A randomised controlled trial of breathing modes for adaptive aerosol delivery in children with cystic fibrosis

The effects of airway disease on the deposition of inhaled drugs

INTRODUCTION

The deposition of inhaled medications is the first step in the pulmonary pharmacokinetic process to produce a therapeutic response. Not only lung dose but more importantly the distribution of deposited drug in the different regions of the lung determines local bioavailability, efficacy, and clinical safety. Assessing aerosol deposition patterns has been the focus of intense research that combines the fields of physics, radiology, physiology, and biology.

AREAS COVERED

The review covers the physics of aerosol transport in the lung, experimental, and in-silico modeling approaches to determine lung dose and aerosol deposition patterns, the effect of asthma, chronic obstructive pulmonary disease, and cystic fibrosis on aerosol deposition, and the clinical translation potential of determining aerosol deposition dose.

EXPERT OPINION

Recent advances in in-silico modeling and lung imaging have enabled the development of realistic subject-specific aerosol deposition models, albeit mainly in health. Accurate modeling of lung disease still requires additional refinements in existing imaging and modeling approaches to better characterize disease heterogeneity in peripheral airways. Nevertheless, recent patient-centric innovation in inhaler device engineering and the incorporation of digital technology have led to more consistent lung deposition and improved targeting of the distal airways, which better serve the clinical needs of patients.

Nebuliser systems for drug delivery in cystic fibrosis

BACKGROUND

Nebuliser systems are used to deliver medications to the lungs, to control the symptoms and the progression of lung disease in people with cystic fibrosis (CF). There are many different nebulised-medications prescribed for people with CF and there are many different types of nebuliser systems. Some of these nebulised medications are licenced for, and can be taken via only one type of nebuliser system; some are licensed for, and can be taken via more than one type of nebuliser system. This is an update to a previous systematic review.

OBJECTIVES

To assess the time efficiency, effectiveness, safety, cost and impact of use (e.g. burden of care, adherence, quality of life (QoL)) of different nebuliser systems, when used with different inhaled medications for people with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching of relevant journals and abstract books containing conference proceedings. We searched the reference lists of each study for additional publications and approached the manufacturers of both nebuliser systems and nebulised medications for published and unpublished data. We also searched online trial registries. Date of the most recent search: 9 August 2023.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing nebuliser systems, including conventional nebulisers, vibrating mesh technology (VMT) systems, adaptive aerosol delivery (AAD) systems and ultrasonic nebuliser systems.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion. They also independently extracted data and assessed the risk of bias. A third review author assessed studies where agreement could not be reached. They assessed the certainty of the evidence using GRADE.

MAIN RESULTS

The search identified 216 studies with 33 of these (2270 participants) included in the review. These studies compared the delivery of tobramycin, colistin, dornase alfa, hypertonic saline and other solutions through the different nebuliser systems in children and adults with CF. This review demonstrates variability in the delivery of medication depending on the nebuliser system used. The certainty of the evidence ranged from low to very low. Some conventional nebuliser systems providing higher flows, higher respirable fractions, and smaller particles decrease treatment time, increase deposition (the amount of drug reaching the lung), and may be preferred by people with CF, as compared to other conventional nebuliser systems providing lower flows, lower respirable fractions and larger particles. Newer nebuliser systems using AAD, or VMT (or both) reduce treatment time compared to conventional systems. Deposition (as a percentage of priming dose) with AAD is greater than with conventional systems. VMT systems may give greater deposition than conventional systems when measuring sputum levels. The available data indicate that these newer systems are safe when used with an appropriate priming dose, which may be different to the priming dose used for conventional systems. There is an indication that adherence is maintained or improved and that individuals prefer AAD or VMT systems, but also that some nebuliser systems using VMT may be subject to increased system failures. There is limited, unclear evidence on the impact of different nebuliser systems on lung function and a lack of data on the impact of different nebuliser systems on our outcomes of quality of life (QoL), adverse effects, respiratory exacerbations and related implications, adherence, satisfaction, cost and device reliability.

