Drugs pharmacokinetics during veno-venous extracorporeal membrane oxygenation in pediatrics

A physiologically-based pharmacokinetic modeling approach for dosing amiodarone in children on ECMO

Extracorporeal membrane oxygenation (ECMO) is a cardiopulmonary bypass device commonly used to treat cardiac arrest in children. The American Heart Association guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care recommend using amiodarone as a first-line agent to treat ventricular arrhythmias in children with cardiac arrest. However, there are no dosing recommendations for amiodarone to treat ventricular arrhythmias in pediatric patients on ECMO. Amiodarone has a high propensity for adsorption to the ECMO components due to its physicochemical properties leading to altered pharmacokinetics (PK) in ECMO patients. The change in amiodarone PK due to interaction with ECMO components may result in a difference in optimal dosing in patients on ECMO when compared with non-ECMO patients. To address this clinical knowledge gap, a physiologically-based pharmacokinetic model of amiodarone was developed in adults and scaled to children, followed by the addition of an ECMO compartment. The pediatric model included ontogeny functions of cytochrome P450 (CYP450) enzyme maturation across various age groups. The ECMO compartment was parameterized using the adsorption data of amiodarone obtained from ex vivo studies. Model predictions captured observed concentrations of amiodarone in pediatric patients with ECMO well with an average fold error between 0.5 and 2. Model simulations support an amiodarone intravenous (i.v) bolus dose of 22 mg/kg (neonates), 13 mg/kg (infants), 8 mg/kg (children), and 6 mg/kg (adolescents). This PBPK modeling approach can be applied to explore the dosing of other drugs used in children on ECMO.

Infectious diseases and infection control prevention strategies in adult and pediatric population on ECMO

As survival after ECMO improves and use of ECMO support increases in both pediatric and adult population, there is a need to focus on both the morbidities and complications associated with ECMO and how to manage and prevent them. Infectious complications during ECMO often have a significant clinical impact, resulting in increased morbidity or mortality irrespective of the underlying etiology necessitating cardiorespiratory support. In this review article, we discuss the prevention, management, challenges, and differences of infectious complications in adult and pediatric patients receiving ECMO support.

Population Pharmacokinetic Model of Linezolid and Probability of Target Attainment in Patients with COVID-19-Associated Acute Respiratory Distress Syndrome on Veno-Venous Extracorporeal Membrane Oxygenation-A Step toward Correct Dosing

During veno-venous extracorporeal membrane oxygenation (vv ECMO) therapy, antimicrobial drugs are frequently used, and appropriate dosing is challenging due to there being limited data to support the dosage. Linezolid is effective against multidrug-resistant Gram-positive pathogens frequently isolated in ECMO patients. In total, 53 steady-state linezolid levels were obtained following 600 mg intravenous (IV) injections every 8 h, and these were used to develop a population pharmacokinetic (PopPK) model in patients with COVID-19-associated acute respiratory distress syndrome (CARDS) on vv ECMO. The data were analyzed using a nonlinear mixed-effects modelling approach. Monte Carlo simulation generated 5000 patients' individual PK parameters and corresponding concentration-time profiles using the PopPK model, following the administration of 600 mg/8 h (a higher-than-standard dosing) and 600 mg/12 h (standard). The probabilities of pharmacokinetic/pharmacodynamic (PK/PD) target attainment (PTA) and the cumulative fraction of responses (CFR) for three pathogens were calculated and compared between the two dosing scenarios. Linezolid 600 mg/8 h was predicted to achieve greater than or equal to 85%Tf>MIC in at least 90% of the patients with CARDS on vv ECMO compared to only approximately two thirds of the patients after dosing every 12 h at a minimal inhibitory concentration (MIC) of 2 mg/L. In addition, for the same MIC, fAUC24/MIC ≥ 80 was achieved in almost three times the number of patients following an 8-h versus a 12-h interval. PopPK simulation predicted that a significantly higher proportion of the patients with CARDS on vv ECMO would achieve the PK/PD targets following the 8-h dosing interval compared to standard linezolid dosing. Nevertheless, the safety concern, in particular, for thrombocytopenia, with higher-than-standard linezolid dosage is reasonable, and consequently, monitoring is essential.

