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Chapron BD, Chapron A, Leeder JS. Recent advances in the ontogeny of drug disposition. Br J Clin Pharmacol 2021; 88:4267-4284. [PMID: 33733546 DOI: 10.1111/bcp.14821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 02/12/2021] [Accepted: 02/22/2021] [Indexed: 12/11/2022] Open
Abstract
Developmental changes that occur throughout childhood have long been known to impact drug disposition. However, pharmacokinetic studies in the paediatric population have historically been limited due to ethical concerns arising from incorporating children into clinical trials. As such, much of the early work in the field of developmental pharmacology was reliant on difficult-to-interpret in vitro and in vivo animal studies. Over the last 2 decades, our understanding of the mechanistic processes underlying age-related changes in drug disposition has advanced considerably. Progress has largely been driven by technological advances in mass spectrometry-based methods for quantifying proteins implicated in drug disposition, and in silico tools that leverage these data to predict age-related changes in pharmacokinetics. This review summarizes our current understanding of the impact of childhood development on drug disposition, particularly focusing on research of the past 20 years, but also highlighting select examples of earlier foundational research. Equally important to the studies reviewed herein are the areas that we cannot currently describe due to the lack of research evidence; these gaps provide a map of drug disposition pathways for which developmental trends still need to be characterized.
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Affiliation(s)
- Brian D Chapron
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, USA
| | - Alenka Chapron
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, USA
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Hospital, Kansas City, MO, USA.,Schools of Medicine and Pharmacy, University of Missouri-Kansas City, MO, USA
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Opioids: A Review of Pharmacokinetics and Pharmacodynamics in Neonates, Infants, and Children. Eur J Drug Metab Pharmacokinet 2020; 44:591-609. [PMID: 31006834 DOI: 10.1007/s13318-019-00552-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Pain management in the pediatric population is complex for many reasons. Mild pain is usually managed quite well with oral acetaminophen or ibuprofen. Situations involving more severe pain often require the use of an opioid, which may be administered by many different routes, depending on clinical necessity. Acute and chronic disease states, as well as the constantly changing maturational process, produce unique challenges at every level of pediatrics in dosing and management of all medications, especially with regard to high-risk opioids. Although there has been significant progress in the understanding of opioid pharmacokinetics and pharmacodynamics in neonates, infants, children, and adolescents, somewhat limited data exist from which necessary information, concerning the safe and effective use of these agents, may be drawn. The evidence here provided is intended to be helpful in directing the practitioner to patient-specific reasons for preferring one opioid over another. As our knowledge of opioids and their effects has grown, it has become clear that older medications like codeine and meperidine (pethidine) have very limited use in pediatrics. This review provides pharmacokinetic and pharmacodynamic evidence on the currently available opioids: morphine, fentanyl (and derivatives), codeine, meperidine, oxycodone, hydrocodone, hydromorphone, methadone, buprenorphine, butorphanol, nalbuphine, pentazocin, ketobemidone, tramadol, piritramide, naloxone and naltrexone. Morphine, being the most studied opioid analgesic, is the standard against which all others are compared. Pharmacokinetic parameters of morphine that have been found in neonates, i.e., higher volume of distribution, immature metabolic processes that develop at various rates, elimination that is variable based on age and weight, as well as treated and untreated disease processes, are an example of all opioids in the population discussed in this review. Outside the premature and neonatal population, the use of opioids in infants, children, and adolescents quickly begins to resemble the established values found in adults. As such, the concerns (risks) of these medications become comparable to those seen in adults.
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Matlock MK, Tambe A, Elliott-Higgins J, Hines RN, Miller GP, Swamidass SJ. A Time-Embedding Network Models the Ontogeny of 23 Hepatic Drug Metabolizing Enzymes. Chem Res Toxicol 2019; 32:1707-1721. [PMID: 31304741 DOI: 10.1021/acs.chemrestox.9b00223] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pediatric patients are at elevated risk of adverse drug reactions, and there is insufficient information on drug safety in children. Complicating risk assessment in children, there are numerous age-dependent changes in the absorption, distribution, metabolism, and elimination of drugs. A key contributor to age-dependent drug toxicity risk is the ontogeny of drug metabolism enzymes, the changes in both abundance and type throughout development from the fetal period through adulthood. Critically, these changes affect not only the overall clearance of drugs but also exposure to individual metabolites. In this study, we introduce time-embedding neural networks in order to model population-level variation in metabolism enzyme expression as a function of age. We use a time-embedding network to model the ontogeny of 23 drug metabolism enzymes. The time-embedding network recapitulates known demographic factors impacting 3A5 expression. The time-embedding network also effectively models the nonlinear dynamics of 2D6 expression, enabling a better fit to clinical data than prior work. In contrast, a standard neural network fails to model these features of 3A5 and 2D6 expression. Finally, we combine the time-embedding model of ontogeny with additional information to estimate age-dependent changes in reactive metabolite exposure. This simple approach identifies age-dependent changes in exposure to valproic acid and dextromethorphan metabolites and suggests potential mechanisms of valproic acid toxicity. This approach may help researchers evaluate the risk of drug toxicity in pediatric populations.
