MR Spectroscopy Shows Long Propylene Glycol Half-Life in Neonatal Brain.

INTRODUCTION: Neonatal propylene glycol (PG) clearance is low with long plasma half-life. We hypothesized that neonatal brain PG clearance is diminished and may be related to perinatal asphyxia, infection, or stroke, via different blood-brain barrier permeability. This study aimed to estimate cerebral PG half-life with a clearance model including PG measured with MR spectroscopy (MRS) in neonates that received phenobarbital as the only PG source and to evaluate whether PG clearance was related to intracerebral pathology, for example, perinatal asphyxia, infection, or stroke. METHODS: In this retrospective cohort study, 45 neonates receiving any dose of phenobarbital underwent MRS (short echo time single-voxel MRS at 1.5 T). Cumulative phenobarbital/PG doses were calculated. MRS indications were perinatal asphyxia (n = 22), infection (n = 4), stroke (n = 10), metabolic disease (n = 4), and others (n = 5). RESULTS: Medians (interquartile range) included gestational age 39.4 (3.1) weeks, birth weight 3,146 (1,340) g, and cumulative PG dose 700 (1,120) mg/kg. First-order kinetics with mono-exponential decay showed cerebral PG half-life of 40.7 h and volume of distribution of 1.6 L/kg. Zero-order kinetics showed a rate constant of 0.048 mM/h and a volume of distribution of 2.3 L/kg, but the fit had larger residuals than the first-order model. There were no differences in ΔPG (i.e., PG estimated with clearance model minus PG observed with MRS) in infants with perinatal asphyxia, infection, or stroke. DISCUSSION/CONCLUSION: This study showed a long cerebral PG half-life of 40.7 h in neonates, unrelated to perinatal asphyxia, infection, or stroke. These findings should increase awareness of possible toxic PG concentrations in neonatal brain due to intravenous PG-containing drugs.

Effectiveness and Safety of Nadroparin Therapy in Preterm and Term Neonates with Venous Thromboembolism.

INTRODUCTION: Optimal neonatal nadroparin dosages to treat venous thromboembolism (VTE) are unknown. OBJECTIVE: To evaluate therapeutic nadroparin dosages to reach therapeutic target ranges (TTR: 0.5-1.0 International Unit (IU)/mL) and the effectiveness and safety of nadroparin in neonatal VTE. METHODS: Retrospective study including neonates with VTE on nadroparin in a tertiary center between 2007 and 2018. Two groups were distinguished: neonates before (group 1) and after (group 2) switch to higher starting dosages in 2014. RESULTS: Sixty-one neonates (44 preterm, 17 term) with 64 VTEs were included. TTR was reached in 32/64 (50%) VTEs (group 1: 35.7%; group 2: 61.1%). Median nadroparin dosage to reach TTR was 197 (97.9-330.3) IU/kg/12 h. No therapy-related deaths occurred. Recurrent VTE developed in 6 (9.8%) neonates. Complete clot resolution was observed in 31/41 (75.6%) VTEs. TTR was reached in 58.1% VTEs with complete clot resolution. No major bleeding occurred. Non-major clinically relevant bleedings occurred in 3/64 (4.7%) VTEs, consisting of large hematomas due to the use of subcutaneous catheters. CONCLUSIONS: High nadroparin dosages are needed to reach TTR in neonates, which seem to be safe. Clot resolution may occur without reaching TTR. Subcutaneous catheters may cause important bleeding complications.

Supplementation of vitamins, trace elements and electrolytes in the PEPaNIC Randomised Controlled Trial: Composition and preparation of the prescription.

