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Codaccioni M, Southall RL, Dinh J, Johnson TN. Prediction of Pediatric Pharmacokinetics for CYP3A4 Metabolized Drugs: Comparison of the Performance of Two Hepatic Ontogeny Within a Physiologically Based Pharmacokinetic Model. J Clin Pharmacol 2024. [PMID: 38696325 DOI: 10.1002/jcph.2452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 04/09/2024] [Indexed: 05/04/2024]
Abstract
The rapid growth in the use of pediatric physiologically based pharmacokinetic (PBPK) models, particularly for regulatory applications, has focused emphasis on model verification and ensuring system parameters are robust, including how these change with age. Uncertainty remains regarding the ontogeny of some enzymes and transporters, in this study 2 published ontogeny profiles for hepatic CYP3A4 were compared. Clinical pharmacokinetic data on 4 intravenously administered CYP3A4 substrates (alfentanil, fentanyl, midazolam, and sildenafil) used across the pediatric age range was collected from the literature. The PBPK models were verified in the adult population and then used to compare the Salem and a modified Upreti ontogeny profiles for CYP3A4 in terms of parent drug clearance and area under the curve from birth onward. Overall, the modified Upreti ontogeny profile resulted in 15 out of 17 age-related predictions within 2-fold and 12 out of 17 predictions within 1.5-fold ranges of observed values, for the Salem ontogeny these values were 12 out of 17 and 8 out of 17, respectively. The Upreti ontogeny profile performed better than Salem, average fold error and absolute average fold error were 1.14 and 1.35 compared to 1.56 and 1.90, respectively. Identifying the optimal CYP3A4 ontogeny is important for regulatory use of PBPK especially given the number of drugs cleared by this enzyme. This study broadens the evidence from previous studies that Upreti is more favorable than Salem, but further work is needed especially in the neonatal and early infant age range.
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Affiliation(s)
- Marc Codaccioni
- Certara Predictive Technologies Division, Certara UK Limited, Sheffield, UK
| | | | - Jean Dinh
- Certara Predictive Technologies Division, Certara UK Limited, Sheffield, UK
| | - Trevor N Johnson
- Certara Predictive Technologies Division, Certara UK Limited, Sheffield, UK
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2
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van Saet A, Tibboel D. The influence of cardiopulmonary bypass on pediatric pharmacokinetics. Expert Opin Drug Metab Toxicol 2023; 19:333-344. [PMID: 37334571 DOI: 10.1080/17425255.2023.2227556] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 06/16/2023] [Indexed: 06/20/2023]
Abstract
INTRODUCTION Every year thousands of children undergo surgery for congenital heart disease. Cardiac surgery requires the use of cardiopulmonary bypass, which can have unexpected consequences for pharmacokinetic parameters. AREAS COVERED We describe the pathophysiological properties of cardiopulmonary bypass that may influence pharmacokinetic parameters, with a focus on literature published in the last 10 years. We performed a PubMed database search with the keywords 'Cardiopulmonary bypass' AND 'Pediatric' AND 'Pharmacokinetics'. We searched related articles on PubMed and checked the references of articles for relevant studies. EXPERT OPINION Interest in the influence of cardiopulmonary bypass on pharmacokinetics has increased over the last 10 years, especially due to the use of population pharmacokinetic modeling. Unfortunately, study design usually limits the amount of information that can be obtained with sufficient power and the best way to model cardiopulmonary bypass is yet unknown. More information is needed on the pathophysiology of pediatric heart disease and cardiopulmonary bypass. Once adequately validated, PK models should be integrated in the patient electronic database integrating covariates and biomarkers influencing PK, making it possible to predict real-time drug concentrations and guide further clinical management for the individual patient at the bedside.
