Spacer inhalation technique and deposition of extrafine aerosol in asthmatic children

Small Airways Disease Affects Aerosol Deposition in Children with Severe Asthma: A Functional Respiratory Imaging Study

Background: Small airways disease (SAD) in severe asthma (SA) is associated with high disease burden. Effective treatment of SAD could improve disease control. Reduced end-expiratory flows (forced expiratory flow [FEF]25-75 and FEF75) are considered sensitive indicators of SAD. Inhaled medication should be delivered to the smaller peripheral airways to treat SAD effectively. Aerosol deposition is affected by structural airway changes. Little is known about the effect of SAD on aerosol delivery to the smaller peripheral airways. Functional respiratory imaging (FRI) is a validated technique using 3D reconstructed chest computed tomography (CT) and computational fluid dynamics to predict aerosol deposition in the airways. Aim: This study aims to compare central and peripheral (= small airways) deposition between children with SA and SAD and children with SA without SAD, with different inhaler devices and inhalation profiles. Methods: FRI was used to predict the deposition of beclomethasone/formoterol dry powder inhaler (DPI), beclomethasone/formoterol pressurized metered dose inhaler with valved holding chamber (pMDI/VHC), and salbutamol pMDI/VHC for different device-specific inhalation profiles in chest-CT of 20 children with SA (10 with and 10 without SAD). SAD was defined as FEF25-75 and FEF75 z-score < -1.645 and forced vital capacity (FVC) z-score > -1.645. No SAD was defined as forced expiratory volume (FEV)1, FEF25-75, FEF75, and FVC z-score > -1.645. The intrathoracic, central, and peripheral airways depositions were determined. Primary outcome was difference in central-to-peripheral (C:P) deposition ratio between children with SAD and without SAD. Results: Central deposition was significantly higher (∼3.5%) and peripheral deposition was lower (2.9%) for all inhaler devices and inhalation profiles in children with SAD compared with children without SAD. As a result C:P ratios were significantly higher for all inhaler devices and inhalation profiles, except for beclomethasone administered through DPI (p = .073), in children with SAD compared with children without SAD. Conclusion: Children with SA and SAD have higher C:P ratios, that is, higher central and lower peripheral aerosol deposition, than children without SAD. The intrathoracic, central, and peripheral deposition of beclomethasone/formoterol using DPI was lower than using pMDI/VHC.

Pharmacokinetic Bioequivalence between Generic and Originator Orally Inhaled Drug Products: Validity of Administration of Doses above the Approved Single Maximum Dose

Pharmacokinetic bioequivalence of orally inhaled drug products is a critical component of the US FDA's "weight of evidence" approach, and it can serve as the sole indicator of safety and effectiveness of follow-on inhalation products approved in Europe and some other geographic areas. The approved labels of the orally inhaled drug products recommend the maximum number of actuations that can be administered in a single dose on one occasion. This single maximum dose may consist of one or more inhalations depending upon the product. Bioequivalence studies for the inhalation drug product registrations in the US and EU have employed single and multiple actuation doses, in some cases over and above the approved single maximum labeled doses, thus, inconsistent with the approved labeling of the reference products. Pharmacokinetics of inhaled drug products after single and multiple doses may be different, with implications for bioequivalence determined at single and multiple doses. Scientific literature indicates that the relative bioavailability of the Test and Reference products may differ between administrations of doses in one and multiple inhalations. Multiple doses not only alter the pharmacokinetics but also may reduce the sensitivity of the bioassay to actual differences between the Test and Reference product performances. Ability of the pharmacokinetic bioassay to accurately determine the extent of difference between two products may also be substantially reduced at high doses. Therefore, in our opinion, pharmacokinetic bioequivalence to support regulatory approvals of inhalation products at doses above the recommended single maximum dose should be avoided. Furthermore, the bioequivalence of products (if any) established at doses exceeding the approved single maximum doses should be revisited to determine if the products maintain bioequivalence when evaluated at the clinically relevant single maximum doses.

Optimal Inhalation Profile of Pressurized Metered Dry Powder Inhaler Using a Valved Holding Chamber: A Dynamic Analysis

Background: The combined use of a pressurized metered-dose inhaler and valved holding chamber (pMDI+VHC) is recommended to improve efficiency and safety; however, aerosol release is likely to vary with the inhalation maneuver. This in vitro study investigated the aerodynamic characteristics and aerosol release features of pMDI+VHC (Aerochamber, Trudell Medical International). Methods: The static and dynamic changes in the airway resistance (Raw) during inhalation (withdrawal) through pMDI+VHC were measured. Subsequently, the aerosol released from pMDI+VHC was measured using simplified laser photometry during withdrawal with either fast ramp-up then steady or slow ramp-up followed by gradual decrement at different intensities and times to peak flow (TPWF). Results: Raw increased linearly with changes in the withdrawal flow (WF) rate between 10 and 50 L/min. The slope was steep in the low WF range (<50 L/min) and became milder in the higher range. The aerosol mass tended to increase with an increase in the peak WF (PWF) of slow ramp-up profile. When three different WF increment slopes (TPWF: 0.4, 1.4, and 2.4 seconds) were compared, the released aerosol mass tended to decrease, and the aerosol release time was prolonged at longer TPWF. When the PWF was increased, the aerosol release time became shorter, and the withdrawn volume required for 95% aerosol release became larger; however, it did not exceed 0.4 L at suitable TPWF (0.4 seconds). Conclusion: Raw analysis suggests that inhalation at 30-50 L/min is suitable for pMDI+VHC in this setting. Rapid (TPWF, 0.4 seconds) inhalation, but not necessarily long (maximum 2.0 seconds) and deep (but larger than 0.55 L), is also recommended. Practically, direct inhalation to be weaker than usual breathing, as fast as possible, and far less than 2.0 seconds.

Handling Errors in the Use of Inhalation Devices: Inhalation Technique Skills and Knowledge in Pediatric Nurses

BACKGROUND

Children suffering from bronchial diseases need assistance from nurses in the use of inhalation devices.

PURPOSE

We aimed to assess nurses' skills and knowledge concerning drug administration with inhalation devices in hospitalized pediatric patients.

METHODS

An expert panel defined medication errors in drug administration with inhalation devices in children. We monitored 241 inhalation procedures to investigate nurses' inhalation technique skills. Twenty-nine nurses completed a questionnaire to assess nurses' knowledge.

RESULTS

Skills: In 93 of 241 (39%) inhalation procedures, the mask/mouthpiece did not fit airtight. In none of the 11 inhalations administering a glucocorticoid, the patient's mouth was thoroughly cleaned afterward. Knowledge: Ten of 29 nurses (34%) thought a distance between mask and the patient's face was acceptable. Only 16 of 29 (55%) knew that it is necessary to thoroughly clean the patient's mouth after the inhalation of budesonide.

CONCLUSIONS

We found that education on inhalation procedures including practical training is required to increase patient safety.