Current knowledge gaps in extracorporeal respiratory support

Extracorporeal life support (ECLS) for acute respiratory failure encompasses veno-venous extracorporeal membrane oxygenation (V-V ECMO) and extracorporeal carbon dioxide removal (ECCO2R). V-V ECMO is primarily used to treat severe acute respiratory distress syndrome (ARDS), characterized by life-threatening hypoxemia or ventilatory insufficiency with conventional protective settings. It employs an artificial lung with high blood flows, and allows improvement in gas exchange, correction of hypoxemia, and reduction of the workload on the native lung. On the other hand, ECCO2R focuses on carbon dioxide removal and ventilatory load reduction ("ultra-protective ventilation") in moderate ARDS, or in avoiding pump failure in acute exacerbated chronic obstructive pulmonary disease. Clinical indications for V-V ECLS are tailored to individual patients, as there are no absolute contraindications. However, determining the ideal timing for initiating extracorporeal respiratory support remains uncertain. Current ECLS equipment faces issues like size and durability. Innovations include intravascular lung assist devices (ILADs) and pumpless devices, though they come with their own challenges. Efficient gas exchange relies on modern oxygenators using hollow fiber designs, but research is exploring microfluidic technology to improve oxygenator size, thrombogenicity, and blood flow capacity. Coagulation management during V-V ECLS is crucial due to common bleeding and thrombosis complications; indeed, anticoagulation strategies and monitoring systems require improvement, while surface coatings and new materials show promise. Moreover, pharmacokinetics during ECLS significantly impact antibiotic therapy, necessitating therapeutic drug monitoring for precise dosing. Managing native lung ventilation during V-V ECMO remains complex, requiring a careful balance between benefits and potential risks for spontaneously breathing patients. Moreover, weaning from V-V ECMO is recognized as an area of relevant uncertainty, requiring further research. In the last decade, the concept of Extracorporeal Organ Support (ECOS) for patients with multiple organ dysfunction has emerged, combining ECLS with other organ support therapies to provide a more holistic approach for critically ill patients. In this review, we aim at providing an in-depth overview of V-V ECMO and ECCO2R, addressing various aspects of their use, challenges, and potential future directions in research and development.

Impaired Pharmacokinetics of Amiodarone under Veno-Venous Extracorporeal Membrane Oxygenation: From Bench to Bedside

Background: Adjusting drug therapy under veno-venous extracorporeal membrane oxygenation (VV ECMO) is challenging. Although impaired pharmacokinetics (PK) under VV ECMO have been reported for sedative drugs and antibiotics, data about amiodarone are lacking. We evaluated the pharmacokinetics of amiodarone under VV ECMO both in vitro and in vivo. Methods: In vitro: Amiodarone concentration decays were compared between closed-loop ECMO and control stirring containers over a 24 h period. In vivo: Potassium-induced cardiac arrest in 10 pigs with ARDS, assigned to either control or VV ECMO groups, was treated with 300 mg amiodarone injection under continuous cardiopulmonary resuscitation. Pharmacokinetic parameters C_max, T_max AUC and F were determined from both direct amiodarone plasma concentrations observation and non-linear mixed effects modeling estimation. Results: An in vitro study revealed a rapid and significant decrease in amiodarone concentrations in the closed-loop ECMO circuitry whereas it remained stable in control experiment. In vivo study revealed a 32% decrease in the AUC and a significant 42% drop of C_max in the VV ECMO group as compared to controls. No difference in T_max was observed. VV ECMO significantly modified both central distribution volume and amiodarone clearance. Monte Carlo simulations predicted that a 600 mg bolus of amiodarone under VV ECMO would achieve the amiodarone bioavailability observed in the control group. Conclusions: This is the first study to report decreased amiodarone bioavailability under VV ECMO. Higher doses of amiodarone should be considered for effective amiodarone exposure under VV ECMO.

Individual Meropenem Clearance in Infants on ECMO and CVVHDF is Difficult to Predict: A Case Report and Review of the Literature

OBJECTIVES

Meropenem is a broad-spectrum carbapenem antibiotic with mostly renal excretion. Conflicting data are available regarding meropenem pharmacokinetics in critically ill neonates on concomitant continuous renal replacement therapy (CRRT) and/or extracorporeal membrane oxygenation (ECMO). Our objectives were to assess meropenem clearance in a neonate on CRRT and ECMO, compare it to previously published data and assess whether dose recommendations can be generalized in this population.

