Effect of a volumatic spacer and mouth rinsing on systemic absorption of inhaled corticosteroids from a metered dose inhaler and dry powder inhaler

Treating asthma in the time of COVID

The Precision Interventions for Severe and/or Exacerbation-Prone Asthma clinical trials network is actively assessing novel treatments for severe asthma during the coronavirus disease (COVID-19) pandemic and has needed to adapt to various clinical dilemmas posed by the COVID-19 pandemic. Pharmacologic interactions between established asthma therapies and novel drug interventions for COVID-19 infection, including antivirals, biologics, and vaccines, have emerged as a critical and unanticipated issue in the clinical care of asthma. In particular, impaired metabolism of some long-acting beta-2 agonists by the cytochrome P4503A4 enzyme in the setting of antiviral treatment using ritonavir-boosted nirmatrelvir (NVM/r, brand name Paxlovid) may increase risk for adverse cardiovascular events. Although available data have documented the potential for such interactions, these issues are largely unappreciated by clinicians who treat asthma, or those dispensing COVID-19 interventions in patients who happen to have asthma. Because these drug-drug interactions have not previously been relevant to patient care, clinicians have had no guidance on management strategies to reduce potentially serious interactions between treatments for asthma and COVID-19. The Precision Interventions for Severe and/or Exacerbation-Prone Asthma network considered the available literature and product information, and herein share our considerations and plans for treating asthma within the context of these novel COVID-19-related therapies.

Oral Candidal Load and Oral Health Status in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Case-Cohort Study

Objective

The objective of this study was to determine the candidal load of the patients with Chronic Obstructive Pulmonary Disease (COPD) and evaluate the oral health status of subjects with COPD. Material and Methods. N = 112 COPD subjects and N = 100 control subjects were included in the study. The selection of COPD cases was confirmed based on the set criteria from the American College of Physicians. The oral health status was assessed as per WHO criteria to determine the score of decayed, missing, and filled teeth (DMFT), significant caries index (SiC), community periodontal index and treatment needs (CPITN), and oral hygiene index-simplified (OHI-S). Gram staining was performed to identify Candida using the whole saliva. Quantitative evaluation of the candidal load was carried out using Sabouraud Dextrose Agar (SDA). Chrome agar was used to differentiate between the commensal carriages. A statistical analysis paired t-test and 95% confidence interval (CI) for proportions was carried out using STATA software.

Results

Candidal growth was found in 21.42% (n = 24) of COPD cases and 1.1% (n = 11) of control cases (p < 0.05) (95% CI 0.45, 0.59). The DMFT score was 8.26 in COPD subjects and 4.6 in controls, the SiC score was 16.42 in COPD subjects and 10.25 in controls, and the CPITN score for both COPD and control cases was score 2.

Conclusion

In conclusion, there was a higher candidal load among subjects suffering from COPD. Theophylline medication can be a risk factor for increased candidal load in COPD patients.

Implementation of mouth rinsing after use of inhaled corticosteroids in Australia

BACKGROUND

Clinical guidelines recommend that patients using inhaled corticosteroids should rinse their mouth following inhalation. There is however, a paucity of research regarding patient implementation of this recommendation and the impact it has on the occurrence of adverse effects.

OBJECTIVE

The aim of this study was to determine how well patients implement mouth rinsing after using inhaled corticosteroids in practice and their understanding of the rationale, information sources and the impact of mouth rinsing on adverse effects.

SETTING

Australians aged 18 years and over with a diagnosis of asthma and/or chronic obstructive pulmonary disease who were currently using an inhaled corticosteroid.

METHOD

Participants were recruited via Facebook to complete an online survey.

MAIN OUTCOME MEASURE

Implementation of a mouth rinse which aligned to current guideline recommendations.

RESULTS

Of 380 eligible responses, 30.5% of patients reported suboptimal mouth rinsing after using inhaled corticosteroids. Receiving advice on mouth rinsing from a healthcare professional increased the likelihood of correct implementation (P < 0.001) and improved patient understanding of the rationale (P = 0.01). Whilst most (90.0%) patients were aware rinsing may reduce oropharyngeal adverse effects, few (5.5%) were aware of its potential to reduce systemic adverse effects. Patients were more likely to report their rinsing procedure had a positive impact if they had experienced oral candidiasis (P < 0.001) or sore mouth/throat (P = 0.01), compared to cough or hoarse voice.

CONCLUSION

Almost one-third of patients reported a suboptimal mouth rinsing procedure after using an inhaled corticosteroid. Interventions are required to improve awareness and correct implementation of mouth rinsing.

Real-Life Outcomes for Patients with Asthma Prescribed Spacers for Use with Either Extrafine- or Fine-Particle Inhaled Corticosteroids

BACKGROUND

Spacers are often used with pressurized metered-dose inhalers (pMDIs) to eliminate the need for coordinating inhalation with actuation.

OBJECTIVE

To investigate the real-life effectiveness of spacers prescribed for use with either extrafine- or fine-particle inhaled corticosteroids (ICSs).

METHODS

This historical matched cohort study examined anonymous medical record data over 2 years (1-year baseline, 1-year outcome) for patients with asthma aged 12 to 80 years initiating ICSs by pMDI with or without prescribed spacer. We compared outcomes for spacer versus no-spacer arms, matched for key baseline and asthma-related characteristics, within 2 ICS cohorts: (1) extrafine-particle ICS (beclomethasone) and (2) fine-particle ICS (fluticasone). Effectiveness end points were compared using conditional regression methods.

RESULTS

Matched spacer and no-spacer arms of the extrafine-particle ICS cohort each included 2090 patients (69% females; median age, 46-47 years) and the 2 arms of the fine-particle ICS cohort each included 444 patients (67% females; median age, 45 years). With extrafine-particle ICS, we observed no significant difference between spacer and no-spacer arms in severe exacerbation rate (primary end point): adjusted rate ratio, 1.01 (95% CI, 0.83-1.23). With fine-particle ICS, the severe exacerbation rate ratio with spacers was 0.77 (0.47-1.25). Oropharyngeal candidiasis incidence was low and similar in spacer and no-spacer arms for both ICS cohorts.

CONCLUSIONS

We found no evidence that prescribed spacer devices are associated with improved asthma outcomes for extrafine- or fine-particle ICS administered by pMDI. These findings challenge long-standing assumptions that spacers should improve pMDI effectiveness and indicate the need for pragmatic trials of spacers in clinical practice.

Inhaled corticosteroids and the occurrence of oral candidiasis: a prescription sequence symmetry analysis

OBJECTIVES

The primary aim of the study was to gain insight into the relative risk of clinically relevant oral candidiasis following inhaled corticosteroid (ICS) initiation over time. A secondary aim was to analyse the influence of patient characteristics and co-medication on the occurrence of this adverse effect.

METHODS

Drug prescription data from 1994 to 2011 were retrieved from the IADB.nl database. To study the influence of ICS use on occurrence of oral candidiasis, a prescription symmetry analysis was used, including patients using medication for oral candidiasis up to 1 year before or after ICS initiation. The relative risk was calculated by dividing the number of patients receiving medication for oral candidiasis after ICS initiation by the number of patients receiving the same medication before ICS initiation. Sub-analyses were conducted to compare the relative risks at several time points after ICS initiation and to account for therapy persistence by only including chronic users of ICS. A multivariate logistic regression model was used to identify predictive factors.