Aerosolized drug delivery in awake and anesthetized children to treat bronchospasm

Bronchospasm is a common respiratory adverse event in pediatric anesthesia. First-line treatment commonly includes inhaled salbutamol. This review focuses on the current best practice to deliver aerosolized medications to awake as well as anesthetized pediatric patients and discusses the advantages and disadvantages of various administration techniques. Additionally, we detail the differences between various airway devices used in anesthesia. We highlight the unmet need for innovation of orally inhaled drug products to deliver aerosolized medications during pediatric respiratory critical events such as bronchospasm. It is therefore important that clinicians remain up to date with the best clinical practice for aerosolized drug delivery in order to prevent and efficiently treat pediatric patients experiencing life-threatening respiratory emergencies.

Mask Use with Spacers/Valved Holding Chambers and Metered Dose Inhalers among Children with Asthma

Inhaler misuse is highly prevalent and associated with high morbidity and costs. For metered dose inhalers, proper use can be supported with devices such as spacers/valved holding chambers (VHCs) and masks to effectively deliver inhaled medication to the lungs. However, guidelines are vague about which children with asthma should use spacers/VHCs with masks to deliver medication from metered dose inhalers as well as when they should transition to spacers/VHCs with mouthpieces. In this paper, we provide a focused review of the evidence for mask use, highlighting unclear and conflicting information in guidelines and studies. We synthesize the differences in recommendations and practice. Based on these findings, we call for future research to determine the appropriate age and necessary skills for transitioning children from using metered dose inhalers with spacers/VHCs and masks to using spacers/VHCs and mouthpieces. Guidelines about mask use should be standardized to help ensure optimal medical delivery for patients, provide consistent inhaler prescriptions and education across settings, and support team-based care to help lower pediatric asthma morbidity and costs.

Measurements of deposited aerosol dose in infants and small children

Pediatric patients are very dependent on inhaled aerosol medications. There are significant differences in how these aerosols deposit in the lungs of children vs. adults that may affect the efficacy of the therapies. Inefficient aerosol delivery to children, caused by factors such as high mouth and throat deposition during oral inhalation, significant losses within adjunct devices such as masks, and high rates of nasal deposition during cannula delivery, can lead to dosing that is difficult to control. Here we discuss the methods, such as deposition scintigraphy, that are used to assess inhaled dose in vivo and review previous studies where these techniques have been applied to measure dosing in children. This includes studies of nebulizers and metered dose inhalers and delivery through adjuncts such as facemasks and nasal cannulas. We discuss the factors that can lead to inefficient inhaled drug delivery and high levels of mouth and throat deposition in children. Finally, we propose areas of innovation to improve inhaled drug delivery to this population. There is a need for child-specific technologies for inhaled drug delivery. This includes the use of smart devices that can guide pediatric breathing patterns and better engage children during treatments, the use of smaller aerosols which are less likely to deposit in the upper airways after inhalation, and the design of better nasal cannula interfaces for aerosol delivery to infants.

A path to successful patient outcomes through aerosol drug delivery to children: a narrative review

Although using aerosolized medications is a mainstay of treatment in children with asthma and other respiratory diseases, there are many issues in terms of device and interface selection, delivery technique and dosing, as well as patient and parental education that have not changed for half a century. Also, due to many aerosol devices and interfaces available on the market and the broad range of patient characteristics and requirements, providing effective aerosol therapy to children becomes a challenge. While aerosol delivery devices are equally effective, if they are age-appropriate and used correctly, the majority of aerosol devices require multiple steps to be used efficiently. Unfortunately, many children with pulmonary diseases have problems with the correct delivery technique and do not gain therapeutic benefits from therapy that result in poor disease management and increased healthcare costs. Therefore, the purpose of this paper is to review the current knowledge on aerosol delivery devices used in children and guide clinicians on the optimum device- and interface-selection, delivery technique, and dosing in this patient population. Strategies on how to deliver aerosolized medications in crying and distressed children and how to educate parents on aerosol therapy and promote patient adherence to prescribed medications are also provided. Future directions of aerosol therapy in children should focus on these issues and implement policies and clinical practices that highlight the potential solutions to these problems.

Comparison of pulmonary deposition of nebulized 99m technetium-diethylenetriamine-pentaacetic acid through 3 inhalation devices in healthy dogs

Background

Inhalation treatment frequently is used in dogs and cats with chronic respiratory disease. Little is known however about the performance of delivery devices and the distribution of aerosolized drugs in the lower airways.

Objective

To assess the performance of 3 delivery devices and the impact of variable durations of inhalation on the pulmonary and extrapulmonary deposition of nebulized ^99mtechnetium‐diethylenetriamine‐pentaacetic acid (^99mTc‐DTPA).

Animals

Ten university‐owned healthy Beagle dogs.

Methods

Prospective crossover study. Dogs inhaled the radiopharmaceutical for 5 minutes either through the Aerodawg spacer with a custom‐made nose‐muzzle mask, the Aerochamber spacer with the same mask, or the Aerodawg spacer with its original nose mask. In addition, dogs inhaled for 1 and 3 minutes through the second device. Images were obtained by 2‐dimensional planar scintigraphy. Radiopharmaceutical uptake was calculated as an absolute value and as a fraction of the registered dose in the whole body.

Results

Mean (±SD) lung deposition for the 3 devices was 9.2% (±5.0), 11.4% (±4.9), and 9.3% (±4.6), respectively. Differences were not statistically significant. Uptake in pulmonary and extrapulmonary tissues was significantly lower after 1‐minute nebulization, but the mean pulmonary/extrapulmonary deposition ratio (0.38 ± 0.27) was significantly higher than after 5‐minute nebulization (0.16 ± 0.1; P = .03). No significant differences were detected after 3‐ and 5‐minute nebulization.

Conclusion and Clinical Importance

The performance of a pediatric spacer with a custom‐made mask is comparable to that of a veterinary device. One‐minute nebulization provides lower pulmonary uptake but achieves a better pulmonary/extrapulmonary deposition ratio than does 5‐minute nebulization.

