A Textbook of Pharmacology–III provides a comprehensive and systematic coverage of drugs acting on the respiratory and gastrointestinal systems, chemotherapy, antimicrobial agents, anticancer drugs, immunopharmacology, toxicology, and chronopharmacology. The book explains fundamental principles, classifications, mechanisms of action, therapeutic uses, and adverse effects of drugs in a clear and student-friendly manner. Structured across five units, it includes detailed discussions on antibiotics, antitubercular, antiviral, antifungal, antiparasitic agents, chemotherapy of malignancies, poisoning management, and newer advances. Designed to meet the curriculum needs of pharmacy and allied health science students, this textbook serves as a reliable academic and reference resource.