The textbook has been prepared in accordance with the concept of the five main components of clinical pharmacy: fundamentals of clinical medicine, clinical pharmacology, pharmaceutical chemistry, toxicology and pharmacokinetics. At modern level it presents the symptoms of the most widespread diseases of internal organs, methods of pharmacotherapy and prevention of basic pathological conditions, the most important aspects of clinical pharmacology of drugs, conditions of their rational use and ways to prevent and eliminate side effects. The textbook is intended for students of medical institutions. The book will be useful for students of medical and pharmacy faculties, workers of practical pharmacy, including medical practitioners and family doctors.