo (95% confidence interval for the absolute difference of 1% [-8% to 10%]). The proportion of patients in the BDP group who were hospitalized was 7% compared with 19% for patients in the placebo group (95% confidence interval for the difference of 12% [-6%, 30%]).

CONCLUSION

In this group of patients with mild to moderately severe asthma, 5 mg BDP delivered by MDI during the initial 4 hours of an emergency visit was of no added benefit over standard therapy, as measured by improvement in FEV1 % predicted at 6 hours. However, a trend toward a difference in admission favoring BDP was observed. [Afilalo M, Guttman A, Colacone A, Dankoff J, Tselios C, Stern E, Wolkove N, Kreisman H: Efficacy of inhaled steroids (beclomethasone dipropionate) for treatment of mild to moderately severe asthma in the emergency department: A randomized clinical trial.

The long-term influence of therapeutic interventions in asthma with emphasis on inhaled steroids and early disease

The data available to show the long-term benefits of any pharmacological interventions in asthma is scanty. Usually the beneficial effects disappear gradually when the treatment is withdrawn. The evidence showing that treatment with drugs could change the natural course of asthma is largely lacking. Only a few controlled studies have lasted more than 1 year, while asthma can be a disease for life. Nevertheless, the short-term benefits of treatment with inhaled steroids justify their introduction as soon as the diagnosis of asthma is established. Regular use of inhaled steroids especially during the early stages of asthma often makes it a less troublesome disease. Regular use of long-acting beta2-agonists is useful in preventing exacerbations in persistent asthma, but their influence on the long-term outcome is quite unknown. Exploration of the possible disease outcome modifying effect of new innovations such as leukotriene antagonists should be put in the clinical study programmes. In future, the combination of immunological and pharmacological treatments may offer the key for more permanent results in asthma therapy.

Exhaled nitric oxide; relationship to clinicophysiological markers of asthma severity

Bronchial asthma is an airway disorder associated with bronchial hyperresponsiveness, variable airflow obstruction and elevated levels of nitric oxide (NO) in exhaled air. The variables all reflect, in part, the underlying airway inflammation in this disease. To understand their interrelationships we have investigated the relationship between exhaled NO levels and clinicophysiological markers of asthma severity. Twenty-six steroid naive atopic asthmatics participated in the analysis. All were given diary cards and were asked to record their peak expiratory flow (PEF) rates twice daily together with their asthma symptom scores and beta-agonist use. Diary cards were collected 2 weeks later and measurements of exhaled NO levels, FEV1 and histamine bronchial hyperreactivity (PC20 histamine) were undertaken. Exhaled NO levels were significantly higher in our study population than in normal control subjects and correlated negatively with PC20 histamine (r = -0.51; P = 0.008) and positively with PEF diurnal variability (r = 0.58; P = 0.002), but not with symptom scores, beta-agonist use of FEV1 (%). We conclude that a significant relationship exists between exhaled NO levels and the two characteristic features and markers of asthma severity, namely bronchial hyperreactivity and PEF diurnal variability. The lack of correlation between symptom score and beta-agonist use, of FEV1 (%) predicted and exhaled NO suggests that these measures are reflective of differing aspects of asthma.

Inhaled glucocorticoid therapy of childhood asthma is associated with reduced peripheral blood T cell activation and 'Th2-type' cytokine mRNA expression

OBJECTIVE

To investigate the role of activated T cells and their cytokine products in the pathogenesis of childhood asthma.

METHODS

PBMC were obtained from 17 symptomatic asthmatic children (age 7 to 15 yr) and 7 nonasthmatic controls matched for age and atopic status. Asthmatics were placed in 2 groups with initial prebronchodilator FEV1 <75% (Group I, n = 9) or >/=75% (Group II, n = 8) predicted. Expression of activation markers on peripheral blood T cells (asthmatics), and expression of cytokine mRNA (asthmatics and controls) were measured using flow cytometry and in situ hybridization respectively. Measurements were repeated in the asthmatics 3 to 6 months later following initiation or escalation of inhaled GC therapy for control of symptoms.