RESULTS

A total of 52,279 incident users of ICS therapy were identified, of which 1,081 received medication for oral candidiasis up to 1 year before or after ICS initiation. A total of 701 patients received medication for oral candidiasis after ICS initiation, while 361 received these medications in the reversed sequence, resulting in a sequence ratio (SR) of 1.94 (95 % CI 1.71-2.21). In the first 3 months after ICS initiation, the SR was 2.72 (95 % CI 2.19-3.38) and then decreased to 1.47 (95 % CI 1.11-1.95) 9-12 months after ICS initiation. Predictive factors were higher daily dose of ICS and concomitant use of oral corticosteroids.

CONCLUSIONS

This study found a significant and clinically relevant increased number of patients receiving medication for oral candidiasis in the first year after therapy initiation with ICS. Relative risk is highest in the first 3 months, but remains increased up to at least 1 year after ICS initiation. This study stresses the need for patient education and inhalation instruction.

The efficacy of immediate diet for reducing local adverse events of inhaled corticosteroid: a pilot study

Background

Local adverse events associated with inhaled corticosteroid use, including dysphonia, pharyngitis and oral candidiasis, can affect adherence for treatment. 'Mouth rinsing method' has been used for reducing local adverse events, but it cannot ensure complete prevention. The goal of this pilot study was to identify whether the 'immediate diet method' can reduce local adverse events in a limited number of patients.

Methods

The study was conducted in a total of 98 patients, who had been prescribed a medium-dose fluticasone propionate for the first time, from January to October in 2010. One training nurse had performed the education on how to use the inhaler, including the mouth rinsing method. And with follow-ups at one month intervals, any patient who experienced such adverse events were educated on the immediate diet method, having a meal within 5 minutes after using an inhaler and they were checked on any incurrence of adverse events with one month intervals for 2 months.

Results

The mean age of patients was 65.9 years old. The local adverse events had incurred from 18.4% of the study subjects. When performed the follow-up observation in 18 patients with local adverse events after education on the immediate diet method, 14 patients (77.8%) had shown symptomatic improvements. Three of 4 patients did not show any improvement, in spite of implementing the immediate diet method. The other 1 patient did not practice the immediate diet method properly.

Conclusion

The immediate diet method may be useful in reducing the local adverse events, caused by the use of inhaled corticosteroid.

Inappropriate home albuterol use during an acute asthma exacerbation

BACKGROUND

Increased asthma morbidity and mortality is associated with inappropriate home self-management skills.

OBJECTIVES

To examine the proportion of children presenting to the emergency department (ED) with an acute asthma exacerbation with incorrect home use of their albuterol inhaler and to identify factors associated with improper treatment.

METHODS

Caregivers of children with asthma aged 4 to 14 years, presenting to the ED with an asthma exacerbation, participated in the study. Interviewers collected caregiver's perceived severity of the asthma exacerbation and home albuterol use before the ED visit. National Asthma Education and Prevention Program guidelines were used to classify home albuterol use as appropriate or inappropriate.

RESULTS

Home albuterol use for the current asthma exacerbation was categorized as inappropriate (56 [68%]) and appropriate (26 [32%]) for 84 participants. Thirty-nine of the inappropriate group undertreated, with 24 not giving albuterol frequently enough and 15 without albuterol at home. Other reasons for incorrect home albuterol use included: no spacer, overtreating, overreacting, and using a controller medicine for quick relief. Those with appropriate albuterol use were more likely to have their child hospitalized for asthma in the past 48 months (P=.004). Caregivers with inappropriate use perceived their child's asthma exacerbation as more severe (P<.001) compared with physician rating. Physicians rated asthma severity higher in the appropriate group than the inappropriate group (P<.001).

CONCLUSION

A significant proportion of caregivers incorrectly treat children's asthma exacerbation with albuterol. Despite perceiving their children's asthma exacerbations as more severe, most undertreat with albuterol. Correctly assessing asthma symptom severity and appropriate home albuterol use may be linked to disease experience.

Comparison of a Multidose Powder Inhaler Containing Beclomethasone Dipropionate (BDP) with a BDP Metered Dose Inhaler with Spacer in the Treatment of Asthmatic Patients

OBJECTIVE

The clinical efficacy, tolerability and acceptability of a new multidose powder inhaler (MDPI) [Easyhaler((R)), Orion Pharma, Finland] containing a high dose (500 microg/dose) of beclomethasone dipropionate (BDP) were compared with those of BDP metered dose inhaler administered with a large volume spacer (MDI-spacer).

PATIENTS AND STUDY DESIGN

Recruited patients were adult asthmatics currently receiving 800 to 1000 microg/day of inhaled corticosteroid. The dose of BDP during the study was 1000 mg/day. The study was an open, randomised, parallel-group multicentre study and included a 2-week run-in period followed by a 12-week treatment period.

RESULTS

74 patients were randomised to both groups. During the run-in period the mean morning peak expiratory flow (PEF) was 489 and 478 L/min in the MDPI and MDI-spacer groups, respectively. During the last 2 weeks of the study the morning PEF was 485 L/min in the MDPI group and 477 L/min in the MDI-spacer group. Asthma symptom scores and use of rescue medication were low in both groups. The median dose of histamine required to decrease forced expiratory volume in 1 second (FEV(1)) by 15% was 1.05mg in the MDPI group and 0.64mg in the MDI-spacer group. The most frequent adverse events were hoarseness and sore throat. Mean serum cortisol levels were not affected in either treatment group. Patients' personal opinion regarding acceptability of the devices clearly favoured the MDPI.

CONCLUSION

In conclusion, the novel powder inhaler was well tolerated and at least equally effective compared with the conventional MDI-spacer combination in the treatment of asthma with BDP. However, in everyday use the patients clearly favoured the powder inhaler.

Influence of dentures on residual inhaled corticosteroids in the mouths of elderly asthma patients

BACKGROUND

The influence of dentures on residual inhaled corticosteroids (ICSs) in the mouths of elderly asthmatic patients and the appropriate time for gargling after inhaling ICSs are unclear.

METHODS

Twenty elderly patients in whom moderate persistent asthma was stably controlled using fluticasone propionate Diskus (FP, n = 10) or hydrofluoroalkane-beclomethasone dipropionate (HFA-BDP, n = 10) for more than 3 months and who wore dentures daily were switched to the other type of ICS for 4 weeks in a crossover manner. The residual amount of each ICS in their mouths after inhalation was measured along with determination of peak inspiratory flow (PIF) and pharyngeal culture for detecting Candida albicans.

RESULTS

The total amounts of residual ICSs in gargling fluids (μg) with HFA-BDP were significantly greater than those with FP (15.6 ± 14.6 vs. 11.5 ± 13.8, p = 0.028). The residual amounts of HFA-BDP were significantly greater in the patients with complete dentures than in those with partial dentures. The residual amounts of FP were significantly correlated with the PIF values in the FP treatment (p = 0.013) but not in the HFA-BDP treatment (p = 0.202). No residual ICSs remained after the third gargling in either treatment. The occurrence of candidiasis during the HFA-BDP period was significantly higher than that during the FP treatment (p = 0.046).

CONCLUSION

The dentures of elderly asthmatics affect the oral residues of ICSs and occurrence of candidiasis in HFA-BDP treatment; meanwhile, the PIF values affected these factors in FP treatment. Three times gargling after inhaling ICSs is required.

