Essential Pharmacology
How Drugs Alter Signaling Pathways in the Body
1. Edition March 2026
128 Pages, Softcover
Wiley & Sons Ltd
Master how drugs modulate the body's signaling pathways
Most medicines work not by creating new physiological processes, but by modulating the body's existing signaling systems, the internal language of hormones, neurotransmitters, and cellular messengers. Essential Pharmacology illuminates this central concept while providing accessible yet rigorous mathematical foundations for understanding quantitative pharmacology.
Written by Carl E. Creutz, Harrison Professor of Medical Teaching in Pharmacology, Emeritus at the University of Virginia, this text guides students through drug absorption, distribution, and biotransformation; clinical pharmacokinetics with practical dosing models; and comprehensive pharmacodynamics including receptor theory, competitive antagonism, and partial agonists. The book explores G-protein coupled receptors, second messenger cascades, and signaling networks that drugs target. By emphasizing general principles, it complements specialized texts in clinical therapeutics, veterinary medicine, toxicology, antimicrobial therapy, and nursing practice.
Readers will find:
* Quantitative pharmacology presented with mathematical rigor yet accessible to students with undergraduate science and mathematics training
* Complete drug-receptor interaction models covering competitive antagonists, partial agonists, allosteric mechanisms, and spare receptor theory
* Clinical pharmacokinetics with single-dose and steady-state models enabling rational drug dosing and therapeutic monitoring
* Detailed receptor-effector mechanisms including G-protein signaling, second messengers, and the networks controlling physiological responses
* Focus on the unifying principle that modern pharmacology modulates endogenous signaling rather than creating novel body processes
Essential Pharmacology serves medical, nursing, pharmacy, and other health professional students building theoretical foundations in pharmacology. It equally benefits biomedical researchers, pharmaceutical scientists, and public policy professionals seeking to understand drug development principles and therapeutic limitations.
Chapter 1: Introduction 1
Chapter 2: Definition and Scope of Pharmacology 3
Chapter 3: Movement of Drugs to and from Sites of Action 5
3.1 Physicochemical Factors in the Transfer of Drugs Across Membranes 6
3.2 Active, Carrier-Mediated Transport 7
3.3 Weak Electrolytes and Influence of pH 7
3.4 Absorption of Drugs 13
3.5 Bioavailability and Bioequivalence 15
3.6 Distribution of Drugs 15
Chapter 4: Biotransformation of Drugs 19
4.1 Consequences of Drug Metabolism 20
4.2 Enzymatic Biotransformation Reactions 20
4.3 Metabolizing Systems in the Smooth Endoplasmic Reticulum ("Microsomal" Fraction of Cell Homogenates) 21
Chapter 5: Excretion of Drugs 26
Chapter 6: Clinical Pharmacokinetics 28
6.1 Introduction 28
6.2 Pharmacokinetic Parameters and Variables 29
6.3 A Simple Pharmacokinetic Model 35
6.4 A "Dose-Dependent" (or "Non-Linear") Pharmacokinetic Model 47
6.5 Intermittent Oral Dosing 52
6.6 Pharmacokinetics of Single Doses 54
6.7 Recapitulation of Equations (These are the "Need-to-Know" Equations for Pharmacokinetics) 55
Chapter 7: Pharmacodynamics I: Determining Effects in Intact Organisms; Dose-Response Relationships in Patients 56
7.1 Graded Responses: Plots of Dose (Dosage) Versus Intensity of Effect 56
7.2 Therapeutic Index and Therapeutic Window 58
Chapter 8: Pharmacodynamics II: Determining Sites and Mechanisms of Action of Drugs 60
8.1 Introduction 60
8.2 Specificity of Drugs 62
8.3 Nature of Drug Receptors: Molecules that Combine with the Drug and Mediate its Actions 63
Chapter 9: Pharmacodynamics III: Quantitative Analysis of Drug-Receptor Interactions 64
9.1 The "Simple Occupancy Model" 65
9.2 "Competitive" or "Surmountable" Antagonists 68
9.3 "Noncompetitive" or "Insurmountable" Antagonists 71
9.4 Irreversible Antagonists 73
9.5 Partial Agonists 73
9.6 The Allosteric Model for Drug-Receptor Interaction 77
9.7 "Spare Receptors" 81
9.8 Displacement of the Activation Curve to the Right of the Binding Curve: Fractional Occupancy Threshold 86
9.9 Review: The Use of the Dose-Response Curve to Characterize Drugs and Receptors 87
Chapter 10: Biological Receptor-Effector Mechanisms 90
10.1 Receptor Identification and Classification 90
10.2 Location of Receptors 92
10.3 Second Messengers: The Intracellular Language 92
10.4 Signaling Networks of Protein Kinases and Transcription Factors 93
10.5 Importance of Second Messengers in Pharmacology 94
10.6 Receptor Structure and Proximal Effector Systems 94
10.7 G-Protein Coupled Receptors 96
10.8 The G-Protein Activation Cycle 96
10.9 The G-Proteins Provide Amplification, Diffusion, and Integration of Signals 99
10.10 Signaling Homeostasis and Receptor Metabolism 100
10.11 Diseases Resulting From Receptor Malfunction 102
Chapter 11: Testing and Evaluation of New Drugs 103
Chapter 12: Further Study in Pharmacology 105
Index 107