Enantiomer specific pharmacokinetics of ibuprofen in preterm neonates with patent ductus arteriosus

When will the Glomerular Filtration Rate in Former Preterm Neonates Catch up with Their Term Peers?

AIMS

Whether and when glomerular filtration rate (GFR) in preterms catches up with term peers is unknown. This study aims to develop a GFR maturation model for (pre)term-born individuals from birth to 18 years of age. Secondarily, the function is applied to data of different renally excreted drugs.

METHODS

We combined published inulin clearance values and serum creatinine (Scr) concentrations in (pre)term born individuals throughout childhood. Inulin clearance was assumed to be equal to GFR, and Scr to reflect creatinine synthesis rate/GFR. We developed a GFR function consisting of GFRbirth (GFR at birth), and an Emax model dependent on PNA (with GFRmax, PNA50 (PNA at which half ofGFR max is reached) and Hill coefficient). The final GFR model was applied to predict gentamicin, tobramycin and vancomycin concentrations.

RESULT

In the GFR model, GFRbirth varied with birthweight linearly while in the PNA-based Emax equation, GA was the best covariate for PNA50, and current weight for GFRmax. The final model showed that for a child born at 26 weeks GA, absolute GFR is 18%, 63%, 80%, 92% and 96% of the GFR of a child born at 40 weeks GA at 1 month, 6 months, 1 year, 3 years and 12 years, respectively. PopPK models with the GFR maturation equations predicted concentrations of renally cleared antibiotics across (pre)term-born neonates until 18 years well.

CONCLUSIONS

GFR of preterm individuals catches up with term peers at around three years of age, implying reduced dosages of renally cleared drugs should be considered below this age.

Grading the level of evidence of neonatal pharmacotherapy: midazolam and phenobarbital as examples

BACKGROUND

Many drugs are used off-label or unlicensed in neonates. This does not mean they are used without evidence or knowledge. We aimed to apply and evaluate the Grading and Assessment of Pharmacokinetic-Pharmacodynamic Studies (GAPPS) scoring system for the level of evidence of two commonly used anti-epileptic drugs.

METHODS

Midazolam and phenobarbital as anti-epileptics were evaluated with a systematic literature search on neonatal pharmacokinetic (PK) and/or pharmacodynamic [PD, (amplitude-integrated) electroencephalography effect] studies. With the GAPPS system, two evaluators graded the current level of evidence. Inter-rater agreement was assessed for dosing evidence score (DES), quality of evidence (QoE), and strength of recommendation (REC).

RESULTS

Seventy-two studies were included. DES scores 4 and 9 were most frequently used for PK, and scores 0 and 1 for PD. Inter-rater agreements on DES, QoE, and REC ranged from moderate to very good. A final REC was provided for all PK studies, but only for 25% (midazolam) and 33% (phenobarbital) of PD studies.

CONCLUSIONS

There is a reasonable level of evidence concerning midazolam and phenobarbital PK in neonates, although using a predefined target without integrated PK/PD evaluation. Further research is needed on midazolam use in term neonates with therapeutic hypothermia, and phenobarbital treatment in preterms.

IMPACT

There is a reasonable level of evidence concerning pharmacotherapy of midazolam and phenobarbital in neonates. Most evidence is however based on PK studies, using a predefined target level or concentration range without integrated, combined PK/PD evaluation. Using the GAPPS system, final strength of recommendation could be provided for all PK studies, but only for 25% (midazolam) to 33% (phenobarbital) of PD studies. Due to the limited PK observations of midazolam in term neonates with therapeutic hypothermia, and of phenobarbital in preterm neonates these subgroups can be identified for further research.