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Affiliation(s)
- Annewil van Saet
- Department of Anesthesiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Dick Tibboel
- Department of Intensive Care and Pediatric Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
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3
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Kumar S, Memon D, Raj M, Sen AC, Jayasankar JP, Leeladharan SP, Sudhakar A, Kumar RK. Comparison of intravenous sildenafil with inhaled nitric oxide for acute vasodilator testing in pulmonary arterial hypertension. Pulm Circ 2022; 12:e12180. [PMID: 36583117 PMCID: PMC9791914 DOI: 10.1002/pul2.12180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/17/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Acute vasodilator testing (AVT) identifies acute responders for initiation of calcium channel blockers in pulmonary arterial hypertension (PAH) and operability in congenital heart disease (CHD). We sought to determine the feasibility of intravenous sildenafil (ivS) as an alternative to inhaled nitric oxide (iNO) in AVT. All patients with PAH undergoing cardiac catheterization for AVT (November 2015 to December 2020) were prospectively enrolled. Hemodynamic data were obtained at baseline, with iNO 20 ppm and ivS (0.25 mg/kg for children and 10 mg for adults). We studied 44 patients with a mean age of 20.5 ± 14.4 years (27 [61%] females and 20 [45%] children). There were 17 (38.6%) patients in the CHD group for operability assessment and 27 patients in non-CHD group (idiopathic pulmonary arterial hypertension-16 [36.3%], residual PAH after shunt closure-7 [15.9%], and 2 cases [4.5%] each of familial PAH and portopulmonary hypertension). There was an excellent intraclass correlation for mean pulmonary artery pressures (0.903, 95% confidence interval, CI: 0.809-0.949, p < 0.001), mean aortic pressures (0.745, 95% CI: 0.552-0.858, p < 0.001), pulmonary vascular resistance index (0.920, 95% CI: 0.858-0.956, p < 0.001), systemic vascular resistance (SVR) index (0.828, 95% CI: 0.706-0.902, p < 0.001), and the ratio of pulmonary and SVR indices (0.857, 95% CI: 0.752-0.919, p < 0.001) between the two agents. There were two responders, both in non-CHD group, and were identified by iNO and ivS. The hemodynamic effects of ivS show excellent correlation with iNO and could be a potential alternative agent for identifying acute responders during AVT.
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Affiliation(s)
- Shine Kumar
- Department of Pediatric Cardiology, Pulmonary Hypertension Clinic, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
| | - Danish Memon
- Department of Pediatric Cardiology, Pulmonary Hypertension Clinic, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
| | - Manu Raj
- Department of Pediatrics and Health Sciences Research, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
| | - Amitabh C. Sen
- Department of Cardiac AnesthesiologySultan Qaboos University HospitalMuscatOman
| | - Jessin P. Jayasankar
- Department of Cardiac Anesthesiology, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
| | - Sreelakshmi P. Leeladharan
- Department of Cardiac Anesthesiology, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
| | - Abish Sudhakar
- Department of Pediatric Cardiology, Pulmonary Hypertension Clinic, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
| | - Raman K. Kumar
- Department of Pediatric Cardiology, Pulmonary Hypertension Clinic, Amrita Institute of Medical SciencesAmrita Vishwa Vidyapeetham UniversityKochiKeralaIndia
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Lin S, Gong J, Canas GC, Winkle P, Pelletier K, LaBadie RR, Ginman K, Pithavala YK. A Phase I Study to Evaluate the Pharmacokinetics and Safety of Lorlatinib in Adults with Mild, Moderate, and Severe Renal Impairment. Eur J Drug Metab Pharmacokinet 2022; 47:235-245. [PMID: 35018553 PMCID: PMC8917008 DOI: 10.1007/s13318-021-00747-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2021] [Indexed: 11/07/2022]
Abstract
Background and Objectives Lorlatinib is approved (100 mg once daily [QD]) for the treatment of patients with anaplastic lymphoma kinase- (ALK) positive metastatic non-small cell lung cancer. This study evaluated the impact of varying degrees of renal impairment on the safety and pharmacokinetics of lorlatinib. Methods Participants were assigned to mild, moderate, and severe renal impairment groups and to a matching normal renal function group based on absolute estimated glomerular filtration rate (eGFR, based on the Modification of Diet in Renal Disease equation and adjusted for body surface area [BSA]) and were evaluated for pharmacokinetics and safety. Results A total of 29 participants (5 with severe renal impairment; 8 each with moderate and mild impairment and normal renal function) were enrolled and received a single dose of lorlatinib 100 mg. One of the participants with severe renal impairment had end-stage renal disease with a baseline absolute eGFR of 10.3 mL/min. No serious adverse events (AEs) were reported. Eighteen AEs, all mild or moderate in severity, were reported by 12 participants (5, 2, 4, and 1 in the normal, mild, moderate, and severe groups, respectively). Area under the plasma concentration–time profile from time zero extrapolated to infinity (AUCinf) for lorlatinib was increased by 4%, 19%, and 41% in the mild, moderate, and severe renal impairment groups, respectively, compared with the normal renal function cohort. Conclusion Lorlatinib 100 mg was well tolerated. As participants with mild and moderate renal impairment did not experience clinically meaningful increases in lorlatinib exposure, no lorlatinib dose adjustment is recommended in these populations. Patients with severe renal impairment are recommended to reduce the starting dose of lorlatinib from 100 mg QD to 75 mg QD. Clinicaltrials.gov identifier NCT03542305 (available May 31, 2018 on clinicaltrials.gov)
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Affiliation(s)
- Swan Lin
- Pfizer Inc., Global Product Development, San Diego, CA, USA.