RESULTS

The more severe (Group I) as compared with the milder (Group II) asthmatics showed evidence of increased peripheral blood T cell activation, with elevated percentages of CD4 cells expressing the activation markers CD25 and HLA-DR, and CD8 cells expressing CD25. Elevated percentages of CD4 cells also expressed CD45RO, consistent with ongoing cellular activation. The asthmatics had higher percentages of PBMC expressing mRNA encoding IL-5, IL-4, GM-CSF and IL-2, but not IFN-gamma, as compared with controls. The percentages of PBMC expressing IL-5 mRNA correlated with disease severity (% predicted FEV1). During follow up, patients in both groups required increased mean daily dosages of inhaled GC. In Group I this was associated with improvements in PEFR, FEV1 and night time wheeze and reduced percentages of CD4/CD25 and CD4/HLA-DR peripheral blood T cells. Reductions in the percentages of CD4/CD25 T cells correlated with improvements in baseline FEV1. Group II patients showed improvement in FEV1 and day time cough and wheeze but no significant changes in PEFR, other symptoms or peripheral blood T cell marker expression. Increased GC therapy of both groups taken together was associated with significant reductions in the percentages of PBMC expressing mRNA encoding IL-5, IL-4 and IL-2 and an increase in those expressing IFN-gamma mRNA.

CONCLUSIONS

Compared with controls, children with symptomatic asthma have higher percentages of activated peripheral blood T cells synthesising cytokines believed to regulate bronchial mucosal eosinophilic inflammation. Clinical improvement with increased inhaled GC therapy is associated with reduced T cell activation and cytokine mRNA expression.

Anti-inflammatory drugs do not alleviate bronchial hyperreactivity in Sjögren's syndrome

Bronchial hyperreactivity (BHR) is found in Sjögren's syndrome, as in a number of other conditions such as asthma. BHR associated with asthma can be effectively treated with corticosteroids or sodium cromoglycate. We treated 19 Sjögren's syndrome patients with BHR with inhaled budesonide and inhaled cromoglycate for 6 weeks each. None of the treatment had any significant effect on symptoms of hyperreactivity or lung function. There was no effect on BHR measured as methacholine reactivity. Primary Sjögren's syndrome is a disease with inflammation not only in the salivary and lacrimal glands but also in the pulmonary alveoli and the bronchi. The main inflammatory cell is the lymphocyte, whereas, in the bronchi in asthma, the eosinophil granulocyte is the characteristic inflammatory cell. The cause of the discrepancy with regard to treatability of BHR in asthma and in Sjögren's syndrome is not known. Possibly not all BHR is caused by inflammation. There is not a perfect correlation between inflammation and hyperreactivity even in asthma. Even in the bronchial inflammation and the asthma symptoms are easy to treat with anti-inflammatory medicines, a considerable component of BHR usually still remains, as measured with methacholine or histamine.

Steroid therapy in obstructive airway diseases

Asthma and chronic obstructive pulmonary disease (COPD) are two common illnesses that cause significant morbidity and mortality. Steroids are widely used in both conditions. They act through steroid or glucocorticoid receptors (GR) causing up or down regulation of protein synthesis resulting in an increase in lipocortin 1 and beta 2 adrenergic receptors, and decreased levels and activities of cytokines or cytokine receptors, which reduces the inflammatory process in the airways and decreases bronchial hyperreactivity. Consequently symptoms of airway obstruction are alleviated and lung function is improved. In asthma, steroids have been convincingly shown to be effective in the treatment of both acute exacerbations and chronic condition. In COPD, however, only a subset of patients seem to respond favourably to steroid therapy. Therapeutic trials are therefore recommended before committing to a long-term treatment in order to determine this subset of patients, as no markers of steroid responsiveness can be identified. The inhaled steroids currently available have a good safety profile with significant side effects occurring only occasionally. Such side effects are usually confined to the oropharynx, causing local irritation, candidiasis and dysphonia, which can be easily overcome. Biochemical abnormalities involving bone, adrenal, carbohydrate and lipid profiles have been noted with high doses of inhaled steroids; however, these have no significant clinical effects.

Prevalence of inhaled corticosteroid use among patients with chronic obstructive pulmonary disease: a survey

OBJECTIVE

To determine the extent of inhaled corticosteroid use among patients with chronic obstructive pulmonary disease (COPD).

DESIGN

Review of medical records.

SETTING

Tertiary-care university teaching hospital.

PATIENTS

Seventy-two consecutive patients prescribed an inhaled corticosteroid during hospitalization.

INTERVENTION

None.

MEASUREMENTS

Patient demographics, inhaled corticosteroid regimen, respiratory diagnosis, and inhaled corticosteroid use before and during hospitalization.

