Pharmacokinetics of Oral and Intravenous Oseltamivir Treatment of Severe Influenza B Virus Infection Requiring Organ Replacement Therapy

Successful Treatment of Complicated Influenza A(H3N2) Virus Infection and Rhabdomyolysis with Compassionate Use of IV Zanamivir

In 2019, EMA licensed intravenous (IV) zanamivir for severe influenza virus infection in children over 6 months as well as adults. Prior to that, it was possible via a compassionate use program. We present successful compassionate use of IV zanamivir in a 14-year-old female with severe influenza A(H3N2) and multi-organ failure, who had failed oral oseltamivir. Her illness was complicated by acute respiratory distress syndrome and rhabdomyolysis requiring extracorporeal membrane oxygenation and hemofiltration. Considering the broad safety margins with neuraminidase inhibitors, an adult dose of 600 mg IV BID was administered in this 60 kg patient. Influenza virus was cleared rapidly and undetectable on day 13. Creatine kinase (CK) values were dropping from 38,000 to 500 within nine days. Given the recent licensure of IV zanamivir, multi-center prospective observational studies in pediatric Intensive Care Unit patients would be beneficial to guide the most appropriate use of IV zanamivir in this vulnerable age group.

Incidence, Disease Severity, and Follow-Up of Influenza A/A, A/B, and B/B Virus Dual Infections in Children: A Hospital-Based Digital Surveillance Program

Influenza virus (IV) coinfection, i.e., simultaneous infection with IV and other viruses, is a common occurrence in humans. However, little is known about the incidence and clinical impact of coinfection with two different IV subtypes or lineages (“dual infections”). We report the incidence, standardized disease severity, and follow-up of IV dual infections from a hospital-based digital surveillance cohort, comprising 6073 pediatric patients fulfilling pre-defined criteria of influenza-like illness in Berlin, Germany. All patients were tested for IV A/B by PCR, including subtypes/lineages. We assessed all patients at the bedside using the mobile ViVI ScoreApp, providing a validated disease severity score in real-time. IV-positive patients underwent follow-up assessments until resolution of symptoms. Overall, IV dual infections were rare (4/6073 cases; 0.07%, incidence 12/100,000 per year) but showed unusual and/or prolonged clinical presentations with slightly above-average disease severity. We observed viral rebound, serial infection, and B/Yamagata-B/Victoria dual infection. Digital tools, used for instant clinical assessments at the bedside, combined with baseline/follow-up virologic investigation, help identify coinfections in cases of prolonged and/or complicated course of illness. Infection with one IV does not necessarily prevent consecutive or simultaneous (co-/dual) infection, highlighting the importance of multivalent influenza vaccination and enhanced digital clinical and virological surveillance.

Pharmacokinetics of Commonly Used Medications in Children Receiving Continuous Renal Replacement Therapy: A Systematic Review of Current Literature

BACKGROUND AND OBJECTIVE

The use of continuous renal replacement therapy (CRRT) for renal support has increased substantially in critically ill children compared with intermittent modalities owing to its preferential effects on hemodynamic stability. With the expanding role of CRRT, the quantification of extracorporeal clearance and the effect on primary pharmacokinetic parameters is of the utmost importance. Within this review, we aimed to summarize the current state of the literature and compare published pharmacokinetic analyses of commonly used medications in children receiving CRRT to those who are not.

METHODS

A systematic search of the literature within electronic databases PubMed, EMBASE, Cochrane Library, and Web of Science was conducted. Published studies that were included contained relevant information on the use of commonly administered medications to children, from neonates to adolescents, receiving CRRT. Pharmacokinetic parameters that were analyzed included volume of distribution, total clearance, extracorporeal clearance, area under the curve, and elimination half-life. Information regarding CRRT circuit, flow rates, and membrane components was analyzed to investigate differences in pharmacokinetics between each modality.

RESULTS

Forty-five studies met the final inclusion criteria within this systematic review, totaling 833 pediatric patients, with 586 receiving CRRT. Antimicrobials were the most common pharmacological class represented within the literature, representing 81% (35/43) of studies analyzed. Children receiving CRRT largely had similar volume of distribution and total clearance to critically ill children not receiving CRRT, suggesting reno-protective dose adjustments may lead to subtherapeutic dosing regimens in these patients. Overall, there was a tendency for hydrophilic agents, with a low protein binding to undergo elevated total clearance in these children. However, results should be interpreted with caution because of the large variability amongst patient populations and heterogeneity with CRRT modalities, flow rates, and use of extracorporeal membrane oxygenation within studies. This review was able to identify that variation in solute removal, or CRRT modalities, properties (i.e., flow rates), and membrane composition, may have differing effects on the pharmacokinetics of commonly administered medications.

