Therapeutic drug monitoring-guided dosing for pediatric cystic fibrosis patients: recent advances and future outlooks.

INTRODUCTION: Medicine use in children with cystic fibrosis (CF) is complicated by inconsistent pharmacokinetics at variance with the general population, a lack of research into this and its effects on clinical outcomes. In the absence of established dose regimens, therapeutic drug monitoring (TDM) is a clinically relevant tool to optimize drug exposure and maximize therapeutic effect by the bedside. In clinical practice though, use of this is variable and limited by a lack of expert recommendations. AREAS COVERED: We aimed to review the use of TDM in children with CF to summarize recent developments, current recommendations, and opportunities for future directions. We searched PubMed for relevant publications using the broad search terms "cystic fibrosis" in combination with the specific terms "therapeutic drug monitoring (TDM)" and "children." Further searches were undertaken using the name of identified drugs combined with the term "TDM." EXPERT OPINION: Further research into the use of Bayesian forecasting and the relationship between exposure and response is required to personalize dosing, with the opportunity for the development of expert recommendations in children with CF. Use of noninvasive methods of TDM has the potential to improve accessibility to TDM in this cohort.

Patient and family perceptions of the provision of medicines as part of virtual outpatient consultations for children during COVID-19 pandemic.

OBJECTIVES: To evaluate (1) views and perceptions of patients/parents/carers and healthcare professionals on the medicines optimisation (MO) process following virtual outpatient clinic (VOC) during the COVID-19 pandemic and (2) the processes introduced at this time, identifying areas for improvements and suggest potential solutions. DESIGN: A mixed-methods service evaluation using qualitative and quantitative methods of the MO pathway in children aged 0-18 years following VOC across three specialist children's units.Semi-structured interviews were conducted over the telephone with the participants exploring their experiences and categorised into themes.Process mapping sessions with the multidisciplinary team identified areas for improvement and an ease impact framework developed for potential solutions.Outcome measures included: (1) themes from interviews, (2) patients satisfaction rates, (3) process maps and (4) development of a simplified future process. RESULTS: One hundred and twenty-five patients' families were contacted: 71 families consented to participate and their views were categorised into four main themes: (1) patient experience, (2) communication, (3) need for virtual video consultations for patient education by hospital pharmacists and (4) need for electronic processes to send prescriptions to local pharmacies.Median patient satisfaction rate was 96% (range 67%-100%). The convenience of receiving medications directly to patient's homes; access to medicines information helplines and education provided by pharmacists were regarded as valuable. Communication between care providers, development of virtual video consultations by hospital pharmacists and electronic transfer of some prescriptions directly to community pharmacies were identified as areas of improvement. CONCLUSIONS: Participants appreciated the pharmacy processes adopted during the pandemic, however, challenges and recommendations for improvement in delivering MO VOC were identified. As digital innovations evolve within the NHS, future research should focus on integrated care and improved communication between care providers with selected medications prescribed directly to community pharmacies using electronic prescription service, with clinical screening and education provided by hospital pharmacists.

Going the Extra Mile: Why Clinical Research in Cystic Fibrosis Must Include Children.

This is an exciting time for research and novel drug development in cystic fibrosis. However, rarely has the adage, "Children are not just little adults" been more relevant. This article is divided into two main sections. In the first, we explore why it is important to involve children in research. We discuss the potential benefits of understanding a disease and its treatment in children, and we highlight that children have the same legal and ethical right to evidence-based therapy as adults. Additionally, we discuss why extrapolation from adults may be inappropriate, for example, medication pharmacokinetics may be different in children, and there may be unpredictable adverse effects. In the second part, we discuss how to involve children and their families in research. We outline the importance and the complexities of selecting appropriate outcome measures, and we discuss the role co-design may have in improving the involvement of children. We highlight the importance of appropriate staffing and resourcing, and we outline some of the common challenges and possible solutions, including practical tips on obtaining consent/assent in children and adolescents. We conclude that it is unethical to simply rely on extrapolation from adult studies because research in young children is challenging and that research should be seen as a normal part of the paediatric therapeutic journey.

An Update on CFTR Modulators as New Therapies for Cystic Fibrosis.

Over the past decade there have been significant developments in the field of Cystic Fibrosis Transmembrane Regulator modulator drugs. Following treatment in patients with cystic fibrosis with common gating mutations using the potentiator drug ivacaftor, successive development of corrector drugs used in combination has led to highly effective modulator therapy being available to more than 85% of the cystic fibrosis population over 12 years of age in the form of elexacaftor/tezacaftor/ivacaftor. In this article, we review the evidence from clinical trials and mounting real-world observational and registry data that demonstrates the impact highly effective modulators have on both pulmonary and extra-pulmonary manifestations of cystic fibrosis. As clinical trials progress to younger patient groups, we discuss the challenges to demonstrating drug efficacy in early life, and also consider practicalities of drug development in an ever-shrinking modulator-naïve population. Drug-drug interactions are an important consideration in people with cystic fibrosis, where polypharmacy is commonplace, but also as the modulated population look to remain healthier for longer, we identify trials that aim to address treatment burden too. Inequity of care, through drug cost or ineligibility for modulators by genotype, is widening without apparent strategies to address this; however, we present evidence of hopeful early-stage drug development for non-modulatable genes and summarise the current state of gene-therapy development.

