The guide outlines the features of drug therapy in elderly and senile people, as one of the essential methods of influencing the body of a sick person, rational tactics in elderly and senile patients, allowing for the greatest effectiveness with minimal risk of complications. The principles of drug dosing in geriatrics, features of drug interactions, and ways to increase the resistance of the body of older people to the undesirable effects of medications are considered. The methodological approaches to pharmacotherapy developed by the authors are relevant and will certainly arouse interest among doctors of all specialties. The guide is intended for a wide range of practicing doctors, therapists, cardiologists, gerontologists, and medical students.