Current options in aerosolised drug therapy for children receiving respiratory support.

Inhalation of aerosolised medications are the mainstay of treatment for a number of chronic lung diseases and have several advantages over systemically-administered medications. These include more rapid onset of action for drugs such as ß-adrenergic agonists when compared with oral medication, high luminal doses for inhaled antibiotics when used to treat endobronchial infection, and an improved therapeutic index compared with systemic delivery for these and other classes of drugs such as corticosteroids. The use of aerosolised drugs to treat patients whose tracheas are intubated is less well established, in part because systemic delivery via the intravenous route can be a simpler alternative for many drugs. Consequently, research in this area is largely limited to a number of in vitro studies and very few clinical trials. Unfortunately, a lack of focus in this area has resulted in a number of practices which at best are ineffective, and at worst dangerous for the patient. Although there have been some attempts to re-invigorate research in order to improve delivery systems, current devices are, to a great extent, based on long-standing technology developed more than 50 years ago. In this review, we explore current knowledge and provide guidance as to when and how the inhaled route may be of value when treating patients whose tracheas are intubated, and we set out the challenges facing those attempting to advance the topic. We conclude by reviewing current areas of interest that may lead to more effective and widespread use of aerosols in the treatment of intubated patients.

International consensus on (ICON) pediatric asthma.

Asthma is the most common chronic lower respiratory disease in childhood throughout the world. Several guidelines and/or consensus documents are available to support medical decisions on pediatric asthma. Although there is no doubt that the use of common systematic approaches for management can considerably improve outcomes, dissemination and implementation of these are still major challenges. Consequently, the International Collaboration in Asthma, Allergy and Immunology (iCAALL), recently formed by the EAACI, AAAAI, ACAAI, and WAO, has decided to propose an International Consensus on (ICON) Pediatric Asthma. The purpose of this document is to highlight the key messages that are common to many of the existing guidelines, while critically reviewing and commenting on any differences, thus providing a concise reference. The principles of pediatric asthma management are generally accepted. Overall, the treatment goal is disease control. To achieve this, patients and their parents should be educated to optimally manage the disease, in collaboration with healthcare professionals. Identification and avoidance of triggers is also of significant importance. Assessment and monitoring should be performed regularly to re-evaluate and fine-tune treatment. Pharmacotherapy is the cornerstone of treatment. The optimal use of medication can, in most cases, help patients control symptoms and reduce the risk for future morbidity. The management of exacerbations is a major consideration, independent of chronic treatment. There is a trend toward considering phenotype-specific treatment choices; however, this goal has not yet been achieved.

What the pulmonary specialist should know about the new inhalation therapies.

A collaboration of multidisciplinary experts on the delivery of pharmaceutical aerosols was facilitated by the European Respiratory Society (ERS) and the International Society for Aerosols in Medicine (ISAM), in order to draw up a consensus statement with clear, up-to-date recommendations that enable the pulmonary physician to choose the type of aerosol delivery device that is most suitable for their patient. The focus of the consensus statement is the patient-use aspect of the aerosol delivery devices that are currently available. The subject was divided into different topics, which were in turn assigned to at least two experts. The authors searched the literature according to their own strategies, with no central literature review being performed. To achieve consensus, draft reports and recommendations were reviewed and voted on by the entire panel. Specific recommendations for use of the devices can be found throughout the statement. Healthcare providers should ensure that their patients can and will use these devices correctly. This requires that the clinician: is aware of the devices that are currently available to deliver the prescribed drugs; knows the various techniques that are appropriate for each device; is able to evaluate the patient's inhalation technique to be sure they are using the devices properly; and ensures that the inhalation method is appropriate for each patient.

Diagnosing and preventing chronic suppurative lung disease (CSLD) and bronchiectasis.

Current diagnostic labelling of childhood bronchiectasis by radiology has substantial limitations. These include the requirement for two high resolution computerised tomography [HRCT] scans (with associated adversity of radiation) if criteria is adhered to, adoption of radiological criteria for children from adult data, relatively high occurrence of false negative, and to a smaller extent false positive, in conventional HRCT scans when compared to multi-detector CT scans, determination of irreversible airway dilatation, and absence of normative data on broncho-arterial ratio in children. A paradigm presenting a spectrum related to airway bacteria, with associated degradation and inflammation products causing airway damage if untreated, entails protracted bacterial bronchitis (at the mild end) to irreversible airway dilatation with cystic formation as determined by HRCT (at the severe end of the spectrum). Increasing evidence suggests that progression of airway damage can be limited by intensive treatment, even in those predestined to have bronchiectasis (eg immune deficiency). Treatment is aimed at achieving a cure in those at the milder end of the spectrum to limiting further deterioration in those with severe 'irreversible' radiological bronchiectasis.