Prevalence and risk factors of lactic acidosis in children with acute moderate and severe asthma, a prospective observational study

Lactic acidosis is a common complication of status asthmaticus in adults. However, data is sparse in children. The aim of this study was to describe the prevalence and risk factors for lactic acidosis in children hospitalised for acute moderate or severe asthma. A total of 154 children 2-17 years of age were enrolled in a prospective observational study conducted in a tertiary hospital. All had capillary blood gas assessment 4 h after the first dose of salbutamol in hospital. The primary endpoint was the prevalence of lactic acidosis. Potential contributing factors such as age, sex, BMI, initial degree of asthma severity, type of salbutamol administration (nebuliser or inhaler), steroids, ipratropium bromide, and glucose-containing maintenance fluid represented secondary endpoints. All in all, 87% of patients had hyperlactatemia (lactate concentration > 2.2 mmol/l). Lactic acidosis (lactate concentration > 5 mmol/l and anion gap ≥ 16 mmol/l) was observed in 26%. In multivariate analysis, age more than 6 years (OR = 2.8, 95% CI 1.2-6.6), glycemia above 11 mmol/l (OR = 3.2 95% CI 1.4-7.4), and salbutamol administered by nebuliser (OR = 10, 95% CI 2.7-47) were identified as risk factors for lactic acidosis in children with moderate or severe asthma.Conclusion: Lactic acidosis is a frequent and early complication of acute moderate or severe asthma in children. What is Known: • Lactic acidosis during acute asthma is associated with b2-mimetics administration. • Salbutamol-related lactic acidosis is self-limited but important to recognise, as compensatory hyperventilation of lactic acidosis can be mistaken for respiratory worsening and lead to inappropriate supplemental bronchodilator administration. What is New: • Lactic acidosis is a frequent complication of acute asthma in the paediatric population. • Age older than 6 years, hyperglycaemia, and nebulised salbutamol are risk factors for lactic acidosis during asthma.

BET 1: Efficacy of different techniques using a metered-dose inhaler with Spacer to relieve symptoms in children with acute asthma

A shortcut review was carried out to establish which inhaler with spacer technique provides the greatest improvement in symptoms in children with acute asthma. Four relevant papers were identified for inclusion using the reported search strategy. The author, date and country of publication; group studied; study type; relevant outcomes; results and study weaknesses of these papers are tabulated. It is concluded that a 'tidal breathing' technique, with a minimum of three breaths per inhaler activation, is likely equivalent in efficacy to a 'single breath and hold technique', and easier for a breathless child to perform.

Comparative pharmacokinetics of salbutamol inhaled from a pressurized metered dose inhaler either alone or connected to a newly enhanced spacer design

BACKGROUND

Coordination between actuation of a pressurized metered dose inhaler (pMDI) and inhalation is a critical manoeuvre that many patients fail to perform correctly. pMDIs connected to spacers do not require hand-lung coordination. This study evaluated the relative lung and systemic bioavailability and oropharyngeal deposition of salbutamol post-inhalation from Ventolin® Evohaler® (GlaxoSmithKline) either alone following verbal inhaler technique counselling (VC) or connected to a newly improved Able Spacer® (AS).

METHODS

In a two-period, randomized crossover study, 16 healthy adults inhaled 2 × 100 µg salbutamol puffs (1 min gap) from Ventolin using VC or AS. Immediately after each puff inhalation, each subject gargled with 20 mL water for oropharyngeal deposition (OD) determination. Urine samples were collected 0.5 h (pre-) and 0.5, 1.0 and 2.0 h post-inhalation. Urine was then pooled 2-24 h post-inhalation. The relative lung bioavailability (0-0.5 h urinary salbutamol excretion - USAL0.5) and systemic bioavailability (0-24 h urinary excretion of salbutamol and its metabolite - USALMET24) were determined. A one week washout separated VC and AS use.

RESULTS

The mean (SD) USAL0.5 of VC and AS was 5.36 (4.48) and 12.80 (10.83) µg, respectively. The mean (SD) OD was 11.35 (3.37) and 0.48 (0.30) µg, respectively. VC and AS were significantly different in USAL0.5 and OD (p<0.001). USALMET24 was comparable (p>0.05).

CONCLUSIONS

Compared with VC, AS doubled the inhaled salbutamol lung dose and minimised its precipitation in the oral cavity. The results suggest this inhalation aid can add therapeutic and safety benefits particularly in patients with continued pMDI technique issues despite repeated VC.

Spacer devices for inhaled therapy: why use them, and how?

We present an extensive review of the literature to date pertaining to the rationale for using a spacer/valved holding chamber (VHC) to deliver inhaled therapy from a pressurised, metered-dose inhaler, a discussion of how the properties of individual devices may vary according to their physical characteristics and materials of manufacture, the potential risks and benefits of ancillaries such as valves, and the evidence that they contribute tangibly to the delivery of therapy. We also reiterate practical recommendations for the correct usage and maintenance of spacers/VHCs, which we trust offer practical help and advice to patients and healthcare professionals alike.

Optimizing the Delivery of Inhaled Medication for Respiratory Patients: The Role of Valved Holding Chambers

Valved holding chambers (VHCs) have been used with pressurized metered-dose inhalers since the early 1980s. They have been shown to increase fine particle delivery to the lungs, decrease oropharyngeal deposition, and reduce side effects such as throat irritation, dysphonia, and oral candidiasis that are common with use of pressurized metered-dose inhalers (pMDIs) alone. VHCs act as aerosol reservoirs, allowing the user to actuate the pMDI device and then inhale the medication in a two-step process that helps users overcome challenges in coordinating pMDI actuation with inhalation. The design of VHC devices can have an impact on performance. Features such as antistatic properties, effective face-to-facemask seal feedback whistles indicating correct inhalation speed, and inhalation indicators all help improve function and performance, and have been demonstrated to improve asthma control, reduce the rate of exacerbations, and improve quality of life. Not all VHCs are the same, and they are not interchangeable. Each pairing of a pMDI device plus VHC should be considered as a unique delivery system.

Use of spacers for patients treated with pressurized metered dose inhalers: focus on the VENTOLIN™ Mini Spacer

INTRODUCTION

Spacers offer a multitude of benefits by reducing the requirement to coordinate inhalation with actuation and improving inhaler technique in patients using a pressurized metered dose inhaler (pMDI). Spacers improve drug targeting by retaining within the spacer large particles normally deposited in the oropharynx, and by creating a prolonged aerosol cloud of fine particles to give the user increased time to inhale after actuation. This is particularly important in young children and the elderly to effectively deliver medication to the airways.

AREAS COVERED

By investigating the history and features of spacers, we demonstrate that the advantages of using spacers far outweigh their limitations. We also discuss the optimal characteristics of spacers in terms of shape, volume, presence of valve and static charge, and present a detailed discussion of the VENTOLIN™ Mini Spacer.

EXPERT OPINION

Generally, the shape and size of spacers makes them inherently inconvenient. Consideration of human factors and modern design may make them more attractive to patients. However, the incentive to use spacers should be their ability to help patients correctly use inhaled medications delivered by pMDIs. Understanding of these principles through education is key to their acceptance by patients.

Scintigraphic Assessment of Deposition of Radiolabeled Fluticasone Delivered from a Nebulizer and Metered Dose Inhaler in 10 Healthy Dogs

Background

Aerosolized medications are increasingly being used to treat respiratory diseases in dogs. No previous studies assessing respiratory tract deposition of radiolabeled aerosols have been performed in conscious dogs.

Hypothesis/Objectives

Assess respiratory tract deposition of radiolabeled, inhalant corticosteroid (fluticasone propionate labeled with ^99mTc) delivered from a nebulizer and metered dose inhaler (MDI) to healthy dogs.