| | - Jason Gong
- Pfizer Inc., Global Product Development, New York, NY, USA
| | - George C Canas
- Prism Research Inc., Prism Clinical Research, St. Paul, MN, USA
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Hill KD, Maharaj AR, Li JS, Thompson E, Barker PC, Hornik CP. A Randomized, Controlled Pharmacokinetic and Pharmacodynamics Trial of Ambrisentan After Fontan Surgery. Pediatr Crit Care Med 2020; 21:e795-e803. [PMID: 32639468 PMCID: PMC7483887 DOI: 10.1097/pcc.0000000000002410] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVES To determine the pharmacokinetics, pharmacodynamics, and safety of the hepatically metabolized endothelin receptor antagonist, ambrisentan in children after Fontan surgery. DESIGN Prospective, randomized, double-blind, placebo-controlled pharmacokinetic/pharmacodynamics and safety trial. SETTING Single-center, postoperative cardiac ICU. PATIENTS Children undergoing elective Fontan surgery. INTERVENTIONS Subjects randomized on postoperative day number 1 to short-term (3 d) treatment with oral ambrisentan (2.5 mg in suspension, daily) versus placebo (4:1 randomization). MEASUREMENTS AND MAIN RESULTS Plasma drug concentrations were measured at 0.5, 1, 2, 4, and 18-36 hours after the first dose. We developed a population pharmacokinetic model in NONMEM 7.2 (Icon Solutions, Ellicott City, MD) and applied the model to dose-exposure simulations. Pharmacodynamics endpoints were assessed at baseline and 3 hours after study drug administration, using postoperative hemodynamic monitoring lines. The analysis included 16 patients, 13 on ambrisentan (77 plasma samples); median age 36 months (range, 26-72 mo), weight 13.3 kg (11.1-17.6 kg), and nine males. There were no differences in baseline characteristics between ambrisentan and controls. A one-compartment model with first-order absorption and lag-time characterized the data well. Allometrically scaled weight was the only covariate retained in the final model. Typical values for clearance and volume of distribution were lower than previously reported in adults, 1 L/hr/70 kg and 13.7 L/70 kg, respectively. Simulated exposures with doses of 0.1-0.2 mg/kg approximated therapeutic exposures in adults with pulmonary arterial hypertension receiving 5 mg or 10 mg doses. Ambrisentan lowered plasma brain natriuretic peptide concentrations (452 ± 479 to 413 ± 462; p = 0.046), Fontan pressures (16.8 ± 2.9 to 15.6 ± 2.9; p = 0.01), and indexed pulmonary vascular resistance (2.3 ± 0.9 to 1.8 ± 0.6; p = 0.01) with no drug-related adverse events. CONCLUSIONS Ambrisentan clearance is reduced following Fontan surgery, perhaps reflecting abnormal hepatic metabolism in this population. The observed safety profile appears favorable and hemodynamic effects of ambrisentan may be beneficial for Fontan patients.
