Pharmacokinetics of Drugs

ISBN-13: 9783642786822 / Angielski / Miękka / 2011 / 537 str.

J.G. Wagner;G.L. Amidon;J.P.F. Bai

Opis

The author of this Foreword has recently retired after spending 25 years in academia and 15 years in the pharmaceutical industry. Most of this time has been spent following and, hopefully in some instances, contributing to advancement of the discipline of pharmacokinetics. During the last 40 years, pharmacokinetics has grown from a fledgling in the 1950s to an adult in the 1990s. The late development of the discipline of pharmacokinetics, relative to other disciplines such as chemistry, bio- chemistry, and pharmacology, probably stems both from general ignorance of the importance of the time course of concentration-effect relationships in drug therapy and from our technical inability to do anything about it had we been more enlightened. Just as the end of the historical dark ages had to await the beginning of the Carolingian revival, so the end of the pharma- co kinetic dark age had to await the discovery of adequate analytical methods and also an intellectual leap of faith to accept that drug action is in some way dependent on receptor site occupancy, and therefore on drug con- centration. The recent evolution of pharmacokinetics has occurred in three phases which may be identified as those of discovery, stabilization, and rationaliz- ation. The discovery phase, which occurred in the 1950s and 1960s, esta- blished the mathematics and concepts of "modern" pharmacokinetics and sought areas of application, ranging from model-independent methods, through compartment approaches, to complex physiological models.

Spis treści

A. Introduction.- 1 Role of Pharmacokinetics in Drug Discovery and Development.- A. Historical Background.- B. Regulatory Submissions.- C. The Process.- D. Discovery.- E. Preclinical Development.- I. Toxicology and Toxicokinetics.- II. Pharmacokinetic — Pharmacodynamic Relationships.- III. Interactions.- F. Clinical Development.- I. Phase 1.- II. Phase 2.- III. Phase 3.- IV. Interactions.- V. Regulatory Submissions.- G. Postsubmission and Postmarketing Studies.- H. Summary.- References.- B. Analytical Methods.- 2 Contemporary Aspects of Radioimmunoassay Development for Drug Analysis.- A. Introduction.- B. Synthesis of Drug Derivatives for Immunogen Preparation.- I. Coupling of Hapten Carboxyl Group to Carrier Protein.- II. Addition of Carboxyl to Existing Functional Group.- III. Addition of a Functional Group for Bridge to Carboxylic Acid.- IV. Altering the Basic Structure of the Hapten.- C. Immunogen Preparation.- I. Hapten-Carrier Protein Ratios.- II. Carrier Protein Characteristics.- D. Immunization Considerations.- I. Species Effects.- II. Use of Adjuvants.- III. Immunization Sites and Schedules.- E. Matrix Effects of Biological Fluids.- I. Methods for Sample Matrix Effect Elimination.- 1. Filtration/Precipitation of Protein.- 2. Solvent Extraction.- 3. Solid Phase Chromatographic Extraction.- 4. High-Performance Liquid Chromatographic Sample Preparation.- II. Elimination of Sample Matrix Effect by Sample Size.- F. The Suitability of Radioimmunoassay for Drug Analysis.- References.- 3 Mass Spectrometry in Drug Disposition and Pharmacokinetics.- A. Introduction.- B. Ionization Techniques.- I. Electron Ionization.- II. Positive Chemical Ionization.- III. Electron Capture Negative Chemical Ionization.- IV. Liquid Secondary Ion/Fast Atom Bombardment.- V. Thermospray.- VI. Atmospheric Pressure Ionization.- VII. Collision-Induced Dissociation.