Animals

Ten healthy Foxhounds.

Methods

Prospective, randomized, cross‐over pilot study. Initial inhalation method (nebulizer or MDI) was randomly assigned. Treatments were crossed over after a 7‐day washout period. Treatments initially were performed using sedation. Dogs were imaged using 2‐dimensional planar scintigraphy, with respiratory tract deposition quantified by manual region‐of‐interest analysis. Deposition calculated as percentage of delivered dose. Six of 10 dogs were randomly selected and reassessed without sedation.

Results

Inhalation method had significant effect on respiratory tract deposition (P = 0.027). Higher deposition was achieved by nebulization with mean deposition of 4.2% (standard deviation [SD], 1.4%; range, 1.9–6.1%); whereas MDI treatment achieved a mean of 2.3% (SD, 1.4%; range, 0.2–4.2%). Nebulization achieved higher respiratory tract deposition than MDI in 7 of 10 dogs. No statistical difference (P = 0.68) was found between mean respiratory tract deposition achieved in dogs when unsedated (3.8%; SD, 1.5%) or sedated (3.6%; SD, 1.7%).

Conclusions and Clinical Importance

Study confirms respiratory tract deposition of inhalant medications delivered from a nebulizer and MDI in healthy dogs, breathing tidally with and without sedation. Respiratory tract deposition in these dogs was low compared to reported deposition in adult humans, but similar to reported deposition in children.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Dilemmas, Confusion, and Misconceptions Related to Small Airways Directed Therapy

During the past decade, there has been increasing evidence that the small airways (ie, airways < 2 mm in internal diameter) contribute substantially to the pathophysiologic and clinical expression of asthma and COPD. The increased interest in small airways is, at least in part, a result of innovation in small-particle aerosol formulations that better target the distal lung and also advanced physiologic methods of assessing small airway responses. Increasing the precision of drug deposition may improve targeting of specific diseases or receptor locations, decrease airway drug exposure and adverse effects, and thereby increase the efficiency and effectiveness of inhaled drug delivery. The availability of small-particle aerosols of corticosteroids, bronchodilators, or their combination enables a higher total lung deposition and better peripheral lung penetration and provides added clinical benefit, compared with large-particle aerosol treatment. However, a number of questions remain unanswered about the pragmatic approach relevant for clinicians to consider the role of small airways directed therapy in the day-to-day management of asthma and COPD. We thus have tried to clarify the dilemmas, confusion, and misconceptions related to small airways directed therapy. To this end, we have reviewed all studies on small-particle aerosol therapy systematically to address the dilemmas, confusion, and misconceptions related to small airways directed therapy.

Small-particle Inhaled Corticosteroid as First-line or Step-up Controller Therapy in Childhood Asthma

BACKGROUND

Because randomized controlled trials of established pediatric asthma therapies are expensive and difficult to perform, observational studies may fill gaps in the evidence base.

OBJECTIVES

To compare the effectiveness of representative small-particle inhaled corticosteroid (ICS) with that of standard size-particle ICS for children initiating or stepping up ICS therapy for asthma (analysis 1) and to compare the effectiveness of ICS dose step-up using small-particle ICS with adding long-acting β2-agonist (LABA) to the ICS (analysis 2).

METHODS

These historical matched cohort analyses drew on electronic medical records of children with asthma aged 5 to 11 years. Variables measured during 2 consecutive years (1 baseline year for confounder definition and 1 outcome year) included risk-domain asthma control (no hospital attendance for asthma, acute oral corticosteroids, or lower respiratory tract infection requiring antibiotics) and rate of severe exacerbations (asthma-related emergency, hospitalization, or oral corticosteroids).

RESULTS

In the initiation population (n = 797 in each cohort), children prescribed small-particle ICS versus standard size-particle ICS experienced greater odds of asthma control (adjusted odds ratio, 1.49; 95% CI, 1.10-2.02) and lower severe exacerbation rate (adjusted rate ratio, 0.56; 95% CI, 0.35-0.88). Step-up outcomes (n = 206 in each cohort) were also significantly better for small-particle ICS, with asthma control adjusted odds ratio of 2.22 (95% CI, 1.23-4.03) and exacerbations adjusted rate ratio of 0.49 (95% CI, 0.27-0.89). The number needed to treat with small-particle ICS to achieve 1 additional child with asthma control was 17 (95% CI, 9-107) for the initiation population and 5 (95% CI, 3-78) for the step-up population. Outcomes were not significantly different for stepped-up small-particle ICS dose versus ICS/LABA combination (n = 185 in each cohort).

CONCLUSIONS

Initiating or stepping up the ICS dose with small-particle ICS rather than with standard size-particle ICS is more effective and shows similar effectiveness to add-on LABA in childhood asthma.

In vitro characterization of the OptiChamber Diamond valved holding chamber

BACKGROUND

Use of a valved holding chamber (VHC) in conjunction with a pressurized metered dose inhaler (pMDI) can reduce issues relating to poor actuation-inhalation coordination and potentially improve the lung deposition of aerosol, compared with use of a pMDI alone. However, the performance of a VHC is influenced by different device-related factors, including the size and shape of the VHC and the material it is manufactured from (conventional versus antistatic). This study aimed to provide an in vitro characterization of an antistatic VHC, the OptiChamber Diamond VHC, comparing the aerodynamic particle size distribution of aerosol delivered via this VHC with results from a second antistatic VHC and a conventional VHC.

METHODS

The pMDI drug formulations (albuterol, suspension; beclomethasone dipropionate, solution) were connected to a Next Generation Impactor, either directly (pMDI alone tests) or via a VHC (VHC tests). The pMDIs were actuated (×10 per product pair) and tested at extraction flow rates of 15 L/min and 30 L/min, without any time delay between actuation and inhalation. Dose delivery using the two pMDI drug formulations was compared, and is presented with reference to key aerodynamic particle size parameters.

RESULTS

Compared with tests on pMDIs alone, use of a VHC increased the dose of aerosol within the respirable range, particularly at a 15 L/min flow rate. Between-VHC comparisons indicated that the two antistatic VHCs were equivalent. Delivery of albuterol appeared to be influenced by the VHC used, but beclomethasone dipropionate seemed unaffected.

CONCLUSIONS

The two antistatic VHCs were equivalent for both pMDI brands. Aerosol delivered from the antistatic VHCs at 15 L/min had a higher proportion of fine particles compared with the conventional VHC.

Lung deposition of 99mTc-radiolabeled albuterol delivered through a pressurized metered dose inhaler and spacer with facemask or mouthpiece in children with asthma

BACKGROUND

Research on the use of a pressurized metered dose inhaler (pMDI) with spacer (pMDI/spacer) in children has indicated oral inhalation via the spacer mouthpiece is more efficient than the combination of oral and nasal inhalation that occurs when a pMDI/spacer is used with a facemask. Changes in pMDI formulations and developments in spacer and facemask designs have highlighted the need for new comparative studies of spacer use, particularly focusing on the age at which children can be taught to transition from use of a pMDI/spacer with facemask to use of the spacer mouthpiece.