Current knowledge, challenges and innovations in developmental pharmacology: A combined conect4children Expert Group and European Society for Developmental, Perinatal and Paediatric Pharmacology White Paper

Developmental pharmacology describes the impact of maturation on drug disposition (pharmacokinetics, PK) and drug effects (pharmacodynamics, PD) throughout the paediatric age range. This paper, written by a multidisciplinary group of experts, summarizes current knowledge, and provides suggestions to pharmaceutical companies, regulatory agencies and academicians on how to incorporate the latest knowledge regarding developmental pharmacology and innovative techniques into neonatal and paediatric drug development. Biological aspects of drug absorption, distribution, metabolism and excretion throughout development are summarized. Although this area made enormous progress during the last two decades, remaining knowledge gaps were identified. Minimal risk and burden designs allow for optimally informative but minimally invasive PK sampling, while concomitant profiling of drug metabolites may provide additional insight in the unique PK behaviour in children. Furthermore, developmental PD needs to be considered during drug development, which is illustrated by disease- and/or target organ-specific examples. Identifying and testing PD targets and effects in special populations, and application of age- and/or population-specific assessment tools are discussed. Drug development plans also need to incorporate innovative techniques such as preclinical models to study therapeutic strategies, and shift from sequential enrolment of subgroups, to more rational designs. To stimulate appropriate research plans, illustrations of specific PK/PD-related as well as drug safety-related challenges during drug development are provided. The suggestions made in this joint paper of the Innovative Medicines Initiative conect4children Expert group on Developmental Pharmacology and the European Society for Developmental, Perinatal and Paediatric Pharmacology, should facilitate all those involved in drug development.

The Effect of Ibuprofen Exposure and Patient Characteristics on the Closure of the Patent Ductus Arteriosus in Preterm Infants

Spontaneous closure of the ductus arteriosus depends on gestational age (GA) and might be delayed in preterm infants, resulting in patent ductus arteriosus (PDA). Ibuprofen can be administered to enhance closure, but the exposure‐response relationship between ibuprofen and the closure of PDA remains uncertain. We investigated the influence of patient characteristics and ibuprofen exposure on ductus closure. A cohort of preterm infants with PDA and treated with ibuprofen was analyzed. Ibuprofen exposure was based on a previously developed population pharmacokinetic study that was in part based on the same study population. Logistic regression analyses were performed with ductus closure (yes/no) as outcome, to analyze the contribution of ibuprofen exposure and patient characteristics. In our cohort of 263 preterm infants (median GA 26.1 (range: 23.7–30.0) weeks, birthweight 840 (365–1,470) g) receiving ibuprofen treatment consisting of 3 doses that was initiated at a median postnatal age (PNA_start) of 5 (1–32) days, PDA was closed in 55 (21%) patients. Exposure to ibuprofen strongly decreased with PNA_start. Overall, the probability of ductus closure decreased with PNA_start (odds ratio (OR): 0.7, 95% CI: 0.6–0.8) and Z‐score for birthweight (Z_{Birthweight‐for‐GA}; OR: 0.8, 95% CI: 0.6‐1.0), and increased with GA (OR: 1.5, 95% CI: 1.1–1.9). For patients with PNA_start < 1 week, concentrations of ibuprofen, GA, and Z_{Birthweight‐for‐GA} predicted probability of ductus closure. During a window of opportunity for ductus closure within the first days of life, probability of closure depends on GA, Z_{Birthweight‐for‐GA}, and ibuprofen exposure. Increased, yet unstudied dosages might increase the effectivity of ibuprofen beyond the first week of life.

Pharmacokinetics of oral versus intravenous ibuprofen for closure of patent ductus arteriosus: A pilot randomised controlled study

AIM

This pilot study aimed to compare the pharmacokinetic profiles of oral (PO) and intravenous (IV) ibuprofen for treatment of patent ductus arteriosus (PDA) in preterm neonates.

METHODS

In a single-centre, parallel, randomised open-label trial, neonates ≤35 weeks, weight <1800 g with haemodynamically significant PDA during the first week of life were recruited between June 2017 and February 2019 and randomised to receive either PO or IV ibuprofen at standard dosage of 10, 5 and 5 mg/kg every 24 h for three consecutive days. Plasma concentrations of ibuprofen were quantified using a validated high-performance liquid chromatography method and pharmacokinetic parameters were calculated. Treatment outcomes were recorded.