BACKGROUND AND AIMS: Following the results of the paediatric early versus late parenteral nutrition in critical illness (PEPaNIC) multicentre, randomised, controlled trial, the new ESPGHAN/ESPEN/ESPR/CSPEN and ESPNIC guidelines recommend to consider withholding parenteral macronutrients for 1 week, while providing micronutrients, in critically ill children if enteral nutrition is insufficient. Critically ill children are suspected to be vulnerable to micronutrient deficiencies due to inadequate enteral nutrition, increased body's demands and excessive losses. Hitherto, micronutrient requirements in PICU are estimated based on recommended daily intakes for healthy children and expert opinion. We aimed to provide an overview of the current practice of micronutrient administration and practical considerations in the three participating centres of the PEPaNIC study, and compare these therapies with the recommendations in the new ESPGHAN/ESPEN/ESPR/CSPEN guidelines. METHODS: We describe the current composition and preparation of the prescribed parenteral micronutrients (consisting of vitamins, trace elements and electrolytes) in the three centres (Leuven, Rotterdam and Edmonton) that participated in the PEPaNIC RCT, and compare this per micronutrient with the ESPGHAN/ESPEN/ESPR/CSPEN guidelines recommendations. RESULTS: The three centres use a different micronutrient supplementation protocol during the first week of critical illness in children, with substantial differences regarding the amounts administered. Leuven administers commercial vitamins, trace elements and electrolytes in separate infusions both in 4 h. Rotterdam provides commercial vitamins and trace elements simultaneously via 8-h infusion and electrolytes continuously over 24 h. Lastly, Edmonton administers commercial vitamins and institutionally prepared trace elements solutions in 1 h and electrolytes on demand. Comparison with the ESPGHAN/ESPEN/ESPR/CSPEN guidelines yields in differences between the recommendations and the administered amounts, which are most substantial for vitamins. CONCLUSION: The practice of intravenous micronutrient administration differs substantially between the three PEPaNIC centres and in comparison with the current guideline recommendations. This deviation is at least partially explained by the inability to provide all recommended amounts with the currently available commercial products and by the lack of strong evidence supporting these recommendations.

An Accidental Repetitive 10-Fold Overdose of Sildenafil in a Young Infant with Pulmonary Hypertension.

Sildenafil is a selective phosphodiesterase type-5 inhibitor that is increasingly used to treat pulmonary hypertension (PH) in neonates. Only little is known about the relation between the dose of sildenafil, plasma concentrations, and the degree of toxicity. Here, we present a young infant with congenital diaphragmatic hernia and PH who received an unintentional 10-fold overdose of oral sildenafil for 6 consecutive days. This overdose, compared to the therapeutic dose, resulted in increased plasma concentrations of sildenafil from 42 to 521 mcg/L and desmethylsildenafil from 81 to 393 mcg/L. However, the high exposure only led to diarrhea, without any other serious adverse events. This case describes the mild symptoms upon an overdose with the role of therapeutic drug monitoring to monitor exposure in relation to symptoms and therewith support clinical decision-making.

Spectroscopic detection of brain propylene glycol in neonates: Effects of different pharmaceutical formulations of phenobarbital.

BACKGROUND: The first choice for treatment of neonatal convulsions is intravenous phenobarbital, which contains propylene glycol (PG) as a solvent. Although PG is generally considered safe, the dosage can exceed safety thresholds in neonates. High PG levels can cause lactic acidosis. PURPOSE/HYPOTHESIS: To investigate a relationship between brain PG concentration and medication administered to neonates, and to study if a correlation between spectroscopically detected PG and lactate was present. STUDY TYPE: Retrospective. POPULATION: Forty-one neonates who underwent MRI/MRS. FIELD STRENGTH/SEQUENCE: Short echo time single voxel MRS at 1.5T. ASSESSMENT: Spectra were quantified. Concentrations of PG were correlated with medication administered, because intravenously administered phenobarbital solutions contained 10, 25, or 50 mg phenobarbital per ml, all containing 350 mg PG per ml. The interval between medication and MRI/MRS was determined. STATISTICAL TESTS: Chi-square test, Student's t-test, Mann-Whitney U-test and Spearman correlation. RESULTS: Eighteen neonates had brain PG >1 mM (median 3.4 mM, maximum 9.5 mM). All 18 neonates with high brain PG and 14 neonates with low brain PG (<1 mM) received phenobarbital as the only source of PG. Nine neonates did not receive any phenobarbital/PG-containing medication. Neonates with high brain PG more often received 10 mg/ml phenobarbital, resulting in higher PG dose (high vs. low brain PG (median [interquartile range]: 1400 [595] vs. 350 [595] mg/kg, respectively, P < 0.01). In addition, the interval between the last phenobarbital dose and MRI was shorter in the high brain PG group (high vs. low brain PG: 16 [21] vs. 95 [83] hours, respectively, P < 0.001). Within neonates that received phenobarbital, there was no conclusive correlation between spectroscopically detected PG and lactate (Spearman's rho = 0.23, P = 0.10). DATA CONCLUSION: These MRS findings may increase awareness of potentially toxic PG concentrations in the neonatal brain due to intravenous phenobarbital administration and its dependence on the phenobarbital formulation used. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;49:1062-1068.

Flucloxacillin Results in Suboptimal Plasma Voriconazole Concentrations.

Combining voriconazole and flucloxacillin is indicated in patient cohorts experiencing both invasive aspergillosis and Gram-positive infections (e.g., patients with chronic granulomatous disease or postinfluenza pulmonary aspergillosis). We report a highly relevant interaction between voriconazole and flucloxacillin, resulting in subtherapeutic plasma voriconazole concentrations in more than 50% of patients, that poses a severe threat if not managed properly.