- C. Chromatographic Techniques.- I. Gas Chromatography/Mass Spectrometry.- II. Liquid Chromatography /Mass Spectrometry.- D. Metabolism Studies.- I. In Vitro Studies.- II. In Vivo Studies in Animal Models.- III. In Vivo Studies in Humans.- E. Pharmacokinetic Studies.- I. Introduction.- II. Animal Models.- III. Humans.- F. Summary.- References.- 4 Analytical Methods for Biotechnology Products.- A. Introduction.- B. Methods.- I. Radiolabels.- 1. Selection of Radiolabel.- 2. Whole-Body Autoradiography.- 3. Radiolabel Realities.- II. Immunoassays.- 1. Enzyme Immunoassays.- 2. Radiolabel-Based Immunoassays.- 3. Immunoassay Limitations.- 4. Immunoassay Interferences.- III. Bioassays.- IV. Other Immunological Techniques.- V. Chromatography.- VI. Electrophoretic Techniques.- VII. Mass Spectrometry.- C. Conclusions.- References.- C. In Vitro Methods-Protein and Tissue Binding.- 5 Metabolism: Scaling-up from In Vitro to Organ and Whole Body.- A. Introduction.- B. Correlation of In Vitro and In Vivo Data.- I. Concept of Organ Clearance.- 1. Hepatic Clearance Models.- 2. In Vitro-Organ Correlations.- II. Concept of Total Body Clearance.- 1. From In Vitro to In Vivo: Compartmental Modeling.- 2. From In Vitro to In Vivo: Physiological Modeling.- 3. From Perfused Organs to In Vivo.- C. Poor Correlations Between In Vitro and Perfused Organs.- I. Inadequacy of In Vitro Estimates.- 1. Estimation of Enzymatic Parameters.- 2. Multiplicity of Enzymes.- 3. Membrane-Bound Enzymes.- 4. Time-Dependent Kinetics.- II. Structural Considerations and Physiological Variables.- 1. Flow.- 2. Protein Binding.- 3. Transmembrane Limitation.- 4. Cosubstrate.- 5. Acinar Heterogeneity.- D. Reasons for Poor Correlations Between In Vitro, Perfused Organs, and In Vivo.- E. Conclusions.- References.- 6 Gastrointestinal Transport of Peptide and Protein Drugs and Prodrugs.- A. Introduction.- B. Mucosal Cell Absorption.- I. Paracellular Absorption.- II. Transcellular Absorption.- 1. Simple Diffusion.- 2. Carrier-Mediated Process.- 3. Endocytosis.- C. Mucosal Cell Transport of Peptide Drugs.- I. Characteristics of Small Peptide Transport.- 1. Substrate Structural Requirements.- II. Carrier-Mediated Transport of Peptide Drugs.- 1. ?-Lactam Antibiotics.- 2. ACE Inhibitors.- D. Estimating Extent of Drug Absorption.- I. Fraction of Dose Absorbed — Permeability Correlation.- II. Comparison of Passive and Carrier-Mediated Transport.- E. Peptide Prodrug Approaches to Improving Intestinal Absorption.- I. Peptide Prodrugs of ?-Methyldopa.- II. Peptide Prodrug Approaches for Acidic Drugs.- III. Other Peptide Prodrugs.- F. Summary.- References.- D. Classical Problems.- 7 Stereoselectivity in Metabolic Reactions of Toxication and Detoxication.- A. Introduction.- B. Principles of Stereoselective Xenobiotic Metabolism.- I. Chiral Recognition and Stereoselective Processes in Xenobiotic Metabolism and Disposition.- II. Substrate Stereoselectivity and Product Stereoselectivity.- III. Substrate-Product Stereoselectivity.- IV. Relevance to Molecular Toxicology.- C. Toxicologically Relevant Examples of Stereoselective Metabolism.- I. Introduction.- II. Substrate Stereoselectivity in Drug Oxidation: Disopyramide and Mianserin.- III. Product Stereoselectivity in Drug Oxidation and Reduction: Phenytoin and Nabilone.- IV. Substrate Stereoselectivity in Xenobiotic Conjugation: Fenvalerate.- D. The Case of Profens.- I. Metabolic Chiral Inversion: In Vivo and In Vitro Studies.- II. Mechanism of Inversion.- III. Toxicological Consequences of Chiral Inversion.