METHODS

Twelve children aged 3-5 years (7 males) with stable asthma were recruited. Of these, 10 children (6 males) completed both arms of the study. A transmission scan of each compliant subject was taken using a 37 MBq (99m)Tc flood source. Actuations (2-3) of a (99m)Tc-radiolabeled albuterol pMDI were administered through an antistatic spacer (OptiChamber Diamond) via either a facemask (medium LiteTouch facemask), or the spacer mouthpiece. The subject's inhalation pattern was simultaneously recorded using a pMDI Datalogger, and narrative data relating to tolerance and compliance were documented. Anterior and posterior planar scintigraphic scans were taken immediately after aerosol administration.

RESULTS

Mean (SD) lung deposition (% total dose) was 18.1 (9.1)% with the facemask and 22.5 (7.9)% with the spacer mouthpiece (p>0.05). Peripheral lung deposition (expressed as peripheral:central (P:C) ratio) was higher in 7 out of 10 children with the facemask compared with the spacer mouthpiece: 1.3 (0.26) vs. 1.2 (0.35); (p=0.11). Head and neck deposition was higher with use of the facemask compared with the spacer mouthpiece: 19.7 (10.6)% vs. 10.8 (5.3)% (p=0.011).

CONCLUSIONS

Lung deposition achieved using the spacer with facemask was higher than previously reported, with a difference of only 4.4% of total dose measured compared to the deposition with mouthpiece. This may be due to a combination of factors including pMDI formulation, and use of an antistatic spacer with a flexible, well-fitting facemask.

The evolution of spacers and valved holding chambers

Spacers and valved holding chambers (VHCs) are pressurized metered dose inhaler (pMDI) accessory devices, designed to overcome problems that patients commonly experience when administering aerosol via a pMDI. Spacers were developed in direct response to patient-related issues with pMDI technique, particularly, poor coordination between actuation and inhalation, and local side-effects arising from oropharyngeal deposition. Current clinical guidelines indicate the need for widespread prescription and use of spacers, but, despite their apparent ubiquity, the devices themselves are, unfortunately, all too commonly "disused" by patients. An understanding of the background from which spacers developed, and the key factors influencing the optimization of the spacer and the later VHC, is crucial to developing an appreciation of the potential of these devices, both contemporary and future, for improving the delivery of pressurized aerosols to patients. This review, informed by a full patent search and an extensive scientific literature review, takes into account the clinical and laboratory evidence, commercial developments, and the sometimes serendipitous details of scientific anecdotes to form a comprehensive perspective on the evolution of spacers, from their origins, in the early days of the pMDI, up to the present day.

Pediatric in vitro and in silico models of deposition via oral and nasal inhalation

Respiratory tract deposition models provide a useful method for optimizing the design and administration of inhaled pharmaceutical aerosols, and can be useful for estimating exposure risks to inhaled particulate matter. As aerosol must first pass through the extrathoracic region prior to reaching the lungs, deposition in this region plays an important role in both cases. Compared to adults, much less extrathoracic deposition data are available with pediatric subjects. Recently, progress in magnetic resonance imaging and computed tomography scans to develop pediatric extrathoracic airway replicas has facilitated addressing this issue. Indeed, the use of realistic replicas for benchtop inhaler testing is now relatively common during the development and in vitro evaluation of pediatric respiratory drug delivery devices. Recently, in vitro empirical modeling studies using a moderate number of these realistic replicas have related airway geometry, particle size, fluid properties, and flow rate to extrathoracic deposition. Idealized geometries provide a standardized platform for inhaler testing and exposure risk assessment and have been designed to mimic average in vitro deposition in infants and children by replicating representative average geometrical dimensions. In silico mathematical models have used morphometric data and aerosol physics to illustrate the relative importance of different deposition mechanisms on respiratory tract deposition. Computational fluid dynamics simulations allow for the quantification of local deposition patterns and an in-depth examination of aerosol behavior in the respiratory tract. Recent studies have used both in vitro and in silico deposition measurements in realistic pediatric airway geometries to some success. This article reviews the current understanding of pediatric in vitro and in silico deposition modeling via oral and nasal inhalation.

How to match the optimal currently available inhaler device to an individual child with asthma or recurrent wheeze

Inhaled medications are the cornerstone of treatment in early childhood wheezing and paediatric asthma. A match between patient and device and a correct inhalation technique are crucial for good asthma control. The aim of this paper is to propose an inhaler strategy that will facilitate an inhaler choice most likely to benefit different groups of children. The main focus will be on pressurised metered dose inhalers and dry powder inhalers. In this paper we will discuss (1) practical difficulties with the devices and with inhaled therapy and (2) the optimal location for deposition of medicines in the lungs, and (3) we will propose a practical and easy way to make the best match between the inhaler device and the individual patient. We hope that this paper will contribute to an increased likelihood of treatment success and improved adherence to therapy.

Evaluation of asthma control, parents' quality of life and preference between AeroChamber Plus and AeroChamber Plus Flow-Vu spacers in young children with asthma

OBJECTIVE

The AeroChamber Plus (AC) valved holding chamber has been enhanced to include the Flow-Vu (FV) inspiratory flow indicator that provides visual inhalation feedback during use. We have investigated if FV alters asthma control and whether parents accept it.

METHODS

At visit 1, children with asthma, age 1-5 years, used an AC with their pressurised metered dose inhaler and 2 weeks later (visit 2) they were randomised to use either AC or FV. Subjects returned 6 (visit 3) and 12 (visit 4) weeks later. The Asthma Control (ACQ) and Paediatric Asthma Caregiver's Quality of Life (PACQLQ) questionnaires were scored at each visit, and their peak inhalation flow (PIF) when they used their spacer was measured.

RESULTS

Forty participants in each group completed the study. There was no difference in the ACQ scores from visits 2 to 4 between the two groups. The improvements in the PACQLQ scores were greater in the FV group (p = 0.029). The mean difference (95% confidence interval) for the change from visits 2 to 4 between FV and AC groups was 0.05 (-0.33, 0.43) and 0.39 (0.035, 0.737) for the ACQ and PACQLQ, respectively. Most parents preferred the FV (p < 0.001). There was no difference in the PIF rates at each visit and between the two spacers.

CONCLUSIONS

There was no change in asthma control of the young children but that of their parents improved. Parents preferred the FV and this could be related to their improved perception of their children's asthma control by better PACQLQ scores.

