Inhalers and nebulizers: which to choose and why

Inhaled drug delivery for the targeted treatment of asthma

Asthma is a chronic lung disease affecting millions worldwide. While classically acknowledged to result from allergen-driven type 2 inflammatory responses leading to IgE and cytokine production and the influx of immune cells such as mast cells and eosinophils, the wide range in asthmatic pathobiological subtypes lead to highly variable responses to anti-inflammatory therapies. Thus, there is a need to develop patient-specific therapies capable of addressing the full spectrum of asthmatic lung disease. Moreover, delivery of targeted treatments for asthma directly to the lung may help to maximize therapeutic benefit, but challenges remain in design of effective formulations for the inhaled route. In this review, we discuss the current understanding of asthmatic disease progression as well as genetic and epigenetic disease modifiers associated with asthma severity and exacerbation of disease. We also overview the limitations of clinically available treatments for asthma and discuss pre-clinical models of asthma used to evaluate new therapies. Based on the shortcomings of existing treatments, we highlight recent advances and new approaches to treat asthma via inhalation for monoclonal antibody delivery, mucolytic therapy to target airway mucus hypersecretion and gene therapies to address underlying drivers of disease. Finally, we conclude with discussion on the prospects for an inhaled vaccine to prevent asthma.

Pulmonary drug delivery: an effective and convenient delivery route to combat COVID-19

The recent outbreak of coronavirus disease 2019 (COVID-19) in Wuhan, China has spread rapidly around the world, leading to a widespread and urgent effort to develop and use comprehensive approaches in the treatment of COVID-19. While oral therapy is accepted as an effective and simple method, since the primary site of infection and disease progression of COVID-19 is mainly through the lungs, inhaled drug delivery directly to the lungs may be the most appropriate route of administration. To prevent or treat primary SARS-CoV-2 infections, it is essential to target the virus port of entry in the respiratory tract and airway epithelium, which requires rapid and high-intensity inhibition or control of viral entry or replication. To achieve success in this field, inhalation therapy is the most attractive treatment approach due to efficacy/safety profiles. In this review article, pulmonary drug delivery as a unique treatment option in lung diseases will be briefly reviewed. Then, possible inhalation therapies for the treatment of symptoms of COVID-19 will be discussed and the results of clinical trials will be presented. By pulmonary delivery of the currently approved drugs for COVID-19, efficacy of the treatment would be improved along with reducing systemic side effects.

Indian Guidelines on Nebulization Therapy

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

An expert opinion on respiratory delivery of high dose powders for lung infections

INTRODUCTION

High dose powder inhalation is evolving as an important approach to to treat lung infections. It is important to its identify applications, consider the factors affecting high dose powder delivery, and assess the effect of high dose drugs in patients.

AREA COVERED

Both current and pipeline high dose inhalers and their applications have been summarized. Challenges and opportunities to high dose delivery have been highlighted after reviewing formulation techniques in the context of factors affecting aerosolization, devices, and patient factors.

EXPERT OPINION

High dose inhaled delivery of antimicrobials is an innovative way to increase treatment efficacy of respiratory infections, tackle drug resistance, and the scarcity of new antimicrobials. The high dose inhaled technology also has potential for systemic action; however, innovations in formulation strategies and devices are required to realize its full potential. Advances in formulation strategies include the use of excipients or the engineering of particles to decrease the cohesive property of microparticles and their packing density. Similarly, selection of a synergistic drug instead of an excipient can be considered to increase aerosolization and stability. Device development focused on improving dispersion and loading capacity is also important, and modification of existing devices for high dose delivery can also be considered.

E-cigarette aerosol collection using converging and straight tubing Sections: Physical mechanisms

HYPOTHESIS

Identification and quantification of harmful chemicals in e-cigarette aerosol requires collecting the aerosolized e-liquid for chemical analysis. In 2016, Olmedo at al. empirically developed a simple method for aerosol collection by directing the aerosol through a sequence of alternating straight and converging tubing sections, which drain the recovered e-liquid into a collection vial. The tubing system geometry and flow conditions promote inertial impaction of aerosolized e-liquid on tube walls, where it deposits and flows into the collection vial.

EXPERIMENTS

We use high-speed optical imaging to visualize aerosol transport in proxies of the collection system. We also determined collection efficiencies of various configurations of the collection system.

FINDINGS

A turbulent jet emerges from converging conical sections and impinges onto the wall of downstream tubing sections, resulting in inertial impaction and deposition of the aerosol. For inertial impaction to occur the tip radius of the converging section must be small enough for a jet to be formed and the sequence of tubing sections must be curved in a polygon-like manner such that the jet emerging from a converging section impinges on the downstream tube wall. The collection efficiency is significantly smaller without such curvature.

Efficacy of inhaled medications in asthma and COPD related to disease severity

INTRODUCTION

The administration of medication by inhalation has become the most important route in treating airway diseases. The efficacy of this route depends on several factors like correct inhalation techniques, compliance and the size of the particles. The flow properties and internal flow distribution contribute to the deposition pattern. Areas covered: What has been less well studied is the effect of the internal flow distribution. We know from recent studies that using systemic anti-inflammatory compounds that open up the distal airways redistributes flow internally and enhances the deposition of inhaled particles to the active site of bronchoconstriction or airway inflammation. We discuss this in more detail in this paper, and also make reference to the use of functional respiratory imaging (FRI) that allows for the description of this flow pattern starting from chest CT followed by post processing with segmentation software and the application of fluid dynamics. Expert opinion: The method that was previously validated does show the importance of redistribution of flow in the final clinical results that could be obtained with inhaled medication, especially in more severe obstructive airway diseases. Based on these insights and novel diagnostic tools, patients in end stage respiratory failure would benefit from a personalized approach with inhaled medication.