RESULTS

The majority of patients (85%) were receiving their prescribed corticosteroid inhaler prior to admission. Beclomethasone dipropionate 250 micrograms/puff was the most commonly prescribed inhaled corticosteroid formulation accounting for 43% of the total corticosteroid inhaler orders. COPD was the most common respiratory diagnosis (43%) associated with inhaled corticosteroid use, followed by asthma (37%), COPD/asthma (13%), and no diagnosis (7%). During the study period, the proportion of all hospitalized patients with COPD who also received inhaled corticosteroid prescriptions (35%) was not significantly different from all hospitalized patients with asthma who received inhaled corticosteroid prescriptions (33%).

CONCLUSIONS

The rate of inhaled corticosteroid use far exceeds the rate expected among the general population of patients with COPD. Educational intervention is needed to encourage compliance with published guidelines for the management of COPD.

The effects of combined intravenous and inhaled steroids (beclomethasone dipropionate) for the emergency treatment of acute asthma. The Asthma ED Study Group

OBJECTIVE

To compare the efficacy of high-dose inhaled steroids in conjunction with IV steroids with that of IV steroids alone in the emergency treatment for acute asthma.

METHODS

A double-blind, placebo-controlled, randomized trial was conducted on 60 ED patients presenting with acute asthma. All patients received nebulized salbutamol, and IV methylprednisolone, 80 mg at baseline and 40 mg at 6 hours. In addition to the above therapy, the experimental group received beclomethasone dipropionate (BDP) 7 mg over 8 hours via a metered-dose inhaler (MDI) attached to a holding chamber, while the control group received a placebo administered in the same fashion. Patients were treated on the protocol for 12 hours with the primary outcome measure being the change in % predicted FEV1.

RESULTS

Of 60 patients, 30 were randomized to BDP (age: 42 +/- 16 years; FEV1: 0.97 +/- 0.42 L) and 30 were randomized to placebo (age: 37 +/- 18 years; FEV1: 0.98 +/- 0.35 L). Spirometry and dyspnea measured by the Borg Scale improved significantly in both groups compared with baseline (p < 0.001). Changes in spirometry measures, dyspnea, and vital signs did not differ between treatment groups over the 12 hours of study (p > 0.05).

CONCLUSION

Inhaled BDP added to the standard regimen of IV methylprednisolone, and beta-agonist did not further improve flow rates or dyspnea scores measured for up to 12 hours after presentation to the ED.

Relative effects of inhaled corticosteroids on immunopathology and physiology in asthma: a controlled study

BACKGROUND

Although corticosteroids are recognised as the most efficacious treatment for bronchial asthma, their mode of action remains unclear. A placebo controlled trial was undertaken of the effect of inhaled corticosteroids on physiological and immmunopathological parameters in asthmatic patients in whom the correlations between these indices were tested after treatment.

METHODS

Sixteen patients (two women) with asthma entered a double blind, placebo controlled, parallel study during which they inhaled either budesonide 800 micrograms twice daily or matching placebo for six weeks. Spirometric parameters and bronchial reactivity to histamine and terbutaline were measured and endobronchial biopsy samples were taken before and after treatment. Patients recorded morning and evening flow rates during the treatment period. The biopsy samples were subjected to immunohistological analysis to determine the disposition of inflammatory cells within the bronchial wall.

RESULTS

Treatment with budesonide resulted in a significant improvement in the 25-75% forced expiratory flow (FEF25-75) from a mean of 133 l/min before treatment to 169 l/min after treatment, and in the morning peak expiratory flow rate (PEFR) from a mean of 384 l/min before treatment to 415 l/min after treatment. No changes were seen in the placebo group. Comparison between the changes in the immunopathological indices after six weeks of treatment with placebo or budesonide showed a significant reduction in the numbers of mast cells (0.5/unit area to 0.2/ unit area), activated eosinophils, and the expression of HLA-DR antigens (relative density -1.9 before to 1.02 after treatment) on inflammatory cells in response to treatment with budesonide. Although reductions in the numbers of other inflammatory cells within the bronchial wall were recorded using immunohistological analysis, these changes were not statistically significant. Significant correlations were found between changing immunological indices and lung physiology.

CONCLUSIONS

This controlled study shows that inhaled corticosteroids cause improvement in physiological and immunopathological parameters in patients with stable asthma that are not seen with placebo, and that cause and effect relationships may exist between these two measures of disease status.