AUTHORS' CONCLUSIONS

Newer technologies e.g. AAD and VMT have advantages over conventional systems in terms of treatment time, deposition as a percentage of priming dose, preference and adherence. Data are lacking for all varieties of medications which are used in CF care, including different inhaled antibiotics or hypertonic saline, with all delivery (nebuliser system) possibilities. Long-term RCTs are needed to evaluate different nebuliser systems to determine patient-focused outcomes (such as QoL and burden of care), safe and effective dosing levels of a wide variety of medications, clinical outcomes (such as hospitalisations and need for antibiotics), and an economic evaluation of their use. There are insufficient data to establish whether one nebuliser system is better than another overall. Clinicians should be aware of the variability in the performance of different nebuliser systems, compatibility with specific nebulised medication, and they must work with their patients to choose the best nebuliser system for each individual. This is likely to be an ongoing process as the needs and circumstances of each individual change over time.

Digital technology for monitoring adherence to inhaled therapies in people with cystic fibrosis

BACKGROUND

Improved understanding and treatment of cystic fibrosis (CF) has led to longer life expectancy, which is accompanied by an increasingly complex regimen of treatments. Suboptimal adherence to the treatment plan, in the context of respiratory disease, has been found to be associated with poorer health outcomes. With digital technology being more accessible, it can be used to monitor adherence to inhaled therapies via chipped nebulisers, mobile phone apps and web-based platforms. This technology can allow monitoring of adherence as well as clinical outcomes, and allow feedback to both the person with CF and their healthcare team.

OBJECTIVES

To assess the effects of using digital technology to monitor adherence to inhaled therapies and health status in adults and children with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books.  Date of last search: 28 October 2021. We also searched Embase and three clinical trial registries and checked references of included studies. Date of last search: 9 November 2021.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) looking at the effects of a digital technology for monitoring adherence of children and adults with CF to inhaled therapies.

DATA COLLECTION AND ANALYSIS

Two review authors screened the search results for studies eligible for inclusion in the review and extracted their data. We used Risk of Bias 2 for assessing study quality. We assessed the overall certainty of the evidence using GRADE.

MAIN RESULTS

We included two studies in our review, with 628 participants aged five to 41 years. There was one study each for two different comparisons.  Nebuliser target inhalation mode versus standard inhalation mode The included parallel study was carried out over 10 weeks after a run-in period of four to six weeks. The study compared the effects of a digitally enhanced inhalation mode (target inhalation mode) for nebulised antibiotics compared to standard mode in children attending a regional CF clinic in the United Kingdom. The study's primary outcome was the time taken to complete the inhaled treatment, but investigators also reported on adherence to therapy. The results showed that there may be an improvement in adherence with the target inhalation mode when this intervention is used (mean difference (MD) 24.0%, 95% confidence interval (CI) 2.95 to 45.05; low-certainty evidence). The target inhalation mode may make little or no difference to forced expiratory volume in one second (FEV1) % predicted (MD 1.00 % predicted, 95% CI -9.37 to 11.37; low-certainty evidence). The study did not report on treatment burden, quality of life (QoL) or pulmonary exacerbations. eNebuliser with digital support versus eNebuliser without support One large multicentre RCT monitored adherence via data-tracking nebulisers. The intervention group also receiving access to an online web-based platform, CFHealthHub, which offered tailored, flexible support from the study interventionist as well as access to their adherence data, educational and problem-solving information throughout the 12-month trial period. We graded all evidence as moderate certainty. Compared to usual care, the digital intervention probably improves adherence to inhaled therapy (MD 18%, 95% CI 12.90 to 23.10); probably leads to slightly reduced treatment burden (MD 5.1, 95% CI 1.79 to 8.41); and may lead to slightly improved FEV1 % predicted (MD 3.70, 95% CI -0.23 to 7.63). There is probably little or no difference in the incidence of pulmonary exacerbations or QoL between the two groups.