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Affiliation(s)
- Matthew K Matlock
- Department of Pathology and Immunology , Washington University in St. Louis , Saint Louis , Missouri 63110 , United States
| | - Abhik Tambe
- Department of Pathology and Immunology , Washington University in St. Louis , Saint Louis , Missouri 63110 , United States
| | - Jack Elliott-Higgins
- Department of Pathology and Immunology , Washington University in St. Louis , Saint Louis , Missouri 63110 , United States
| | - Ronald N Hines
- National Health and Environmental Effects Research Laboratory , United States Environmental Protection Agency , Research Triangle Park , North Carolina 27709 , United States
| | - Grover P Miller
- Department of Biochemistry and Molecular Biology , University of Arkansas for Medical Sciences , Little Rock , Arkansas 72205 , United States
| | - S Joshua Swamidass
- Institute for Informatics , Washington University in St. Louis , Saint Louis , Missouri 63110 , United States
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T'jollyn H, Snoeys J, Vermeulen A, Michelet R, Cuyckens F, Mannens G, Van Peer A, Annaert P, Allegaert K, Van Bocxlaer J, Boussery K. Physiologically Based Pharmacokinetic Predictions of Tramadol Exposure Throughout Pediatric Life: an Analysis of the Different Clearance Contributors with Emphasis on CYP2D6 Maturation. AAPS JOURNAL 2015. [PMID: 26209290 DOI: 10.1208/s12248-015-9803-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This paper focuses on the retrospective evaluation of physiologically based pharmacokinetic (PBPK) techniques used to mechanistically predict clearance throughout pediatric life. An intravenous tramadol retrograde PBPK model was set up in Simcyp® using adult clearance values, qualified for CYP2D6, CYP3A4, CYP2B6, and renal contributions. Subsequently, the model was evaluated for mechanistic prediction of total, CYP2D6-related, and renal clearance predictions in very early life. In two in vitro pediatric human liver microsomal (HLM) batches (1 and 3 months), O-desmethyltramadol and N-desmethyltramadol formation rates were compared with CYP2D6 and CYP3A4 activity, respectively. O-desmethyltramadol formation was mediated only by CYP2D6, while N-desmethyltramadol was mediated in part by CYP3A4. Additionally, the clearance maturation of the PBPK model predictions was compared to two in vivo maturation models (Hill and exponential) based on plasma concentration data, and to clearance estimations from a WinNonlin® fit of plasma concentration and urinary excretion data. Maturation of renal and CYP2D6 clearance is captured well in the PBPK model predictions, but total tramadol clearance is underpredicted. The most pronounced underprediction of total and CYP2D6-mediated clearance was observed in the age range of 2-13 years. In conclusion, the PBPK technique showed to be a powerful mechanistic tool capable of predicting maturation of CYP2D6 and renal tramadol clearance in early infancy, although some underprediction occurs between 2 and 13 years for total and CYP2D6-mediated tramadol clearance.