RESULTS

Eleven neonates participated in the trial, six and five patients receiving PO and IV ibuprofen, respectively. Pharmacokinetic analysis reveals similar ibuprofen exposure levels in treatment groups. Median dose- and weight-normalised C_max values of PO and IV groups were 2.12 and 2.53 g/mL respectively (P = 0.082) and median AUC_0-24 levels were comparable (PO: 34.6 g*h/mL vs. IV: 50.7.6 g*h/mL, P = 0.25).

CONCLUSION

This exploratory study demonstrates comparable pharmacokinetics of PO and IV formulations of ibuprofen in preterm neonates. Larger prospective studies are required to validate these findings.

Novel strategy to personalise use of ibuprofen for closure of patent ductus arteriosus in preterm neonates

OBJECTIVE

Exploration of a novel therapeutic drug monitoring (TDM) strategy to personalise use of ibuprofen for closure of patent ductus arteriosus (PDA) in preterm neonates.

DESIGN

Prospective, single-centre, open-label, pharmacokinetics study in preterm neonates.

SETTING

Neonatal intensive care unit at McMaster Children's Hospital.

PATIENTS

Neonates with a gestational age ≤28⁺⁶ weeks treated with oral ibuprofen for closure of a PDA.

METHODS

Population pharmacokinetic parameters, concentration-time profiles and exposure metrics were obtained using pharmacometric modelling and simulation.

MAIN OUTCOME MEASURE

Association between ibuprofen plasma concentrations measured at various sampling time points on the first day of treatment and attainment of the target exposure over the first 3 days of treatment (AUC_0-72h >900 mg·hour/L).

RESULTS

Twenty-three preterm neonates (median birth weight 780 g and gestational age 25.9 weeks) were included, yielding 155 plasma ibuprofen plasma samples. Starting from 8 hours' postdose on the first day, a strong correlation between ibuprofen concentrations and AUC_0-72h was observed. At 8 hours after the first dose, an ibuprofen concentration >20.5 mg/L was associated with a 90% probability of reaching the target exposure.

CONCLUSION

We designed a novel and practical TDM strategy and have shown that the chance of reaching the target exposure (AUC_0-72h >900 mg·hour/L) can be predicted with a single sample collection on the first day of treatment. This newly acquired knowledge can be leveraged to personalise ibuprofen dosing regimens and improve the efficacy of ibuprofen use for pharmacological closure of a PDA.

Ibuprofen enantiomers in premature neonates with patent ductus arteriosus: Preliminary data on an unexpected pharmacokinetic profile of S(+)-ibuprofen

S(+)-ibuprofen (S-IBU) and R(-)-ibuprofen (R-IBU) concentrations were measured in 16 neonates with patent ductus arteriosus during a cycle of therapy (three intravenous doses of 10-5-5 mg kg-1 at 24-h intervals), at the end of the first infusion and 6, 24, 48, and 72 h later. Data were analyzed with a PK model that included enantiomer elimination rate constants and the R- to S-IBU conversion rate constant. The T½ of S-IBU in the newborn was much longer than in adults (41.8 vs. ≈2 h), whereas the T½ of R-IBU appeared to be the same (2.3 h). The mean fraction of R- to S-IBU conversion was much the same as in adults (0.41 vs. ≈0.60). S-IBU concentrations measured 6 h after the first dose were higher than at the end of the infusion in 10 out of 16 cases, and in five cases, they remained higher even after 24 h. This behavior is unprecedented and may be attributable to a rapid R-to-S conversion overlapping with a slow S-IBU elimination rate. In 13 of the 16 neonates, S-IBU concentrations at 48 and/or 72 h were lower than expected, probably due to the rapid postnatal maturation of the newborn's liver metabolism.