- E. Conclusion.- References.- 8 Interethnic Differences in Drug Disposition and Response: Relevance for Drug Development, Licensing, and Registration.- A. Introduction.- B. Case Reports.- I. Unexpected Behavior.- II. A Biopharmaceutical Dilemma.- III. The Drug Which Did Not Become a Case.- IV. The Drug Which Is Not a Case.- C. Basic Concepts and Definitions.- D. Integration of Pharmacokinetic, Pharmacodynamic, and Toxicokinetic Principles in Drug Development.- I. The Conceptual Framework.- II. Preclinical Studies.- III. Phase 1 Studies.- IV. Phase 2 Studies.- V. Phase 3 Clinical Studies.- VI. Regulatory Considerations.- VII. Interethnic Differences in Drug Behavior and Action and PK/PD Integration.- E. Preclinical Studies.- F. Phase 1 Studies and Interethnic Differences.- I. Investigational Pharmacokinetics.- II. Investigational Pharmacodynamics.- III. Bioavailability Investigations.- IV. Bioequivalence Studies.- G. Phase 2 Studies.- H. Phase 3 Studies.- I. Phase 4 Studies in the Context of Drug Product Licensing.- I. Pharmacoanthropological Considerations.- II. Studies in Healthy Volunteers.- III. Studies in Patients.- J. Conclusions.- References.- Appendix. Selected References on Interethnic Differences in Drug Kinetics.- 9 Clinical Relevance of Pharmacogenetics.- A. Introduction.- B. The Genetic Polymorphism of the Sparteine/Debrisoquine Oxidation.- I. Molecular Mechanisms of the Sparteine/Debrisoquine Polymorphism.- II. Clinical Consequences of the Sparteine/Debrisoquine Polymorphism and Assignment of Genotype or Phenotype.- C. The Genetic Polymorphism of Mephenytoin Oxidation.- I. Molecular Mechanisms of the Mephenytoin Polymorphism.- II. Clinical Consequences of Polymorphic Mephenytoin Oxidation and Assignment of Genotype or Phenotype.- D. The Genetic Polymorphism of N-Acetylation.- I. Molecular Mechanisms of Polymorphic N-Acetylation.- II. Clinical Consequences of Polymorphic Acetylation and Assignment of Genotype or Phenotype.- E. Genetic Polymorphisms and Drug Development.- F. Genetic Polymorphisms and Drug Interactions.- G. Conclusions.- References.- 10 Role of Environmental Factors in the Pharmacokinetics of Drugs: Considerations with Respect to Animal Models, P-450 Enzymes, and Probe Drugs.- A. Introduction.- B. Relevant Environmental Factors.- I. What Are “Relevant” Environmental Factors?.- II. Examples.- 1. Cigarette Smoking.- 2. Alcohol Drinking.- 3. Drugs.- 4. Occupational Chemicals.- 5. Other Factors.- C. Animal Models.- I. Environmental Regulation of P-450 Isoforms in the Rat.- II. Similarities and Differences Between Species.- III. Reasons for Interspecies Differences.- IV. Model Experiments in Animals.- D. Important (Iso)enzymes in Man.- I. P-450 Enzymes.- 1. P-450 1A1.- 2. P-450 1A2.- 3. P-450 2A6.- 4. P-450 2B6.- 5. P-450 2C.- 6. P-450 2D6.- 7. P-450 2E1.- 8. P-450 3A.- II. Conjugative Enzymes.- III. Heterologous Expression Systems.- E. Probe Drugs.- I. The Probe Drug Concept.- 1. The “Ideal” Probe Drug.- 2. “General” vs “Specific” Probe Drugs.- II. Importance of Enzyme Specificity.- III. Selected Probe Drugs.- 1. Antipyrine.- 2. Aminopyrine.- 3. Caffeine.- 4. Theophylline.- 5. Nifedipine.- 6. Barbiturates.- 7. Tolbutamide.- 8. Warfarin.- 9. Other Potential Probes.- 10. Endogenous Probes.- IV. Cocktail Approach.- F. Practical Considerations for Human Studies.- G. Final Considerations.- References.- 11 Time Course of Drug Effect.- A. Introduction.- I. Why Prediction of Effect Over Time Is Important.- 1. Drug Development.- 2. Dosage Individualization.