Definition, assessment and treatment of wheezing disorders in preschool children: an evidence-based approach.

There is poor agreement on definitions of different phenotypes of preschool wheezing disorders. The present Task Force proposes to use the terms episodic (viral) wheeze to describe children who wheeze intermittently and are well between episodes, and multiple-trigger wheeze for children who wheeze both during and outside discrete episodes. Investigations are only needed when in doubt about the diagnosis. Based on the limited evidence available, inhaled short-acting beta(2)-agonists by metered-dose inhaler/spacer combination are recommended for symptomatic relief. Educating parents regarding causative factors and treatment is useful. Exposure to tobacco smoke should be avoided; allergen avoidance may be considered when sensitisation has been established. Maintenance treatment with inhaled corticosteroids is recommended for multiple-trigger wheeze; benefits are often small. Montelukast is recommended for the treatment of episodic (viral) wheeze and can be started when symptoms of a viral cold develop. Given the large overlap in phenotypes, and the fact that patients can move from one phenotype to another, inhaled corticosteroids and montelukast may be considered on a trial basis in almost any preschool child with recurrent wheeze, but should be discontinued if there is no clear clinical benefit. Large well-designed randomised controlled trials with clear descriptions of patients are needed to improve the present recommendations on the treatment of these common syndromes.

Persistent of respiratory syncytial virus in human dendritic cells and influence of nitric oxide.

The annual epidemics of respiratory syncytial virus (RSV) infection are probably explained by poor herd immunity and the existence of a dormant reservoir of virus that is activated by an unknown trigger. The virus causes particular problems in infants, the elderly and patients with chronic obstructive airways disease (COPD). During two consecutive winters, human monocyte-derived dendritic cells (DCs) were exposed on a single occasion to one of two forms of RSV labelled with a fluorescent expresser genes (rgRSV or rrRSV) during the epidemic season. The cultures were maintained for many months, with fresh DCs being added at monthly intervals. The cultures were variously exposed to 600 parts per billion (ppb) nitric oxide for 15 min, nitric oxide (NO) donors and NO inhibitors outside the RSV epidemic season. The pattern of productive infection of DCs in vitro appeared to parallel the natural epidemics, in that DCs exhibited evidence of viral replication and productive infection only as manifested by intracellular fluorescence and infection of HeLa cells during the RSV epidemic season. When the long-term cultures were exposed to the above agents outside the RSV epidemic season there was again evidence of vigorous replication and productive infection, as shown by the reappearance of fluorescence and productive infection of HeLa cells. The results indicate that RSV may remain dormant in dendritic cells for prolonged periods and that replication appears to be activated by suppression of endogenous NO production. These observations may be key to our understanding of the mechanisms contributing to the annual epidemics of RSV infection.

A pilot study of oral L-arginine in cystic fibrosis.

Exhaled nitric oxide has previously been found to be low in cystic fibrosis. The aim of this study was to determine whether exhaled nitric oxide levels would increase in response to oral L-arginine supplementation administered daily for 4 weeks. Exhaled and nasal nitric oxide was measured weekly. Plasma L-arginine levels increased in response to supplementation but this was not reflected in an increase in eNO levels.

Anticholinergic drugs for wheeze in children under the age of two years.