Clinical pharmacokinetics and dose recommendations for posaconazole gastroresistant tablets in children with cystic fibrosis.

OBJECTIVES: To investigate the population pharmacokinetics of posaconazole gastroresistant tablets in children with cystic fibrosis (CF) and perform simulations to recommend optimal doses. PATIENTS AND METHODS: Children from a paediatric CF centre who had received posaconazole tablets and underwent therapeutic drug monitoring were identified from pharmacy records. Relevant clinical data were collated from case notes and electronic patient records and used to develop an allometrically scaled population pharmacokinetic model. A stepwise covariate model-building exercise evaluated the influence of interacting medicines and liver function. RESULTS: One hundred posaconazole serum concentrations were collected from 37 children with a median age of 14 years (range 7-17). Posaconazole pharmacokinetics were adequately described by a one-compartment model with inter-individual variability on clearance. Dose simulations demonstrated a 77%-83% probability of attaining a trough target of 1 mg/L with a dose of 300 mg every 12 h for two doses then 300 mg once daily (OD) in children aged 6-11 years; and 86%-88% with a dose of 400 mg every 12 h for two doses then 400 mg OD in adolescents aged 12-17 years. This dose scheme also yielded a 90% probability of achieving an AUC of 30 mg·h/L. AUC and trough concentration were highly correlated (r2 = 0.98). Simulations showed that trough concentrations of >0.75 mg/L would exceed an AUC of 30 mg·h/L in 90% of patients. CONCLUSIONS: A starting dose of 300 mg OD in those aged 6-11 years and 400 mg OD in those aged 12-17 years (following loading doses) yields a 90% probability of attaining an AUC of 30 mg·h/L.

Initiating Self-Administration of Medicines for inpatients with cystic fibrosis.

INTRODUCTION: Children with cystic fibrosis (CF) take a multitude of therapies at home. Self-Administration of Medicines (SAM) is a scheme whereby the parent/carer and/or older child keep control of their own medicines in hospital. We initiated a scheme and assessed drug errors, cost implications, and parent and nurse satisfaction. METHODS: Following a pilot stage, the SAM protocol was initiated and amended as necessary. Drug errors were analysed from the Datix hospital electronic reporting system. Cost analysis of use of the patents own drugs was carried out. Questionnaires were given to parents and nursing staff. RESULTS: In the initial 10 months, 97 children had 159 admissions, and 60% were deemed suitable for SAM. Drug errors still occurred-33 in 5 years. Cost savings for the hospital over 1 year were £20 022 for 123 admissions. Patient/parent satisfaction was high, and all wished to partake in SAM for further admissions. CONCLUSIONS: The scheme was a success although it took 3 years to bring to fruition. Drug errors still occurred but we were able to amend the protocol appropriately to react to these. Cost savings are an incidental benefit from use of patient's own medication. The SAM scheme is applicable to all children with chronic disease on long term medications when they are in hospital.

Combination antifungal therapy for Scedosporium species in cystic fibrosis.

OBJECTIVE: To evaluate safety and efficacy of oral posaconazole and terbinafine for Lomentospora prolificans and Scedosporium apiospermum in children with cystic fibrosis. METHODS: Retrospective case review. RESULTS: There were five children (four girls), median age 15.0 years; three had S. apiospermum and two had L. prolificans. Treatment duration: median 5 months (range: 5-18 m). In no patient was eradication achieved, with the follow-up range being 6 months to 4 years. Effect on lung function was variable but encouraging. No adverse effects were reported, one child had transient elevation of liver enzymes. CONCLUSIONS: While the combination therapy was well tolerated, it was unsuccessful at eradication.

SELF-ADMINISTRATION OF IN-PATIENT MEDICATIONS: A PILOT STUDY IN CHILDREN WITH CYSTIC FIBROSIS.