Clinical pharmacokinetics of inhaled antimicrobials

Administration of inhaled antimicrobials affords the ability to achieve targeted drug delivery into the respiratory tract, rapid entry into the systemic circulation, high bioavailability and minimal metabolism. These unique pharmacokinetic characteristics make inhaled antimicrobial delivery attractive for the treatment of many pulmonary diseases. This review examines recent pharmacokinetic trials with inhaled antibacterials, antivirals and antifungals, with an emphasis on the clinical implications of these studies. The majority of these studies revealed evidence of high antimicrobial concentrations in the airway with limited systemic exposure, thereby reducing the risk of toxicity. Sputum pharmacokinetics varied widely, which makes it challenging to interpret the result of sputum pharmacokinetic studies. Many no vel inhaled antimicrobial therapies are currently under investigation that will require detailed pharmacokinetic studies, including combination inhaled antimicrobial therapies, inhaled nanoparticle formulations of several antibacterials, inhaled non-antimicrobial adjuvants, inhaled antiviral recombinant protein therapies and semi-synthetic inhaled antifungal agents. Additionally, the development of new inhaled delivery devices, particularly for mechanically ventilated patients, will result in a pressing need for additional pharmacokinetic studies to identify optimal dosing regimens.

Influence of anti-asthmatic medications on dental caries in children in Slovenia

OBJECTIVE.  The study investigated the influence of exposure to anti-asthmatic medications and of various factors on the caries prevalence in children in Slovenia. METHODS.  The study population consisted of children aged 2 to 17 years (n = 220) under treatment for asthma, who had used anti-asthmatic medications for at least 1 year; 220 controls were matched for age. Caries status was determined by the number of decayed, missing, and filled surfaces through clinical examination by two calibrated dentists using the International Caries Detection and Assessment System-II scoring criteria. Questionnaires completed by parents and data from the patients' medical records provided information on various confounding factors. RESULTS.  Asthmatic children had significantly higher (P ≤ 0.01) prevalence of caries on primary and permanent teeth in all age groups, and the proportion of caries-free children was significantly smaller (P ≤ 0.05). In multivariate regression analysis, asthma diagnosis, child's age, daily use of inhaled glucocorticoids, length and frequency of medicine application, spacer use, mouth rinsing with water after medicine application, parents' education, frequent food and drink consumption, and frequency of toothbrushing were associated with caries experience of asthmatic children. CONCLUSION.  Children with asthma who had used anti-asthmatic medications had higher caries experience in primary and permanent teeth.

Inhaler devices - from theory to practice

This brief overview of the factors determining lung deposition of aerosols provides background information required by health care providers when instructing patients to use their prescribed inhalers. We discuss differences in the optimal inhalation manoeuvres for each type of aerosol generator and the difficulties patients face. Provision of short, clear instructions with demonstration of critical steps and checking technique during later clinical visits are necessary if these aerosolised medications are to be fully beneficial.

Dental care utilization among dentate adults with asthma: findings from the 2008 Behavioral Risk Factor Surveillance System

OBJECTIVES

This study investigated dental care service utilization among dentate adults with asthma and identified factors affecting dental care use among this population.

METHODS

Data from 414,509 adults in the United States who participated in the 2008 Behavioral and Risk Factor Surveillance System were used to estimate the percentage of dentate adults with asthma who had at least one dental visit within the past year.

RESULTS

The proportion of respondents with asthma who had at least one dental visit within the past year compared with the general population was significantly lower (67.4 percent versus 71.2 percent, P < 0.001 for dental visit for any reason; 64.3 percent versus 69.6 percent, P < 0.001 for dental cleaning). The adjusted odds of a dental visit for any reason within the past year for those with asthma were 0.86 [95% confidence interval (CI), 0.81-0.91], and for dental cleaning 0.82 (95% CI, 0.78-0.87) times that of those without asthma, respectively. Multivariable modeling showed dentate adults with asthma who are male, high school or less educated, unemployed, lower income, current smokers, and have lost more than six teeth were less likely to have a dental visit within the past year.

CONCLUSIONS

Compared with nonasthmatic individuals, dentate adults with asthma had a lower frequency of dental visits in the past year. Given a higher risk of oral disease among this population, healthcare providers should focus more effort on educating certain subgroups of patients with asthma on the importance of regular dental care.

Inhaled chemotherapy in lung cancer: future concept of nanomedicine

Regional chemotherapy was first used for lung cancer 30 years ago. Since then, new methods of drug delivery and pharmaceuticals have been investigated in vitro, and in animals and humans. An extensive review of drug delivery systems, pharmaceuticals, patient monitoring, methods of enhancing inhaled drug deposition, safety and efficacy, and also additional applications of inhaled chemotherapy and its advantages and disadvantages are presented. Regional chemotherapy to the lung parenchyma for lung cancer is feasible and efficient. Safety depends on the chemotherapy agent delivered to the lungs and is dose-dependent and time-dependent. Further evaluation is needed to provide data regarding early lung cancer stages, and whether regional chemotherapy can be used as neoadjuvant or adjuvant treatment. Finally, inhaled chemotherapy could one day be administered at home with fewer systemic adverse effects.

Ultrasonic nebulization platforms for pulmonary drug delivery

IMPORTANCE OF THE FIELD

Since the 1950s, ultrasonic nebulizers have played an important role in pulmonary drug delivery. As the process in which aerosol droplets are generated is independent and does not require breath-actuation, ultrasonic nebulizers, in principle, offer the potential for instantaneously fine-tuning the dose administered to the specific requirements of a patient, taking into account the patient's breathing pattern, physiological profile and disease state. Nevertheless, owing to the difficulties and limitations associated with conventional designs and technologies, ultrasonic nebulizers have never been widely adopted, and have in recent years been in a state of decline.

AREAS COVERED IN THIS REVIEW

An overview is provided on the advances in new miniature ultrasonic nebulization platforms in which large increases in lung dose efficiency have been reported.

WHAT THE READER WILL GAIN

In addition to a discussion of the underlying mechanisms governing ultrasonic nebulization, in which there appears to be widely differing views, the advantages and shortcomings of conventional ultrasonic nebulization technology are reviewed and advanced state-of-the-art technologies that have been developed recently are discussed.

