Abstract
Individualized pharmacotherapy is a fundamental principle of modern clinical medicine. The same medicinal product and standard dose may produce different therapeutic responses in different patients because pharmacokinetic and pharmacodynamic characteristics are influenced by age, body composition, organ function, physiological state, concomitant diseases, and other patient-related factors. Children, adults, older people, pregnant women, and patients with impaired renal or hepatic function require particularly careful consideration when medicines are selected and dosed. This article examines the clinical pharmacological principles of individualized treatment with emphasis on age-related and physiological characteristics. Changes in drug absorption, distribution, metabolism, and elimination are considered together with alterations in receptor sensitivity and homeostatic mechanisms. Particular attention is given to pediatric and geriatric pharmacotherapy, pregnancy and lactation, body weight, renal and hepatic function, polypharmacy, drug interactions, adherence, and therapeutic monitoring. Individualization is presented not as an isolated calculation of dose, but as a continuous clinical process that includes diagnosis, risk assessment, medicine selection, dose and route determination, monitoring of efficacy and safety, and subsequent treatment adjustment. The application of these principles can improve therapeutic outcomes, reduce preventable adverse drug reactions, and promote rational use of medicines in clinical practice.