BACKGROUND: Wheeze in infancy and early childhood is common and appears to be increasing though the magnitude of any increase is unclear. Most wheezing episodes in infancy are precipitated by respiratory viral infections. Treatment of very young children with wheeze remains controversial. Anti-cholinergics are often prescribed but practice varies widely and the efficacy of this form of therapy remains the subject for debate. OBJECTIVES: Wheeze in infancy and early childhood is common and appears to be increasing. Most wheezing episodes in infancy are a result of viral infection. Bronchodilator medications such as beta2-agonists and anti-cholinergic agents are often used to relieve symptoms, but patterns of use vary. The objective of this review was to assess the effects of anti-cholinergic therapy in the treatment of wheezing infants. This is a second update of this review. SEARCH STRATEGY: We searched the Cochrane Airways Group Specialised Register of trials and the reference lists of articles. We contacted researchers in the field and industry sources. Searches were current as of June 2004. SELECTION CRITERIA: Randomised trials that compared anti-cholinergic therapy with placebo or beta2-agonists in wheezing children under two years of age. Children with acute bronchiolitis and chronic lung disease were excluded. DATA COLLECTION AND ANALYSIS: Eligibility for inclusion and quality of trials were assessed independently by two reviewers. MAIN RESULTS: Six trials involving 321 infants in three different settings were included. Compared with beta2-agonist alone, the combination of ipratropium bromide and beta2-agonist was associated with a reduced need for additional treatment, but no difference was seen in treatment response, respiratory rate or oxygen saturation improvement in the emergency department. There was no significant difference in length of hospital stay between ipratropium bromide and placebo; or between ipratropium bromide and beta2-agonist combined compared with beta2-agonist alone. However, combined ipratropium bromide and beta2-agonist compared to placebo showed significantly improved clinical scores at 24 hours. Parents preferred ipratropium bromide over nebulised water or placebo for relief of their children's symptoms at home. A further updated search conducted in June 2004 did not yield any new studies. AUTHORS' CONCLUSIONS: There is not enough evidence to support the uncritical use of anti-cholinergic therapy for wheezing infants, although parents using it at home were able to identify benefits.

Bronchiolitis. Origins and optimal management.

There is currently no prospect of an end to the annual epidemics of acute bronchiolitis, which cause considerable morbidity in previously healthy infants and are a major threat to the well-being of infants with underlying cardiac, respiratory or immunological disease. The respiratory syncytial virus remains the major cause of this condition, and prospects of developing a vaccine remain bleak while our understanding of the viral-host interaction remain incomplete. Treatment of patients with this condition has remained essentially unchanged for more than 30 years. Correction of hypoxia with oxygen, minimal handling to reduce the risk of exhaustion and careful noninvasive monitoring for complications such as apnoea and respiratory failure are the mainstays of management. Mortality in at-risk groups has fallen substantially during the past 10 years. This appears to be due to improved supportive and intensive care. The role of the antiviral agent ribavirin in the improved outcome, if any, is unclear. Other novel therapies have been tried, but none have been shown to significantly alter the natural history of the condition. The only effective preventive intervention currently available is strict adherence to measures designed to prevent nosocomial infection. This condition is likely to remain a continuing challenge to paediatricians for the foreseeable future.

Treatment of childhood asthma. Options and rationale for inhaled therapy.

Epidemiological studies suggest the prevalence of asthma is increasing, though some remain sceptical as to the magnitude or indeed the presence of an increase. However, despite improved diagnosis and the availability of the potent drugs now available there remains considerable respiratory morbidity associated with asthma. It is clear from a number of studies that failure to deliver drugs to the lungs when using inhaler devices is a factor contributing to this high level of morbidity. Failure of drug delivery may result from the prescribing of inappropriate devices, failure to use devices appropriately or failure to comply with a treatment regimen. For most of the currently available forms of asthma therapy there are significant advantages to be gained from administering them in aerosol form. The benefits to be derived from administering these drugs as an aerosol include a rapid onset of action for drugs such as beta-agonists and a low incidence of systemic effects from drugs such as beta-agonists and corticosteroids. Over the past 25 years our understanding of the nature of asthma has changed. Though this has been reflected in the emphasis on inhaled corticosteroid therapy in recent guidelines, it has not been reflected in the range of inhaler devices available. Manufacturers continue to place drugs such as corticosteroids in the same devices as short acting beta-agonists even though the requirements for these different drug classes are very different. It is likely that this contributes to suboptimal therapeutic responses with inhaled corticosteroids. However, the variability associated with current delivery systems is relatively small compared with the variability introduced by poor compliance. There is no work currently available to indicate how the use of cheap disposable devises which do not incorporate any form of positive feedback influence compliance with inhaled steroids. Optimising aerosolised drug delivery in childhood involves consideration of the class of drugs, the particular drug within a class but more importantly, the age and abilities of the child. Devices must be selected to suit a particular child's needs and abilities. Devices utilising tidal breathing are generally used such as spacing chambers or, less commonly these days, nebulisers. A screaming or struggling child, or failure to use a closely fitting mask, reduces drug delivery to the lungs enormously. Failure to respond to inhaled therapy in early childhood may be attributable to failure of drug delivery. Drug delivery in early childhood using current devices remains more an art than a science.