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Affiliation(s)
- Kevin D. Hill
- Duke University Pediatric and Congenital Heart Center, Durham, NC
- Duke Clinical Research Institute, Durham NC
| | | | - Jennifer S. Li
- Duke University Pediatric and Congenital Heart Center, Durham, NC
- Duke Clinical Research Institute, Durham NC
| | | | | | - Christoph P. Hornik
- Duke University Pediatric and Congenital Heart Center, Durham, NC
- Duke Clinical Research Institute, Durham NC
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Safety and efficacy of sildenafil citrate to reduce operative birth for intrapartum fetal compromise at term: a phase 2 randomized controlled trial. Am J Obstet Gynecol 2020; 222:401-414. [PMID: 31978434 DOI: 10.1016/j.ajog.2020.01.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/07/2020] [Accepted: 01/13/2020] [Indexed: 02/01/2023]
Abstract
BACKGROUND AND OBJECTIVE Sildenafil citrate is a vasodilator used in erectile dysfunction and pulmonary hypertension. We tested whether it reduces emergency operative births for fetal compromise and improves fetal or uteroplacental perfusion in labor in a phase 2 double-blind randomized controlled trial. STUDY DESIGN Women at term in early labor or undergoing scheduled induction of labor at Mater Mother's Hospital, Brisbane, Australia, were randomly allocated 50 mg of sildenafil citrate orally 8 hourly up to 150 mg or placebo. Intrapartum fetal monitoring followed Royal Australian and New Zealand College of Obstetricians and Gynaecologists guidelines. Primary outcomes were (1) emergency operative birth (by cesarean delivery or instrumental vaginal birth) for intrapartum fetal compromise and (2) mean indices of fetal and uteroplacental perfusion using Doppler ultrasound. Analysis was by intention-to-treat. TRIAL REGISTRATION NUMBER ANZCTRN12615000319572 RESULTS: Between September 2015 and January 2019, 300 women were randomized equally to sildenafil citrate or placebo. Sildenafil citrate reduced the risk of emergency operative birth by 51% (18% vs 36.7%; relative risk, 0.49, 95% confidence interval, 0.33-0.73, P=.0004, number needed to treat = 5 [3-11]). There was no difference in indices of fetal and uteroplacental perfusion, but these were ascertained in only 71 women. Sildenafil citrate reduced the risk of meconium-stained liquor or pathologic fetal heart rate patterns by 43% (25.3% vs 44.7%; relative risk, 0.57, 95% confidence interval, 0.41-0.79, P=.0005), but its effects on fetal scalp sampling rates (2.0% vs 6.7%; relative risk, 0.30, 95% confidence interval, 0.08-1.07, P=.06) and adverse neonatal outcome (20.7% vs 21.3%; relative risk, 0.97, 95% confidence interval, 0.62-1.50, P=.89) were inconclusive. Only 3.6% of maternal levels of sildenafil citrate or its metabolite were detected in cord blood. No differences in maternal adverse events were seen. CONCLUSION Sildenafil citrate reduced operative birth for intrapartum fetal compromise, but much larger phase 3 trials of its effects on mother and child are needed before it can be routinely recommended.