AUTHORS' CONCLUSIONS

Digital monitoring plus tailored support via an online platform probably improves adherence to inhaled therapies and reduces treatment burden (but without a corresponding change in QoL) in the medium term (low- and moderate-certainty evidence). In a shorter time frame, technological enhancement of inhaling antibiotics may improve adherence to treatment (low-certainty evidence). There may be little or no effect on lung function with either intervention, and online monitoring probably makes no difference to pulmonary exacerbations.  Future research should assess the effect of digital technology on adherence in both children and adults. Consideration of adherence to the total treatment regimen is also important, as an improvement in adherence to inhaled therapies could come at the cost of adherence to other parts of the treatment regimen.

Pharmacokinetics and safety of tobramycin nebulization with the I-neb and PARI-LC Plus in children with cystic fibrosis: A randomized, crossover study

AIMS

We aimed to compare the pharmacokinetics (PK) and safety profile of tobramycin inhalation solution (TIS) using the I-neb device to the standard PARI-LC Plus nebulizer in children with cystic fibrosis.

METHODS

A randomized, open-label, crossover study was performed. In 2 separate study visits, blood samples from 22 children were collected following TIS nebulization with I-neb (75 mg) and PARI-LC Plus (300 mg). Study visits were separated by 1 month, in which 1 of the study nebulizers was used twice daily. Tobramycin PK for both nebulizers was established using measured tobramycin concentrations and Bayesian PK modelling software. Hearing and renal function tests were performed to test for aminoglycoside associated toxicity. In addition to standard estimated glomerular filtration rate values, biomarkers for tubular injury (KIM-1 and NAG) were measured. Patient and nebulizer satisfaction were assessed.

RESULTS

Inhalations were well tolerated and serum trough concentrations below the predefined toxic limit were reached with no significant differences in PK parameters between nebulizers. Results of audiometry and estimated glomerular filtration rate revealed no abnormalities. However, increased urinary NAG/creatinine ratios at visit 2 for both nebulizers suggest TIS-induced subclinical tubular kidney injury. Nebulization time was 50% shorter and patient satisfaction was significantly higher with the I-neb.

CONCLUSIONS

Nebulization of 75 mg TIS with the I-neb in children with cystic fibrosis resulted in comparable systemic exposure to 300 mg TIS with the PARI-LC Plus and was well tolerated and preferred over the PARI-LC Plus. Long-term safety of TIS nebulization should be monitored clinically, especially regarding the effects on tubular kidney injury.

Opportunities in respiratory drug delivery

A wide range of asthma and chronic obstructive pulmonary disease products are soon to be released onto the inhaled therapies market and differentiation between these devices will help them to gain market share over their competitors. Current legislation is directing healthcare towards being more efficient and cost-effective in order to continually provide quality care despite the challenges of aging populations and fewer resources. Devices and drugs that can be differentiated by producing improved patient outcomes would, therefore, be likely to win market share. In this perspective article, the current and potential opportunities for the successful delivery and differentiation of new inhaled drug products are discussed.

Advances in device and formulation technologies for pulmonary drug delivery

Inhaled pharmaceuticals are formulated and delivered differently according to the therapeutic indication. However, specific device-formulation coupling is often fickle, and new medications or indications also demand new strategies. The discontinuation of chlorofluorocarbon propellants has seen replacement of older metered dose inhalers with dry powder inhaler formulations. High-dose dry powder inhalers are increasingly seen as an alternative dosage form for nebulised medications. In other cases, new medications have completely bypassed conventional inhalers and been formulated for use with unique inhalers such as the Staccato® device. Among these different devices, integration of software and electronic assistance has become a shared trend. This review covers recent device and formulation advances that are forming the current landscape of inhaled therapeutics.