Budesonide/formoterol in a single inhaler versus inhaled corticosteroids alone in the treatment of asthma.

The aim of this study was to evaluate the efficacy (expressed as effect on lung function) and tolerability of Symbicort (budesonide/formoterol in a single inhaler) in children with asthma. This was a double-blind, double-dummy, randomized, parallel-group, multicenter trial. After a 2-4-week run-in period, 286 asthmatic children (177 boys, 109 girls; mean age, 11 years; mean forced expiratory volume in 1 sec (FEV(1)), 75% predicted normal), previously treated with inhaled corticosteroids (average dose 548 microg/day), were randomized to 12 weeks' treatment with either budesonide/formoterol 80/4.5 microg, two inhalations twice daily (n = 148), or an equivalent dose of budesonide 100 microg, two inhalations twice daily (n = 138). Efficacy variables included morning and evening peak expiratory flow (PEF), spirometery, asthma symptoms, and use of rescue medication (beta(2)-agonists). Serial FEV(1) assessments were carried out on a subgroup of children (budesonide/formoterol, n = 41; budesonide, n = 40) at randomization and at week 12. Relative to baseline, morning PEF (primary variable) increased to a significantly greater extent with budesonide/formoterol than with budesonide alone (7.22% predicted normal vs 3.45% predicted normal; P < 0.001). Evening PEF also increased significantly with budesonide/formoterol (6.13% predicted normal vs. 2.73% predicted normal; P < 0.001), as did mean FEV(1) and serial FEV(1) measured over 12 hr (both P < 0.05). Similar improvements in asthma symptoms and rescue medication use were observed in both groups. The two treatment groups were similar in terms of their adverse-event profile and rates of discontinuation. Budesonide/formoterol in a single inhaler provided rapid improvements in PEF and FEV(1) compared to inhaled budesonide alone. These improvements were sustained throughout the study period. Budesonide/formoterol was well-tolerated in children with moderate persistent asthma.

The effect of ribavirin to treat previously healthy infants admitted with acute bronchiolitis on acute and chronic respiratory morbidity.

The role of ribavirin in the treatment of acute bronchiolitis is controversial. It has been suggested that the use of ribavirin may be of benefit during the acute illness and may reduce subsequent recurrent respiratory morbidity. This randomized, double-blind, placebo-controlled study was designed to determine whether ribavirin administered during the acute illness would have an influence on respiratory morbidity during both the acute illness and during the following year. Bronchial reactivity 6 months after the acute illness was also assessed. Forty previously well infants with moderately severe acute bronchiolitis were recruited during three winter epidemics. Subjects received study medication for 18 h a day. Management was otherwise unaltered. Subjects were evaluated daily by the investigator and subsequently assessed at 6 weeks, 6 months and 1 year following the acute illness. Assessment of bronchial hyper-responsiveness was assessed at 6 months of age using total body plethysmography and an established ultra-sonically nebulized distilled water challenge. A total of 40 patients (21 ribavirin, 19 placebo) were entered into the study. The two groups did not differ with respect to age, gender or clinical severity on entry to the trial. No significant differences were identified in the rate of clinical improvement over the first 24 h, the time to discharge, bronchial responsiveness at 6 months of age, frequency of significant respiratory symptoms over the first year of life and the frequency of prescribed bronchodilators and inhaled steroids during the year of follow-up. This study was unable to demonstrate any clinical benefit from the use of ribavirin in the acute illness or during subsequent follow-up for 1 year.

Flow early in the inspiratory manoeuvre affects the aerosol particle size distribution from a Turbuhaler.