TAKE HOME MESSAGE

Recent advances in ultrasonic nebulization technology demonstrate significant potential for the development of smart, portable inhalation therapy platforms for the future. Nevertheless, there remain considerable challenges that need to be addressed before such personalized delivery systems can be realized. These have to be addressed across the spectrum from fundamental physics through to in vivo device testing and dealing with the relevant regulatory framework.

Relief of incident dyspnea in palliative cancer patients: a pilot, randomized, controlled trial comparing nebulized hydromorphone, systemic hydromorphone, and nebulized saline

Acute episodic breathlessness in patients receiving palliative care is a distressing symptom with little evidence-base to inform management. This pilot, double-blind, controlled, crossover study compared the effects of nebulized hydromorphone, systemic hydromorphone and nebulized saline for the relief of episodic breathlessness in advanced cancer patients. On three occasions of acute breathlessness, patients randomly received either nebulized hydromorphone, a systemic breakthrough dose of hydromorphone or nebulized saline together with a blinding agent. Breathlessness was scored before and 10, 20, 30, and 60 minutes post-treatment completion using a 100 mm visual analog scale. Twenty patients completed the trial. Ratings did not differ significantly across pretest treatments. Change in ratings from pretest to 10 minutes after completion of nebulization (about 20 minutes after administration of systemic hydromorphone) indicated that each of the treatments resulted in statistically significant improvements in breathlessness, with no significant differences between treatments. Over time, breathlessness decreased significantly for all treatments, with no significant differences between treatments. Only nebulized hydromorphone produced a rapid improvement in breathlessness that reached a magnitude considered to be clinically important. Interpretation of these results is considered in relation to our definition of clinical significance, the dose of hydromorphone used and the possibility of a placebo effect. This study can serve to inform the design of future trials to investigate the management of incident breathlessness.

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.

Optimal management of asthma in elderly patients: strategies to improve adherence to recommended interventions

Adherence to asthma medications presents a problem in all age groups, and older people with chronic illnesses such as asthma also have multiple co-morbidities and consequently complex healthcare needs. It has been suggested that older people are also less likely to adhere to medication and treatment than younger people. Although the prevalence of asthma in older people is similar to that of the general population, over two-thirds of those who die from asthma are >50 years of age and there is strong evidence for under-diagnosis. Clinicians therefore face specific challenges in providing healthcare with respect to both asthma diagnosis and treatment in older age groups. Non-adherence to medication can be defined as either 'intentional' or 'unintentional'. Unintentional non-adherence is more likely to be associated with sociodemographic or physical barriers to the use of medication. Intentional non-adherence results from the balance of individual reasoning of risks versus the benefits of taking medication and acceptance of asthma diagnosis. Intentional non-adherence can be addressed through strategies that influence health beliefs and concerns about the adverse effects of medicine. Unintentional adherence can be addressed by assessing and educating the patient in relation to device use and providing education and clear written instructions about medication requirements. However, some barriers to medication use, such as financial ones, may be systematic. Most studies of medication use, efficacy, adverse effects and adherence in patients with asthma primarily involve younger people. Studies of strategies to improve asthma adherence outcomes specifically in older people are urgently needed.

Rationale for the Selection of an Aerosol Delivery System for Gene Delivery

Genetic therapeutics show great promise toward the treatment of illnesses associated with the lungs; however, current methods of delivery such as jet and ultrasonic nebulization decrease the activity and effectiveness of these treatments. Extremely low transfection rates exhibited by non-complexed plasmid DNA in these nebulizers have been primarily attributed to poor translocation and loss of molecular integrity as a consequence of shear-induced degradation. Current research focusing on methods to increase transfection rates via the pulmonary delivery route has largely concentrated on the incorporation of carbon dioxide in the air stream to increase breath depth as well as the addition of cationic agents that condense DNA into compact, ordered complexes. The purpose of this study was to examine the impact of several classic as well as the latest atomization devices on the structure of non-complexed DNA. Various sizes of plasmid and cosmid DNA were processed through an electrostatic spray, ultrasonic nebulizer, vibrating mesh nebulizer, and jet nebulizer. Results varied dramatically based upon atomization device as well as DNA size. This may explain the inefficiency experienced by genetic therapeutics during pulmonary delivery. More importantly, this suggests that the selection of an atomization device should consider DNA size in order to achieve optimal gene delivery to the lungs.

Use of nebulized inhaled corticosteroids among older adult patients: an assessment of outcomes

BACKGROUND

Inhaled corticosteroids (ICSs) are used by patients of all ages, but older patients may have difficulty with conventional inhalation devices and therefore may benefit from the easy-to-use delivery mechanism of the nebulizer.

OBJECTIVE

To compare the outcomes, resource use, and health care costs of patients prescribed nebulized ICSs before and after treatment.

METHODS

All patients 50 years and older prescribed nebulized ICSs were identified from a nationally representative managed care claims database (1999-2003). Patients with 1 year of continuous enrollment were analyzed using a retrospective cohort design; outcomes, resource use, and costs were measured and compared 6 months before and 6 months after the initial nebulized ICS prescription.

RESULTS

A total of 2,178 patients were identified for participation in the study, of whom 668 were analyzed. Patients were prescribed nebulized ICSs primarily for asthma (57.4%) and chronic obstructive pulmonary disease (52.1%). Nebulized ICSs were prescribed mostly by primary care physicians and pulmonologists. More than 40% of patients used nebulized ICSs persistently (at least 1 refill); persistent users averaged 123.4 days of use during 6 months of follow-up. There was a significant decrease in systemic corticosteroid use among persistent users (48.0% vs 38.8%; odds ratio, 0.7; 95% confidence interval, 0.5-1.0; P = .03). There was an emergency department visit in 20.2% and 15.0% of persistent users before and after the index date, respectively (odds ratio, 0.7; 95% confidence interval, 0.45-1.09; P = .12); 20.5% and 17.5% were hospitalized before and after the index date, respectively (odds ratio, 0.8; 95% confidence interval, 0.54-1.27; P = .38). No significant difference occurred in total health care costs during follow-up compared with baseline.