Ibuprofen-based advanced therapeutics: breaking the inflammatory link in cancer, neurodegeneration, and diseases

Ibuprofen is a classical nonsteroidal anti-inflammatory drug (NSAID) highly prescribed to reduce acute pain and inflammation under an array of conditions, including rheumatoid arthritis, osteoarthritis, dysmenorrhea, and gout. Ibuprofen acts as a potential inhibitor for cyclooxygenase enzymes (COX-1 and COX-2). In the past few decades, research on this small molecule has led to identifying other possible therapeutic benefits. Anti-tumorigenic and neuroprotective functions of Ibuprofen are majorly recognized in recent literature and need further consideration. Additionally, several other roles of this anti-inflammatory molecule have been discovered and subjected to experimental assessment in various diseases. However, the major challenge faced by Ibuprofen and other drugs of similar classes is their side effects, and tendency to cause gastrointestinal injury, generate cardiovascular risks, modulate hepatic and acute kidney diseases. Future research should also be conducted to deduce new methods and approaches of suppressing the unwanted toxic changes mediated by these drugs and develop new therapeutic avenues so that these small molecules continue to serve the purposes. This article primarily aims to develop a comprehensive and better understanding of Ibuprofen, its pharmacological features, therapeutic benefits, and possible but less understood medicinal properties apart from major challenges in its future application.KEY POINTSIbuprofen, an NSAID, is a classical anti-inflammatory therapeutic agent.Pro-apoptotic roles of NSAIDs have been explored in detail in the past, holding the key in anti-cancer therapies.Excessive and continuous use of NSAIDs may have several side effects and multiple organ damage.Hyperactivated Inflammation initiates multifold detrimental changes in multiple pathological conditions.Targeting inflammatory pathways hold the key to several therapeutic strategies against many diseases, including cancer, microbial infections, multiple sclerosis, and many other brain diseases.

A Pilot Randomized Controlled Trial of Early Targeted Patent Ductus Arteriosus Treatment Using a Risk Based Severity Score (The PDA RCT)

OBJECTIVES

To evaluate the feasibility of recruiting preterm infants to a randomized controlled trial of patent ductus arteriosus (PDA) treatment based on a PDA severity score (PDAsc) and to characterize challenges in obtaining consent, compliance with the protocol, and PDA closure rates.

STUDY DESIGN

This single-center, randomized control pilot study of 60 infants <29 weeks of gestation with a high PDAsc (≥5.0) at 36-48 hours of age receiving either ibuprofen or placebo intravenously. The study protocol did not allow for additional PDA therapy within the first 2 weeks. We reported the rate of consent, open label treatment, and PDA closure rates. The primary outcome was chronic lung disease or death.

RESULTS

We approached 83 families for enrollment with 73 (88%) providing consent; 13 infants had a PDAsc of <5; of the remaining infants, 30 were assigned ibuprofen and 30 received placebo. Eight infants received open label treatment in the first 2 weeks (12%). The overall PDA closure rate after treatment was 57% in the intervention group and 17% in the control group (P < .01). There was no difference in the primary clinical outcome (OR, 0.8; 95% CI, 0.3-2.1).

CONCLUSIONS

Using a PDAsc for infant recruitment to a PDA treatment randomized controlled trial is feasible. There is a high rate of consent and relatively low rate of open-label PDA treatment. The overall PDA closure rate in the intervention arm was low placing the emphasis on devising more effective PDA closure strategies in future randomized controlled trials.

TRIAL REGISTRATION

ISRCTN (13281214) and European Union Drug Regulating Authorities Clinical Trials Database (2015-004526-33).

Creatinine Trends to Detect Ibuprofen-Related Maturational Adverse Drug Events in Neonatal Life: A Simulation Study for the ELBW Newborn

Background: Recognizing a change in serum creatinine concentrations is useful to detect a renal adverse drug reaction signal. Assessing and characterizing the nephrotoxic side-effects of drugs in extremely low birth weight (ELBW, ≤1000 g) neonates remain challenging due to the high variability in creatinine in this population. This study aims to investigate and quantify the impact of ibuprofen treatment on kidney function, reflected by serum creatinine.

Method: A recently developed dynamical model for serum creatinine was used to simulate creatinine profiles for typical, reference ELBW neonates with varying gestational and postnatal ages whilst being exposed to ibuprofen treatment.

Results: The increase of serum creatinine concentrations due to ibuprofen treatment is most apparent during the first week of life. The difference in serum creatinine values between ibuprofen-exposed vs. non-exposed neonates decreases with increasing postnatal age, independent of gestational age.