CONCLUSIONS

The current state of the literature regarding medications administered to children receiving CRRT largely focuses on antimicrobials. Significant gaps remain with other commonly used medications such as sedatives and analgesics. Overall reporting of patient clinical characteristics, CRRT settings, and circuit composition was poor, with only 10% of articles including all relevant information to assess the impact of CRRT on total clearance. Changes in pharmacokinetics because of CRRT often required higher than labeled doses, suggesting renally adjusted or reno-protective doses may lead to subtherapeutic dosing regimens. A thorough understanding of the interplay between patient, drug, and CRRT-circuit factors are required to ensure adequate delivery of dosing regimens to this vulnerable population.

Advancing challenges in Paediatric Virology: An interview with Professor Barbara A. Rath, Co-founder and Chair of the Vienna Vaccine Safety Initiative

The Vienna Vaccine Safety Initiative (ViVI) is an international, scientific, non-profit, research organization, which aims to promote research, clinical practice and communication on Paediatric Infectious Diseases (PID) in a globalized healthcare setting, to facilitate the implementation of high standards in vaccine safety and efficacy and to support international and interdisciplinary scientific collaboration. Professor Barbara A. Rath, Chair and Co-founder of the Vienna Vaccine Safety Initiative, advocates for the establishment of global research networks in the field of neonatal and paediatric viral infections. Viruses do not respect borders, and large datasets are required and joint action is necessary to further strengthen efforts towards viral diseases eradication and prevention. She encourages the paediatric community to embrace the new opportunities technology offers for healthcare and medical education. To date, the Vienna Vaccine Safety Initiative has developed a number of innovative mobile applications and diagnostic tools, such as the ‘VAccApp’, which helps parents understand which vaccines were administered to their children, the ‘ViVI Disease Severity Score’, which measures clinical severity in patients with acute respiratory infections and flu-like illnesses, the ‘VACC Tool’, which assesses patient's clinical presentation to a set of diagnostic algorithms for adverse events following immunization and the ‘ViVI Health Survey’, which enables children and young adults on the move to report health needs securely and confidentially. Professor Rath agrees that during this decade there is momentum in the field of Paediatric Virology, as new antivirals and vaccines emerge and are finally becoming available to children. In the future, ‘in-house’ specialists for Paediatric Virology could be helpful to provide quality of care and reduce antimicrobial resistance by providing individual as well as hospital-wide consultations and advice. She estimates that Paediatric Virology will eventually find its place in the context of PID and Vaccinology.

Partnering for enhanced digital surveillance of influenza-like disease and the effect of antivirals and vaccines (PEDSIDEA)

BACKGROUND

Standardised clinical outcome measures are urgently needed for the surveillance of influenza and influenza-like illness (ILI) based on individual patient data (IPD).

OBJECTIVES

We report a multicentre prospective cohort using a predefined disease severity score in routine care.

PATIENTS/METHODS

The Vienna Vaccine Safety initiative (ViVI) Disease Severity Score ("ViVI Score") was made available as an android-based mobile application to three paediatric hospitals in Berlin and Athens between 2013 and 2016. Healthcare professionals assessed ILI patients at the point of care including severity, risk factors and use of antibiotics/antivirals/vaccines. RT-PCR for influenza A/B viruses was performed at the Hellenic Pasteur Institute and the Robert Koch Institute. PCR testing was blinded to severity scoring and vice versa.

RESULTS

A total of 1615 children aged 0-5 years (54.4% males) were assessed at the three sites. The mean age was 1.7 years (SD 1.5; range 0-5.9). The success rate (completion of the scoring without disruption to the ER workflow) was 100%. ViVI Disease Severity Scores ranged from 0 to 35 (mean 13.72). Disease severity in the Berlin Cohort was slightly higher (mean 15.26) compared to the Athens Cohorts (mean 10.86 and 11.13). The administration of antibiotics was most prevalent in the Berlin Cohort, with 41.2% on antibiotics (predominantly cefuroxime) as opposed to only 0.5% on neuraminidase inhibitors. Overall, Risk-adjusted ViVI Scores were significantly linked to the prescription of both, antibiotics and antivirals.

CONCLUSIONS

The Risk-adjusted ViVI Score enables a precision medicine approach to managing ILI in multicentre settings. Using mobile applications, severity data will be obtained in real time with important implications for the evaluation of antiviral/vaccine use.