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7
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Gonzalez D, Laughon MM, Smith PB, Ge S, Ambalavanan N, Atz A, Sokol GM, Hornik CD, Stewart D, Mundakel G, Poindexter BB, Gaedigk R, Mills M, Cohen‐Wolkowiez M, Martz K, Hornik CP. Population pharmacokinetics of sildenafil in extremely premature infants. Br J Clin Pharmacol 2019; 85:2824-2837. [PMID: 31475367 PMCID: PMC6955411 DOI: 10.1111/bcp.14111] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 08/06/2019] [Accepted: 08/22/2019] [Indexed: 11/30/2022] Open
Abstract
AIMS To characterize the population pharmacokinetics (PK) of sildenafil and its active metabolite, N-desmethyl sildenafil (DMS), in premature infants. METHODS We performed a multicentre, open-label trial to characterize the PK of sildenafil in infants ≤28 weeks gestation and < 365 postnatal days (cohort 1) or < 32 weeks gestation and 3-42 postnatal days (cohort 2). In cohort 1, we obtained PK samples from infants receiving sildenafil as ordered per the local standard of care (intravenous [IV] or enteral). In cohort 2, we administered a single IV dose of sildenafil and performed PK sampling. We performed a population PK analysis and dose-exposure simulations using the software NONMEM®. RESULTS We enrolled 34 infants (cohort 1 n = 25; cohort 2 n = 9) and collected 109 plasma PK samples. Sildenafil was given enterally (0.42-2.09 mg/kg) in 24 infants in cohort 1 and via IV (0.125 or 0.25 mg/kg) in all infants in cohort 2. A 2-compartment PK model for sildenafil and 1-compartment model for DMS, with presystemic conversion of sildenafil to DMS, characterized the data well. Coadministration of fluconazole (n = 4), a CYP3A inhibitor, resulted in an estimated 59% decrease in sildenafil clearance. IV doses of 0.125, 0.5 and 1 mg/kg every 8 hours (in the absence of fluconazole) resulted in steady-state maximum sildenafil concentrations that were generally within the range of those reported to inhibit phosphodiesterase type 5 activity in vitro. CONCLUSIONS We successfully characterized the PK of sildenafil and DMS in premature infants and applied the model to inform dosing for a follow-up, phase II study.
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MESH Headings
- Administration, Oral
- Cohort Studies
- Cytochrome P-450 CYP3A/blood
- Cytochrome P-450 CYP3A/genetics
- Fluconazole/administration & dosage
- Fluconazole/pharmacokinetics
- Gestational Age
- Humans
- Hypertension, Pulmonary/blood
- Hypertension, Pulmonary/drug therapy
- Infant
- Infant, Newborn
- Infant, Premature/blood
- Infant, Premature, Diseases/blood
- Infant, Premature, Diseases/drug therapy
- Injections, Intravenous
- Models, Biological
- Phosphodiesterase 5 Inhibitors/administration & dosage
- Phosphodiesterase 5 Inhibitors/blood
- Phosphodiesterase 5 Inhibitors/pharmacokinetics
- Phosphodiesterase 5 Inhibitors/therapeutic use
- Sildenafil Citrate/administration & dosage
- Sildenafil Citrate/blood
- Sildenafil Citrate/pharmacokinetics
- Sildenafil Citrate/therapeutic use
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Affiliation(s)
- Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNCUSA
| | - Matthew M. Laughon
- Department of Pediatrics, School of MedicineThe University of North Carolina at Chapel HillChapel HillNCUSA
| | - P. Brian Smith
- Department of PediatricsDuke University School of MedicineDurhamNCUSA
- Duke Clinical Research InstituteDurhamNCUSA
| | - Shufan Ge
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of PharmacyThe University of North Carolina at Chapel HillChapel HillNCUSA
| | - Namasivayam Ambalavanan
- Division of Neonatology, School of MedicineUniversity of Alabama at BirminghamBirminghamALUSA
| | - Andrew Atz
- Department of PediatricsMedical University of South Carolina Children's HospitalCharlestonSCUSA
| | - Gregory M. Sokol
- Section of Neonatal‐Perinatal MedicineIndiana University School of MedicineIndianapolisINUSA
| | - Chi D. Hornik
- Department of PediatricsDuke University School of MedicineDurhamNCUSA
- Duke Clinical Research InstituteDurhamNCUSA
- Department of PharmacyDuke University Medical CenterDurhamNCUSA
| | - Dan Stewart
- University of Louisville Norton Children's HospitalLouisvilleKYUSA
| | - Gratias Mundakel
- Kings County Hospital Center/SUNY Downstate Medical CenterBrooklynNYUSA
| | | | - Roger Gaedigk
- Department of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children's Mercy‐Kansas CityUniversity of Missouri‐Kansas City School of MedicineKansas CityMOUSA
| | - Mary Mills
- Duke Clinical Research InstituteDurhamNCUSA
| | - Michael Cohen‐Wolkowiez
- Department of PediatricsDuke University School of MedicineDurhamNCUSA
- Duke Clinical Research InstituteDurhamNCUSA
| | | | - Christoph P. Hornik
- Department of PediatricsDuke University School of MedicineDurhamNCUSA
- Duke Clinical Research InstituteDurhamNCUSA
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Brussee JM, Krekels EHJ, Calvier EAM, Palić S, Rostami-Hodjegan A, Danhof M, Barrett JS, de Wildt SN, Knibbe CAJ. A Pediatric Covariate Function for CYP3A-Mediated Midazolam Clearance Can Scale Clearance of Selected CYP3A Substrates in Children. AAPS JOURNAL 2019; 21:81. [PMID: 31250333 PMCID: PMC6597607 DOI: 10.1208/s12248-019-0351-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/07/2019] [Indexed: 12/12/2022]