CONCLUSIONS

In this retrospective cohort study, older patients who used nebulized ICSs persistently demonstrated fewer emergency department visits and systemic corticosteroid use than before nebulized ICS use. These improved outcomes were not associated with an increase in health care costs.

Pulmonary drug delivery. Part II: the role of inhalant delivery devices and drug formulations in therapeutic effectiveness of aerosolized medications

Research in the area of pulmonary drug delivery has gathered momentum in the last several years, with increased interest in using the lung as a means of delivering drugs systemically. Advances in device technology have led to the development of more efficient delivery systems capable of delivering larger doses and finer particles into the lung. As more efficient pulmonary delivery devices and sophisticated formulations become available, physicians and health professionals will have a choice of a wide variety of device and formulation combinations that will target specific cells or regions of the lung, avoid the lung's clearance mechanisms and be retained within the lung for longer periods. It is now recognized that it is not enough just to have inhalation therapy available for prescribing; physicians and other healthcare providers need a basic understanding of aerosol science, inhaled formulations, delivery devices, and bioequivalence of products to prescribe these therapies optimally.

Use of inhaler devices in pediatric asthma

Inhalation is the preferred route for asthma therapy, since it offers a rapid onset of drug action, requires smaller doses, and reduces systemic effects compared with other routes of administration. Unfortunately, inhalation devices are frequently used in an empirical manner rather than on evidence-based awareness.A wide variety of nebulizers are available. Conventional jet nebulizers are highly inefficient, as much of the aerosol is wasted during exhalation. However, incorporating an extra open vent into the system has considerably increased the amount of drug that patients receive. Breath-assisted open vent nebulizers limit the loss of aerosol during exhalation, but are dependent on the patient's inspiratory flow. Ultrasonic nebulizers produce a high mass output and have a short nebulization time, but are inefficient for delivering suspensions or viscous solutions. Adaptive aerosol delivery devices release a precise dose that is tailored to the individual patient's breathing pattern. Nebulizers have several drawbacks, and their use should be limited to patients who cannot correctly manage other devices.Pressurized metered-dose inhalers (pMDI) are practical, cheap and multidose. However, there are several problems with their use. Breath-actuated MDI are easy to use and can be activated by very low flow. However, young children may not be able to use them efficiently. Dry powder inhalers (DPI) are portable and easy to use. They are indicated either for rescue bronchodilator therapy or for regular treatment with inhaled corticosteroids and long-acting bronchodilators. The use of spacers reduces oropharyngeal deposition and improves drug delivery to the lung. Spacers do not require patient coordination, but some general rules must be followed for their optimal use.Thus, the choice of a delivery device mainly depends on the age of the patient, the drug to be administered and the condition to be treated. Proper education is also essential when prescribing an inhalation device.

The inhalation manager: a new computer-based device to assess inhalation technique and drug delivery to the patient

The rational choice of an inhalation device is a cornerstone in the effective management of asthma and COPD. In this publication, we describe the development of a new system, the Inhalation Manager, which, for the first time, offers the possibility to assess the entire inhalation maneuver of patients using original devices under everyday conditions. So far the Inhalation Manager allows the measurement of inspiratory maneuvers of patients through placebo inhalation devices of the most common breath-actuated CFC-free inhalers in the market for the three main glucocorticosteroids Budesonide [Turbohaler (TH), dry powder inhaler (DPI)], Beclomethasone dipropionate [Autohaler (AH), breath-actuated pressurized metered dose inhaler (pMDI)], and Fluticasone propionate [Diskus (DI), DPI] by means of a pneumotachometer. In addition, it allows allocation of the individual maneuver to the expected drug delivery values (mass output and particle size distribution) of these three devices. In a field trial, the inhalation technique of 628 (TH), 794 (AH), and 795 (DI) patients, respectively, was tested in 72 pulmonologist practices with the Inhalation Manager. For patients in the 18-59-year-old group, the Inhalation Manager detected the following percentages needing improvement: 1.5% for the Autohaler device, 16.7% for the Diskus, and 38.9% for the Turbohaler. In the 60-99-year-old group, percentages needing improvement were 1.5%, 31.5%, and 66.1% for the Autohaler, Diskus, and Turbohaler, respectively. Therefore, the Inhalation Manager could become an essential tool in asthma management by finding the most suitable inhaler for an individual patient and by training the optimal inhalation technique.

Long-term outcomes in paediatric asthma

Over the years the aims of asthma management have changed markedly from effective prednisolone treatment of symptoms and exacerbations towards more use of continuous prophylactic treatment. With our new understanding of the disease and its management definition of the aims of treatment and assessment of optimal asthma control have become much more complex. Even in times of evidence-based medicine our asthma management is based upon findings of effects on various outcomes in somewhat short-term (<1 year) controlled studies. However, assumptions about long-term effects upon the basis of findings in such studies should be made with great caution. Good examples of this are studies which assess the risk of systemic effects and clinical adverse effects of inhaled corticosteroids. From such studies it has become clear that systemic effects detected in short-term trials may have no predictive value of long-term adverse effects. Thus steroid-induced changes in lower leg growth rates assessed by knemometry do not predict long-term statural growth. Moreover, steroid-induced changes in statural growth over 1 year are not predictive of effects upon attained adult height. In contrast, reduced growth caused by uncontrolled asthma disease also seems to affect attained adult height adversely. These findings suggest that long-term outcomes should play a larger role when future asthma management strategies are decided. Some important long-term outcomes of asthma management in children include cure or remission of the disease, prevention of complications of the disease (airway remodelling, adverse effects upon growth/adult height, peak bone mineral density, physical impairment and psychosocial development) or its pharmacological management (adverse effects upon adult height, peak bone mineral density). More controlled long-term studies (several years) are needed to provide a better understanding of how these outcomes are best achieved.

