Handbook of Pediatric Cardiovascular Drugs - part 1 docx

[...]... Hemoglobin (Hgb), 13 .0 g/dL; VO 2, 55.8 mL/min; body surface area (BSA), 0.25 m2 (continued) 14 B Feingold and R Munoz Table 1- 1 (Continued) Using Fick Equation: Qp = VO2 / [Hgb (g/dL) × 13 .6 × (PVsat − PAsat)] = 55.8 / [13 × 13 .6 × (0.98 − 0.88)] = 3.2 L/min Qs = VO2 / [Hgb (g/dL) × 13 .6 × (Aosat − MVsat)] = 55.8 / [13 × 13 .6 × (0.98 − 0.68)] = 1. 1 L/min Thus, Qp:Qs = 3.2 /1. 1 ~ 3 :1 Alternately, because... Aorta a 10 10 32 /14 20 (mean) 11 85/55 Oxygen saturation 72% 79% 83% 83% 99% 99% Hgb, 12 .6 g/dL; VO2, 86 mL/min; BSA, 0.7 m2 Qpi = 4.48 L/min/m2 Qsi = 2.65 L/min/m2 Qp:Qs = 4.48 / 2.65 = 1. 69 :1 PVR = TPG / Qpi = (20 − 11 mmHg) / 2.65 L/min/m2 = 3.4 indexed Wood units 1 Cardiac Physiology Review 15 Table 1- 4 Tetralogy of Fallota Pressure (mmHg) Right atrium Right ventricle Pulmonary artery PCWP Aorta 10 ... drug-warfarin exposure .11 Data in pediatric populations are generally lacking, although Novak et al reported a 3% incidence of serious drug-drug interactions in pediatric patients receiving chronic antiepilepsy drugs. 12 Implications of CYP-450 Drug-Drug Interactions of Cardiovascular Drugs The CYP-450 system may have significant effects on cardiovascular drug therapy β-adrenergic-blocking agents, such as propranolol,... infants have significantly lower body fat (1% ) when compared with full-term infants (15 %) and adults (20%) Lipid-soluble drugs, such as benzodiazepines, would, therefore, demonstrate lower Vd estimates in premature infants, leading to augmented clinical effects .1 Protein-Binding Effects Drugs in plasma bind to proteins, including albumin, -1 -acid-glycoprotein ( -1 -AG), and lipoproteins Albumin is the major... brief discussions of principles of pediatric pharmacokinetics and knowledge of the effects of disease states on disposition of cardiovascular drugs affecting safe and effective drug therapy Pediatric Pharmacokinetics Drug Absorption Oral Administration The rate of drug absorption is generally slowed in infancy when compared with older children and adults .1, 3 Efficiency of absorption of drugs after oral... several years of age, achieving 66% of adult values by that age.4 Deficiency in infancy may contribute to adverse effects in infants of selective serotonin reuptake inhibitor (SSRI)-treated mothers .1 CYP2E1 isoenzymes develop to 40% of adult values by age 1 year, with eventual adult values at 1 to 10 years.4 Age-dependent increases in drug clearance in children younger than 10 years of age are reported... “Hemodynamic Calculations” for examples in Tables 1- 1 to 1- 4 , and a list of commonly used formulas, and to the end of this chapter for suggested reference texts Hemodynamic Calculations Table 1- 1 Large, unrestrictive ventricular septal defect in an 8-week-old infant a Pressure (mmHg) Superior vena cava Right ventricle Pulmonary artery PCWP Aorta 8 85/55 70 (mean) 15 85/55 Oxygen saturation 68% 88% 88% 98%... Carvedilol is a racemic mixture of both R- and S-enantiomers, with metabolism by CYP2C9, CYP1A2, and CYP3A4, as well as CYP2D6; this complex pattern of metabolism may mitigate effects of inhibitor drugs on carvedilol .13 Although angiotensin-converting enzyme (ACE) inhibitor prodrugs may undergo metabolism via CYP-450 enzyme systems, no significant CYP450-mediated drug-drug interactions have been documented... in a decreased rate of Phase 0 depolarization and mild prolongation of repolarization .1 1 Cardiac Physiology Review Figure 1- 2 The action potential of a Purkinje fiber Phase 4 is the resting state before electrical stimulation Phase 0 is the rapid depolarization as a result of Na+ influx Phase 1 is the initial stage of repolarization caused by closure of Na+ channels and efflux of Cl− Phase 2, or the... Webber, MBChB, MRCP Department of Pediatrics University of Pittsburgh School of Medicine Division of Cardiology Children’s Hospital of Pittsburgh Pittsburgh, PA, USA David L Wessel, MD Department of Pediatrics (Anasthesia) Harvard Medical School Cardiology and Anesthesia Cardiac Intensive Care Children’s Hospital Boston Boston, MA, USA Charles I Yang, MD University of Pittsburgh School of Medicine Pittsburgh, . 3. Pediatric cardiology I. Munoz, Ricardo 618 .9′ 210 61 ISBN: 97 8 -1 -8 462 8-9 5 2 -1 e-ISBN: 97 8 -1 -8 462 8-9 5 3-9 Library of Congress Control Number: 2007928820 © Springer-Verlag London Limited 2008 Apart. (until 31st of March 2007) British Library Cataloguing in Publication Data Handbook of pediatric cardiovascular drugs 1. Cardiovascular agents 2. Cardiovascular system - Diseases - Chemotherapy .