In-vitro adsorption and sieving coefficient of ticarcillin-clavulanate during continuous haemofiltration

There are very limited data on ticarcillin-clavulanate elimination by haemofiltration. We measured in vitro ticarcillin-clavulanate adsorption to polyacrylonitrile (PAN) filters and the sieving coefficient using a well-described bench model of haemofiltration. The dose of ticarcillin-clavulanate was 60/2 mg or 180/3 mg, and 0 or 12 g albumin was added to the 1 L of circulating blood-crystalloid mixture to produce four different experimental conditions. The experiment was repeated four times under each condition. Median (interquartile range [IQR] ) ticarcillin adsorption varied from 28 (27-30) mg to 85 (78-90) mg. Adsorption was increased when the dose of ticarcillin was higher (P<0.001), but was not affected by the addition of albumin. Median (IQR) adsorption of clavulanate ranged from 0.67 (0.55-0.75) mg to 1.8 (0.33-3.5) mg and was neither dose dependent (P = 0.505) nor significantly affected by the addition of albumin. Median (IQR) ticarcillin sieving coefficient ranged from 0.73 (0.67-0.75) to 0.99 (0.97-1.03). It was significantly higher with a higher dose of ticarcillin (P = 0.021) and without addition of albumin (P = 0.015). Median (IQR) clavulanate sieving coefficient ranged from 1.03 (1.00-2.24) to 2.0 (1.98-2.47). Clavulanate sieving coefficient was not significantly affected by dose or the addition of albumin. These data indicate that significant adsorption of both ticarcillin and clavulanate occurs in vitro; however, this requires confirmation by clinical pharmacokinetic studies. The sieving coefficient data may help guide appropriate dosing of critically ill patients receiving haemofiltration until more extensive clinical pharmacokinetic data are available.

Influenza and other respiratory viruses: standardizing disease severity in surveillance and clinical trials

INTRODUCTION

Influenza-Like Illness is a leading cause of hospitalization in children. Disease burden due to influenza and other respiratory viral infections is reported on a population level, but clinical scores measuring individual changes in disease severity are urgently needed. Areas covered: We present a composite clinical score allowing individual patient data analyses of disease severity based on systematic literature review and WHO-criteria for uncomplicated and complicated disease. The 22-item ViVI Disease Severity Score showed a normal distribution in a pediatric cohort of 6073 children aged 0-18 years (mean age 3.13; S.D. 3.89; range: 0 to 18.79). Expert commentary: The ViVI Score was correlated with risk of antibiotic use as well as need for hospitalization and intensive care. The ViVI Score was used to track children with influenza, respiratory syncytial virus, human metapneumovirus, human rhinovirus, and adenovirus infections and is fully compliant with regulatory data standards. The ViVI Disease Severity Score mobile application allows physicians to measure disease severity at the point-of care thereby taking clinical trials to the next level.

Post-influenza aspergillosis, do not underestimate influenza B

Our objective is to highlight and focus on post-influenza aspergillosis, triggered by influenza B virus. This relatively new clinical entity is often associated with a fulminant course of respiratory decline and high mortality. A 51-year immunocompetent woman, without any medical history or risk factors for developing a complicated influenza infection, was admitted to the intensive care unit. During admission, she presented with an afebrile flu-like syndrome, myocarditis, rhabdomyolysis, multiple organ failure, and evolved to severe respiratory distress. The broncho-alveolar lavage contained influenza B RNA, and the culture revealed Aspergillus fumigatus. Despite maximal organ support, immunoglobulin, antiviral and antifungal therapy, the patient died. This case demonstrates that influenza B virus may be life threatening even to immunocompetent adults and may trigger an invasive Aspergillus superinfection.

The pharmacological management of severe influenza infection - 'existing and emerging therapies'

INTRODUCTION

Over the last century several influenza outbreaks have traversed the globe, most recently the influenza A(H1N1) 2009 pandemic. On each occasion, a highly contagious, virulent pathogen has emerged, leading to significant morbidity and mortality amongst those affected. Areas covered: Early antiviral therapy and supportive care is the mainstay of treatment. Treatment should be started as soon as possible and not delayed for the results of diagnostic testing. Whilst oseltamivir is still the first choice, in case of treatment failure, oseltamivir resistance should be considered, particularly in immunosuppressed patients. Here we review the antivirals currently used for management of influenza and explore a number of investigational agents that may emerge as effective antivirals including parenteral agents, combination antiviral therapy and novel agents in order to adequately target influenza virulence. Expert Commentary: New tools for rapid diagnosis and susceptible strains will help if a patient is not improving because of a resistant strain or an inadequate immune response. Further randomized control trials will be conducted to investigate the use of new antivirals and co-adjuvant therapies that will help to elucidate the process of immune modulation, particularly in immunocompetent patients.