Development of new spacer device geometry: a CFD study (part I)

Asthma is a widespread disease, affecting more than 300 million individuals. The treatment in children is based upon an administration of a pressurised metered-dose inhaler added with a spacer. The efficiency of drug delivery to the patient is strongly affected by the transient airflow pattern inside the spacer device. This paper presents a computational fluid dynamics (CFD) analysis of airflow inside a commercially available spacer device with wide application. This study, carried out in Fluent™, was the basis of an optimisation procedure developed to improve the geometry of the spacer and develop a more efficient product. The results show that an appropriate control of the boundary layer development, by changing the spacer shape, reduces the length of the recirculation zones and improves the flow. It can be concluded that CFD is a powerful technique that can be successfully applied to optimise the geometry of such medical devices.

New treatment options in allergic rhinitis: patient considerations and the role of ciclesonide

Allergic rhinitis (AR) is a chronic inflammatory respiratory disease affecting 5%-50% of the worldwide population and its prevalence is increasing (Herman 2007). In addition, AR is associated with asthma and other co-morbidities such as conjunctivitis and sinusitis. The main symptoms are nasal congestion, rhinorrea, sneezing, itching, and post-nasal drainage induced after allergen exposure by an IgE-mediated inflammation of the membranes lining the nose. AR is not a life-threatening disease, but it has been shown to have a significant impact on quality of life. The Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines propose a classification of AR in intermittent and persistent, each graded as mild or moderate-severe, and provide a stepwise approach to the treatment. Inhaled steroids and antihistamine are the main tools in AR therapy but more safe and effective drugs are, however, needed. Inhaled steroid ciclesonide appears to be safe and effective.

Side effects with inhaled corticosteroids: the physician's perception

The National Asthma Education and Prevention Program 1997 guidelines and 2002 update provide an overview of potential local and systemic side effects associated with inhaled corticosteroids (ICS) and suggest ways of minimizing the risk of these side effects occurring. Despite the guidelines and extensive clinical experience of the safe use of ICS, a significant number of physicians retain concerns regarding side effects. Local side effects may lead to patients discontinuing therapy, with or without the knowledge of their physicians. In particular, concerns regarding systemic side effects, such as growth retardation in children and osteoporosis, remain relatively widespread. Pharmacokinetic studies reveal that different ICS compounds and formulations result in different degrees of systemic bioavailability, indicating possible differences in their potential to cause systemic side effects. However, clinical studies that can be used to differentiate between ICS formulations are generally lacking. Consequently, there is a need to continue to further our understanding of side effects with ICS, with the aim of identifying formulations, devices, and doses with an optimal risk/benefit ratio. The introduction of new agents with potentially improved safety profiles may reassure physicians and patients as to the relative benefits of ICS therapy in asthma.

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.

Higher patient perceived side effects related to higher daily doses of inhaled corticosteroids in the community: a cross-sectional analysis

The range and extent of inhaled corticosteroid (ICS) side effects experienced by patients in the general community are likely to be underestimated.

AIMS

To identify the side effects of ICS perceived by patients in the community and, through the use of a self-report questionnaire, measure their intensity, prevalence and relationship with daily medication dose.

METHODS

Focus groups and in-depth interviews were conducted to identify side effects that patients associated with their use of ICS. In an international multicentre cross-sectional survey, 395 inhaler users from community pharmacy (mean age 50, 53% female), divided into 4 daily dosage groups (beta2-agonist without ICS n=66, beclometasone dipropionate (BDP) equivalent ICS low dose 400 microg, n=109; mid dose 401-800 microg, n=151; and high dose>800 microg, n=69) reported how much they were affected by these side effects on a 7-point Likert scale.

RESULTS

Focus groups and interviews revealed 57 side effects that were associated with ICS use. Cross-sectional survey results showed significant differences in side effect perception between the four dosage groups for 31 items (all P0.01) and a rising intensity with increasing ICS dose for total side effect score (P<0.001). For ICS users reporting the most bothersome side effects (scoring 3 on 0-6 scale) there was a rising prevalence as ICS dose increased for 34 items. A multivariate model confirmed that mid and high ICS dosages were statistically significantly associated with side effect perception after controlling for the other factors and covariates.

CONCLUSIONS

Higher daily ICS doses were associated with a higher intensity and a higher prevalence of many patient perceived side effects, lending support to the call for dose titration in clinical practice. Results indicate the usefulness of patient self-report scales for understanding the burden of side effects of ICS in the community.

Influence of Mouth Washing Procedures on the Removal of Drug Residues Following Inhalation of Corticosteroids

Mouth washing after inhalation of corticosteroids is effective for prevention of local adverse effects such as hoarseness and oropharyngeal candidiasis. To establish an optimal procedure for such mouth washing, we investigated the removal rates of drug residues remaining on the oropharyngeal mucosa using various mouth washing methods following inhalation. A beclomethasone dipropionate metered dose inhaler (BDP-MDI) (100 microg) and a fluticasone propionate dry powder inhaler (FP-DPI) (100 microg) were used. The effects of different mouth washing methods were evaluated by quantification of drugs in the expectorated rinse solution using an HPLC method. The amounts of BDP recovered in the rinse after gargling and rinsing for 5 s each were 47.1+/-13.6 microg, while they were 42.9+/-9.4 microg after rinsing alone for 10 s and 38.7+/-9.2 microg after gargling alone for 10 s. Under the same conditions, FP amounts were 32.9+/-7.3 microg, 28.9+/-2.4 microg, and 27.1+/-7.9 microg, respectively. In a comparison of washing time, the amounts of BDP recovered were 49.8+/-9.7 microg after gargling and rinsing for 2 s each, 53.5+/-10.2 microg after those for 3 s each, and 47.1+/-13.6 microg after those for 5 s each, while the amounts of FP under the same conditions were 36.4+/-2.4 microg, 33.3+/-6.4 microg, and 32.9+/-7.4 microg, respectively. As for the effect of time lag before mouth washing, the amount of BDP recovered decreased by 65.7% with a lag time of 1 min and by 5.6% after 10 min, while that of FP decreased by 51.1% with a lag time of 1 min and by 7.7% after 10 min. Our results suggest that the amount of drugs removed by mouth washing is significantly associated with the time lag between inhalation and mouth washing. We concluded that immediate gargling and rinsing after inhalation is most useful for the removal of drugs following inhalation of corticosteroids.

Deposition and effects of inhaled corticosteroids

Inhaled corticosteroids are now recommended as maintenance therapy for all but the mildest cases of asthma, and may be delivered by a variety of devices and formulations. Drug delivery may be assessed by both in vitro and in vivo methods. Although drug deposition in the lungs is expected to predict clinical response, this relationship is often masked by the flat nature of corticosteroid dose-response curves. The effects of inhaled corticosteroids depend not only upon the pharmacology of the drug being administered, but also upon its delivery system, with more efficient devices not only improving therapeutic effect but also potentially increasing systemic adverse effects. Modern delivery systems that enhance drug targeting to the lungs make it possible to use lower dosages of inhaled corticosteroid, such that the clinical response is maintained but systemic exposure reduced.

Investigation of pulmonary deposition of a nebulized radiopharmaceutical agent in awake cats

OBJECTIVE

To determine whether conscious, unsedated cats will inhale a nebulized material administered via a facemask and whether this material will reach the lower airways.

ANIMALS

20 healthy adult cats.