Delivery of inhalation drugs to children for asthma and other respiratory diseases

Infants and children constitute a patient group that has unique requirements in pulmonary drug delivery. Since their lungs develop continuously until they reach adulthood, the airways undergo changes in dimensions and number. Computational models have been devised on the growth dynamics of the airways during childhood, as well as the particle deposition mechanisms in these growing lungs. The models indicate that total aerosol deposition in the body decreases with age, while deposition in the lungs increases with age. This has been observed on paediatric subjects in in vivo studies. Issues unique to children in pulmonary drug delivery include their lower tidal volume, highly variable breathing patterns, air leaks from facemasks, and the off-label or unlicensed use of pharmaceutical products due to lack of clinical data for this age group. The aerosol devices used are essentially those developed for adult patients that have been adapted to paediatric use. Facemasks should be used with nebulisers and spacers for infants and young children. An idealised throat that mimic the average particle deposition in paediatric throats has been designed to obtain more clinically relevant aerosol dispersion data in vitro. More effort should be spent on studying particle deposition in the paediatric lung and developing products specific for this subpopulation to meet their needs.

Orally inhaled fixed-dose combination products for the treatment of asthma and chronic obstructive pulmonary disease: not simple math

Over the past decade, orally inhaled fixed-dose combination products (FDCs) have emerged as an important therapeutic class for the treatment of asthma and chronic obstructive pulmonary disease. However, the conceptual simplicity of inhaled FDCs belies both the complexity of their development, and the profound advantages they offer patients. The benefits of combining agents are not merely additive, and range from increased compliance via simple convenience to complex receptor-level synergies. Similarly, though, the development challenges often exceed the sum of their parts. FDC formulation and analytical method development is generally more complex than for two monotherapy products. Likewise, FDC clinical programs can easily eclipse those of their monotherapy peers and their inherent complexity is often furthered by the diverse regulatory requirements for worldwide approval. As such, the proposition of developing an orally inhaled FDC for global registration often represents a significant increase in both the potential rewards and assumed risks of drug development.

Comparison of in vitro deposition of pharmaceutical aerosols in an idealized child throat with in vivo deposition in the upper respiratory tract of children

PURPOSE

Deposition of drug emitted from two commercially available inhalers was measured in an in vitro child oral airway model and compared to existing in vivo data to examine the ability of the child model to replicate in vivo deposition.

METHODS

In vitro deposition of drug from a QVAR® pressurized metered dose inhaler (pMDI) and Pulmicort® Turbuhaler® dry powder inhaler (DPI) in an Idealized Child Throat (1) and downstream filter was measured using UV spectroscopy and simulated realistic breathing profiles. Potential effects of ambient relative humidity ranging from 10% to 90% on deposition were also considered.

RESULTS

In vitro QVAR pMDI deposition in the idealized mouth-throat at 50% RH (39.2 ± 2.3% of delivered dose) compared well (p>0.05) with in vivo extrathoracic deposition in asthmatic children age 8 to 14 (45.8 ± 12.3%). In vitro Turbuhaler DPI deposition in the idealized mouth-throat at 50% RH (69.0 ± 1.5%) matched in vivo extrathoracic deposition (p>0.05) in 6 to 16 year old children with cystic fibrosis (70.4 ± 21.2%). The effects of ambient humidity were found to be insignificant for Turbuhaler and minor for QVAR.

CONCLUSIONS

The Idealized Child Throat successfully mimics in vivo deposition data in school age children for the inhalers tested, and may provide a standard platform for optimizing pediatric treatment with inhaled pharmaceutical aerosols.

Asthma medication delivery: mists and myths

Asthma is usually treated with inhaled corticosteroids (ICS) and bronchodilators generated from pressurized metered dose inhalers (pMDI), dry powder inhalers (DPI), or nebulizers. The target areas for ICS and beta 2-agonists in the treatment of asthma are explained. Drug deposition not only depends on particle size, but also on inhalation manoeuvre. Myths regarding inhalation treatments lead to less than optimal use of these delivery systems. We discuss the origin of many of these myths and provide the background and evidence for rejecting them.

Inhaler devices for patients with COPD

Chronic obstructive pulmonary disease (COPD) continues to be associated with increased morbidity and mortality risk in spite of updated guidelines and a better understanding of this condition. Progressive airflow limitation and resultant hyperinflation-the respiratory hallmarks of this complex and often under-diagnosed disease-can be treated with pharmacotherapies emitted via nebulizers, pressurized metered-dose inhalers, dry powder inhalers, or a Soft Mist inhaler. Pharmaceutical company proprietary issues, technological innovations, and societal pressure have expanded the list of available inhalers, with a limited range of medications available for any one device. Each device has different operating and maintenance instructions, and successful use of a given drug/device combination requires that patients understand, maintain, and use each of their devices properly in order to ensure consistent and optimal pulmonary drug delivery. Clinicians are faced with a range of physical and psychosocial issues unique to each patient with COPD that must be overcome in order to match a suitable inhaler to the individual. Improved drug delivery afforded by next-generation inhalers, coupled with an awareness of device-specific and patient-specific variables affecting inhaler use, may improve clinical outcomes in the treatment of COPD.

The effect of beclomethasone dipropionate in ultrafine particles on bronchial hyper-reactivity in young children

AIM

Bronchial hyper-reactivity (BHR) provides a tool for asthma diagnosis, assessment of severity and response to treatment. The effect of beclomethasone dipropionate in ultrafine particles (BDP-HFA) on BHR as measured by the adenosine challenge test in young children has not yet been determined. Our aim was to determine the effect of BDP-HFA (100 μg twice daily) on BHR as evaluated by a reduction of 20% from baseline FEV1 (PC20-FEV1) values in young asthmatic children.

METHODS

Twenty-one young children (13 males), mean age 4.95 ± 1.05 years, with partially controlled or controlled asthma completed a double-blind randomized, placebo-controlled, cross-over study. Each child received 4 weeks of treatment with either 100 μg BDP-HFA twice daily or placebo, and after a 2-week washout period the other way around. Primary outcomes were PC20-FEV1 concentration, and the stage number at which FEV1 values dropped by 20%.

RESULTS

Following 4 weeks of treatment, median PC20-FEV1 was 81.28 mg/mL while on BDP-HFA, compared with 9.64 mg/mL on placebo (p < 0.001). The median increase in stages required to achieve PC20 on BDP-HFA compared with placebo was three (95% CI 2.28-4.86).

CONCLUSION

Four weeks of treatment with BDP-HFA resulted in significantly decreased BHR in young children.

[Inhalation devices: characteristics, modeling, regulation and use in routine practice. GAT Aerosolstorming, Paris 2011]

Aerosoltherapy is a first-line treatment for chronic obstructive respiratory diseases such as asthma and COPD. Treatment modalities and devices are varied and the choice of the device must be adapted to and optimized for every patient. Spacers can be used for some categories of patients for whom the use of other devices turns out to be complicated. The improvement of these treatments requires the optimization of the lung deposition of inhaled particles; lung modeling plays an essential role in the understanding of the mechanisms of flow in the airways. Regulations must frame prescription of inhaled treatments to optimize its quality and, thus, the care for these chronic diseases. Many generally-accepted ideas concerning these treatments turn out to be false. Inhaled treatments are constantly evolving, both pharmacologically and technologically.