Several in vitro and in vivo studies have emphasized the importance of generating a high inspiratory flow when using a dry powder inhaler. Little attention has been paid to the influence of the inspiratory flow profile on the particle size distribution contained in aerosols generated by these devices. The internal volume of a device such as the Turbuhaler is small compared with a vital capacity breath and it is possible that all the powder has been drawn from the device before peak inspiratory flow has been achieved, particularly if the time to peak inspiratory flow is prolonged. A series of experiments were performed to assess the effect of different flow profiles through the Turbuhaler, each with a peak flow of 60 1 min-1. A 400 microgram budesonide Turbuhaler was enclosed in a chamber allowing air to pass unimpeded through the dosing channels and entrainment ports. A large three-way tap was used to blow powder from the device across a Malvern Mastersizer laser particle sizer which produced a profile of the particle size distribution within the aerosol. The rate of increase in flow through the Turbuhaler was determined by the rate at which the three-way tap was turned, and recorded by means of a pneumotachograph. The rate of increase in flow was found to significantly affect the particle size-distribution within the aerosol. Failure to attain a flow of 30 1 min-1 before 150 ml of air had passed through the device resulted in the aerosol volume median diameter increasing from less than 6.6 microns to greater than 45.3 microns. These results indicate that flow during the initial part of the inspiratory effort may be important in determining the characteristics of the aerosol generated by a dry powder inhaler. With more sophisticated equipment, it might be possible to explore the relationship between flow profile and particle size distribution generated by dry powder devices in more detail.

Anti-cholinergic drugs for wheeze in children under the age of two years.

BACKGROUND: Wheeze in infancy and early childhood is common and appears to be increasing though the magnitude of any increase is unclear. Most wheezing episodes in infancy are precipitated by respiratory viral infections. Treatment of very young children with wheeze remains controversial. Anti-cholinergics are often prescribed but practice varies widely and the efficacy of this form of therapy remains the subject for debate. OBJECTIVES: Wheeze in infancy and early childhood is common and appears to be increasing. Most wheezing episodes in infancy are a result of viral infection. Bronchodilator medications such as beta2-agonists and anti-cholinergic agents are often used to relieve symptoms, but patterns of use vary. The objective of this review was to assess the effects of anti-cholinergic therapy in the treatment of wheezing infants. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and the reference lists of articles. We contacted researchers in the field and industry sources. SELECTION CRITERIA: Randomised trials that compared anti-cholinergic therapy with placebo or beta2-agonists in wheezing children under two years of age. Children with acute bronchiolitis and chronic lung disease were excluded. DATA COLLECTION AND ANALYSIS: Eligibility for inclusion and quality of trials were assessed independently by two reviewers. MAIN RESULTS: Six trials involving 321 infants in three different settings were included. Compared with beta2-agonist alone, the combination of ipratropium bromide and beta2-agonist was associated with a reduced need for additional treatment, but no difference was seen in treatment response, respiratory rate or oxygen saturation improvement in the emergency department. There was no significant difference in length of hospital stay between ipratropium bromide and placebo; or between ipratropium bromide and beta2-agonist combined compared with beta2-agonist alone. However, combined ipratropium bromide and beta2-agonist compared to placebo showed significantly improved clinical scores at 24 hours. Parents preferred ipratropium bromide over nebulised water or placebo for relief of their children's symptoms at home. REVIEWER'S CONCLUSIONS: There is not enough evidence to support the uncritical use of anti-cholinergic therapy for wheezing infants, although parents using it at home were able to identify benefits.

Omega-3 fatty acids (from fish oils) for cystic fibrosis.