PROCEDURE

Technetium Tc 99m-diaminetriaminopentaacetic acid (99mTc-DTPA) was nebulized into a spacer and administered to the cats via a closely fitting facemask. By use of a gamma camera, images were then immediately obtained to determine the distribution of 99mTc-DTPA within the lower airways.

RESULTS

Images obtained by use of the gamma camera revealed that all 20 cats had inhaled 99mTc-DTPA from the facemask. In each cat, deposition of the radiopharmaceutical agent was evident throughout the lung fields.

CONCLUSIONS AND CLINICAL RELEVANCE

Awake cats that were not used to the application of a facemask did inhale substances from such a device. Aerosolization of medications may be a feasible route of administration for cats with lower airway disease.

Provocation with adenosine 5'-monophosphate, but not methacholine, induces sputum eosinophilia

INTRODUCTION

Bronchial hyper-responsiveness is usually measured with direct stimuli such as methacholine (MCh) or histamine. Adenosine 5'-monophosphate (AMP), which acts indirectly via the secondary release of mediators, is another stimulus to measure bronchial hyper-responsiveness.

AIM

To investigate whether provocation with inhaled AMP itself initiates an inflammatory response resulting in an influx of eosinophils into the airway lumen.

METHODS

We have included 21 non-smoking atopic asthmatic subjects (mean FEV1 101% predicted, mean age 34 years). Each subject performed three sputum inductions on different days, at least seven days apart: one without previous provocation, one hour after PC20 methacholine, and one hour after PC20 AMP.

RESULTS

After provocation with AMP, but not methacholine, the percentage of sputum eosinophils increased significantly (from 1.9+/-0.5% to 4.5+/-1% (P<0.01) and 1.9+/-0.5% (P=0.89)). No changes in the percentages of neutrophils, lymphocytes, macrophages, or bronchial epithelial cells were found.

CONCLUSION

A provocation test with AMP leads to an increased percentage of sputum eosinophils. This observation cannot be explained by a non-specific response of the airways to a vigorous bronchoconstriction, since methacholine had no effect on inflammatory cells.

Treatment of childhood asthma: how do the available options compare?

The National Asthma Council of Australia suggests that "the aim of preventive therapy should be to enable patients to enjoy a normal life (comparable with that of non-asthmatic children), with the least amount of medication and at minimal risk of adverse events. The level of maintenance therapy should be determined by symptom control and lung function in the interval periods." The British Thoracic Society/Scottish Intercollegiate Guidelines Network states that the aims of the pharmacological treatment of asthma should be to control symptoms, prevent exacerbations and achieve the best possible lung function with minimal adverse effects. We have used the current published international guidelines to highlight the international differences in management recommendations, and compared the possible pharmacological options with a focus on the above ideals. Cromones have been used for many years in childhood asthma. Most evidence suggests they now have little role. Regarding inhaled corticosteroids (ICS), beclomethasone and budesonide are essentially similar in their efficacy. Fluticasone propionate is equally as effective at one-half the equivalent dose of budesonide or beclomethasone. Adverse effects are rare in dosages <400 microg/day of budesonide and beclomethasone or <200 microg/day of fluticasone propionate, but may occur in individual patients. Relevant clinical adverse effects are rare and pharmacological systemic effects are less noticeable with budesonide and fluticasone propionate than with beclomethasone, but data are conflicting. Long-acting beta2-adrenoceptor agonists (beta2-agonists) are recommended once low-dose ICS have failed to control symptoms. The main pharmacological difference between the agents is that formoterol is a full beta2-adrenergic agonist, whereas salmeterol is a partial agonist at the beta2-adrenoceptor and has a unique pharmacological action. The main clinical distinction between these two agents is that their onset of bronchodilation differs. Bronchodilation begins at about 3 minutes after inhalation of formoterol, which is similar to the short-acting agents, whereas salmeterol has a much slower onset of action at about 15-30 minutes. The many in vitro differences between the two drugs are probably not clinically relevant. There are no comparative pediatric data on the leukotriene modifiers to make clear recommendations.

The influence of inhaler selection on efficacy of asthma therapies

Many different devices are available to aid inhalational drug delivery. Although each device is claimed to have advantages over its rivals, the evidence to support greater efficacy of a particular device is scanty. Most comparative studies are underpowered or flawed in their design. They may use inappropriate end-points, or involve healthy subjects, whose response may be very different from the patient with acute severe asthma. The dosage of drug used in a trial may be at the shallow part of the dose-response curve, masking differences in devices. Only in a few cases have clinical trials detected a significant difference between devices, and trials have rarely taken patient preference into account. The most efficacious device in practice is likely to be the one that the patient will use regularly and in accordance with a health care workers' recommendations.

Effect of detergent-coated versus non-coated spacers on bronchodilator response in children with asthma

OBJECTIVE

Previous studies have demonstrated that coating spacers with ionic detergents minimizes the static charge and thereby improves in vivo drug deposition. The present study aims to examine the effect of coated spacers versus non-coated spacers in the clinical situation.

METHODS

A randomized, double-blind study in children with asthma and a ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC) of < or =72% predicted was carried out. Spirometry was performed at baseline and at 10 min and 20 min after inhalation of two puffs of salbutamol (100 microg/puff) through either a detergent-coated or a non-coated spacer.

RESULTS

Fifty children were studied (mean age 11.6 years, range 7-18 years): 26 in the group using coated spacers (CG); and 24 in the group using non-coated spacers (NCG). The mean percentage change in FEV1 from baseline 10 min after inhalation was 18.8% (range 5-50%) in the CG versus 18.5% (range 3-35%) in the NCG. At 20 min after inhalation, the per cent increase in FEV1 was 19.8% (range 0-50%) in the CG versus 19.5% (range 9-35%) in the NCG. There was no significant difference between groups in the percentage change in FEV1 after 10 min (P = 0.91), or after 20 min (P = 0.93).

CONCLUSIONS

There was no improvement in bronchodilatation from detergent-coated spacers in the present study, possibly because a maximal bronchodilator response was achieved with the lower output.

Management of asthma in adults: current therapy and future directions

Asthma is increasing in prevalence worldwide and results in significant use of healthcare resources. Although most patients with asthma can be adequately treated with inhaled corticosteroids, an important number of patients require additional therapy and an increasing number of options are available. A further minority of patients develop severe persistent asthma which remains difficult to manage despite current pharmacological therapies. This review discusses the various treatment options currently available for each stage of asthma severity, highlights some of the limitations of current management, and outlines directions which may improve the management of asthma in the future.

Treatment of allergic asthma

Asthma is a chronic inflammatory disorder of the airways that causes recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning. The airway inflammation also increases bronchial hyperresponsiveness to a variety of stimuli. After evaluation that includes spirometry, patients with intermittent asthma are treated with a short-acting bronchodilator on an as-needed basis. Patients with persistent asthma should receive inhaled corticosteroids as first-line anti-inflammatory therapy and long-acting inhaled beta(2)-agonists as preferred adjunctive therapy. Leukotriene modifiers can be used as maintenance therapy in patients with mild persistent asthma, or added to the regimen of patients with moderate or severe persistent asthma. In patients with asthma and concomitant allergic rhinitis, antihistamines may be useful as adjunctive therapy.

Combined budesonide/formoterol turbuhaler treatment of asthma

OBJECTIVE

To provide product information; review and analyze the clinical literature studying combination therapy, budesonide, and formoterol in asthmatics; and to define the role for this therapy in asthma treatment.