The role of corticosteroids in respiratory diseases of children

Glucocorticosteroids are potent anti-inflammatory agents and have an important role in a variety of respiratory diseases. Although their exact mode of action is unknown, it is thought that they exert their effects by binding to cytoplasmic glucocorticoid receptors. In certain conditions, such as asthma, the value of steroids cannot be questioned, and inhaled steroids have revolutionized management. In other situations, such as interstitial lung disease, the true role of steroids is still to be defined. In the management of diseases such as tuberculosis, the use of steroids is solely based on anecdotal experience.

Near-fatal asthma in South Australia: descriptive features and medication use

BACKGROUND

Self-reported prior morbidity levels and medication use among survivors of a near-fatal asthma attack (NFA) were studied.

AIMS

To identify deficiencies in asthma management and opportunities for intervention.

METHODS

A hundred and twenty-seven consecutive patients aged 15 years or more presenting with a NFA to accident and emergency departments of teaching hospitals were interviewed.

RESULTS

High levels of morbidity due to asthma were reported. Most cases (79%) reported symptoms occurring at least weekly in the three months before their NFA. A mean of 20.8 days was reportedly lost from work, school or other usual daily activity in the 12 months before these events. Regular use of beta agonist as nebuliser solution was reported by 27% of cases, increasing to 34.5% in response to increased symptoms, while 41% reported use of nebulised beta agonist in response to the NFA event. Less than half of all cases (46%) reported using an inhaled corticosteroid on a regular basis. Oral corticosteroids were used by 33% of cases at times of increased symptoms in the preceding 12 months. However, only 7% of cases reported initiating or increasing oral corticosteroids at the time of the NFA.

CONCLUSIONS

Despite high levels of prior asthma morbidity, regular preventive inhaled corticosteroid use was not widespread in this series of NFA asthmatics. By comparison, over-reliance on regular beta agonist medication was common. Oral corticosteroids were rarely commenced in response to the NFA.

Relationship of non-specific airway hyperresponsiveness (AHR) to measures of peak expiratory flow (PEF) variability

BACKGROUND

The relationship between airway hyper-responsiveness (AHR) and clinical asthma remains controversial and unclear.

AIMS

To test the hypothesis that serial measures of variability of peak expiratory flow rate (PEF) correlate with serial measures of AHR, and to determine which mathematical expression of variability provides the best correlation.

METHODS

A longitudinal study over 180 days of 20 atopic, moderately severe asthmatics was undertaken. A diary of medication use and morning and evening PEFR before and after beta agonist was kept and AHR (PD20 histamine) was measured at three-weekly intervals. Using group data (128 sets) in PD20 was correlated with various measures of PEF variability over 9 days.

RESULTS

[Table: see text] Within the group there was a weak but highly statistically significant correlation between AHR and measures of PEF variability--the strongest correlation being with mean morning PEF. Within individual subjects, however, the correlation was not a consistent finding and only four patients had a statistically significant relationship (p < 0.05) between AHR and mean morning PEF.

CONCLUSIONS

These results suggest that while PEF variability may reflect AHR for the purposes of epidemiologic studies, it is unlikely to be useful as a simple 'non-invasive' means of assessing AHR in individual patients. More complex measures of PEF variability do not have an advantage over simpler measures such as mean morning PEF.

Increased frequency of bronchial hyperresponsiveness in patients with inflammatory bowel disease

Although bronchopulmonary manifestations are rare in inflammatory bowel disease (IBD), subclinical abnormalities have been described in up to 50% of cases. The pathophysiology of these abnormalities remains unknown. However, a latent inflammation of the bronchial mucosa secondary to the inflammation of the intestinal mucosa has been suggested. This subclinical inflammation may lead to increased bronchial responsiveness. We studied the bronchial responsiveness in 38 inflammatory bowel disease (IBD) patients, using the methacholine test. Bronchial hyperresponsiveness was defined by a PC20M < 16 mg/ml. Twenty-four healthy controls were also studied. There was no significant difference in baseline FEV1 between IBD patients and controls. However, there was a significantly greater fall in FEV1 in the IBD patients at the concentrations of methacholine tested. The frequency of bronchial hyperresponsiveness was significantly higher in the IBD population (45%) than in controls (17%; P < 0.03). Atopy, defined by skin test, was more common in IBD patients (42%) than in controls (21%). Even when only nonatopic subjects were considered, the frequency of bronchial hyperresponsiveness was significantly higher in IBD patients (41%) than in controls (5%; P < 0.02). Thus, subclinical bronchial hyperresponsiveness is common in IBD, and may be considered a further extraintestinal manifestation.