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Affiliation(s)
- Huybrecht T'jollyn
- Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
| | - Jan Snoeys
- Janssen Research & Development, Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - An Vermeulen
- Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium
| | - Robin Michelet
- Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium
| | - Filip Cuyckens
- Janssen Research & Development, Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Geert Mannens
- Janssen Research & Development, Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Achiel Van Peer
- Janssen Research & Development, Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, B-2340, Beerse, Belgium
| | - Pieter Annaert
- Drug Delivery & Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O&N2, Herestraat, 49-box 921, B-3000, Leuven, Belgium
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven and Neonatal Intensive Care Unit, University Hospitals Leuven, B-3000, Leuven, Belgium
| | - Jan Van Bocxlaer
- Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium
| | - Koen Boussery
- Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium
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Yilmaz B, Erdem AF. Simultaneous Determination of Tramadol and Its Metabolite in Human Urine by the Gas Chromatography–Mass Spectrometry Method. J Chromatogr Sci 2015; 53:1037-43. [DOI: 10.1093/chromsci/bmu214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Indexed: 11/13/2022]
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Bloor M, Paech MJ, Kaye R. Tramadol in pregnancy and lactation. Int J Obstet Anesth 2012; 21:163-7. [PMID: 22317891 DOI: 10.1016/j.ijoa.2011.10.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 10/22/2011] [Indexed: 10/14/2022]
Abstract
Tramadol produces analgesic effects through both non-opioid and weak opioid activity and is commonly used to treat mild to moderate pain. It has been in use for over 30 years and has a well-established safety profile in the general population. Since tramadol is not licensed for use in pregnancy and lactation, there is limited clinical research on its use in this patient population. A systematic review was undertaken of articles published in English before June 2011, searching Pubmed, Medline, CINAHL, Embase and Cochrane databases using the terms 'tramadol and pregnancy', 'tramadol and breastfeeding', 'tramadol and lactation', and 'tramadol and neonate'.
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Affiliation(s)
- M Bloor
- Department of Anaesthesia and Pain Medicine, King Edward Memorial Hospital for Women, Subiaco, Australia
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Edmondson MA, Duran SH, Boothe DM, Stewart AJ, Ravis WR. Pharmacokinetics of tramadol and its major metabolites in alpacas following intravenous and oral administration. J Vet Pharmacol Ther 2011; 35:389-96. [PMID: 21883285 DOI: 10.1111/j.1365-2885.2011.01332.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Tramadol, a centrally acting opioid analgesic with monamine reuptake inhibition, was administered to six alpacas (43-71 kg) randomly assigned to two treatment groups, using an open, single-dose, two-period, randomized cross-over design at a dose of 3.4-4.4 mg/kg intravenously (i.v.) and, after a washout period, 11 mg/kg orally. Serum samples were collected and stored at -80°C until assayed by HPLC. Pharmacokinetic parameters were calculated. The mean half-lives (t(1/2)) i.v. were 0.85±0.463 and 0.520±0.256 h orally. The Cp(0) i.v. was 2467±540 ng/mL, and the C(max) was 1202±1319 ng/mL orally. T(max) occurred at 0.111±0.068 h orally. The area under the curve (AUC(0-∞)) i.v. was 895±189 and 373±217 ng*h/mL orally. The volume of distribution (V(d[area])) i.v. was 5.50±2.66 L/kg. Total body clearance (Cl) i.v. was 4.62±1.09 h; Cl/F for oral administration was 39.5±23 L/h/kg. The i.v. mean residence time (MRT) was 0.720±0.264. Oral adsorption (F) was low (5.9-19.1%) at almost three times the i.v. dosage with a large inter-subject variation. This may be due to binding with the rumen contents or enzymatic destruction. Assuming linear nonsaturable pharmacokinetics and absorption processes, a dosage of 6.7 times orally would be needed to achieve the same i.v. serum concentration of tramadol. The t(1/2) of all three metabolites was longer than the parent drug; however, O-DMT, N-DMT, and Di-DMT metabolites were not detectable in all of the alpacas. Because of the poor bioavailability and adverse effects noted in this study, the oral administration of tramadol in alpacas cannot be recommended without further research.
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Affiliation(s)
- M A Edmondson
- Department of Clinical Sciences, Auburn University, Auburn, AL 36849, USA.