Breathing easier: addressing the challenges of aerosolizing medications to infants and preschoolers

An increasing number of patients are dependent on aerosolized therapy to manage pulmonary diseases, including asthma, cystic fibrosis, and pulmonary arterial hypertension. An aerosol therapy is only useful if it can be appropriately and consistently delivered in the desired dose to the lower respiratory tract. Many factors affect this deposition in young children, including anatomical and physiologic differences between adults and children, patient-mask interface issues, the challenge of administering medication to uncooperative children, and behavioral adherence. Moreover, the techniques used to assess aerosol delivery to pediatric patients need to be carefully evaluated as new therapies and drug-device combinations are tested. In this review, we will address some of the challenges of delivering aerosolized medications to pediatric patients.

Clinical experimentation with aerosol antibiotics: current and future methods of administration

Currently almost all antibiotics are administered by the intravenous route. Since several systems and situations require more efficient methods of administration, investigation and experimentation in drug design has produced local treatment modalities. Administration of antibiotics in aerosol form is one of the treatment methods of increasing interest. As the field of drug nanotechnology grows, new molecules have been produced and combined with aerosol production systems. In the current review, we discuss the efficiency of aerosol antibiotic studies along with aerosol production systems. The different parts of the aerosol antibiotic methodology are presented. Additionally, information regarding the drug molecules used is presented and future applications of this method are discussed.

New insights in the production of aerosol antibiotics. Evaluation of the optimal aerosol production system for ampicillin-sulbactam, meropenem, ceftazidime, cefepime and piperacillin-tazobactam

BACKGROUND

Several aerosol antibiotics are on the market and several others are currently being evaluated. Aim of the study was to evaluate the aerosol droplet size of five different antibiotics for future evaluation as an aerosol administration.

MATERIALS AND METHODS

The nebulizers Sunmist(®), Maxineb(®) and Invacare(®) were used in combination with four different "small <6 ml" residual cups and two "large <10 ml" with different loadings 2-4-6-8 ml (8 ml only for large residual cups) with five different antibiotic drugs (ampicilln-sulbactam, meropenem, ceftazidime, cefepime and piperacillin-tazobactam). The Mastersizer 2000 (Malvern) was used to evaluate the produced droplet size from each combination

RESULTS

Significant effect on the droplet size produced the different antibiotic (F=96.657, p<0.001) and the residual cup design (F=68.535, p<0.001) but not the different loading amount (p=0.127) and the nebulizer (p=0.715). Interactions effects were found significant only between antibiotic and residual cup (F=16.736, p<0.001). No second order interactions were found statistically significant.

CONCLUSION

Our results firstly indicate us indirectly that the chemical formulation of the drug is the main factor affecting the produced droplet size and secondly but closely the residual cup design.

Nebuliser systems for drug delivery in cystic fibrosis

BACKGROUND

Nebuliser systems are used to deliver medications to control the symptoms and the progression of lung disease in people with cystic fibrosis. Many types of nebuliser systems are available for use with various medications; however, there has been no previous systematic review which has evaluated these systems.

OBJECTIVES

To evaluate effectiveness, safety, burden of treatment and adherence to nebulised therapy using different nebuliser systems for people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching of relevant journals and abstract books of conference proceedings. We searched the reference lists of each study for additional publications and approached the manufacturers of both nebuliser systems and nebulised medications for published and unpublished data. Date of the most recent search: 15 Oct 2012.

SELECTION CRITERIA

Randomised controlled trials or quasi-randomised controlled trials comparing nebuliser systems including conventional nebulisers, vibrating mesh technology systems, adaptive aerosol delivery systems and ultrasonic nebuliser systems.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies for inclusion. They also independently extracted data and assessed the risk of bias. A third author assessed studies where agreement could not be reached.