CASE DESCRIPTION

A 2.5 kg male infant with a large diaphragmatic hernia was delivered by cesarean section at week 35 and immediately mechanically ventilated due to shock and respiratory insufficiency. He underwent surgical correction of the hernia, but developed recurrent sepsis, multiorgan failure and pulmonary hypertension. He remained mechanically ventilated and required ECMO and continuous venovenous hemodiafiltration. He was started on meropenem 40 mg/kg/dose, every 8 hs for Enterobacter cloacae bacteremia and sepsis, but due to lack of clinical and microbiologic response despite in vitro susceptibility, he was started on a continuous meropenem infusion of 240 mg/kg/d, based on dose recommendations in a similar case. We measured steady state meropenem plasma concentrations on 2 occasions, during ECMO and continuous venovenous hemodiafiltration (CVVHDF) and then on CVVHDF only.

RESULTS

Meropenem serum concentrations were 90 and 64 mg/L on the first and second occasion (therapeutic target concentration, 10 mg/L) corresponding to a clearance of 1.9 and 2.6 mL/kg/min. This clearance estimate was substantially lower than that reported in toddlers on CRRT and ECMO in some studies.

CONCLUSION

In neonates and infants, meropenem clearance is difficult to predict because of dynamic ontogenetic changes in renal function. This problem is further aggravated in acutely ill infants with decreased renal function, renal replacement therapy and/or ECMO. Therefore, Target Concentration Intervention based on meropenem plasma concentrations is indispensable to ensure therapeutic exposure in this population.

Pharmacokinetics of Antibiotics in Pediatric Intensive Care: Fostering Variability to Attain Precision Medicine

Children show important developmental and maturational changes, which may contribute greatly to pharmacokinetic (PK) variability observed in pediatric patients. These PK alterations are further enhanced by disease-related, non-maturational factors. Specific to the intensive care setting, such factors include critical illness, inflammatory status, augmented renal clearance (ARC), as well as therapeutic interventions (e.g., extracorporeal organ support systems or whole-body hypothermia [WBH]). This narrative review illustrates the relevance of both maturational and non-maturational changes in absorption, distribution, metabolism, and excretion (ADME) applied to antibiotics. It hereby provides a focused assessment of the available literature on the impact of critical illness—in general, and in specific subpopulations (ARC, extracorporeal organ support systems, WBH)—on PK and potential underexposure in children and neonates. Overall, literature discussing antibiotic PK alterations in pediatric intensive care is scarce. Most studies describe antibiotics commonly monitored in clinical practice such as vancomycin and aminoglycosides. Because of the large PK variability, therapeutic drug monitoring, further extended to other antibiotics, and integration of model-informed precision dosing in clinical practice are suggested to optimise antibiotic dose and exposure in each newborn, infant, or child during intensive care.

A successful daptomycin and micafungin dosing strategy in veno-venous ECMO and continuous renal replacement

WHAT IS KNOWN AND OBJECTIVE

Studies have demonstrated that ECMO leads to pharmacokinetic changes, with alterations in volume of distribution, clearance and drug sequestration by the circuit. We describe a successful dosing approach for daptomycin and micafungin for the treatment of VRE faecium bacteremia and C. glabrata fungemia in a patient receiving veno-venous ECMO and CRRT.

CASE SUMMARY

We report a case of a patient with ARDS on veno-venous ECMO complicated by VRE faecium bacteremia and C. glabrata fungemia. The patient was treated with daptomycin 10 mg/kg every 24 h and micafungin 150 mg every 24 h for 14 days. Key observations included the documented bacteremia and fungemia clearance without the need for ECMO circuit exchange.

WHAT IS NEW AND CONCLUSION

This case report demonstrates successful bacteremia and fungemia clearance in an adult without the need for ECMO circuit exchange. It also highlights the need for more research to identify optimal antimicrobial dosing strategies in similar scenarios.

Pediatric Drug-Drug Interaction Evaluation: Drug, Patient Population, and Methodological Considerations

Hospitalized pediatric patients and those with complex or chronic conditions treated on an outpatient basis are commonly prescribed multiple drugs, resulting in increased risk for drug-drug interactions (DDIs). Although dedicated DDI evaluations are routinely performed in healthy adult volunteers during drug development, they are rarely performed in pediatric patients because of ethical, logistical, and methodological challenges. In the absence of pediatric DDI evaluations, adult DDI data are often extrapolated to pediatric patients. However, the magnitude of a DDI in pediatric patients may differ from adults because of age-dependent physiological changes that can impact drug disposition or response and because of other factors related to the drug (eg, dose, formulation) and the patient population (eg, disease state, obesity). Therefore, the DDI magnitude needs to be assessed in children separately from adults, although a lack of clinical DDI data in pediatric populations makes this evaluation challenging. As a result, pediatric DDI assessment relies on the predictive performance of the pharmacometric approaches used, such as population and physiologically based pharmacokinetic modeling. Therefore, careful consideration needs to be given to adequately account for the age-dependent physiological changes in these models to build high confidence for such untested DDI scenarios. This review article summarizes the key considerations related to the drug, patient population, and methodology, and how they can impact DDI evaluation in the pediatric population.