- B. Methodological Considerations Relevant to Measuring Effects.- I. Standardization.- II. Continuous Scale Versus Discrete Response.- III. Baseline and Placebo Effect.- C. Pharmacokinetic-Pharmacodynamic Models.- I. Pharmacokinetics.- II. Kietics of Receptor Binding.- III. Steady-State Pharmacodynamic Models.- IV. Non-Steady-State Pharmacodynamic Models.- 1. Effect Compartment.- 2. Physiological Mediator.- V. Placebo Effect.- 1. Pharmacokinetics.- 2. Placebo Effect Model.- 3. Placebo Efficacy.- VI. Disease Time Course and Drug Effects.- 1. Disease Time Course.- 2. Models of Drug Effect on Disease Progression.- VII. Tolerance.- 1. Pharmacokinetics.- 2. Pharmacodynamics.- D. Conclusion.- References.- E. Future Trends in Pharmacokinetics.- 12 Biotechnology Products.- A. Introduction.- B. Pharmacokinetic/Pharmacodynamic Studies.- I. Oligonucleotides.- II. Proteins.- 1. Insulin.- 2. Relaxin.- 3. Interferon-?-2A.- C. Regimen-Dependent Effects.- I. Growth Hormone.- II. Parathyroid Hormone.- III. Tissue Plasminogen Activator.- D. Binding Proteins/Inhibitors.- I. Growth Hormone.- II. Tissue Plasminogen Activator.- III. Insulin-like Growth Factor-I.- IV. Deoxyribonuclease.- E. Catabolism of Biotechnology Products.- I. Catabolism at Extravascular Sites of Administration.- F. Drug Interactions.- References.- 13 Peptide and Protein Drugs.- A. Introduction.- I. Differences Between the Pharmacokinetics of Peptides/Proteins and Other Drugs.- II. Scope of This Review.- B. Pharmacokinetic Mechanisms.- I. Distribution in the Body.- II. Inactivation and Elimination.- 1. Glomerular Filtration.- 2. Peptidolysis.- 3. Receptor-Mediated Clearance.- III. Uptake from Site of Administration.- 1. Subcutaneous or Intramuscular Injection.- 2. Intranasal Administration.- 3. Oral or Rectal Administration.- IV. Pharmacokinetic Behavior Resulting from the Distribution and Elimination Processes.- C. Experimental Approaches.- I. Analytical Methods.- 1. Ex Vivo Bioassay.- 2. Radioimmunoassay.- 3. Radiolabeling.- 4. High-Performance Liquid Chromatography.- 5. Radiosequencing.- II. Plasma Pharmacokinetics.- 1. Intravenous Bolus and Infusion Studies.- 2. Methods of Assaying Samples.- 3. Information That can Be Derived from Plasma Pharmacokinetic Studies.- 4. Use of Organ Ablation to Locate Clearance Sites.- III. Distribution, Metabolism, and Elimination.- 1. Typical Experiments and Results.- 2. Difficulties in Interpreting Results.- 3. Problems in Carrying Out Drug Elimination Studies.- IV. Organ Clearance.- V. Receptor-Mediated Clearance Kinetics.- VI. Absorption (Bioavailability) Measurement.- 1. Oral Route.- 2. Nasal Route.- D. Conclusions.- References.- 14 Toxicokinetics.- A. Introduction.- B. Principles of Toxicokinetics.- C. Bioanalytical Procedures to Support Toxicokinetic Studies.- D. Dose-Plasma Concentration Relationship (Linear-Nonlinear Kinetics).- E. Changes in Concentrations upon Multiple Dosing.- F. Designing Troubleshooting Studies to Explain Aberrant Data.- I. Absorption Issues.- 1. Dose Proportionality.- 2. Effect of Diet.- 3. Effect of Vehicles.- II. Metabolism Issues.- 1. Enzyme Induction.- 2. Effect of Age.- 3. Sex Dependency.- G. Species Comparisons and Interspecies (Allometric) Scaling.- H. Utilization of Pharmacokinetic/Toxicokinetic Data in the Design of Early Clinical Trials.- References.- 15 The Population Approach: Rationale, Methods, and Applications in Clinical Pharmacology and Drug Development.- A. Introduction.- B. Rationale.- I. “Population Studies” in Large Samples of Subjects.