Impact of ibuprofen administration on renal drug clearance in the first weeks of life

Appendix to the Society of Interventional Radiology Consensus Guidelines for the Periprocedural Management of Thrombotic and Bleeding Risk in Patients Undergoing Percutaneous Image-Guided Interventions: Pediatric Considerations

PURPOSE

To provide guidance on the use of anticoagulant and antithrombotic agents in pediatric patients undergoing interventional radiology procedures.

MATERIALS AND METHODS

A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were developed for procedural risk and medication dosage and withholding. A modified Delphi technique was used to achieve consensus agreement on the recommendations.

RESULTS

A total of 24 studies, including systematic reviews and meta-analyses, randomized controlled trials, and prospective and retrospective cohort studies, were identified as relevant. The expert writing group agreed on procedural risk categorization, laboratory testing thresholds, and medication dosage and withholding recommendations specific to pediatric practice. They additionally described the nuances of anticoagulation in clinical conditions specific to pediatrics.

CONCLUSIONS

The Society of Interventional Radiology recommends following the guidance provided in the document when developing multidisciplinary management protocols for anticoagulation and antithrombotic treatment in pediatric patients undergoing interventional radiology procedures.

Physiologically based pharmacokinetic (PBPK) modeling and simulation in neonatal drug development: how clinicians can contribute

Introduction: Legal initiatives to stimulate neonatal drug development should be accompanied by development of valid research tools. Physiologically based (PB)-pharmacokinetic (PK) modeling and simulation are established tools, accepted by regulatory authorities. Consequently, PBPK holds promise to be a strong research tool to support neonatal drug development. Area covered: The currently available PBPK models still have poor predictive performance in neonates. Using an illustrative approach on distinct PK processes of absorption, distribution, metabolism, excretion, and real-world data in neonates, we provide evidence on the need to further refine available PBPK system parameters through generation and integration of new knowledge. This necessitates cross talk between clinicians and modelers to integrate knowledge (PK datasets, system knowledge, maturational physiology) or test and refine PBPK models. Expert opinion: Besides refining these models for 'small molecules', PBPK model development should also be more widely applied for therapeutic proteins and to determine exposure through breastfeeding. Researchers should also be aware that PBPK modeling in combination with clinical observations can also be used to elucidate age-related changes that are almost impossible to study based on in vivo or in vitro data. This approach has been explored for hepatic biliary excretion, renal tubular activity, and central nervous system exposure.

Population pharmacokinetic study of gentamicin in a large cohort of premature and term neonates

AIM

This study aims to investigate the clinical and demographic factors influencing gentamicin pharmacokinetics in a large cohort of unselected premature and term newborns and to evaluate optimal regimens in this population.

METHODS

All gentamicin concentration data, along with clinical and demographic characteristics, were retrieved from medical charts in a Neonatal Intensive Care Unit over 5 years within the frame of a routine therapeutic drug monitoring programme. Data were described using non-linear mixed-effects regression analysis ( nonmem®).

RESULTS

A total of 3039 gentamicin concentrations collected in 994 preterm and 455 term newborns were included in the analysis. A two compartment model best characterized gentamicin disposition. The average parameter estimates, for a median body weight of 2170 g, were clearance (CL) 0.089 l h(-1) (CV 28%), central volume of distribution (Vc ) 0.908 l (CV 18%), intercompartmental clearance (Q) 0.157 l h(-1) and peripheral volume of distribution (Vp ) 0.560 l. Body weight, gestational age and post-natal age positively influenced CL. Dopamine co-administration had a significant negative effect on CL, whereas the influence of indomethacin and furosemide was not significant. Both body weight and gestational age significantly influenced Vc . Model-based simulations confirmed that, compared with term neonates, preterm infants need higher doses, superior to 4 mg kg(-1) , at extended intervals to achieve adequate concentrations.

CONCLUSIONS

This observational study conducted in a large cohort of newborns confirms the importance of body weight and gestational age for dosage adjustment. The model will serve to set up dosing recommendations and elaborate a Bayesian tool for dosage individualization based on concentration monitoring.

Treatment of patent ductus arteriosus (PDA) using ibuprofen: renal side-effects in VLBW and ELBW newborns

OBJECTIVES

This study aims to determine whether or not treatment of preterm neonates with PDA using IV ibuprofen can impair renal function and in what range of birth weights and gestational ages the risk of major renal side-effects due to ibuprofen is highest.

METHODS

134 preterm newborns with PDA were enrolled and randomized to receive either placebo or a 3-day-course (10, 5 and 5 mg/kg) of IV ibuprofen. 67 newborns (mGA: 27(+3) w and mBW: 989 g) with PDA received ibuprofen.

RESULTS

Subdividing the infants according to BW and to GA, the values of creatinine and BUN were only significantly higher than initial values at the end of the therapy in newborns with a BW ≤1000 g and/or GA ≤26 weeks. Renal impairment is greater the lower the weight and gestational age of the infant at birth.

CONCLUSIONS

Ibuprofen significantly impairs renal function in preterm infants with a GA ≤26 weeks and/or in ELBW neonates, while it may be considered safe for infants with a BW >1000 g and/or GA >26 weeks. Thus, before starting therapy with IV ibuprofen, it is essential to take into account the BW and GA of newborns and the effective need for treatment from the point of view of the ratio of risks to benefits, due to its substantial renal side-effects.