Differences in aerosol output and airways responsiveness between the DeVilbiss 40 and 45 hand held nebulisers

BACKGROUND

The DeVilbiss 40 glass hand held nebulisers have been widely used for airways responsiveness testing in epidemiological surveys of asthma. These nebulisers have been superseded in some recent studies by the DeVilbiss 45 plastic hand held nebulisers with the assumption that they are interchangeable. This study compared the aerosol outputs of the DeVilbiss 40 and DeVilbiss 45 nebulisers and investigated whether there was any difference in the in vivo measurements of airways responsiveness when using the two nebuliser types.

METHODS

The aerosol output of six DeVilbiss 40 and six DeVilbiss 45 nebulisers was calculated by weight loss per actuation, the usual method of calibrating nebuliser output, and compared with the true amount of aerosol obtained measured by a flouride tracer technique. Airways responsiveness was measured twice in 13 asthmatic patients under identical conditions by the Yan protocol using DeVilbiss 40 and 45 nebulisers in random order.

RESULTS

Weight loss overestimated the true aerosol output of both types of nebulisers. Weight loss was similar for the DeVilbiss 40 and 45 nebulisers but the true aerosol output of the DeVilbiss 45 was nearly twice that of the DeVilbiss 40 nebuliser. The geometric mean PD20 values with the DeVilbiss 40 nebuliser was a mean 1.7 doubling doses of histamine higher than that obtained with the DeVilbiss 45 nebuliser.

CONCLUSIONS

The DeVilbiss 40 and 45 nebulisers should not be used interchangeably for airways responsiveness testing merely because their outputs based on weight loss are similar. Artefactual differences in the prevalence rates of airways responsiveness could occur in longitudinal studies if a change was inadvertently made from using DeVilbiss 40 to DeVilbiss 45 nebulisers.

Risk factors for asthmatic patients requiring intubation. I. Observations in children

There are significant concerns regarding the increased mortality of patients with asthma. Indeed the paradox of improved pharmacotherapy but worsening prognosis has been explored in depth in several studies including observations in epidemiology, access to medical care, and drug toxicity. Because of our ability to track all admissions to a tertiary-care hospital, we attempted to define the demographic data from a population of asthmatic children admitted for asthma in order to identify risk factors for intubation. We performed a retrospective cohort study of all asthma admissions excluding patients with cystic fibrosis. This study included all asthmatics aged 5-12 years admitted over a 10-year period (1984-1994) to the University of California at Davis Medical Center, Sacramento. A total of 300 such asthma admissions were reviewed, involving 135 girls and 165 boys, mean age 7.7 +/- 2.4 years. Of this group, 166 children were black, 70 were Caucasian, 49 were Hispanic, 14 were Asian, and 1 was an American Indian. By National Heart, Lung, and Blood Institute guidelines, this group included 147 mild, 117 moderate, and 36 severe cases. Thirteen children required intubation for their asthma. Significant risk factors identified for children requiring intubation, compared to those who did not require intubation, were secondhand smoke exposure [odds ratio (O.R.) 22.4; 95% confidence interval (C.I.) 7.4, 68.0], psychosocial problems (O.R. 13.5; 95% C.I. 5.1, 36.0), family dysfunction (O.R. 13.0; 95% C.I. 3.9, 43.9), upper respiratory infection (O.R. 10.2; 95% C.I. 3.4, 28.1), little formal education (O.R. 8.7; 95% C.I. 2.4, 31.6), prior asthma emergency room visit in past year (O.R. 7.2; 95% C.I. 1.9, 27.1), prior asthma hospitalization in past year (O.R. 7.1; 95% C.I. 2.2, 22.2), crowding (O.R. 6.9; 95% C.I. 2.5, 19.1), low socioeconomic status (O.R. 6.5; 95% C.I. 2.1, 20.8), steroid-dependent (O.R. 3.8; 95% C.I. 1.2, 12.1), parental history of allergy or asthma (O.R. 3.4; 95% C.I. 1.1, 10.0), and language barrier (O.R. 3.3; 95% C.I. 1.1, 10.6). Nonsignificant mild risk factors included inhaled cromolyn (O.R. 2.7; 95% C.I. 0.7, 10.0), atopy (O.R. 1.9; 95% C.I. 0.6, 5.9), and prior intubation (O.R. 1.6; 95% C.I. 0.2, 13.1). These risk parameters may be important determinants of baseline risk for asthma deaths and their recognition may have a significant impact on preventive measures.