INTRODUCTION: Children with Cystic Fibrosis (CF) have complex medication regimens, where responsibility for administration usually lies with the parent/carer until the child is older and able to take over this role.1 On admission to hospital this role is usually undertaken by nurses, leaving patients/parents/carers feeling disempowered, and unprepared for discharge. AIMS: All CF admissions to be offered the Self-Administration Of Medicines Scheme (SAM).▸ Empower patients/parents/carers with responsibility of administering their own medications▸ Reduce nursing time▸ Educate patients/parents/carers about their medications▸ Cost-saving by utilising Patients Own Medicines (PODs). METHOD: A policy and training programme was developed and approved by the Trust's Medicines Management Board. This provided a framework for staff to use so that they may:▸ Obtain consent▸ Evaluate and re-use PODs▸ Safely store and obtain supplies▸ Continuously negotiate accountability for administration with patient/parent/carer.The study was conducted over a 10 month period, where all families with CF admitted, were assessed for participation in SAM. The nursing teams acted as the primary assessors for SAM and any concerns were referred to the paediatric CF multidisciplinary team. To evaluate the pilot, families were given questionnaires to establish their views about the scheme. Nurses were asked to feedback if SAM decreased time for medication administration. To evaluate the associated cost-saving, data on PODs suitable for re-use was collected. RESULTS: 159 children with CF were admitted to the ward, 95 (60%) were assessed to participate in the scheme and 64 (40%) of these did not join. Reasons for not joining included 32 (50%) short admissions, 13 (20%) refused, 5 (8%) patients were seriously ill and 14 (22%) had 'other' reasons. Those who joined the scheme received questionnaires and 31 (33%) of these were completed. All welcomed the scheme and stated that they would take part again with the main benefits cited as not needing to wait for nurses to administer medications, greater independence and the ability to maintain the same routine as home. When asked what participants would change, 16 (52%) stated nothing, 10 (32%) wanted the assessment process to allow for faster progression through the levels of SAM, 4 (13%) asked for larger medication lockers and 1 (3%) wanted better communication about new medications. 30 nursing questionnaires were completed and highlighted that nursing staff spent less time on administering medicines. Nurses also stated that medication administration was less pressurised as double-checking of doses could be performed with the participant, rather than another nurse. Their main concern was the extra documentation required for SAM. Where PODs were used for patients, the average cost saving per patient over a 3 month period was £1023. CONCLUSION: The pilot scheme has been well received by staff and patients/parents/carers, allowing greater engagement in the administration of medicines and cost-savings. As a result of this, the SAM scheme will be extended to the remaining patients on the ward.

Oral Enoximone as an Alternative to Protracted Intravenous Medication in Severe Pediatric Myocardial Failure.

Phosphodiesterase 3 inhibitors have been used successfully in pediatric patients with acute or chronic myocardial dysfunction over the last two decades. Their protracted continuous intravenous administration is associated with risk of infectious and thromboembolic complications. Weaning intravenous medication and starting oral angiotensin-converting enzyme (ACE) inhibitors and/or beta-blockers can be challenging. We reviewed retrospectively hospital records of 48 patients receiving oral enoximone treatment in a single tertiary pediatric cardiac center between November 2005 and April 2014. Failure to wean from intravenous milrinone infusion and/or intolerance of ACE inhibitors and/or beta-blockers was indications for oral enoximone treatment. Age of the patients ranged between 0.5 and 191 months (median 7.5 months) at the time of starting enoximone treatment. There were 14 patients (29 %) with left ventricular dysfunction due to myocarditis or dilated cardiomyopathy and 34 patients (71 %) with myocardial dysfunction complicating congenital heart disease. Fifteen (44 %) of these 34 patients had left ventricular dysfunction, 13 (38 %) right ventricular dysfunction, and in 6 (18 %) both ventricles were failing. Duration of oral enoximone treatment was between 3 days and 34 months (median of 2.3 months). Myocardial functional recovery allowed for weaning of enoximone treatment in 15 patients (31 %) after 6 days-15 months (median 5 months). No adverse hemodynamic effects were noted. Blood stained gastric aspirates encountered in two patients resolved with concomitant milk administration. Based on our limited experience, oral enoximone is a well-tolerated and promising alternative to intravenous medication and/or other commonly used oral medications in selected pediatric patients with chronic heart failure.

Risk-benefit considerations when prescribing phosphodiesterase-5 inhibitors in children.

INTRODUCTION: Sildenafil (Revatio®) and tadalafil (Adcirca®) are specific inhibitors of the phosphodiesterase-5 enzyme and produce pulmonary vasodilation by inhibiting the breakdown of cyclic guanosine monophosphate (cGMP) in the walls of pulmonary arterioles. AREAS COVERED: We focus on the efficacy and safety of sildenafil and tadalafil in the treatment of pulmonary hypertension (PH) in children through a PubMed literature search. EXPERT OPINION: Although used since 1999 in the treatment of PH in children, it is only in the past few years that robust evidence for the use of sildenafil has emerged principally in the pivotal STARTS-1 study. The open-label extension of this study, STARTS-2, has revealed safety concerns substantiated by FDA post marketing surveillance leading to recommendations to use lower doses. More recently, tadalafil has been introduced allowing once daily dosing with apparently similar efficacy to sildenafil in children. Recently there have been suggestions that sildenafil and tadalafil may have a place in treating muscular dystrophy.