Maturation of the glomerular filtration rate in neonates, as reflected by amikacin clearance

BACKGROUND AND OBJECTIVES

During the newborn period and early infancy, renal function matures, resulting in changes in the glomerular filtration rate (GFR). This study was performed to quantify developmental changes in the GFR in (pre)term neonates by use of amikacin clearance as proof of concept. The model was used to derive a rational dosing regimen in comparison with currently used dosing regimens for amikacin.

METHODS

Population pharmacokinetic modelling was performed in nonlinear mixed-effect modelling software (NONMEM version 6.2) using data from 874 neonates obtained from two previously published datasets (gestational age 24-43 weeks; postnatal age 1-30 days; birthweight 385-4650 g). The influence of different age-related, weight-related and other covariates was investigated. The model was validated both internally and externally.

RESULTS

Postmenstrual age was identified as the most significant covariate on clearance. However, the combination of birthweight and postnatal age proved to be superior to postmenstrual age alone. Birthweight was best described using an allometric function with an exponent of 1.34. Postnatal age was identified using a linear function with a slope of 0.2, while co-administration of ibuprofen proved to be a third covariate. Current bodyweight was the most important covariate for the volume of distribution, using an allometric function. The external evaluation supported the prediction of the final pharmacokinetic model. This analysis illustrated clearly that the currently used dosing regimens for amikacin in reference handbooks may possibly increase the risk of toxicities and should be revised. Consequently, a new model-based dosing regimen based on current bodyweight and postnatal age was derived.

CONCLUSIONS

Amikacin clearance, reflecting the GFR in neonates, can be predicted by birthweight representing the antenatal state of maturation of the kidney, postnatal age representing postnatal maturation, and co-administration of ibuprofen. Finally, the model reflects maturation of the GFR, allowing for adjustments of dosing regimens for other renally excreted drugs in preterm and term neonates.

Renal Side Effects of Non-Steroidal Anti-Inflammatory Drugs in Neonates

Non-steroidal anti-inflammatory drugs like ibuprofen or indomethacin are commonly prescribed drugs to induce pharmacologic closure of a patent ductus arteriosus in preterm neonates. Based on a recently published Cochrane meta-analysis, both drugs are equally effective to induce closure. Drug choice can therefore be based on differences in side effects or pharmaco-economic arguments. The current review quantifies the negative impact of either ibuprofen or indomethacin on renal function, including diuresis, glomerular filtration rate and renal tubular function. Both ibuprofen and indomethacin have a quantifiable impact on renal function. However, compared to ibuprofen, the negative impact of indomethacin is more pronounced.

Ibuprofen in very preterm infants impairs renal function for the first month of life

We carried out a study aiming to determine the renal effect of ibuprofen treatment for patent ductus arteriosus (PDA) in very preterm infants during the first month of life. Infants aged 27-31 weeks gestation were enrolled from October 2004 to August 2006. They were assigned to two different groups according to ibuprofen exposure during care of their PDA status assessed by echocardiography. Infants of both groups were matched based on gestational age, Clinical Risk Index for Babies score, birth weight and inclusion center. Renal function was evaluated at baseline and weekly for 1 month. One hundred and forty-eight infants were enrolled. Glomerular filtration rate (GFR) was significantly decreased in the ibuprofen group after treatment withdrawal (GFR on day 7, ibuprofen versus no ibuprofen: 12.8 +/- 6.2 vs. 18.1 +/- 12.1 ml/min/1.73 m(2); P < 0.001). Adjusted analysis proved this decrease to be sustained during the first month of life. Tubular function was also impaired during the first month in ibuprofen-treated infants. Ibuprofen administered for PDA is associated with a decreased GFR during the first month of life. Renal function of infants receiving ibuprofen should be carefully monitored and drugs that are eliminated by glomerular filtration handled cautiously during this period.

Factors affecting postnatal changes in serum creatinine in preterm infants with gestational age <32 weeks

OBJECTIVE

The Aim of this study was to investigate maternal and neonatal factors associated with serum creatinine (SeCr) changes in a representative cohort of preterm newborns during their first week of life.

STUDY DESIGN

Retrospective study. All the infants born less than 32 weeks of gestational age (GA) and cared for in our neonatal intensive care unit between January 2001 and December 2005 were eligible for the analysis. Epidemiological data of all mother-infant pairs and neonatal SeCr values were recorded.

RESULT

A total of 652 infants were studied. Multivariate regression analysis showed that the main independent factors associated with high SeCr at day 1 were hypertensive disease of pregnancy (P<0.0001) and advancing hour of life (P<0.0001), with minimal contribution of placental abruption (P<0.05) and higher GA (P<0.05). Lower GA (P<0.0001) and ibuprofen-treated patent ductus arteriosus (PDA; P<0.0001) were the main analyzed factors independently associated with higher SeCr peak (defined as the highest SeCr during the week), with less contribution of respiratory distress syndrome (P<0.01) and early onset infection (P<0.05). In infants with hemodynamically significant PDA (hsPDA) SeCr before ibuprofen administration was higher when compared to GA-matched controls without hsPDA (P< 0.0001).

CONCLUSION

SeCr peak was inversely correlated to GA in preterm infants born less than 32 weeks of GA. Neonatal rather than maternal morbidity affected SeCr peak. In hsPDA, SeCr increase preceded ibuprofen administration.