DATA SOURCES

A MEDLINE search (1990-September 2001) was conducted to identify the primary literature. Bibliographies were reviewed for further relevant citations.

STUDY SELECTION/DATA EXTRACTION

All randomized, blinded, controlled studies at least 3 months in duration exploring the efficacy of the combination of budesonide and formoterol (in 1 or separate formulations) compared with other treatments were selected to be included in the review of clinical studies.

DATA SYNTHESIS

The combination of budesonide and formoterol was more effective than increasing the dose of budesonide in patients with moderate or severe persistent asthma and in patients with mild asthma not previously controlled with inhaled corticosteroids. Milder corticosteroid-naïve asthmatics did not derive benefit compared with inhaled corticosteroids alone.

CONCLUSIONS

Combination therapy in 1 device is a preferred treatment option in patients with moderate to severe persistent asthma and in those with milder asthma not controlled with inhaled corticosteroids. Advantages of this product include rapid onset of action, long duration of action, and a wide dosing range to assist with titration. Further research is required to evaluate this therapy in asthmatic children <5 years old and in patients with oral corticosteroid-dependent asthma. Investigations into the effect of this combination product on other disease outcomes, such as quality of life and productivity, will further define the role for this drug therapy.

Adrenal suppression in asthmatic children receiving low-dose inhaled budesonide: comparison between dry powder inhaler and pressurized metered-dose inhaler attached to a spacer

BACKGROUND

Dry powder inhalers (DPI) have in recent years become a common mode for administration of inhaled corticosteroids for preventive therapy of asthma. Inhaled steroids delivered by DPI achieve increased lung deposition compared with pressurized metered-dose inhalers (pMDI), which is associated with increased therapeutic effect. This may be associated with increased systemic absorption.

OBJECTIVE

The purpose of this study was to evaluate the prevalence of adrenal suppression in children using low-dose budesonide given by DPI, as compared with pMDI attached to a large-volume spacer device (pMDI + spacer).

METHODS

In an open-labeled crossover study, 15 asthmatic children aged 5 to 15 years received 200 microg of inhaled budesonide twice daily by DPI (Turbuhaler, Astra, Draco AB, Lund, Sweden) and by pMDI + spacer, 1 month each, in a randomized order. Twenty-four-hour urine collections were performed at baseline and at the end of each of the 2 months of the study period, and urinary cortisol and creatinine were measured.

RESULTS

Baseline urinary cortisol:creatinine was 0.038 +/- 0.012 microg/mg, similar in both groups. After 1 month of DPI therapy, urinary cortisol:creatinine was reduced by 27 +/- 16% to 0.028 +/- 0.012 microg/mg (P = 0.018). Urinary cortisol:creatinine after 1 month of pMDI + spacer therapy was similar to baseline 0.037 +/- 0.019 microg/mg (P = 0.78).

CONCLUSIONS

Treatment of asthmatic children with budesonide 400 microg daily given via a DPI for 1 month was associated with hypothalamic-pituitary-adrenal axis suppression. This effect was not observed with the same dose of budesonide administered via pMDI + spacer. This indicates that systemic absorption might be reduced with pMDI + spacer therapy.

Safety, tolerability and acceptability of two dry powder inhalers in the administration of budesonide in steroid-treated asthmatic patients

The purpose of this randomized, double-blind parallel group study was to compare the safety, tolerability and acceptability of Easyhaler and Turbuhaler dry powder inhalers for the delivery of budesonide 800 microg day(-1) in adult asthmatic patients who had already been treated with inhaled corticosteroids for at least 6 months prior to the study Additionally the efficacy of the products was evaluated. The main objective was to evaluate the systemic safety of budesonide inhaled from Easyhaler (Giona Easyhaler, Orion Pharma, Finland) as determined by serum and urine cortisol measurements. The secondary objective was to compare the tolerability acceptability and efficacy of the two devices in the administration of budesonide. After a 2-week run-in period (baseline), patients were randomized on a 2:1 basis to receive budesonide from Easyhaler (n = 103) or from Turbuhaler (Pulmicort Turbuhaler, AstraZeneca, Sweden) (n = 58) 200 g dose(-1), two inhalations twice daily for 12 weeks. There was no statistically significant change in morning serum cortisol values from baseline to the end of treatment in either group. Urine free cortisol and urine cortisol/ creatinine ratio increased from baseline in both groups. There were no significant differences between the groups in terms of morning serum cortisol, urine cortisol, adverse events or efficacy variables, but Easyhaler was generally considered more acceptable to the patients. In conclusion, at 800 microg day(-1), Giona Easyhaler is as safe and efficacious as Pulmicort Turbuhaler in adult asthmatic patients previously treated with corticosteroids, but more acceptable to patients.

Patient self-management of acute asthma: adherence to national guidelines a decade later

BACKGROUND AND OBJECTIVES

Children in the emergency department (ED) with acute asthma were enrolled to assess the impact of asthma on their activities of daily living and evaluate their access to care and preventive strategies, determine the proportion who adhered to the National Heart, Lung, and Blood Institute (NHLBI) guidelines for proper steps to take at home during an acute asthma exacerbation, and compare adherence rates for those with persistent and mild intermittent asthma.

DESIGN AND METHODS

Children 2 to 18 years old who presented to the Children's Hospital of Philadelphia's ED with acute asthma exacerbations were enrolled prospectively. Parents and patients completed the 108-item Asthma Exacerbation Response Questionnaire with a focus on determining the home management steps they took both at the onset of the asthma exacerbation and just before coming to the ED.

RESULTS

Among the 433 children studied, 76% had at least 1 doctor visit, 75% had at least 1 ED visit, and 43% had at least 1 hospitalization for asthma in the preceding 12 months. Overall, 64% had persistent asthma by NHLBI criteria, yet just 4% were cared for by an allergist or pulmonologist, 38% took daily anti-inflammatory therapy, and 18% received a daily inhaled corticosteroid. Also, 48% did not use a holding chamber with their metered-dose inhalers, and 66% did not use their peak flow meters. Regarding exacerbation response, 71% did not have a written action plan, and 89% did not maintain a symptom diary. Both at the onset of wheezing and just before coming to the ED, administration of a beta2-agonist was the only step that the majority of children performed. One-third or fewer followed the other steps recommended by the NHLBI, including using a peak flow meter, beginning oral corticosteroids, calling or going to see the doctor, or going to the ED. Children with persistent asthma were not more adherent to the guidelines than those with mild intermittent disease.

CONCLUSIONS

Asthma has a significant adverse effect on the lives of these children. The NHLBI guidelines, first published a decade ago, were designed to reduce asthma's increasing morbidity and mortality, but this study uncovered a high rate of nonadherence with many aspects of the guidelines, including preventive strategies and home management of an exacerbation.

History and future perspectives of treating asthma as a systemic and small airways disease

Asthma is an inflammatory disorder in which the small airways of the lung play an important role. There is also evidence for the systemic nature of asthma. No current method adequately measures small airways function alone. Therefore, a combination of functional and clinical parameters should be used to ensure that patients with asthma are adequately treated with due consideration of the small airways. Previously therapeutic strategies have focused on bronchodilation and attenuation of airway inflammation. While early oral therapies had the advantage of reaching the small airways and treating the systemic aspect of asthma, they were associated with serious side-effects. Inhaled therapies were therefore developed to limit these effects. However, inhaled therapies have the disadvantage of limited penetration into the peripheral airways and an inability to treat the systemic component of asthma. They are also associated with local and systemic side-effects. The future for asthma treatment is likely to be a systemically administered medication with few side-effects targeting disease-specific mediators. The leukotriene receptor antagonists and anti-IgE monoclonal antibodies are examples of such therapies and the emergence of other new strategies is awaited.