Vancomycin concentrations during cardiopulmonary bypass in pediatric cardiac surgery: a prospective study

INTRODUCTION

Few data are available regarding intraoperative plasma concentrations of vancomycin administered as prophylaxis in pediatric cardiac surgery. The aims of this study were to investigate during pediatric cardiac surgery with cardiopulmonary bypass(CPB) the attainment of the area-under-the-curve of the vancomycin serum concentrations versus time over surgery to minimum inhibitory concentration ratio(AUC_intra/MIC) of 400 (mg × h)/l and/or a target concentration of 15-20 mg/l.

METHODS

In a prospective study, 40 patients divided into four subgroups (neonates, infants, children <10 years-old, ⩾10 years-old) undergoing cardiac surgery with cardiopulmonary bypass (CPB) were enrolled. A slow vancomycin bolus of 20 mg/kg, up to a maximum dose of 1000 mg was administered before skin incision and a further dose of 10 mg/kg (up to 500 mg) at CPB start. Vancomycin samples were collected intraoperatively at four time points.

RESULTS

The median (interquartile range) age was 241.5 days (47-3898) and the median weight was 7.1 kg (3.1-37). The median AUC_intra/MIC was 254.73 (165.89-508.06). In 11 patients the AUC_intra/MIC target was not reached. Neonates displayed the lowest AUC_intra/MIC values, and these were significantly lower than those of children ⩾10 years old (p = 0.02). Vancomycin concentrations were above the maximal target of 20 mg/l in 82.5% and 80% of patients at surgery and CPB start, respectively. At CPB and surgery end, 42.5% of patients showed vancomycin concentrations above 20 mg/l and 42.5% below 15 mg/l. Patients⩾10 years old showed the highest peak values whereas neonates were those with the lowest troughs. AUC_intra/MIC correlated with age(r:0.36, p = 0.02), weight(r:0.35, p = 0.03), intraoperative protein value(r:0.40, p = 0.01), CPB priming volume/kg(r:-0.33, p = 0.04), CPB duration(r:0.36, p = 0.02) and vancomycin troughs(r:0.35, p = 0.04).

CONCLUSIONS

An AUC_intra/MIC ⩾400 target was not reached in one-quarter of children undergoing heart surgery. Vancomycin peaked before the start of surgery and neonates were those with the lowest troughs. Vancomycin concentrations are affected by CPB hemodilution and by patients' age and weight.

Impact of haemolysis on vancomycin disposition in a full-term neonate treated with extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is a lifesaving support technology for potentially reversible neonatal cardiac and/or respiratory failure. Pharmacological consequences of ECMO-induced haemolysis in neonates are not well understood.

CASE REPORT

We report a case report of a full-term neonate treated for congenital diaphragmatic hernia and sepsis with ECMO and with vancomycin. While the population elimination half-life of 7 h was estimated, fitting of the simulated population pharmacokinetic profile to truly observed drug concentration points resulted in the personalized value of 41 h.

DISCUSSION

The neonate developed ECMO-induced haemolysis with subsequent acute kidney injury resulting in prolonged drug elimination. Whole blood/serum ratio of 0.79 excluded possibility of direct increase of vancomycin serum concentration during haemolysis.

CONCLUSION

Vancomycin elimination may be severely prolonged due to ECMO-induced haemolysis and acute kidney injury, while hypothesis of direct increase of vancomycin levels by releasing the drug from blood cells during haemolysis has been disproved.

Rapid Increase in Clearance of Phenobarbital in Neonates on Extracorporeal Membrane Oxygenation: A Pilot Retrospective Population Pharmacokinetic Analysis

OBJECTIVES

This study characterizes the changes in the pharmacokinetics of phenobarbital associated with extracorporeal membrane oxygenation treatment in neonates, to illustrate our findings and provide guidance on dosing.

DESIGN

Retrospective pilot population pharmacokinetic analysis.