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Stewart AJ, Boothe DM, Cruz-Espindola C, Mitchum EJ, Springfield J. Pharmacokinetics of tramadol and metabolites O-desmethyltramadol and N-desmethyltramadol in adult horses. Am J Vet Res 2011; 72:967-74. [DOI: 10.2460/ajvr.72.7.967] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Prediction of Infant Drug Exposure Through Breastfeeding: Population PK Modeling and Simulation of Fluoxetine Exposure. Clin Pharmacol Ther 2011; 89:830-6. [DOI: 10.1038/clpt.2011.23] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Population pharmacokinetic modeling of tramadol and its O-desmethyl metabolite in plasma and breast milk. Eur J Clin Pharmacol 2011; 67:899-908. [DOI: 10.1007/s00228-011-1023-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 02/21/2011] [Indexed: 10/18/2022]
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Becker ML, Leeder JS. Identifying genomic and developmental causes of adverse drug reactions in children. Pharmacogenomics 2010; 11:1591-602. [PMID: 21121777 PMCID: PMC3044438 DOI: 10.2217/pgs.10.146] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Adverse drug reactions are a concern for all clinicians who utilize medications to treat adults and children; however, the frequency of adult and pediatric adverse drug reactions is likely to be under-reported. In this age of genomics and personalized medicine, identifying genetic variation that results in differences in drug biotransformation and response has contributed to significant advances in the utilization of several commonly used medications in adults. In order to better understand the variability of drug response in children however, we must not only consider differences in genotype, but also variation in gene expression during growth and development, namely ontogeny. In this article, recommendations for systematically approaching pharmacogenomic studies in children are discussed, and several examples of studies that investigate the genomic and developmental contribution to adverse drug reactions in children are reviewed.
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Affiliation(s)
- Mara L Becker
- Children's Mercy Hospitals & Clinics, Division of Clinical Pharmacology, 2401 Gillham Road, Kansas City, MO 64110, USA.
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Abstract
Pharmacogenomics, the study of specific genetic variations and their effect on drug response, will likely give rise to many applications in maternal-fetal and neonatal medicine; yet, an understanding of these applications in the field of obstetrics and gynecology and neonatal pediatrics is not widespread. This review describes the underpinnings of the field of pharmacogenomics and summarizes the current pharmacogenomic inquiries in relation to maternal-fetal medicine-including studies on various fetal and neonatal genetic cytochrome P450 (CYP) enzyme variants and their role in drug toxicities (for example, codeine metabolism, sepsis and selective serotonin reuptake inhibitor (SSRI) toxicity). Potential future directions, including alternative drug classification, improvements in drug efficacy and non-invasive pharmacogenomic testing, will also be explored.
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Leeder JS, Kearns GL, Spielberg SP, van den Anker J. Understanding the relative roles of pharmacogenetics and ontogeny in pediatric drug development and regulatory science. J Clin Pharmacol 2010; 50:1377-87. [PMID: 20150527 DOI: 10.1177/0091270009360533] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Understanding the dose-exposure-response relationship across the pediatric age spectrum from preterm and term newborns to infants, children, adolescents, and adults is a major challenge for clinicians, pharmaceutical companies, and regulatory agencies. Over the past 3 decades, clinical investigations of many drugs commonly used in pediatric therapeutics have provided valuable insights into age-associated differences in drug disposition and action. However, our understanding of the contribution of genetic variation to variability in drug disposition and response in children generally has lagged behind that of adults. This article proposes a systematic approach that can be used to assess the relative contributions of ontogeny and genetic variation for a given compound. Application of the strategy is illustrated using the current regulatory dilemma posed by the safety and effectiveness of over-the-counter cough and cold remedies as an example. The results of the analysis can be used to aid in the design of studies to yield maximally informative data in pediatric populations of different ages and developmental stages and thereby improve the efficiency of study design.
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Affiliation(s)
- J Steven Leeder
- Division of Clinical Pharmacology and Medical Toxicology, Department of Pediatrics, Children's Mercy Hospitals and Clinics, School of Medicine, University of Missouri-Kansas City, 2401 Gillham Road, Kansas City, MO 64108, USA.
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Tramadol withdrawal in a neonate: only one of the clinical presentations to be anticipated…. Eur J Clin Pharmacol 2009; 65:643-4; author reply 645. [DOI: 10.1007/s00228-009-0635-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2009] [Accepted: 02/10/2009] [Indexed: 10/21/2022]
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Allegaert K, van Schaik RHN, Vermeersch S, Verbesselt R, Cossey V, Vanhole C, van Fessem M, de Hoon J, van den Anker JN. Postmenstrual age and CYP2D6 polymorphisms determine tramadol o-demethylation in critically ill neonates and infants. Pediatr Res 2008; 63:674-9. [PMID: 18317231 DOI: 10.1203/pdr.0b013e31816ff712] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
To document determinants of O-demethylation in critically ill (pre)term neonates and infants, tramadol (M) and O-demethyl tramadol (M1) concentrations were quantified in eighty-six 24 h urine collections and 168 plasma samples. A significant correlation of urine log M/M1 (0.98, SD 0.66) and plasma log M/M1 (0.78, SD 0.45) with postmenstrual age (PMA) (r = -0.69 and -0.65) was observed. One-way analysis of variance documented a significant decrease in urine log and plasma log M/M1 with increasing CYP2D6 activity score (F value 11.6 and 22.55). PMA and CYP2D6 activity score determined the urine and plasma log M/M1 (R 0.59 and 0.64) in a forward multiple regression model. We therefore conclude that PMA and CYP2D6 polymorphisms determined O-demethylation activity in (pre)term neonates and young infants, illustrating the impact of pharmacogenetics on drug metabolism in neonates although a relevant part of the interindividual varaibility remained unexplained. Besides compound-specific relevance, CYP2D6 iso-enzyme specific data on in vivo ontogeny of O-demethylation can contribute to safer and more effective administration of drugs metabolized by the same route in this population.