Discharge of the asthmatic patient

Asthma continues to be a challenging disease to treat in both the inpatient and outpatient settings. The growing database on therapeutic interventions at the time of transition from the acute to chronic phase of this disease is encouraging. Glucocorticoids and inhaled beta-agonists clearly reduce readmission and relapse. Other medications and educational interventions also appear effective. Still, no true discharge guidelines have been established. Multiple statements by consensus panels have recommended using FEV1 or PEFR as indicators of readiness for discharge, but this has not been prospectively validated from either the emergency department or inpatient setting. In contrast, some studies argue that pulmonary functions do not accurately predict relapse and readmission, so the usefulness of these discharge recommendations is debatable. Large studies, especially in the adult asthmatic population, are needed to validate these recommendation.

Inhaled corticosteroids reduce growth. Or do they?

The class label warning in the United States for inhaled corticosteroids (ICS's) states that these drugs may reduce growth velocity in children. In this paper, the evidence for this warning is reviewed from a clinical point of view. Children with asthma tend to grow slower than their healthy peers during the prepubertal years because they go into puberty at a later age. However, asthmatic children do achieve a (near) normal adult height. In randomized controlled clinical trials, the use of inhaled beclomethasone, budesonide and fluticasone is associated with a reduced growth during the first months of therapy, in the order of magnitude of approximately 0.5-1.5 cm x yr(-1). It is, however, unlikely that such an effect continues or persists because accumulating evidence shows that asthmatic children, even when they have been treated with ICS for years, attain normal adult height. Individual rare cases have been reported, however, where ICS use was associated with clinically relevant growth suppression. Inhaled corticosteroids are the most effective therapy available for maintenance treatment of childhood asthma. Fear of reduced growth velocity is based on exceptional cases and not on group data. It should, therefore, not be a reason to withhold or withdraw such highly effective treatment in children with asthma.

Bone mineral density in women with asthma on long-term inhaled corticosteroid therapy

BACKGROUND

Inhaled corticosteroids (ICS) have become first line agents in the management of moderate-to-severe asthma. Long-term use of ICS is associated with decreased bone mineral density (BMD).

OBJECTIVE

To investigate the prevalence of BMD loss and its severity in women with asthma on long-term ICS.

METHODS

Fifty-six women with asthma on long-term ICS, attending an inner-city allergy clinic were selected to undergo bone densitometry in order to evaluate the association between BMD and the long-term use of ICS at different dose ranges.

RESULTS

Women (60.7%) had decreased BMD either at the lumbar spine or hip region. Among postmenopausal women, 17.1% of those <65 years and 42.9% of those > or =65 years had osteoporosis compared with 5.7% (95% CI-3.9% to 8.5%) of those <65 and 29.3% (95% CI-25.7%-33.5%) of those > or =65 years reported in the NHANES III survey. The prevalence of low BMD increased as ICS dose increased from 5% in the low dose group to 50% in the high dose group (P < .002). There were significant linear trends of decline by dose in mean BMD for the hip (P < .001) and the lumbar spine (P < .002). Women who received medium or high doses of ICS had significantly greater bone loss than those receiving low doses.

CONCLUSION

The findings of increasing BMD loss with increasing ICS dose reinforce the necessity to monitor BMD periodically in women on ICS, particularly in the high risk postmenopausal group and those on medium to high doses. There should be a concurrent continual attempt to lower the dose by supplemental nonsteroidal controller medications and providing nutritional and pharmacologic treatment of identified BMD loss in these patients.

Nocturnal cortisol secretion in asthmatic patients after inhalation of fluticasone propionate

OBJECTIVES

This study was designed to assess the relationship between the degree of airflow obstruction and the suppression of the hypothalamic-pituitary-adrenal axis after inhalation of fluticasone propionate (FP) in asthmatic patients with varying degrees of airway obstruction.

STUDY DESIGN

The nocturnal cortisol production (from 10:00 PM to 6:00 AM), defined as the integrated area under the curve of nocturnal plasma cortisol, was measured following inhalation of a placebo or a single dose of 500 microg FP at 8:00 PM in 28 patients with mild to moderate asthma, in a single, blind, 2-night study.

RESULTS

The mean morning rise of cortisol decreased significantly following a single dose of inhaled FP. When the total nocturnal cortisol production after the second night (when the FP was inhaled) was compared to that after the first night (when the placebo was administered), it was found to have decreased by 29.4%. There was a statistically significant correlation between the FEV(1) and the fall in cortisol production just before the inhalation of FP (p < 0. 001). There was no correlation between baseline cortisol production and the fall in cortisol production.

CONCLUSIONS

Our findings suggest that the degree of airway obstruction affects the systemic bioavailability of FP. FP is likely to induce a more severe decrease in nocturnal cortisol secretion in less obstructed patients. In order to reduce the risk for systemic side effects, the patient's degree of airway obstruction should be considered when planning inhaled FP treatment.

Evaluation of the effect of a large volume spacer on the systemic bioactivity of fluticasone propionate metered-dose inhaler

BACKGROUND

Inhaled corticosteroids such as fluticasone propionate (FP) have dose-related systemic effects, including adrenal suppression. We have therefore investigated the effect of adding a large volume spacer on the systemic bioactivity of FP given via a pressurized metered-dose inhaler (pMDI).

METHODS

Fourteen healthy volunteers (mean age, 29.9 years old) were studied using an open, randomized, placebo-controlled, three-way crossover design. Single doses of the following were given at 5:00 PM in a randomized sequence: (1) eight puffs of FP by pMDI, 1.76 mg (250 microg ex-valve, 220 microg ex-actuator); (2) eight puffs of FP by pMDI, 250 microg, with 750-mL spacer (Volumatic; Allen & Hanburys; Uxbridge, UK); and (3) eight puffs of placebo by pMDI. Measurements were made after each dose, including overnight and early morning urinary cortisol/creatinine ratios and 8:00 AM serum cortisol.

RESULTS

Significant (p < 0.05) suppression of all three end points occurred with each active treatment compared to treatment with placebo. Furthermore, significant (p < 0.05) additional suppression occurred when comparing FP by pMDI alone to FP by pMDI with spacer. Geometric mean fold differences (95% confidence interval for fold difference) between FP by pMDI alone and FP by pMDI with spacer were 1.94-fold (1.00-3.78) for overnight urinary cortisol/creatinine ratio and 1.98-fold (1.26-3.10) for 8:00 AM serum cortisol. This was mirrored by a twofold rise in the number of values for uncorrected overnight urinary cortisol < 10 nmol/10 h: placebo treatment (none of 14 subjects); FP by pMDI (6 of 14 subjects; 43%); and FP by pMDI with spacer (12 of 14 subjects; 86%).

CONCLUSIONS

The use of a large volume spacer with FP by pMDI results in a twofold increase in the systemic bioavailability as assessed by sensitive measures of adrenal suppression. This, in turn, reflects a twofold improvement in respirable dose delivery with the spacer device.