Lung function changes in asthmatic children treated with HFA-BDP

STUDY OBJECTIVES

Asthma guidelines suggest that normal or near normal lung function should be one of the goals for good asthma control. Therefore, children with chronic persistent asthma and reduced peripheral airway function were assessed after the replacement of conventional inhaled corticosteroids (ICS) with an extrafine aerosol formulation, hydrofluoroalkane-134a beclomethoasone diproprionate (HFA-BDP).

DESIGN AND SETTING

Lung function and clinical details were studied in children with moderate persistent asthma who regularly attended the pediatric pulmonary outpatient clinic at Kosair Children's Hospital, Louisville, Kentucky, USA.

SUBJECTS

A total of 20 children, 7 girls and 13 boys, with stable asthma but reduced forced expiratory flows between 25% and 75% of vital capacity (FEF(25-75) ) were included in the study.

INTERVENTION

After the initial assessment, each subject was switched from conventional ICS to HFA-BDP. All other medications remained the same. Reassessment of lung function and clinical status was performed at least 3 weeks after the intervention.

RESULTS

FEF(25-75) increased from a mean of 50.75% to 68.85% predicted (P < 0.001). Forced expiratory volume in 1 sec (FEV(1)) also increased significantly from 84.6% to 93.8% predicted (P = 0.001). No changes asthma symptoms were observed.

CONCLUSION

Compared to conventional ICS, the use of HFA-BDP in asthmatic children significantly improves airflow in both the large and the peripheral airways without loss of asthma control.

A pilot study to assess lung deposition of HFA-beclomethasone and CFC-beclomethasone from a pressurized metered dose inhaler with and without add-on spacers and using varying breathhold times

BACKGROUND

The study objective of this pilot study was to determine the lung delivery of HFA-134a-beclomethasone dipropionate (HFA-BDP; QVAR™) and CFC-beclomethasone dipropionate (CFC-BDP; Becloforte™) with and without the add-on spacers, Aerochamber™, and Volumatic™. The smaller particles of HFA-BDP were presumed to produce greater lung deposition using spacers, with and without a delay [i.e., metered dose inhaler (MDI) actuation into the spacer and subsequent inhalation 0 and 2 sec later], compared with the larger particles of CFC-BDP. The study included a comparison of breathhold effects (i.e., 1 and 10-sec breatholds) on lung deposition.

METHODS

The study was an open-label design and utilized healthy subjects (n = 12 males). Each arm of the study contained three subjects; thus, outcomes were not powered to assess statistical significance. HFA-BDP and CFC-BDP were radiolabeled with technetium-99m and delivered to subjects.

RESULTS

Results showed that the small particle HFA-BDP lung deposition averaged 52% and was not affected by the use of Aerochamber with or without a spacer delay. The oropharyngeal deposition of HFA-BDP was reduced from approximately 28% to 4% with the Aerochamber. Lung deposition with the large particle CFC-BDP was 3-7% and generally decreased with Aerochamber or Volumatic. A 2-sec time delay between actuation and breath plus the spacer reduced lung deposition slightly but reduced oropharygeal deposition substantially (84% down to 3-20%) using the Aerochamber or Volumatic with and without a spacer delay. HFA-BDP lung deposition was dependent on the breathhold. Lung deposition with HFA-BDP was reduced by 16% with a 1-sec versus 10-sec breathhold. The difference was measured in the increased exhaled fraction, confirming that smaller particles need time to deposit and are exhaled if there is a reduced breathhold. The large particle CFC-BDP lung deposition was not affected by breathhold.

CONCLUSIONS

The use of Aerochamber or Volumatic spacers with HFA-BDP did not alter lung deposition but it did reduce oropharyngeal deposition. However, HFA-BDP displayed reduced oropharyngeal deposition without a spacer.

Similar Results in Children with Asthma for Steady State Pharmacokinetic Parameters of Ciclesonide Inhaled with or without Spacer

Background:

Ciclesonide is an inhaled corticosteroid administered by a metered dose inhaler (MDI) to treat bronchial asthma. After inhalation, the inactive ciclesonide is converted by esterases in the airways to active metabolite desisobutyryl-ciclesonide (des-CIC).

Aim:

To compare the pharmacokinetic (PK) parameters of des-CIC in children after administration of therapeutic dose of ciclesonide with and without spacer (AeroChamber Plus^™).

Methods:

Open-label, 3 period, cross over, repeated dose, PK study in 37 children with mild to moderate stable asthma (age: 6–11 y; body weight: 20–53 kg). During each 7-day treatment period, ciclesonide was inhaled once in the morning: A) 160 μg MDI with spacer, B) 80 μg MDI with spacer, and C) 160 μg MDI without spacer. Serum PK parameters of ciclesonide and des-CIC were determined on Day 7 of each period. The primary PK parameters were the AUC_τ and C_max for des-CIC.

Results:

Inhaling ciclesonide with spacer led to a dose proportional systemic exposure (AUC_τ) of des-CIC (0.316 μg*h/L for 80 μg and 0.663 μg*h/L for 160 μg). The dose-normalized systemic exposure for des-CIC (based on AUC_τ) was 27% higher after inhalation of ciclesonide 80 μg or 160 μg with spacer than without spacer; the corresponding C_max values for des-CIC were, respectively, 63% and 55% higher with spacer. No clinically relevant abnormalities or adverse drug reactions were observed.

Conclusions:

Inhalation of therapeutic ciclesonide dose with spacer led to a slight increase in the systemic exposure of des-CIC, which does not warrant dose adjustment.

Factors that affect the efficacy of inhaled corticosteroids for infants and young children

Infants (0-1 years of age) and young children (1-3 years of age) are a unique subpopulation with regard to inhaled therapies. There are various anatomic, physiological, and emotional factors peculiar to this age group that present significant difficulties and challenges for aerosol delivery. Most studies of therapeutic aerosols that have been performed with patients of this age group, particularly recent studies with inhaled corticosteroids (ICSs), administered aerosols with relatively large particles (ie, >3 microm in mass median aerodynamic diameter). These drugs were designed for use in adults and older children and were administered with masks, which are frequently rejected by patients. Based on these studies, it was recently suggested that ICSs might not be as therapeutically effective in infants and young children as in adults. We review the reasons that large-particle corticosteroid aerosols are not likely to be effective in infants and young children. This patient population differs from adults in airway anatomy and physiology, as well as in behavior and adherence to therapy. We suggest that the benefit of ICSs in this age group requires further evaluation to determine whether better therapeutic outcomes might be achieved with smaller particles.

Particle size of inhaled corticosteroids: does it matter?