MAIN RESULTS

The search identified 40 studies with 20 of these (1936 participants) included in the review. These studies compared the delivery of tobramycin, colistin, dornase alfa, hypertonic sodium chloride and other solutions through the different nebuliser systems. This review demonstrates variability in the delivery of medication depending on the nebuliser system used. Conventional nebuliser systems providing higher flows, higher respirable fractions and smaller particles decrease treatment time, increase deposition and may be preferred by people with CF, as compared to conventional nebuliser systems providing lower flows, lower respirable fractions and larger particles. Nebulisers using adaptive aerosol delivery or vibrating mesh technology reduce treatment time to a far greater extent. Deposition (as a percentage of priming dose) is greater than conventional with adaptive aerosol delivery. Vibrating mesh technology systems may give greater deposition than conventional when measuring sputum levels, but lower deposition when measuring serum levels or using gamma scintigraphy. The available data indicate that these newer systems are safe when used with an appropriate priming dose, which may be different to the priming dose used for conventional systems. There is an indication that adherence is maintained or improved with systems which use these newer technologies, but also that some nebuliser systems using vibrating mesh technology may be subject to increased failures.

AUTHORS' CONCLUSIONS

Clinicians should be aware of the variability in the performance of different nebuliser systems. Technologies such as adaptive aerosol delivery and vibrating mesh technology have advantages over conventional systems in terms of treatment time, deposition as a percentage of priming dose, patient preference and adherence. There is a need for long-term randomised controlled trials of these technologies to determine patient-focused outcomes (such as quality of life and burden of care), safe and effective dosing levels of medications and clinical outcomes (such as hospitalisations and need for antibiotics) and an economic evaluation of their use.

New nebulizer technology to monitor adherence and nebulizer performance in cystic fibrosis

Topical delivery of aerosolized therapies is an established treatment for chronic airway infection and inflammation in cystic fibrosis (CF). Recent developments in nebuliser technology have enabled Adaptive Aerosol Delivery (AAD) of mesh generated aerosol particles resulting in more efficient airway deposition than existing jet nebulizers. An additional feature of these new devices is the ability to record and examine the performance of the device by downloading stored data (electronic data capture). In a series of studies we have used this downloading facility to monitor treatment times and examine adherence to nebulizer therapy in our pediatric patients. We found routine adherence monitoring is possible in busy CF clinic. We have shown that good adherence to treatment can be maintained in both patients chronically infected with Pseudomonas aeruginosa on long-term therapy, and in patients with first/new growths of Pseudomonas on short-term eradication therapy. When adherence was examined from an individual perspective, we demonstrated a wide variation both between and within individual patients. A further modification of AAD technology, Target Inhalation Mode (TIM) optimises patient inhalations through a direct feedback mechanism. This new breathing mode has also been evaluated in our pediatric CF clinic in a recent randomized controlled trial (RCT) and we have shown that children maintain adherence to treatment through the TIM mouthpiece and average treatment times reduced from 6.9 to 3.7 min when using TIM. This is a new era of aerosol delivery and novel advances in medical devices need to be monitored and assessed rigorously, particularly as new and potentially expensive therapies emerge from translational studies. Electronic data capture enables CF teams to work in an open partnership with patients to achieve the common goals of improving drug delivery and reducing patient burden.

Technological and behavioral strategies to reduce treatment burden and improve adherence to inhaled antibiotics in cystic fibrosis

Aerosolized antibiotics are a common treatment option for patients with cystic fibrosis and chronic airway infection, as high doses can be delivered topically to the site of the infection while systemic exposure is minimized. Patients also use other aerosolized therapies (e.g. mucus-active agents, airway-wetting agents, and bronchodilators), adding significantly increase timed and complexity to their daily regimen, and often leading to lower adherence rates. A number of novel technological strategies are available that may reduce dose frequency and increase the speed of drug delivery. Psychologically based therapies may also be used to help modify behavior and thus improve adherence to treatment. Clinicians need to explore both technological and psychological strategies that will assist in the successful maintenance of treatment requirements.