Abstract
Recently a framework was presented to assess whether pediatric covariate models for clearance can be extrapolated between drugs sharing elimination pathways, based on extraction ratio, protein binding, and other drug properties. Here we evaluate when a pediatric covariate function for midazolam clearance can be used to scale clearance of other CYP3A substrates. A population PK model including a covariate function for clearance was developed for midazolam in children aged 1–17 years. Commonly used CYP3A substrates were selected and using the framework, it was assessed whether the midazolam covariate function accurately scales their clearance. For eight substrates, reported pediatric clearance values were compared numerically and graphically with clearance values scaled using the midazolam covariate function. For sildenafil, clearance values obtained with population PK modeling based on pediatric concentration-time data were compared with those scaled with the midazolam covariate function. According to the framework, a midazolam covariate function will lead to systemically accurate clearance scaling (absolute prediction error (PE) < 30%) for CYP3A substrates binding to albumin with an extraction ratio between 0.35 and 0.65 when binding < 10% in adults, between 0.05 and 0.55 when binding > 90%, and with an extraction ratio ranging between these values when binding between 10 and 90%. Scaled clearance values for eight commonly used CYP3A substrates were reasonably accurate (PE < 50%). Scaling of sildenafil clearance was accurate (PE < 30%). We defined for which CYP3A substrates a pediatric covariate function for midazolam clearance can accurately scale plasma clearance in children. This scaling approach may be useful for CYP3A substrates with scarce or no available pediatric PK information.
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Affiliation(s)
- Janneke M Brussee
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands
| | - Elke H J Krekels
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands
| | - Elisa A M Calvier
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands
| | - Semra Palić
- Dutch Cancer Institute (NKI), Amsterdam, The Netherlands
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research, University of Manchester, Manchester, UK.,Simcyp Limited (A Certara Company), Sheffield, UK
| | - Meindert Danhof
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands
| | - Jeffrey S Barrett
- Bill & Melinda Gates Medical Research Institute, Cambridge, Massachusetts, USA.,Department of Pediatrics, Division of Clinical Pharmacology & Therapeutics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Saskia N de Wildt
- Department of Pharmacology and Toxicology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Intensive Care and Department of Pediatric Surgery, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Catherijne A J Knibbe
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands. .,Department of Clinical Pharmacy, St. Antonius Hospital, PO Box 2500, 3430, EM, Nieuwegein, The Netherlands.
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Abstract
BACKGROUND Enteral sildenafil may be used in the intensive care unit for treatment of pulmonary arterial hypertension. We aimed to determine if initial enteral sildenafil dosing is safe in children receiving concurrent vasoactive infusions. METHODS We performed a single-centre retrospective chart review that included patients less than 2 years of age in paediatric and cardiovascular intensive care units at an academic medical centre from 1 January, 2010 to 30 November, 2016. Included patients received concomitant enteral sildenafil and a continuously infused vasoactive agent. Exclusion criteria consisted of mechanical circulatory support, any form of dialysis, or a suspicion of septic shock at the time of sildenafil initiation. We sought to identify patients who developed worsening hemodynamic instability after initiation of enteral sildenafil defined as one or more of the following observations within 24 hours of sildenafil initiation: sildenafil discontinuation, total fluid bolus receipt >10 ml/kg, increased vasoactive support, epinephrine intravenous push administration, and/or the initiation of mechanical circulatory support. RESULTS Worsening hemodynamic instability was identified in 35% of the 130-patient cohort. Patients younger than 4 months were at increased risk of further hemodynamic instability compared with older patients (56% versus 44%, p = 0.0003) despite receiving lower median doses (1.28 mg/kg/day versus 1.78 mg/kg/day, p = 0.01). CONCLUSIONS Critically ill children receiving vasoactive infusions may be at increased risk for further hemodynamic instability after initiation of enteral sildenafil, particularly in younger patients. This population may benefit from lower starting enteral sildenafil doses of 0.25 mg/kg/dose or less every 8 hours to avoid further hemodynamic compromise.