Importance of drug delivery system in steroid aerosol therapy via nebulizer

Aim of our study was to evaluate if the type of nebulizer can influence the effects of steroid aerosol therapy. We considered 27 asthmatics allergic to grasses with FEV1<80% of the predictive value or methacholine PD20 FEV1<750 mcg. The patients were divided into three groups in relation to the type of nebulizer they used and treated 9 weeks by aerosol therapy with beclomethasone dipropionate bid (800 mcg). Respect to the values recorded at the beginning and at the end of the therapy we found different variations of spirometric indeces and PD20 values among the three groups. We can conclude that the type of nebulizer influences steroid aerosol therapy and, particularly, jet nebulizers seem more efficient than ultrasonic nebulizers.

The output of flunisolide from different nebulisers

The objective of this study was to determine the output, in-vitro, solution of a concentrated solution of flunisolide from two different nebulisers under simulated breathing conditions. The BimboNeb and Nebula nebulisers were used to nebulise 2.6 mL of flunisolide solution (600 microg). Particle size was determined by inertial impaction and the total output of drug from the nebulisers under simulated breathing conditions was measured using a sinus flow pump. Two different breathing patterns were used, simulating nebuliser use by a child and an adult. The mass median aerodynamic diameter of flunisolide particles from the BimboNeb and Nebula were both 3.9 microm. With the simulated paediatric breathing pattern, both nebulisers delivered similar amounts of flunisolide (56.4 microg (s.d. 1.4 microg) and 56.1 microg (5 microg) over 5 min from the BimboNeb and Nebula, respectively). With the adult breathing pattern, flunisolide delivery from the BimboNeb was increased to 88.9 microg (3.3 microg), but delivery from the Nebula was only slightly increased to 64.6 microg (1.4 microg). With both nebulisers, little drug was released after 5 min of nebulisation. Both nebulisers delivered 9-15% of the nominal dose of flunisolide to the breathing simulator, a similar percentage to previous studies with budesonide and more than previous studies with beclometasone. Drug delivery from the BimboNeb, but not the Nebula, was affected by the simulated breathing pattern. This study suggests that drug delivery from nebulisers is dependent upon the interaction between the nebuliser, the drug and the patient.

Pulmonary clearance rate of two chemically different forms of inhaled pertechnetate

Attempts to image the pulmonary deposition site of radiolabeled aerosols delivered by dry powder inhalers (DPIs) and pressurized metered-dose inhalers (pMDIs) using single photon emission computed tomography (SPECT) have been limited by the rapid pulmonary clearance of radiolabel. To determine whether aqueous solubility of the radiolabel is a significant factor, the pulmonary clearance rates of two chemically different forms of 99mTc were calculated. A dry powder formulation of terbutaline sulphate was radiolabeled for inhalation by Turbuhaler (AstraZeneca) using the water-soluble salt sodium pertechnetate and the water-insoluble salt tetraphenylarsonium pertechnetate. A pilot study was conducted during which two control subjects each inhaled the two radiolabeled aerosols on separate days. Intrasubject clearance rates for the two species were very similar. It was therefore concluded that water insolubility of the pertechnetate salt alone was not enough to extend the lung residency time of the radiolabel.

Inhalation therapy: new delivery systems

The objective of this article is to provide an overview of recent advances in inhalation drug delivery. Problems, advantages, limitations, and developments encountered by different inhalation devices and the agents used in these for the purpose of pulmonary delivery are discussed. A critical appraisal is presented and finally the future directions especially in research of the inhaled therapeutics and aerosols are described.

Guidelines for devices and choices

Asthma patients can be treated safely and effectively with the compounds and inhalation devices currently available. However, the choice of devices is so wide that the healthcare professional may be easily confused, and the effectiveness of treatment reduced. Clear guidelines are needed to help resolve this difficulty; however, those currently available do not contain enough useful information on the different delivery systems to assist the selection process. The function of the anti-asthma drug (i.e., preventer or reliever) should determine the choice of device. For inhaled corticosteroids, the device should provide effective and reliable delivery, while simplicity in use will aid good inhalation technique. A device that minimizes systemic absorption of these drugs will improve drug safety. The devices of choice are pressurized metered dose-inhalers (pMDIs) with spacers and some dry powder inhalers (DPIs). The main selection criteria for short-acting beta2-agonists are portability and patient acceptability. DPIs and pMDIs are the most suitable systems for these drugs. Cost is an important consideration for both drug types.

Efficacy and safety overview of a new inhaled corticosteroid, QVAR (hydrofluoroalkane-beclomethasone extrafine inhalation aerosol), in asthma

Chlorofluorocarbon (CFC)-containing inhalers are gradually being phased out and replaced with hydrofluoroalkane (HFA)-based alternatives. The reformulation provided the opportunity to improve the inhalation technology and physical characteristics of corticosteroid formulations. QVAR contains HFA-beclomethasone dipropionate (HFA-BDP) with the steroid in solution rather than suspension, which, in combination with improved inhaler technology, produces an extrafine aerosol with a mass median aerodynamic diameter of 1.1 microm (smaller than the 3.5-4.0 microm found with CFC-BDP). It was predicted and demonstrated that the smaller particle size of QVAR would be deposited in the lung to a greater extent than that found with CFC-BDP, particularly in the small airway, a major site of inflammation. Increased lung deposition of QVAR permits a reduction in dosage relative to CFC-BDP. Clinical evidence confirms that adult and elderly patients required approximately half the dose of QVAR to achieve the same degree of asthma control as with CFC-BDP. In long-term assessments, patients taking CFC-BDP could be switched to QVAR at half the daily dose without exacerbation of their asthma symptoms. QVAR was associated with a low overall incidence of side effects and, at the maximum recommended dose of 640 microg/d, caused no more adrenal suppression than 672 microg/d CFC-BDP.

