Chapter 1: Introduction to Pharmacology and Drug Names

The text traces the historical evolution of the discipline from ancient therapeutic rituals and the use of crude herbal preparations—such as opium and castor oil—to the modern era, which is defined by the isolation of pure compounds like morphine and the development of synthetic drugs through advances in chemistry and physiology. The core of the chapter distinguishes between the two primary subdivisions of the field: pharmacokinetics, which analyzes the processes of absorption, distribution, metabolism, and excretion (ADME) to describe what the body does to a drug; and pharmacodynamics, which investigates receptor binding, signal transduction, and dose-response relationships to explain what the drug does to the body. Significant attention is given to drug sources, including natural alkaloids, antibiotics from microbes, animal hormones, and minerals, as well as the pharmaceutical preparations designed to deliver them, such as tablets, capsules, solutions, and suspensions. The summary details various routes of administration, contrasting enteral methods like oral, sublingual, and rectal delivery—which may be influenced by the hepatic first-pass effect—with parenteral routes like intravenous, intramuscular, and subcutaneous injections that bypass absorption barriers to ensure immediate bioavailability. Advanced delivery mechanisms, including transdermal skin patches and sustained-release formulations utilizing osmotic pressure or controlled diffusion, are also examined. Finally, the chapter clarifies the hierarchy of drug nomenclature by differentiating between chemical names, nonproprietary or generic names (USAN) favored in clinical practice, and proprietary brand names used for marketing, while also addressing the regulatory and economic aspects of generic substitution and patent exclusivity.