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Sildenafil Citrate Liposomes for Pulmonary Delivery by Ultrasonic Nebulization. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8081291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Technological advances in lipid vesicles facilitate optimization of their properties to achieve therapeutic goals and promote alternative drug administration routes. Sildenafil citrate (SC) is orally administered for the treatment of pulmonary hypertension, but local release would be advantageous in terms of efficacy and safety. In the present study, liposomes from egg phosphatidylcholine and cholesterol loaded with SC, with and without d-α-tocopheryl polyethylene glycol 1000 succinate (Vit E TPGS), were prepared by sonication of the components. A transmembrane pH gradient was applied for active loading of liposomes, and the size, zeta potential, and entrapment efficiency (EE%) were determined. The liposomes were lyophilized and then nebulized. The nebulized samples were collected and the EE% was determined. The transmembrane pH gradient produced a significant increase in the EE% (from 17.68 ± 4.25% to 89.77 ± 7.64%) and, after lyophilization, the EE% remained the same as that of the originals, but the size and zeta potential were modified. EE% of liposomes decreased upon nebulization, particularly for those with Vit E TPGS. Thus, the additives used for lyoprotection reduced the impact of nebulization. Additional studies are essential, but according to these results, SC-loaded liposomes can be considered as suitable and safe carriers for the local release of sildenafil in the pulmonary system.
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11
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Olguín HJ, Martínez HO, Pérez CF, Mendiola BR, Espinosa LR, Pacheco JLC, Pérez JF, Magaña IM. Pharmacokinetics of sildenafil in children with pulmonary arterial hypertension. World J Pediatr 2017; 13:588-592. [PMID: 28791664 DOI: 10.1007/s12519-017-0043-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/30/2016] [Indexed: 10/19/2022]
Abstract
BACKGROUND Recently, sildenafil was introduced to treat pulmonary arterial hypertension (PAH); however, there are currently few studies on the pharmacokinetics of sildenalfil in children. Therefore, we aimed to carry out a pharmacokinetic study of sildenafil in children with PAH using a single dose. METHODS Twelve children diagnosed with PAH, consisting of with ten males and two females, were recruited for the study after obtaining written consent from their parents or guardians. Blood samples were obtained predose and at 0.25, 0.5, 1, 2, 4, 8 and 12 hours after the oral administration of 1 mg/kg of sildenafil using an extemporal pediatric formulation developed in our laboratory. The samples were analyzed using a previously validated high performance liquid chromatography method. RESULTS A pharmacokinetic analysis using the WinNonlin 3.1 program that considered the Akaike information criterion (AIC) for selecting a more adjustable model was performed. The following pharmacokinetic parameters were obtained: maximal concentration (Cmax): 366±179 ng/mL, time to maximal concentration: 0.92±0.30 hours, elimination half-life (t1/2): 2.41±1.18 hours, total clearance (CLtot/F): 5.85±2.81 L/hour, volume of distribution (Vd/F): 20.13±14.5 L, absorption rate constants (Ka): 0.343 hour-1, elimination rate (Ke): 0.35 hour-1, area under curve from zero to infinity: 2061±618 ng/mL/hour. The data of all patients adjusted to the model of one compartment were corroborated using AIC. CONCLUSIONS The parameters Ka, Ke and t1/2 were found to be similar to those reported in adults; however, the values of Cmax and Vd/F were significantly higher. Based on these findings, we propose that treatment regimen of sildenafil be adjusted in children with PAH.