Budesonide inhalation suspension: a review of its use in infants, children and adults with inflammatory respiratory disorders

Budesonide, a topically active corticosteroid, has a broad spectrum of clinically significant local anti-inflammatory effects in patients with inflammatory lung diseases including persistent asthma. In infants and young children with persistent asthma, day- and night-time symptom scores, and the number of days in which beta2-agonist bronchodilators were required, were significantly lower during randomised, double-blind treatment with budesonide inhalation suspension 0.5 to 2 mg/day than placebo in 3 multicentre trials. Significantly fewer children discontinued therapy with budesonide inhalation suspension than with placebo because of worsening asthma symptoms in a study that included children who were receiving inhaled corticosteroids at baseline. Recent evidence indicates that budesonide inhalation suspension is significantly more effective than nebulised sodium cromoglycate in improving control of asthma in young children with persistent asthma. At a dosage of 2 mg/day, budesonide inhalation suspension significantly reduced the number of asthma exacerbations and requirements for systemic corticosteroids in preschool children with severe persistent asthma. In children with acute asthma or wheezing, the preparation was as effective as, or more effective than oral prednisolone in improving symptoms. In children with croup, single 2 or 4mg dosages of budesonide inhalation suspension were significantly more effective than placebo and as effective as oral dexamethasone 0.6 mg/kg or nebulised L-epinephrine (adrenaline) 4mg in alleviating croup symptoms and preventing or reducing the duration of hospitalisation. Early initiation of therapy with budesonide inhalation suspension 1 mg/day appears to reduce the need for mechanical ventilation and decrease overall corticosteroid usage in preterm very low birthweight infants at risk for chronic lung disease. In adults with persistent asthma, budesonide inhalation suspension < or =8 mg/day has been compared with inhaled budesonide 1.6 mg/day and fluticasone propionate 2 mg/day administered by metered dose inhaler. Greater improvements in asthma control occurred in patients during treatment with budesonide inhalation suspension than with budesonide via metered dose inhaler, whereas fluticasone propionate produced greater increases in morning peak expiratory flow rates than nebulised budesonide. Several small studies suggest that the preparation has an oral corticosteroid-sparing effect in adults with persistent asthma and that it may be as effective as oral corticosteroids during acute exacerbations of asthma or chronic obstructive pulmonary disease. The frequency of adverse events was similar in children receiving budesonide inhalation suspension 0.25 to 2 mg/day or placebo in 12-week studies. During treatment with budesonide inhalation suspension 0.5 to 1 mg/day in 3 nonblind 52-week studies, growth velocity in children was generally unaffected; however, a small but statistically significant decrease in growth velocity was detected in children who were not using inhaled corticosteroids prior to the introduction of budesonide inhalation suspension. Hypothalamic-pituitary-adrenal axis function was not affected by short (12 weeks) or long (52 weeks) term treatment with nebulised budesonide. In conclusion, budesonide inhalation suspension is the most widely available nebulised corticosteroid, and in the US is the only inhaled corticosteroid indicated in children aged > or =1 year with persistent asthma. The preparation is suitable for use in infants, children and adults with persistent asthma and in infants and children with croup.

Treating asthma in children with beclomethasone dipropionate: Pulvinal versus Diskhaler

Seventy-two children (mean age, 10.1 years) with stable moderate asthma who completed a 7-day run-in period were randomized to receive a 4-week treatment with beclomethasone dipropionate (200 micrograms twice daily) administered through two different powder inhalers (Pulvinal; Chiesi Farmaceutici S.p.A, Parma, Italy and Diskhaler; Glaxo-Wellcome, Evreux, France) in a parallel group design. Sixty-nine patients completed the study. Morning and evening peak expiratory flow values, the use of rescue salbutamol, and the severity of clinical symptoms were recorded daily on a diary card. Pulmonary function tests were performed at baseline and then after 2 and 4 weeks of treatment. Pulmonary function values, daily morning and evening peak expiratory flow, and most of the clinical symptoms significantly improved, although the use of rescue salbutamol significantly decreased from the second week of treatment until the end of the study in both groups. Equivalence of efficacy between groups was demonstrated for both pulmonary function and clinical parameters. We conclude that the Pulvinal inhaler is as efficacious as the Diskhaler in beclomethasone-based therapy of asthmatic children.

Comparable efficacy of administration with face mask or mouthpiece of nebulized budesonide inhalation suspension for infants and young children with persistent asthma

A randomized, double-blind, placebo-controlled, parallel-group study including 481 children at 37 centers in the United States demonstrated the efficacy and safety of budesonide inhalation suspension in doses of 0.25 mg once daily, 0.25 mg twice daily, 0.5 mg twice daily, and 1.0 mg daily in infants and young children with persistent asthma. The retrospective analysis presented here compares the efficacy of treatment with the suspension administered through a face mask or mouthpiece. All patients receiving budesonide inhalation suspension via face mask or mouthpiece showed clinical improvements in nighttime and daytime asthma symptoms as compared with administration of a placebo. The improvements were of similar magnitude as those observed in an analysis of all patients treated. Improvements in nighttime asthma symptoms were statistically significant with budesonide at 0.25 mg daily (p = 0.040), 0.25 mg twice daily (p = 0.008), and 0.5 mg twice daily (p = 0.046) delivered by face mask. In patients using mouthpieces, nighttime asthma symptoms improved significantly in the 0.25-mg twice-daily (p = 0.005) and 1.0-mg daily (p = 0.035) groups. Patients receiving budesonide at 0.5 mg twice daily via a face mask improved significantly in daytime asthma symptoms (p = 0.009). The use of breakthrough medication was reduced in patients receiving budesonide via face masks or mouthpieces relative to placebo, and treatment was well tolerated in all study groups. This retrospective analysis suggests that nebulized budesonide inhalation suspension can be administered effectively by either face mask or mouthpiece to young children with persistent asthma.