Conclusion: The difference in serum creatinine concentrations between ibuprofen-exposed vs. non-exposed neonates decreases with postnatal age, indicating an increased clearing capacity and resulting in a weak ibuprofen-related adverse drug reaction signal beyond early neonatal life.

The Neonatal and Juvenile Pig in Pediatric Drug Discovery and Development

Pharmacotherapy in pediatric patients is challenging in view of the maturation of organ systems and processes that affect pharmacokinetics and pharmacodynamics. Especially for the youngest age groups and for pediatric-only indications, neonatal and juvenile animal models can be useful to assess drug safety and to better understand the mechanisms of diseases or conditions. In this respect, the use of neonatal and juvenile pigs in the field of pediatric drug discovery and development is promising, although still limited at this point. This review summarizes the comparative postnatal development of pigs and humans and discusses the advantages of the juvenile pig in view of developmental pharmacology, pediatric diseases, drug discovery and drug safety testing. Furthermore, limitations and unexplored aspects of this large animal model are covered. At this point in time, the potential of the neonatal and juvenile pig as nonclinical safety models for pediatric drug development is underexplored.

Spontaneous Closure of the Ductus Arteriosus in Preterm Infants: A Systematic Review

The optimal management strategy for patent ductus arteriosus in preterm infants remains a topic of debate. Available evidence for a treatment strategy might be biased by the delayed spontaneous closure of the ductus arteriosus in preterm infants, which appears to depend on patient characteristics. We performed a systematic review of all literature on PDA studies to collect patient characteristics and reported numbers of patients with a ductus arteriosus and spontaneous closure. Spontaneous closure rates showed a high variability but were lowest in studies that only included preterm infants with gestational ages below 28 weeks or birth weights below 1,000 g (34% on day 4; 41% on day 7) compared to studies that also included infants with higher gestational ages or higher birth weights (up to 55% on day 3 and 78% on day 7). The probability of spontaneous closure of the ductus arteriosus keeps increasing until at least 1 week after birth which favors delayed treatment of only those infants that do not show spontaneous closure. Better prediction of the spontaneous closure of the ductus arteriosus in the individual newborn is a key factor to find the optimal management strategy for PDA in preterm infants.

Enantiomer specific pharmacokinetics of ibuprofen in preterm neonates with patent ductus arteriosus

Aims

Racemic ibuprofen is widely used for the treatment of preterm neonates with patent ductus arteriosus. Currently used bodyweight‐based dosing guidelines are based on total ibuprofen, while only the S‐enantiomer of ibuprofen is pharmacologically active. We aimed to optimize ibuprofen dosing for preterm neonates of different ages based on an enantiomer‐specific population pharmacokinetic model.

Methods

We prospectively collected 210 plasma samples of 67 preterm neonates treated with ibuprofen for patent ductus arteriosus (median gestational age [GA] 26 [range 24–30] weeks, median body weight 0.83 [0.45–1.59] kg, median postnatal age [PNA] 3 [1–12] days), and developed a population pharmacokinetic model for S‐ and R‐ibuprofen.

Results

We found that S‐ibuprofen clearance (CL_S, 3.98 mL/h [relative standard error {RSE} 8%]) increases with PNA and GA, with exponents of 2.25 (RSE 6%) and 5.81 (RSE 15%), respectively. Additionally, a 3.11‐fold higher CL_S was estimated for preterm neonates born small for GA (RSE 34%). Clearance of R‐ibuprofen was found to be high compared to CL_S (18 mL/h [RSE 24%]), resulting in a low contribution of R‐ibuprofen to total ibuprofen exposure. Current body weight was identified as covariate on both volume of distribution of S‐ibuprofen and R‐ibuprofen.

Conclusion

S‐ibuprofen clearance shows important maturation, especially with PNA, resulting in an up to 3‐fold increase in CL_S during a 3‐day treatment regimen. This rapid increase in clearance needs to be incorporated in dosing guidelines by adjusting the dose for every day after birth to achieve equal ibuprofen exposure.