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Affiliation(s)
- Hugo Juárez Olguín
- Laboratory of Pharmacology, National Institute of Pediatrics, Avenida Imán N° 1, 3rd piso Colonia Cuicuilco, CP 04530, Mexico City, Mexico. .,Department of Pharmacology, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.
| | | | - Carmen Flores Pérez
- Laboratory of Pharmacology, National Institute of Pediatrics, Avenida Imán N° 1, 3rd piso Colonia Cuicuilco, CP 04530, Mexico City, Mexico
| | - Blanca Ramírez Mendiola
- Laboratory of Pharmacology, National Institute of Pediatrics, Avenida Imán N° 1, 3rd piso Colonia Cuicuilco, CP 04530, Mexico City, Mexico
| | - Liliana Rivera Espinosa
- Laboratory of Pharmacology, National Institute of Pediatrics, Avenida Imán N° 1, 3rd piso Colonia Cuicuilco, CP 04530, Mexico City, Mexico
| | - Juan Luis Chávez Pacheco
- Laboratory of Pharmacology, National Institute of Pediatrics, Avenida Imán N° 1, 3rd piso Colonia Cuicuilco, CP 04530, Mexico City, Mexico
| | - Janett Flores Pérez
- Laboratory of Pharmacology, National Institute of Pediatrics, Avenida Imán N° 1, 3rd piso Colonia Cuicuilco, CP 04530, Mexico City, Mexico.,Department of Pharmacology, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
| | - Ignacio Mora Magaña
- Subdirection of Teaching and Educational Programming, National Institute of Pediatrics, Mexico City, Mexico
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Abstract
In the United States, the Best Pharmaceuticals for Children Act and the Pediatric Research Equity Act continue to promote clinical trials in pediatric populations across all age ranges. In 2014 and 2015, over 70 changes were made to drug labels with updates on information regarding pediatric populations. Additionally, multiple new therapies have received first-approvals for the treatment of pediatric indications ranging form rare genetic metabolic diseases to oncology. In the European Union, there have been more than 30 new authorizations for medicines used in children and 130 approved pediatric investigation plans. Despite the progress that has been made over the last two years, much work remains to further the development of safe and effective therapies for pediatric patients.
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Affiliation(s)
- Laura A Wang
- Duke Clinical Research Institute, Duke University Medical Center, 2400 Pratt Street, Durham, NC 27705, USA
| | - Michael Cohen-Wolkowiez
- Duke Clinical Research Institute, Duke University Medical Center, 2400 Pratt Street, Durham, NC 27705, USA; Department of Pediatrics, Children's Health Center, College of Medicine, Duke University, T901, Durham, NC 27705, USA.
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, 301 Pharmacy Lane, CB #7569, Chapel Hill, NC 27599, USA
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13
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Hashish HA. Effect of age on the sildenafil impact on the histological and ultra-structure of the liver in male albino rat. Histol Histopathol 2016. [DOI: 10.7243/2055-091x-3-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Dodgen AL, Hill KD. Safety and tolerability considerations in the use of sildenafil for children with pulmonary arterial hypertension. DRUG HEALTHCARE AND PATIENT SAFETY 2015; 7:175-83. [PMID: 26719728 PMCID: PMC4687613 DOI: 10.2147/dhps.s65571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Sildenafil is a phosphodiesterase type-5 inhibitor approved for treatment of pulmonary arterial hypertension (PAH) in adults. Data from pediatric trials demonstrate a similar acute safety profile to the adult population but have raised concerns regarding the safety of long-term use in children. Interpretation of these trials remains controversial with major regulatory agencies differing in their recommendations – the US Food and Drug Administration recommends against the use of sildenafil for treatment of PAH in children, while the European Medicines Agency supports its use at “low doses”. Here, we review the available pediatric data regarding dosing, acute, and long-term safety and efficacy of sildenafil for the treatment of PAH in children.
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Affiliation(s)
- Andrew L Dodgen
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA
| | - Kevin D Hill
- Department of Pediatrics, Duke University Medical Center, Durham, NC, USA ; Duke Clinical Research Institute, Durham, NC, USA
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