Risk factors for asthmatic patients requiring intubation. II. Observations in teenagers

The asthma mortality rate has increased steadily over the past 15 years in the United States and has only recently shown signs of leveling off. It is widely believed, although unproven, that many asthma deaths may be preventable. We have addressed one critical factor in severe asthma by attempting a definition of risk factors for intubation using demographic data and a retrospective cohort study of hospitalized asthmatic teenagers. This study included all asthmatics aged 13-19 years admitted over a 10-year period (1984-1994) to the University of California Davis Medical Center, Sacramento, California. A total of 143 such asthma admissions were reviewed, involving 68 females and 75 males, mean age 16.4 +/- 2.3 years. Of this group, 85 teenagers were black, 34 were Caucasian, 14 were Hispanic, and 10 were Asian. By National Heart, Lung, and Blood Institute guidelines, there were 42 mild, 85 moderate, and 16 severe cases. Ten of the 143 teenagers studied required intubation for their asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of bronchial inflammation: corticosteroids and other therapeutic agents

We have shown that treatment with inhaled corticosteroid acts to improve asthma-induced changes in the airway mucosa to such an extent that cell type and structure are normalized. More specifically, such treatment increases the number of intraepithelial nerves, decreases the total number of inflammatory cells, and eliminates epithelial eosinophils, as well as decreasing the number of endothelial gaps in the postcapillary venules. In contrast, these effects do not seem to be found following treatment with beta 2-agonists.

Comparison of inhaled beclomethasone dipropionate 1000 micrograms twice daily and oral prednisone 10 mg once daily in asthmatic patients

BACKGROUND

Glucocorticosteroids are widely used as drugs of first choice in the treatment of moderate to severe asthma. The effects of inhaled steroids in high doses have been compared with oral prednisone in asthmatic patients in a double blind crossover study.

METHODS

The trial consisted of a two week run in period followed by two four week treatment periods separated by a four week washout. During the treatment period patients took either 1000 micrograms beclomethasone dipropionate twice daily and placebo tablets once daily, or 10 mg prednisone daily in one morning dose and placebo inhaler twice daily. The effects of treatment on the provocative dose of histamine producing a 20% fall in FEV1 (PC20 histamine), peak flow measurements at home, and spirometric measurements in the clinic, as well as on the basal and stimulated plasma cortisol levels were measured.

RESULTS

Seventeen patients with asthma completed the study. After four weeks of treatment beclomethasone dipropionate showed a significantly better effect on morning peak expiratory flow rate than prednisone. There was a trend to a greater improvement in the PC20 histamine in patients receiving beclomethasone dipropionate than in those receiving prednisone. There were no significant differences in spirometric values, symptom scores, or basal and stimulated cortisol levels between the treatments. The within treatment analysis showed a significant effect of prednisone on stimulated cortisol levels but not of beclomethasone dipropionate.

CONCLUSIONS

Beclomethasone dipropionate 1000 micrograms twice daily has a slightly greater therapeutic effect in this population of asthmatic patients than 10 mg of prednisone once a day with less effect on adrenocortical function.

Corticosteroid withdrawal restores responses to calcium chelators and enhances cholinergic responsiveness

To investigate the importance of the inflammatory response in acute peripheral airway constriction, we measured peripheral airway responses to calcium chelators and acetylcholine in anesthetized Basenji-Greyhound (BG) dogs before, during, and after chronic corticosteroid treatment. A wedged bronchoscope technique was used to measure peripheral airway resistance before and after aerosol challenge with 4% Na2EDTA or acetylcholine (10 micrograms/ml) in contralateral lungs. After the initial measurements, five BG dogs received long-term treatment with methylprednisolone (2 mg/kg/d, subcutaneously), and five dogs were not treated and served as controls. Four weeks of methylprednisolone treatment almost totally abolished responses to Na2EDTA, but responses to acetylcholine did not change significantly. After discontinuing corticosteroid therapy, responses to Na2EDTA returned to levels found before corticosteroid treatment; responses to acetylcholine were significantly enhanced. We conclude that chronic corticosteroid treatment reduces acute response to calcium chelators and that withdrawal of corticosteroid therapy is associated with enhanced cholinergic responsiveness.