SETTING

Neonatal ICU.

PATIENTS

Thirteen critically ill neonates (birth body weight, 3.21 kg [2.65-3.72 kg]; postnatal age at start of treatment: 2 d [0-7 d]; gestational age: 38 wk [38-41 wk]) receiving venovenous or venoarterial extracorporeal membrane oxygenation.

INTERVENTIONS

Phenobarbital administered in a loading dose of 7.5 mg/kg (8.5-16 mg/kg) and maintenance dose of 6.9 mg/kg/d (4.5-8.5 mg/kg/d).

MEASUREMENTS AND MAIN RESULTS

Therapeutic drug monitoring data were available, yielding 5, 31, and 19 phenobarbital concentrations before, during, and after extracorporeal membrane oxygenation, respectively. Population pharmacokinetic analysis was performed using NONMEM 7.3.0 (ICON Development Solutions, Ellicott City, MD). Maturation functions for clearance and volume of distribution were obtained from literature. In a one-compartment model, clearance and volume of distribution for a typical neonate off extracorporeal membrane oxygenation and with a median birth body weight (3.21 kg) at median postnatal age (2 d) were 0.0096 L/hr (relative SE = 11%)) and 2.72 L (16%), respectively. During extracorporeal membrane oxygenation, clearance was found to linearly increase with time. Upon decannulation, phenobarbital clearance initially decreased and subsequently increased slowly driven by maturation. Extracorporeal membrane oxygenation-related changes in volume of distribution could not be identified, possibly due to sparse data collection shortly after extracorporeal membrane oxygenation start. According to the model, target attainment is achieved in the first 12 days of extracorporeal membrane oxygenation with a regimen of a loading dose of 20 mg/kg and a maintenance dose of 4 mg/kg/d divided in two doses with an increase of 0.25 mg/kg every 12 hours during extracorporeal membrane oxygenation treatment.

CONCLUSIONS

We found a time-dependent increase in phenobarbital clearance during the first 12 days of extracorporeal membrane oxygenation treatment in neonates, which results in continuously decreasing phenobarbital exposure and increases the risk of therapeutic failure over time. Due to high unexplained variability, frequent and repeated therapeutic drug monitoring should be considered even with the model-derived regimen.

Therapeutic Drug Monitoring Is a Feasible Tool to Personalize Drug Administration in Neonates Using New Techniques: An Overview on the Pharmacokinetics and Pharmacodynamics in Neonatal Age

Therapeutic drug monitoring (TDM) should be adopted in all neonatal intensive care units (NICUs), where the most preterm and fragile babies are hospitalized and treated with many drugs, considering that organs and metabolic pathways undergo deep and progressive maturation processes after birth. Different developmental changes are involved in interindividual variability in response to drugs. A crucial point of TDM is the choice of the bioanalytical method and of the sample to use. TDM in neonates is primarily used for antibiotics, antifungals, and antiepileptic drugs in clinical practice. TDM appears to be particularly promising in specific populations: neonates who undergo therapeutic hypothermia or extracorporeal life support, preterm infants, infants who need a tailored dose of anticancer drugs. This review provides an overview of the latest advances in this field, showing options for a personalized therapy in newborns and infants.

Meropenem pharmacokinetics during extracorporeal membrane oxygenation and continuous haemodialysis: a case report

OBJECTIVES

Pharmacokinetic (PK) parameters can change significantly during extracorporeal membrane oxygenation (ECMO) and continuous haemodialysis. This case report describes the pharmacokinetics of a 3-h meropenem infusion in an infantile anuric patient on ECMO with continuous haemodialysis.

CASE

A 19-month-old female patient with asplenia syndrome was admitted to the paediatric intensive care unit for postoperative management of an extracardiac total cavopulmonary connection procedure. Veno-arterial ECMO and continuous haemodialysis were initiated on postoperative Day 2 for circulatory insufficiency due to septic shock and thrombosis of the inferior vena cava extending to the pulmonary artery. Blood and ascites cultures were positive for extended-spectrum β-lactamase-producing Escherichia coli, and 3-h meropenem infusions [120-300 mg/kg/day divided every 8 h (q8h)] were commenced. Following dose escalation to 300 mg/kg/day q8h, sustained negative blood cultures were confirmed. The estimated meropenem clearance and volume of distribution (V_d) were 2.21 mL/kg/min and 0.59 L/kg, respectively. These patient-specific PK parameters were used to predict the PK profile of various dosing regimens. Both 1-h and 3-h infusions of meropenem at 60, 120 and 200 mg/kg/day q8h predicted that the free drug concentration would remain above the minimum inhibitory concentration (fT_>MIC) at an MIC of 1 μg/mL for >40% of the dosing interval. However, when the target was set at 100% fT_>MIC, only a 3-h infusion of 200 mg/kg/day q8h could achieve the target in this patient despite the presence of anuria.