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Affiliation(s)
- Karel Allegaert
- Neonatal Intensive Care Unit, University Hospitals, campus Gasthuisberg, B-3000 Leuven, Belgium.
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Allegaert K, Vanhole C, Vermeersch S, Rayyan M, Verbesselt R, de Hoon J. Both postnatal and postmenstrual age contribute to the interindividual variability in tramadol glucuronidation in neonates. Early Hum Dev 2008; 84:325-30. [PMID: 17913403 DOI: 10.1016/j.earlhumdev.2007.08.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Although of pharmacokinetic and -dynamic relevance, data on ontogeny of UDP-glucuronosyltransferase (UGT) activity in neonates are scant. We therefore wanted to assess the impact of both postnatal and postmenstrual age (PNA/PMA) on the interindividual variability of glucuronidation to overall tramadol urinary elimination in neonates. METHODS O-demethyl tramadol (M1) and M1-glucuronide (M1G) were determined in 24 hour urine collections during continuous intravenous tramadol administration in neonates. Glucuronidation fraction (%) was calculated by the ratio of M1G to the sum of M1G and M1 free (M1total). Fractions (%) in early (<day 8) or late neonatal life (day 8-28) were compared (Mann-Whitney U) and forward multiple regression was applied to assess the impact of various covariates. RESULTS Urine collections were available in 59 neonates with a PNA of 6 (1-28) days and a PMA of 38 (SD 4) weeks. Mean M1G/M1total was 27 (SD 15) % and was significantly lower in early compared to late neonatal life (22 versus 32%, p=0.0001). In a forward multiple regression model, both PMA and early versus late neonatal life remained independent variables to explain the interindividual variability in M1G/M1total. CONCLUSIONS Besides PMA, there is an additional, independent impact of PNA since phenotypic glucuronidation activity is significantly lower in the first week of postnatal life. These findings should be taken into account in the assessment of compounds for whom glucuronidation is of pharmacokinetic, pharmacodynamic or toxicological relevance.
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Affiliation(s)
- K Allegaert
- Neonatal Intensive Care Unit, University Hospital, Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium.
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Allegaert K, Rayyan M, Vanhaesebrouck S, Naulaers G. Developmental pharmacokinetics in neonates. Expert Rev Clin Pharmacol 2008; 1:415-428. [DOI: 10.1586/17512433.1.3.415] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Allegaert K, van den Anker J, de Hoon J, van Schaik R, Debeer A, Tibboel D, Naulaers G, Anderson B. Covariates of tramadol disposition in the first months of life. Br J Anaesth 2008; 100:525-532. [DOI: 10.1093/bja/aen019] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Curticapean A, Muntean D, Curticapean M, Dogaru M, Vari C. Optimized HPLC method for tramadol and O-desmethyl tramadol determination in human plasma. ACTA ACUST UNITED AC 2008; 70:1304-12. [DOI: 10.1016/j.jprot.2008.01.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2007] [Revised: 07/01/2007] [Accepted: 01/30/2008] [Indexed: 10/22/2022]
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Ilett KF, Paech MJ, Page-Sharp M, Sy SK, Kristensen JH, Goy R, Chua S, Christmas T, Scott KL. Use of a sparse sampling study design to assess transfer of tramadol and its O-desmethyl metabolite into transitional breast milk. Br J Clin Pharmacol 2008; 65:661-6. [PMID: 18294329 DOI: 10.1111/j.1365-2125.2008.03117.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT There are presently no published data on tramadol transfer into breast milk or on its effects in the breastfed infant. WHAT THIS STUDY ADDS We have provided quantitative data on the absolute and relative infant doses of rac-tramadol and it rac-O-desmethyl metabolite for the breastfed infant. We have also demonstrated a novel sparse sampling data collection method for investigating infant exposure via milk. AIMS To investigate the transfer of rac-tramadol and its rac-O-desmethyl metabolite into transitional milk, and assess unwanted effects in the breastfed infant. METHODS Tramadol HCl (100 mg six hourly) was administered to 75 breastfeeding mothers for postoperative analgesia on days 2-4 after Caesarian section. Milk