- II. Controlled Experimental Studies in Small Groups.- III. The Population Approach.- C. An Overview of Statistical Methodology for Model-Based Population Analysis.- I. Population Model.- II. Population Methods for Data Analysis.- III. Synthesis.- D. Current Experience with the Population Approach and Its Applications to Drug Therapy.- I. Introduction.- II. Detection of Patient Groups with Altered Kinetics.- III. Design of Optimum A Priori Dosage Regimen..- IV. Bayesian Estimation of Individual Pharmacokinetic Parameters.- V. Recent Novel Applications of Nonlinear Mixed Effects Models to Other Drug-Related Areas.- E. Problems and Issues?.- I. Misconceptions.- II. Some Practical Problems.- 1. Reliability of Data and Analysis.- 2. Methodological Issues.- III. Validation of the Results.- F. Integration of the Population Approach into Clinical Drug Development.- I. Introduction.- II. Early Human Studies (Phase I).- III. Early Clinical Studies (Phase II).- IV. Clinical Trials (Late Phase II, Phase III).- V. Late Clinical Trials (Late Phase III, Phase IV).- G. Concluding Remarks.- References.- F. Impact of New Methods on Pharmacokinetics.- 16 Contribution of Positron Emission Tomography to Pharmacokinetic Studies.- A. Introduction.- B. Positron Emitters.- C. Drug Labeling — Radiochemistry.- D. Positron Emission Tomography.- E. Direct Radiolabeled Drug Studies.- I. Drug Distribution.- II. Drug-Drug and Drug-Nutrient Interactions.- III. Drug-Receptor Interactions.- 1. Tranquilizers.- 2. Neuroleptics.- F. Indirect Radioactive Pharmacokinetic Studies.- G. Kinetic Modeling with PET.- I. A Two-Compartment Model: the [15O] Water Model.- II. A Three-Compartment Linear Model: the [18F] Fluorodeoxyglucose Model.- III. A Multicompartment Nonlinear Model: the Ligand- Receptor Model.- IV. Modeling Using Simplified Models.- V. Modeling Using the Multi-injection Approach.- H. Conclusion.- References.- 17 In Vivo Imaging in Drug Discovery and Design.- A. Introduction.- B. Pharmacokinetics.- I. Antimicrobial Agents.- 1. Erythromycin.- 2. Fluconazole.- II. Antineoplastic Agents.- 1. Platinum Compounds.- 2. 5-Fluorouracil.- III. Neuroleptics.- IV. Angiotensin-Converting Enzyme Inhibitors.- V. Nuclear Magnetic Resonance.- C. Pharmacodynamics.- I. Cardiovascular.- 1. Ventricular Function.- 2. Blood Volume.- 3. Cardiac Output.- II. Renal Perfusion and Function.- III. Antineoplastic Agents.- IV. Liver Function.- V. Intestinal Function.- VI. Antimicrobial Agents.- VII. Nuclear Magnetic Resonance.- D. Summary.- References.- G. Appendix.- 18 Considerations on Data Analysis Using Computer Methods and Currently Available Software for Personal Computers.- A. Introduction.- B. Program Features and Requirements.- I. Data Entry.- II. Pharmacokinetic Model Specification.- 1. Compartmental Models.- 2. Noncompartmental Approach.- 3. Pharmacodynamic Models.- 4. Absorption Kinetics and Bioavailability Studies.- 5. Urinary Data Analysis.- 6. Population Pharmacokinetics.- 7. Calculation of Individual Dosage Regimen.- III. Error Model specification.- IV. Parameter Estimation.- 1. Least-Squares and Maximum Likelihood Estimators.- 2. Linear Equations.- 3. Nonlinear Equations.- V. Confidence Limits on Estimated Parameters.- VI. Statistical Measures of Goodness of Fit.- VII. Solving Systems of Differential Equations.- VIII. Graphic Display of Results.- IX. Printing and Plotting Results.- X. User Interface and Documentation.- XI. Hardware and Software Requirements.- C. Directory of Surveyed Software.- D. Conclusion.- References.