Measures of hypothalamic-pituitary-adrenal function in patients with asthma treated with inhaled glucocorticoids: clinical and research implications

In asthmatic patients treated with inhaled glucocorticoids there may be a risk of suppression of hypothalamic-pituitary-adrenal (HPA) function. The aim of the present study was to review peer-refereed data on HPA function in asthmatic patients taking inhaled glucocorticoids, and to discuss the value of HPA function measures in clinical practice and research. There is no evidence that inhaled glucocorticoids in recommended doses cause clinically significant HPA insufficiency. If sensitive measures of basal adrenal activity are used, however, dose-related suppressive effects with specific drugs and application systems can be detected. In adults, fluticasone propionate appears to be more potent than budesonide or triamcinolone acetonide in suppressing measures of basal adrenal activity. Measures of basal adrenal activity are useful in clinical trials that assess and compare systemic activity of specific drugs, application devices, and administration regimens, but have no place in the management of asthma.

Evaluation of the buccal component of systemic absorption with inhaled fluticasone propionate

BACKGROUND

Inhaled corticosteroids have dose related systemic effects determined by oral (swallowed or oropharyngeal absorption) and lung bioavailability. A study was undertaken to evaluate the significance of oropharyngeal absorption for fluticasone propionate.

METHODS

Sixteen healthy volunteers of mean age 29.3 years were studied using an open randomised, placebo controlled, four way crossover design. Treatments were: (a) fluticasone metered dose inhaler (pMDI) 250 microg, 8 puffs; (b) fluticasone pMDI 250 microg, 8 puffs + mouth rinsing/gargling (water); (c) fluticasone pMDI 250 microg, 8 puffs + mouth rinsing/gargling (charcoal); and (d) placebo pMDI, 8 puffs + mouth rinsing/gargling (water). Overnight (ONUC) and early morning (EMUC) urinary cortisol/creatinine ratios and 8 am serum cortisol (SC) levels were measured.

RESULTS

Significant (p<0. 05) suppression of ONUC, EMUC, and SC occurred with each active treatment compared with placebo. The mean values (95% CI for difference from placebo) were: (a) ONUC (nmol/mmol): fluticasone (2. 8, 95% CI 3.6 to 7.9), fluticasone + water (3.1, 95% CI 3.3 to 7.7), fluticasone + charcoal (2.3, 95% CI 4.1 to 8.5); placebo (8.6); (b) EMUC (nmol/mmol): fluticasone (5.6, 95% CI 8.4 to 24.5), fluticasone + water (7.6, 95% CI 6.6 to 22.4); fluticasone + charcoal (5.6, 95% CI 8.7 to 24.5); placebo (22.1). There were no significant differences between active treatments. The numbers of subjects with an overnight urinary cortisol of <20 nmol/10 hours were 0 (placebo), 11 (fluticasone), 12 (fluticasone + water), and 13 (fluticasone + charcoal).

CONCLUSIONS

Oropharyngeal absorption of fluticasone does not significantly contribute to its overall systemic bioactivity as assessed by sensitive measures of adrenal suppression. In view of almost complete hepatic first pass inactivation with fluticasone, there is no rationale to employ mouth rinsing to reduce its systemic effects although it may be of value for reducing oral candidiasis.

Systemic bioavailability and potency of high-dose inhaled corticosteroids: a comparison of four inhaler devices and three drugs in healthy adult volunteers

OBJECTIVES

To compare the systemic bioavailability (assessed by cortisol suppression) of high-dose budesonide when given by four inhaler devices and orally. Also studied are the relative systemic potencies of three inhaled steroids (budesonide, fluticasone propionate, and beclomethasone dipropionate) when given by metered-dose inhaler (MDI) with a large volume spacer.

DESIGN

Double-blind, crossover, placebo-controlled trial.

PARTICIPANTS

Sixteen healthy, steroid-naive adult volunteers.

METHODS

On separate occasions, each subjects took 4 mg of budesonide through the following devices: MDI alone, MDI with 750-mL. spacer, dry-powder inhaler and nebulizer; 4 mg of budesonide was also taken orally to assess the effects of GI absorption. For the drug comparison, each subject took 4 mg of budesonide, fluticasone, and beclomethasone, and 2 mg of budesonide and fluticasone by MDI and spacer.

RESULTS

Greatest percent suppression (95% confidence interval) of 9:00 AM cortisol with budesonide was observed with MDI alone (73% [57 to 90]) and turbohaler (72% [58 to 86]) compared with MDI spacer (42% [22 to 64]) and oral administration (14% [+6- to -34]). Nebulized budesonide produced an insignificant rise in 9:00 AM cortisol level. The most suppressive drug (given by MDI spacer) was fluticasone at 4 mg (86% [82 to 91]) and at 2 mg (72% [59 to 85]). The least suppressive drug was budesonide at 4 mg (43% [22 to 64]) and at 2 mg (25% [3 to 47]). The effects of 4 mg of beclomethasone were intermediate (66% [49 to 82%]).

CONCLUSIONS

The choice of delivery device for administration of budesonide can lead to important differences in systemic bioavailability. Fluticasone has greater systemic potency than budesonide or beclomethasone when given at microgram equivalent dosage. The systemic potency ratio of fluticasone propionate to budesonide in normal human volunteers in the present study is similar to the therapeutic potency ratio of the drug in asthmatic patients (approximately 2:1).

Improving outcomes in elderly patients with asthma

Although often regarded as a disease of childhood, asthma is common in elderly people. Although recent figures show a decline over the past few years in the number of asthma deaths in children and younger adults, the same is not true of older adults, in whom most asthma deaths occur. Differences between asthma in young and old patients are seen not only in response to treatment. The nonspecific presentation of asthma in elderly adults means that the diagnosis of asthma is difficult to make. In addition, research suggests that physicians are reluctant to use spirometry and measurement of reversibility when investigating respiratory symptoms in old people. This leads to a tendency to label breathless or wheezy elderly patients as having chronic obstructive pulmonary disease (COPD) rather than asthma. In turn, patients with a diagnosis of COPD are less likely to be treated with bronchodilators and corticosteroids. Treatment guidelines for the management of asthma in children and younger adults may need to be adapted when applied to older patients. Reduced perception of bronchoconstriction may lead to underuse of bronchodilators prescribed 'as required'. The bronchodilator response to beta2-agonists is attenuated as part of the normal aging process, and other groups of bronchodilator medications should be considered. Inhaler technique can be a particular problem in elderly patients with asthma, requiring careful choice of inhaler device. However, the frequent presence of multiple pathology and multiple medication in this age group enhances the risk of adverse effects from oral preparations, and so the inhaled route should be preferred wherever possible. Underestimation of the severity of an acute exacerbation of asthma by both patient and doctor has been suggested as a contributory factor to poor outcome in older people. Since the cardiovascular responses to hypoxia and bronchoconstriction tend to diminish with increasing age, objective measures of asthma severity (peak flow monitoring and blood gas estimation) are essential in this age group.

Systemic activity of inhaled and swallowed beclomethasone dipropionate and the effect of different inhaler devices

Inhaled glucocorticoids such as beclomethasone dipropionate, which are used in the treatment of asthma, may be associated with systemic adverse effects. To determine whether any systemic absorption following the inhalation of beclomethasone was a result of drug being absorbed from the lung (inhaled fraction) or the gastrointestinal tract (swallowed fraction), we studied normal subjects after the inhalation or swallowing of 2 mg beclomethasone dipropionate. Systemic activity was assessed using early morning cortisol suppression. Both inhaled and swallowed fractions produced significant systemic activity, the degree of which depended on the inhaler device used. Systemic activity was greater using a dry powder inhaler (52%) than using a metered dose inhaler with a large volume spacer (28%). These findings suggest that to limit potential adverse effects from high-dose beclomethasone dipropionate it is better to use a metered dose aerosol with large volume spacer than a dry powder.