CONCLUSION

To optimise meropenem dosing in paediatric patients on ECMO and continuous haemodialysis, further study and PK monitoring are warranted.

Antibiotic dosing during extracorporeal membrane oxygenation: does the system matter?

PURPOSE OF REVIEW

The aims of this review are to discuss the impact of extracorporeal membrane oxygenation (ECMO) on antibiotic pharmacokinetics and how this phenomenon may influence antibiotic dosing requirements in critically ill adult ECMO patients.

RECENT FINDINGS

The body of literature describing antibiotic pharmacokinetic and dosing requirements during ECMO support in critically adult patients is currently scarce. However, significant development has recently been made in this research area and more clinical pharmacokinetic data have emerged to inform antibiotic dosing in these patients. Essentially, these clinical data highlight several important points that clinicians need to consider when dosing antibiotics in critically ill adult patients receiving ECMO: physicochemical properties of antibiotics can influence the degree of drug loss/sequestration in the ECMO circuit; earlier pharmacokinetic data, which were largely derived from the neonatal and paediatric population, are certainly useful but cannot be extrapolated to the critically ill adult population; modern ECMO circuitry has minimal adsorption and impact on the pharmacokinetics of most antibiotics; and pharmacokinetic changes in ECMO patients are more reflective of critical illness rather than the ECMO therapy itself.

SUMMARY

An advanced understanding of the pharmacokinetic alterations in critically ill patients receiving ECMO is essential to provide optimal antibiotic dosing in these complex patients pending robust dosing guidelines. Antibiotic dosing in this patient population should generally align with the recommended dosing strategies for critically ill patients not on ECMO support. Performing therapeutic drug monitoring (TDM) to guide antibiotic dosing in this patient population appears useful.

Drug Disposition and Pharmacotherapy in Neonatal ECMO: From Fragmented Data to Integrated Knowledge

Extracorporeal membrane oxygenation (ECMO) is a lifesaving support technology for potentially reversible neonatal cardiac and/or respiratory failure. As the survival and the overall outcome of patients rely on the treatment and reversal of the underlying disease, effective and preferentially evidence-based pharmacotherapy is crucial to target recovery. Currently limited data exist to support the clinicians in their every-day intensive care prescribing practice with the contemporary ECMO technology. Indeed, drug dosing to optimize pharmacotherapy during neonatal ECMO is a major challenge. The impact of the maturational changes of the organ function on both pharmacokinetics (PK) and pharmacodynamics (PD) has been widely established over the last decades. Next to the developmental pharmacology, additional non-maturational factors have been recognized as key-determinants of PK/PD variability. The dynamically changing state of critical illness during the ECMO course impairs the achievement of optimal drug exposure, as a result of single or multi-organ failure, capillary leak, altered protein binding, and sometimes a hyperdynamic state, with a variable effect on both the volume of distribution (Vd) and the clearance (Cl) of drugs. Extracorporeal membrane oxygenation introduces further PK/PD perturbation due to drug sequestration and hemodilution, thus increasing the Vd and clearance (sequestration). Drug disposition depends on the characteristics of the compounds (hydrophilic vs. lipophilic, protein binding), patients (age, comorbidities, surgery, co-medications, genetic variations), and circuits (roller vs. centrifugal-based systems; silicone vs. hollow-fiber oxygenators; renal replacement therapy). Based on the potential combination of the above-mentioned drug PK/PD determinants, an integrated approach in clinical drug prescription is pivotal to limit the risks of over- and under-dosing. The understanding of the dose-exposure-response relationship in critically-ill neonates on ECMO will enable the optimization of dosing strategies to ensure safety and efficacy for the individual patient. Next to in vitro and clinical PK data collection, physiologically-based pharmacokinetic modeling (PBPK) are emerging as alternative approaches to provide bedside dosing guidance. This article provides an overview of the available evidence in the field of neonatal pharmacology during ECMO. We will identify the main determinants of altered PK and PD, elaborate on evidence-based recommendations on pharmacotherapy and highlight areas for further research.