and plasma samples were collected after administration of four or more doses. Rac-tramadol and rac-O-desmethyltramadol were measured by high performance liquid chromatography. Milk : plasma ratio (M : P) and infant doses were calculated by standard methods. The behavioural characteristics of the exposed breastfed infants and a matched control group of infants not exposed to tramadol were also studied. RESULTS At steady-state, mean (95% CI) M : P was 2.2 (2.0, 2.4) for rac-tramadol and 2.8 (2.5, 3.1) for rac-O-desmethyltramadol. The estimated absolute and relative infant doses were 112 (102, 122) microg kg(-1) day(-1) and 30 (28, 32) microg kg(-1) day(-1), and 2.24% (2.04, 2.44)% and 0.64% (0.59, 0.69)% for rac-tramadol and rac-O-desmethyltramadol, respectively. The exposed infants and control breastfed infants had similar characteristics, including Apgar scores at birth and Neurologic and Adaptive Capacity Scores. CONCLUSIONS The combined relative infant dose of 2.88% at steady-state was low. The similarity of NACS in exposed infants and controls suggests that there were no significant behavioural adverse effects. We conclude that short-term maternal use of tramadol during establishment of lactation is compatible with breastfeeding.
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Affiliation(s)
- Kenneth F Ilett
- Pharmacology and Anaesthesiology Unit, School of Medicine and Pharmacology, University of Western Australia, Crawley, Australia.
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Allegaert K, Verbesselt R, Naulaers G, van den Anker JN, Rayyan M, Debeer A, de Hoon J. Developmental pharmacology: neonates are not just small adults... Acta Clin Belg 2008; 63:16-24. [PMID: 18386761 DOI: 10.1179/acb.2008.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Neonatal drug dosing needs to be based on the physiological characteristics of the newborn and the pharmacokinetic parameters of the drug. Size-related changes can in part be modelled based on allometry and relates to the observation that metabolic rate relates to weight by a kg 0.75 trend. Until adult metabolic activity has been reached, ontogeny, i.e. isoenzyme-specific maturation and maturation of renal clearance also contributes to drug metabolism, making isoenzyme-specific documentation of maturation necessary. Changes in body composition and ontogeny are most prominent in neonates. The body fat content (/kg) is markedly lower and the body water content (/kg) is markedly higher in neonates. These findings have an impact on the distribution volume of both lipophilic and hydrophilic drugs. Drugs are cleared either by metabolism or elimination. While the first is mainly hepatic, the second route is mainly renal. Both hepatic metabolism and renal clearance display maturation in early life although other covariables (e.g. polymorphisms, co-administration of drugs, first pass metabolism, disease characteristics) further contribute to the interindividual variability in drug disposition. Documentation of these maturational processes based on in vivo 'case' studies is of value since these drug-specific observations can subsequently be extrapolated to other drugs which are either already being prescribed or even considered for use in neonates by the introduction of these observations in 'generic physiologically-based pharmacokinetic' models.
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Affiliation(s)
- K Allegaert
- Neonatal Intensive Care Unit, Division of Woman and Child, University Hospital Gasthuisberg, Herestraat 49, Leuven, Belgium.
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Allegaert K, Rayyan M, de Hoon J, Tibboel D, Verbesselt R, Naulaers G, Van den Anker JN, Devlieger H. Contribution of Glucuronidation to Tramadol Disposition in Early Neonatal Life. Basic Clin Pharmacol Toxicol 2006; 98:110-2. [PMID: 16433900 DOI: 10.1111/j.1742-7843.2006.pto_336.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Karel Allegaert
- Neonatal Intensive Care Unit, Department of Pediatrics, University Hospital, Gathuisberg, Leuven, Belgium.
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Abstracts. J Matern Fetal Neonatal Med 2006; 19 Suppl 1:1-148. [PMID: 16707313 DOI: 10.1080/14767050600747348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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