Once-daily inhaled corticosteroids in children with asthma: nebulisation

Current guidelines on the management of childhood asthma have emphasised the important preventive role of inhaled corticosteroids, which should be used at the lowest possible doses that are compatible with good disease control. However, some children do not respond to inhaled corticosteroids, the most common reasons for which are inability to use conventional hand-held inhalers (plus spacers and face masks) effectively or lack of cooperation with them, particularly among infants and young children. In these patients, nebulisers have proved effective in administering corticosteroids, and this form of delivery is often preferred by both the children and their parents, despite their longer administration times (commonly around 10 minutes). Compliance with these devices may therefore be better than with a conventional pressurised metered-dose inhaler plus spacer and face mask. Recent studies with nebulised budesonide have demonstrated that once-daily administration is as effective in maintaining control of asthma symptoms in children as the usual twice-daily administration. In children with moderately severe persistent asthma, the improvement provided by once-daily nebulised doses of 1.0 mg budesonide has been found to be equivalent to that with twice-daily doses of 0.25 or 0.5 mg, indicating that once-daily therapy is an effective option that can be considered in many patients. In view of the time-consuming nature of nebuliser administration, reduction of the frequency of corticosteroid administration from twice to once daily may be useful in simplifying the treatment programme and improving compliance with it. This may be beneficial in reducing under-utilisation of inhaled corticosteroids in children with asthma and improving long term control of the disease.

Keeping children with exercise-induced asthma active

Exercise-induced bronchospasm, exercise-induced bronchoconstriction, and exercise-induced asthma (EIA) are all terms used to describe the phenomenon of transient airflow obstruction associated with physical exertion. It is a prominent finding in children and young adults because of their greater participation in vigorous activities. The symptoms shortness of breath, cough, chest tightness, and wheezing normally follow the brief period of bronchodilation present early in the course of exercise. Bronchospasm typically arises within 10 to 15 minutes of beginning exercise, peaks 8 to 15 minutes after the exertion is concluded, and resolves about 60 minutes later, but it also may appear during sustained exertion. EIA occurs in up to 90% of asthmatics and 40% of patients with allergic rhinitis; among athletes and in the general population its prevalence is between 6% and 13%. EIA frequently goes undiagnosed. Approximately 9% of individuals with EIA have no history of asthma or allergy. Fifty percent of children with asthma who gave a negative history for EIA had a positive response to exercise challenge.6 Among high school athletes, 12% of subjects not considered to be at risk by history or baseline spirometry tested positive. Before the 1984 Olympic games, of 597 members of the US team, 67 (11%) were found to have EIA. Remarkably, only 26 had been previously identified, emphasizing the importance of screening for EIA even in well-conditioned individuals who appear to be in excellent health. The severity of bronchospasm in EIA is related to the level of ventilation, to heat and water loss from the respiratory tree, and also to the rate of airway rewarming and rehydration after the challenge. Postexercise decrease in the peak expiratory flow rate of normal children may be as much as 15%; therefore, only a decrease in excess of 15% should be viewed as diagnostic. EIA is usually provoked by a workload sufficient to produce 80% of maximum oxygen consumption; however, in severe asthmatics even minimal exertion may be enough to produce symptoms. Patients with normal lung function at rest may have severe air flow limitation induced by exercise,10 and as many as 50% of patients who are well-controlled with inhaled corticosteroids still exhibit EIA. A challenge of sufficient magnitude will provoke EIA in all patients with asthma. PHARMACOLOGIC THERAPY: Exercise, unlike exposure to allergens, does not produce a long-term increase in airway reactivity. Accordingly, patients whose symptoms manifest only after strenuous activity may be treated prophylactically and do not require continuous therapy. Most asthma medications, even some unconventional ones such as heparin, furosemide, calcium channel blockers, and terfenadine, given before exercise, suppress EIA. McFadden accounts for the efficacy of these disparate classes of drugs by their potential effect on the bronchial vasculature that modulates the cooling and/or rewarming phases of the reaction. Short-acting -agonists provide protection in 80% to 95% of affected individuals with insignificant side effects and have been regarded for many years as first-line therapy. Two long-acting bronchodilators, salmeterol and formoterol, have been found effective in the prevention of EIA.18-21 A single 50-microg dose of salmeterol protects against EIA for 9 hours; its duration appears to wane in the course of daily therapy. Cromolyn sodium is highly effective in 70% to 87% of those diagnosed with EIA and has minimal side effects. Nedocromil sodium provides protection equal to that of cromolyn in children. Children commonly engage in unplanned physical activity and sometimes are not allowed to carry their own medication. Thus, a simple long-acting regimen given at home is likely to be more effective than short-acting drugs that must be administered in a timely manner. Although the 12-hour protection by salmeterol reported by Bronsky et al may not persist with continued use, the 9-hour duration of action is

The effect of breathing frequency on deposition of drug aerosol using an inhalation-synchronized dosimeter in healthy adults

The deposition of inhaled drug aerosol between the tongue, the upper and lower respiratory tract, the lungs and the gastrointestinal tract (GI tract) in 11 healthy adults was studied by using a nebulizer with an inhalation-synchronized dosimeter. The effect of breathing frequency on deposition was studied using radioaerosol (mixture of salbutamol and technetium bound to diethylenetriamine pentacetate, [99mTc]DTPA) and a gamma-camera. In healthy subjects who were breathing at their own frequency (16 +/- 5 breaths min-1, mean +/- SD), the proportion of inhaled aerosol deposited in the lungs was 48 +/- 14 (mean percentage +/- SD). The proportion deposited in the upper airway tract and the GI tract was 19 +/- 13 and 25 +/- 9 respectively, and the remainder was deposited on the tongue (6 +/- 4) and in the lower airway tract (3 +/- 2). Guided, slower breathing frequency (11 +/- 5 breaths min-1) changed the deposition remarkably. The proportion of the pulmonary deposition of the inhaled dose increased significantly (P < 0.004) to 60 +/- 17, and the proportion of the upper airway tract deposition decreased significantly (P < 0.005) by half of the initial deposition. We conclude that a slow controlled breathing frequency is an important factor if we want to increase the drug deposition in the lungs. It is also essential in decreasing the variation in the deposition of the lungs.