A question with respect to asthma therapy revolves around the issue of whether better efficacy occurs with an ultrafine-particle inhaled corticosteroid because of better lung deposition into the distal airways. This article reviews particle size and delivery devices of different steroids, clinical outcomes of small- versus large-particle steroids, and the issue of pharmacoeconomics.

Aerosol delivery of nebulised budesonide in young children with asthma

BACKGROUND

Lung deposition of inhaled steroids, likely to be of benefit in the anti-inflammatory treatment of asthma in young children, is low. This is explained by age specific anatomical and physiological characteristics as well as poor cooperation with aerosol therapy. However, total lung deposition and the ratio of lung deposition to oropharyngeal deposition are key determinants of clinical efficacy and of systemic side effects of aerosolized drugs.

OBJECTIVES

The aim of this study was to determine lung deposition and ratio of lung deposition to oropharyngeal deposition using a modified vibrating membrane nebuliser to deliver budesonide with a small particle size, taking into account the needs of young children.

PATIENTS AND METHODS

Ten asthmatic children (5 males), mean age 20.3 months (range 6-41 months) inhaled radiolabelled budesonide (MMD 2.6microm) through a modified vibrating membrane nebuliser (modified PARI e-Flow). Lung deposition expressed as a percentage of the emitted dose was measured using scintigraphy and the ratio of lung deposition to oropharyngeal deposition was calculated.

RESULTS

Mean lung deposition (SD) expressed as percentage of emitted dose and mean lung to oropharyngeal deposition ratio (SD) in quietly breathing children (n=5) and in children crying during inhalation were 48.6% (10.5) versus 20.0% (10.9), and 1.0 (0.3) versus 0.3 (0.2), respectively.

CONCLUSIONS

We have shown that by using an improved age-adjusted complementary combination of delivery device and drug formulation to deliver small particles, lung deposition and ratio of lung deposition to oropharyngeal deposition in young asthmatic children is highly improved. But the main factor limiting aerosol delivery in this age group remains cooperation.

Targeting drugs to the airways: The role of spacer devices

AIM

Spacer devices are inhalation aids of varying dimension and complexity, specifically designed to overcome problems with the use of pressurised metered dose inhalers (pMDIs). The aim of this review is to examine the current understanding about these inhalation devices and discuss their advantages and disadvantages.

METHODS

The pertinent literature concerning the characteristics and effects of spacers on delivery and lung deposition of inhaled medications, as well as their clinical efficacy in patients with reversible airway obstruction, is examined.

RESULTS

Spacers minimise problems of poor inhalation technique with pMDI, reduce oropharyngeal deposition and increase lung deposition. Spacers improve the clinical effect of inhaled medications, especially in patients unable to use a pMDI properly. Compared to both pMDIs and dry-powder inhalers, spacers may increase the response to beta-adrenergic bronchodilators, even in patients with correct inhalation technique. A pMDI plus spacer has proven to be viable lower cost alternative to the use of a nebuliser for delivering large bronchodilator doses in patients with severe acute asthma or chronic obstructive pulmonary disease. The use of large-volume spacers is recommended for delivering high doses of inhaled corticosteroids, and may permit a lower maintenance dose to be used.

CONCLUSION

pMDIs may be routinely fitted with a spacer, especially in situations where correct pMDI use is unlikely.

Comparative in vitro evaluation of four corticosteroid metered dose inhalers: Consistency of delivered dose and particle size distribution

INTRODUCTION

Recent developments concerning pressurized metered dose inhalers (pMDIs) with inhaled corticosteroids (ICS) are the introduction of ciclesonide and the replacement of propellants. As the results of in vivo studies depend on pMDIperformance, it is necessary to evaluate pMDIs in vitro for delivered dose and particle size distributions under different conditions.

METHODS

Fluticasone 125microg, budesonide 200microg, beclomethasone HFA100microg, and ciclesonide 160microg were compared for delivered dose and particle size using laser diffraction analysis with inspiratory flow rates of 10, 20 and 30l/s.

RESULTS

The volume median diameter of budesonide was 3.5microm, fluticasone 2.8microm, beclomethasone and ciclesonide both 1.9microm. The mouthpiece retention was up to 30% of the nominal dose for beclomethasone and ciclesonide, 11-19% for the other pMDIs. Lifespan, flow rate, and air humidity had no significant influence on particle size distribution. The delivered dose of beclomethasone, budesonide, and ciclesonide remained constant over the lifespan. The delivered dose of fluticasone 125 decreased from 106% to 63%; fluticasone 250 also decreased whereas fluticasone 50 remained constant.

CONCLUSIONS

There is a significant difference in median particle size distribution between the different ICS pMDIs. Air humidity and inspiratory flow rate have no significant influence on particle size distribution. Ciclesonide 160 and beclomethasone 100 deliver the largest fine particle fractions of 1.1-3.1microm. The changes in delivered dose during the lifespan for the fluticasone 125 and 250 may have implications for patient care.

Comparison of the anti-inflammatory effects of extra-fine hydrofluoroalkane-beclomethasone vs fluticasone dry powder inhaler on exhaled inflammatory markers in childhood asthma

BACKGROUND

Extra-fine hydrofluoroalkane-beclomethasone differs from other inhaled corticosteroids by its fine aerosol characteristics. Therefore, extra-fine hydrofluoroalkane-beclomethasone may be particularly useful for treating peripheral airway inflammation in asthma.

OBJECTIVE

To analyze the anti-inflammatory effects of extra-fine hydrofluoroalkane-beclomethasone vs fluticasone dry powder inhaler (DPI) in asthmatic children by measuring bronchial and alveolar nitric oxide (NO) and inflammatory markers in exhaled breath condensate (EBC).

METHODS

In a 6-month crossover study, 33 children aged 6 to 12 years with moderate persistent asthma were randomly treated with extra-fine hydrofluoroalkane-beclomethasone (200 microg daily via an Autohaler) and fluticasone DPI (200 microg daily via a Diskus). The primary outcome variables were alveolar NO concentration and bronchial NO flux. The secondary outcome variables were levels of inflammatory markers in EBC, lung function indices, symptoms, exacerbations, and adverse effects. All the variables were recorded at baseline and after each treatment period.

RESULTS

Mean +/- SE alveolar NO concentration and bronchial NO flux were comparable after treatment with hydrofluoroalkane-beclomethasone vs fluticasone DPI (4.7 +/- 0.5 vs 4.3 +/- 0.5 ppb, P = .55, and 1,124.3 +/- 253.6 vs 1,029.1 +/- 195.5 pL/s, P = .70, respectively). In addition, levels of inflammatory markers in EBC, lung function indices, and symptoms did not differ between treatments. Patients used fewer beta2-agonists during the last 2 weeks of hydrofluoroalkane-beclomethasone treatment.

CONCLUSION

The anti-inflammatory effects of hydrofluoroalkane-beclomethasone are similar to those of fluticasone DPI in children with moderate persistent asthma.