Clostridium difficile-associated diarrhoea

At our hospital, the number of cases of Clostridium difficile-associated diarrhoea increased from 29 in 1993 to 210 in 1995. The case notes of 110 patients with C difficile-associated diarrhoea during the first 6 months of 1995 were analysed retrospectively. The majority of the patients (106) had received antibiotics before the onset of diarrhoea; 46 had received three or more different antibiotics and 28 had received metronidazole. In 19 patients, the first stool sample after the onset of diarrhoea was negative for C difficile cytotoxin, with a mean delay of 8.2 days before a positive stool sample. We conclude that C difficile-associated diarrhoea was associated with the usage of multiple antibiotics, and that metronidazole did not protect against colonisation by C difficile. We also recommend that more than one stool sample should be tested for the C difficile cytotoxin.

Establishing a therapeutic index for the inhaled corticosteroids: part I. Pharmacokinetic/pharmacodynamic comparison of the inhaled corticosteroids

The inhaled corticosteroids contain physicochemical differences that alter both glucocorticoid receptor-binding characteristics and the pharmacokinetic variables of these drugs. Differences in receptor-binding affinity translate into differences in potency for different drugs. Differences in pharmacokinetics, however, determine the topical effect to systemic effect ratio, or the "pulmonary targeting" of the drug. Beneficial pharmacokinetic properties that may improve pulmonary targeting include low oral bioavailability, rapid systemic clearance, and slow absorption from the lung. Delivery devices can produce clinically significant differences in topical activity by altering the dose deposited in the lung and, for orally absorbed drugs, the amount deposited in the oropharynx and swallowed. Clinical trials have confirmed that differences in potency or drug delivery of 2-fold or more can be detected in patients with asthma. However, because of the relatively flat nature of the dose-response curve for morning peak expiratory flow and forced expiratory volume in 1 second, the trials must be adequately powered and well controlled. The use of bronchial provocation measures are problematic because of the prolonged lag time for response. Study design flaws can lead to misinterpretation of results. Clinical studies have indicated the following relative potency differences: fluticasone propionate > budesonide = beclomethasone dipropionate > triamcinolone acetonide = flunisolide. Current evidence suggests that potency differences can be overcome by giving larger doses of the less potent drug. However, because of these potency differences, studies of systemic effects should not be done in isolation of adequate topical activity studies to define the pulmonary targeting of the drugs.

Comparison of inhaled corticosteroids

OBJECTIVE

To review the comparative studies evaluating both efficacy and safety of inhaled corticosteroids in the management of asthma. Specifically, comparative clinical trials are evaluated that allow clinicians to determine relative potencies of the various inhaled corticosteroids.

METHODS

A critical review was performed of the published clinical trials, either as articles or abstracts, comparing the clinical efficacy or systemic activity of inhaled corticosteroids. No a priori criteria were applied, as this was not a meta-analysis.

FINDINGS

In vitro measures of antiinflammatory activity of corticosteroids consistently demonstrate potency differences among the various corticosteroids. Traditionally, these in vitro measures have been used to develop new corticosteroids with greater topical activity. While no accepted direct measure of antiasthmatic antiinflammatory activity exists, clinical trials using surrogate measures (e.g., forced expiratory volume in 1 second, peak expiratory flow, bronchial hyperresponsiveness, symptom control) indicate that in vitro measures provide a relatively accurate assessment of antiasthmatic potency. The relative antiinflammatory potency of the inhaled corticosteroids is in the following rank order. flunisolide = triamcinolone acetonide < beclomethasone dipropionate = budesonide < fluticasone. Studies of systemic activity appear to confirm this relative order of potency. Currently, no evidence exists for greater efficacy for any of the inhaled corticosteroids when administered in their relative equipotent dosages. The preponderance of current data suggests that when administered in equipotent antiinflammatory doses as a metered-dose inhaler plus spacer or as their respective dry-powder inhaler, the existing inhaled corticosteroids have similar risks of producing systemic effects.

CONCLUSIONS

Delivery systems can significantly affect both topical and systemic activity of inhaled corticosteroids. More direct comparative studies between agents are required to firmly establish comparative topical to systemic activity ratios. The preponderance of evidence suggests that the agents are not equipotent on a microgram basis.

Growth of asthmatic children is slower during than before treatment with inhaled glucocorticoids

Reports on the influence of inhaled glucocorticoids on growth have been controversial. We studied the growth of prepubertal asthmatic children prior to and during glucocorticoid therapy. We collected retrospectively the notes of 201 asthmatic children aged 1-11 years receiving inhaled beclomethasone dipropionate or budesonide. We calculated their height and height velocity standard deviation scores (HSDS and HVSDS, respectively) before the treatment and up to 5 years during the treatment and compared those with the growth of healthy peers. The dose of the medication was calculated and the severity of asthma was assessed. The asthmatic children grew similarly to their healthy peers before treatment with inhaled glucocorticoids: the mean HSDS was +0.02 and the mean HVSDS +0.01 for boys and -0.16 and +0.13 for girls, respectively. Growth retardation took place soon after the start of the treatment, the most profound decrease in the growth velocity (the change in the mean HVSDS from +0.05 to -0.88) occurring during the first year of treatment. The growth-retarding effect of inhaled glucocorticoids was not dose dependent. In the covariance analysis the increasing severity of asthma had a significant interaction with repeated measurements, showing more growth retardation along with more severe asthma, especially during long-term treatment. Asthma per se does not impair growth, but inhaled glucocorticoids may do so. Careful monitoring of the growth of all asthmatic children receiving inhaled glucocorticoids is necessary because the growth-retarding effect of the medication is not dose dependent. Individual sensitivity might explain the differences seen in the growth patterns of children receiving inhaled glucocorticoids.

Current therapies for asthma. Promise and limitations

Effective treatments for asthma exist, but morbidity and mortality have continued to climb. Many attempts have been made to refine rather than change therapy over the past 20 years. Drugs currently used to treat asthma include beta 2-agonists, glucocorticoids, theophylline, cromones, and anticholinergic agents. For acute, severe asthma, the inhaled beta 2-agonists are the most effective bronchodilators. Short-acting forms give rapid relief; long-acting agents provide sustained relief and help nocturnal asthma; and serious adverse effects are rare when these drugs are used properly. First-line therapy for chronic asthma is inhaled glucocorticoids, the only currently available agents that reduce airway inflammation. Their side effects can be reduced by rinsing the mouth or by using large-volume spacers. Theophylline is a bronchodilator that is useful for severe and nocturnal asthma, but recent studies suggest that it may also have an immunomodulatory effect. Although theophylline is inexpensive, monitoring its plasma concentrations is both expensive and inconvenient. Cromones work best for patients who have mild asthma: they have few adverse effects, but their activity is brief, so they must be given four times daily. The anticholinergic bronchodilators are more useful for treating COPD than for chronic asthma. These drugs have virtually no side effects, and their onset is slower and their action longer than inhaled beta 2-agonists. The new direction in treating asthma will be orally administered medication that has few side effects and is targeted specifically to the pathogenesis of asthma.