A randomised controlled trial to assess the relative benefits of large volume spacers and nebulisers to treat acute asthma in hospital

OBJECTIVES

To compare the clinical effectiveness, acceptability, and cost benefit of administering beta2 agonists by means of a metered dose inhaler and large volume spacer with conventional nebulisers to children admitted to hospital with acute asthma.

METHODS

A randomised controlled trial was conducted over five months. Sixty one children older than 3 years admitted to a large teaching hospital and a district general hospital with acute asthma completed the study. Children received either 5 mg of salbutamol up to one hourly by jet nebuliser, or up to 10 puffs of salbutamol 100 microg by means of a metered dose inhaler and spacer up to one hourly.

RESULTS

Median hospital stay was 40 hours in the nebuliser group and 36.5 hours in the spacer group. Asthma disability scores at two weeks after discharge were significantly improved in the spacer group. Drug costs were pound 14.62 less for each patient in the spacer group.

CONCLUSIONS

Large volume spacers are an acceptable, cost effective alternative to nebulisers in treating children admitted with acute asthma, provided that the children can use the mouthpiece, and symptoms are not severe. Their use facilitates effective home treatment by parents, with subsequent reduction in morbidity and re-admission rates.

Turbutest in the training of asthmatic Turbuhaler users

BACKGROUND

Correct utilization of inhalation devices is a key factor in asthma management. Objective assessment of the ability to use inhaler devices is therefore fundamental.

METHODS

The objective was to assess objectively the inhalation technique of Turbuhaler users who reported having no difficulty in using such a device. A total of 600 asthmatic patients of our allergology outpatient department, daily users of Turbuhaler devices, were evaluated with Turbutest. This is a simple portable apparatus which connects a Turbuhaler inhaler with an electronic device to allow semiquantitative assessment of inhalation technique, with a score ranging from 0 (worst) to 3 (best), readily visualized on the apparatus. Patients were allowed to practice with Turbutest, assisted by an allergologist, until they improved their scores. A second Turbutest assessment was performed at a 2-month follow-up visit.

RESULTS

On the first assessment, one-third of the patients had scores inadequate to allow a good inhalation, and only 20% achieved a score of 3. On the second assessment, significantly higher Turbutest scores were observed.

CONCLUSIONS

Turbutest is a valuable tool in asthmatic patients' training, allowing identification and improvement of an inadequate inhalation technique with Turbuhaler.

Randomised placebo controlled trial of beta agonist dose reduction in asthma

BACKGROUND

Many patients continue to take regular beta agonists, often at high doses, contrary to national and international guidelines. Some studies have suggested that this can worsen asthma control, but whether such patients can reduce their dose of beta agonist and whether they would benefit from this has not been determined. Reduction of beta agonist dose was studied in a placebo controlled parallel group study.

METHODS

Following a run in period, 33 subjects with asthma taking regular beta agonists were converted to an equivalent dose of terbutaline via a Turbohaler. Two weeks later terbutaline was continued at the same dose or changed to placebo in two stages a week apart. The change over period was covered by an increased dose of inhaled steroid to attenuate any immediate effects of the change in dose. Subjects then attended weekly for six weeks for measurement of forced expiratory volume in one second (FEV1) and the dose of methacholine that produced a 20% fall in FEV1 (PD20). Peak expiratory flow (PEF) and symptom scores were recorded twice daily throughout the study. Exacerbations, lung function, bronchial responsiveness, bronchodilator response, beta agonist use, and symptoms were compared before and six weeks after reduction in the dose of beta agonist.

RESULTS

Twenty five of the 33 subjects completed the study; three patients in each group withdrew due to an asthma exacerbation. The median terbutaline dose fell from 2500 to 500 micrograms/day in the beta agonist reduction group and from 3000 to 2250 micrograms/day in the control group. There were small non-significant changes in FEV1, PEF, symptom scores and PD20 methacholine over the course of the study. The FEV1 response to a beta agonist was greater in those who reduced their beta agonist dose than in the control group although the final FEV1 achieved was the same.

CONCLUSIONS

Patients with asthma taking high doses of beta agonists can reduce the amount of beta agonist they use without a significant change in their asthma control. There was no evidence of improved asthma control with beta agonist dose reduction.

Asthma in older people

From the clinical perspective, asthma in the older patient may be difficult to diagnose because of the non-specificity of presentation and the wide range of differential diagnoses. Prior to confirmation of asthma in the older patient, both respiratory and cardiac investigation may be necessary. Polypharmacy is inherent in treating older people and accurate drug histories are essential in order to identify patients with drug-induced bronchospasm and avoid interactions with asthma medication. Patient and carer education is vital, and a structured approach to follow-up which includes measurement of lung function and assessment of inhaler technique should be carried out in every asthmatic regardless of age. Finally, there is a great need for health services and those in the commercial sector that are involved in asthma care to ensure that future research and development rises to the challenge of an ageing population.

Starting home nebulizer therapy: patients' expectations and subsequent outcome at 2 months

Twenty-six patients with severe COPD or asthma completed standard questionnaires before, and 2 months after, starting home nebulized bronchodilator therapy. Patients' perceived illness severity and their expectations of treatment with regard to symptoms were examined in the first questionnaire, and outcome was assessed in the second. Before treatment started patients expected a definite improvement in all symptoms studied. After treatment the group showed only a marginal subjective improvement in all symptoms. The improvement attained with regard to breathlessness, ability to get out and about, and general quality of life was significantly lower than had been expected. While home nebulized bronchodilator therapy is well tolerated and confers some subjective benefit in selected individuals, patients appear to have unrealistically high expectations of treatment.