BACKGROUND: Epidemiological (population studies) and other studies suggest that a diet rich in omega-3 essential fatty acids (derived from fish oil) may have beneficial anti-inflammatory effects for chronic conditions such as cystic fibrosis. OBJECTIVES: To determine whether there is evidence that omega-3 polyunsaturated fatty acid supplementation reduces morbidity and mortality. To identify any adverse events associated with omega-3 polyunsaturated fatty acid supplementation. SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group specialised trials register, which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings. Authors and persons interested in the question were contacted. Date of the most recent search of the Group's specialised register: May 2002. SELECTION CRITERIA: Randomised controlled trials in patients with cystic fibrosis in which omega-3 fatty acid supplements were compared with a placebo oil. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected the trials to be included in the review and assessed the methodological quality of the trials using two approaches: Cochrane assessment of allocation concealment and Jadad quality assessment score. Using data acquisition forms, two reviewers independently extracted data. Missing data has been requested. MAIN RESULTS: The initial literature search identified six trials. Two trials, involving 31 participants satisfied our inclusion criteria and were included in the review. Both compared omega-3 fatty acids to olive oil controls for a six week treatment period. One study (19 participants) showed an improvement in FEV1, FVC, Shwachman score and reduction in sputum volume in the fish oil group at the end of this short treatment period. REVIEWER'S CONCLUSIONS: The review of trials found that regular omega-3 supplements may provide some benefits for people with cystic fibrosis with relatively few adverse effects, although the evidence is insufficient to draw firm conclusions. There is insufficient evidence to recommend routine use of supplements of omega-3 fatty acids in people with cystic fibrosis. The most notable feature highlighted by this review was the lack of data for many of the outcomes likely to be meaningful to people with or making treatment decisions about CF. A large, long-term, multi-centre, randomised controlled study is needed in order to determine if there is a significant therapeutic effect and to assess the influence of disease severity, dosage and duration of treatment. Future researchers should note the need for additional pancreatic enzymes.

Anticholinergic drugs for wheeze in children under the age of two years.

BACKGROUND: Wheeze in infancy and early childhood is common and appears to be increasing though the magnitude of any increase is unclear. Most wheezing episodes in infancy are precipitated by respiratory viral infections. Treatment of very young children with wheeze remains controversial. Anti-cholinergics are often prescribed but practice varies widely and the efficacy of this form of therapy remains the subject for debate. OBJECTIVES: Wheeze in infancy and early childhood is common and appears to be increasing. Most wheezing episodes in infancy are a result of viral infection. Bronchodilator medications such as beta2-agonists and anti-cholinergic agents are often used to relieve symptoms, but patterns of use vary. The objective of this review was to assess the effects of anti-cholinergic therapy in the treatment of wheezing infants. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and the reference lists of articles. We contacted researchers in the field and industry sources. SELECTION CRITERIA: Randomised trials that compared anti-cholinergic therapy with placebo or beta2-agonists in wheezing children under two years of age. Children with acute bronchiolitis and chronic lung disease were excluded. DATA COLLECTION AND ANALYSIS: Eligibility for inclusion and quality of trials were assessed independently by two reviewers. MAIN RESULTS: Six trials involving 321 infants in three different settings were included. Compared with beta2-agonist alone, the combination of ipratropium bromide and beta2-agonist was associated with a reduced need for additional treatment, but no difference was seen in treatment response, respiratory rate or oxygen saturation improvement in the emergency department. There was no significant difference in length of hospital stay between ipratropium bromide and placebo; or between ipratropium bromide and beta2-agonist combined compared with beta2-agonist alone. However, combined ipratropium bromide and beta2-agonist compared to placebo showed significantly improved clinical scores at 24 hours. Parents preferred ipratropium bromide over nebulised water or placebo for relief of their children's symptoms at home. REVIEWER'S CONCLUSIONS: There is not enough evidence to support the uncritical use of anti-cholinergic therapy for wheezing infants, although parents using it at home were able to identify benefits.

Aerosol delivery in infants and young children.

Despite extensive use of aerosol therapy to treat infants and young children with respiratory disease, our knowledge of factors influencing drug delivery in this age group remains relatively rudimentary. Recent work with filters used in conjunction with pumps or patients have emphasised some of the factors that will maximise the dose inhaled using different devices though results obtained particularly when used with patients should be interpreted with caution and in context. There are few pharmacokinetic or radiolabelled deposition studies on which to base statements regarding dose likely to reach the lungs of children in this age group. Lung function and clinical results suggest that drugs can be delivered via nebulisers and holding chambers with face masks and inevitably performance of such devices will vary. However, factors such as screaming and non-compliance with treatment are likely to influence the lung dose to a great extent. Hence choice of drug delivery system must be based on patient/parent acceptability as much as on theoretical grounds. Aerosol therapy in this age group is further complicated by our lack of knowledge related to the aetiology of recurrent respiratory symptoms in young children and hence it is quite likely that many children are being treated with effective delivery systems but inappropriate therapeutic agents. Much work is still required before we have a clear understanding of the aetiology and pathology of the distinct sub groups of respiratory disease in young children. Until we have a greater understanding in this area together with improved understanding of delivery systems, drug therapy in this age group will remain very much an empirical art.

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.