Adverse drug reaction-related admissions in paediatrics, a prospective single-centre study.

OBJECTIVE: To investigate the incidence and characteristics of hospital admissions related to adverse drug events in the paediatric setting. DESIGN: Prospective single-centre study. SETTING: A secondary and tertiary paediatric care centre. PARTICIPANTS: A total of 683 acutely admitted patients, aged 0-18 year. All acutely admitted patients, using medication before admission, were prospectively screened for possible Adverse Drug Reactions (ADR)-related admission with a trigger list. Included cases were analysed with the Naranjo score for the assessment of causality. MAIN OUTCOME MEASURES: This research explored the incidence of ADR-related admissions and investigated the relation between ADR and the licensing status of the medicines, as well as the severity and potential to prevent the ADRs. RESULTS: A total of 683 patients were admitted acutely during the study period, 47 of them were exposed to cancer chemotherapy. Fifteen patients not exposed to chemotherapy (2.4%) were admitted due to an ADR. Five of these 15 ADRs (33%) were caused by unlicensed or off-label used drugs. Thirty-two patients exposed to chemotherapy (68.1%) were admitted due to an ADR; 27 of these (84%) were caused by unlicensed or off-label used drugs. CONCLUSIONS: In conclusion, this study shows that ADR-related hospital admissions occur more frequently in the paediatric population compared with adults, and more frequently in patients exposed to cancer chemotherapy. No relation was found between the unlicensed and off-label used drugs and the incidence of ADRs.

Sildenafil exposure in neonates with pulmonary hypertension after administration via a nasogastric tube.

OBJECTIVE: To describe the pharmacokinetics and exposure of oral sildenafil (SIL) in neonates (2-5 kg) with pulmonary hypertension (PH). DESIGN: We included 11 neonates (body weight 2-5 kg, postnatal age 2-121 days) who received SIL and extracorporeal membrane oxygenation (ECMO) treatment for PH. SIL capsules were given via a nasogastric tube. Blood samples were collected via a pre-existing arterial line to quantify SIL and metabolite plasma levels (219 samples). Non-linear mixed effects modelling was used to describe SIL and desmethylsildenafil (DMS) pharmacokinetics. RESULTS: A one-compartment model was suitable for SIL and DMS. Interpatient and intrapatient variability for clearance at 100% bioavailability were 87% and 27% (SIL) and 62% and 26% (DMS). Patient weight, postnatal age and post-ECMO time did not explain variability. Concomitant fluconazole use was associated with a 47% reduction in SIL clearance. The exposure expressed as average plasma concentration area under the curve over 24 h (AUC(24 (SIL+DMS))) ranged from 625 to 13 579 ng/h/ml. An oral dose of 4.2 mg/kg/24 h would lead to a median AUC(24 (SIL+DMS)) of 2650 ng/h/ml equivalent to 20 mg three times a day in adults. Interpatient variability was large, with a simulated AUC(24 (SIL+DMS)) range (10th and 90th percentiles) of 1000-8000 ng/h/ml. CONCLUSIONS: SIL pharmacokinetics are highly variable in post-ECMO neonates and infants. In a median patient, the current dose regimen of 0.5-2.0 mg/kg four times a day leads to an exposure comparable to the recommended adult dose of 20 mg four times a day. Careful dose titration, based on efficacy and the occurrence of hypotension, remains necessary. Follow-up research should include appropriate pharmacodynamic endpoints, with a population pharmacokinetic/pharmacodynamic analysis to assign a suitable exposure window or target concentration.

Simultaneous assay of sildenafil and desmethylsildenafil in neonatal plasma by ultra-performance liquid chromatography-tandem mass spectrometry.

Sildenafil is used to treat pulmonary hypertension in neonatal and pediatric patients. Pharmacokinetic studies in these patients are complicated by the limited sample volume. We present the validation results of an assay method to quantitate sildenafil and desmethylsildenafil simultaneously in 50 microL of plasma. Deuterated sildenafil was used as an internal standard. After liquid-liquid extraction, analytes were separated on an ultra-performance liquid chromatography (UPLC)-column and quantified via tandem mass spectrometry. The calibration range was linear, with acceptable accuracy and a precision of <15% for both compounds. The lower limits of quantification were 1 ng/mL. Matrix effects were present, but inter-plasma batch variability was under 12%. The method was successfully applied to samples from a pharmacokinetic study into sildenafil pharmacokinetics in neonates, making maximum use of the limited number and amount of plasma samples available.