CLINICALLY SIGNIFICANT DRUG–DRUG INTERACTIONS: MECHANISMS, RISK FACTORS, AND IMPLICATIONS FOR PATIENT SAFETY

Abstract

Drug–drug interactions (DDIs) represent a major challenge in clinical pharmacology and are a significant cause of preventable adverse drug events worldwide. The increasing prevalence of polypharmacy, particularly among elderly and chronically ill patients, has amplified the clinical relevance of DDIs. This study aimed to analyze the mechanisms, frequency, and clinical impact of drug–drug interactions in routine medical practice. A structured review of clinical prescriptions and pharmacological databases was conducted, focusing on interactions mediated by pharmacokinetic and pharmacodynamic pathways. The results demonstrate that cytochrome P450 enzyme modulation, altered drug transport, and additive or antagonistic pharmacodynamic effects are the most common mechanisms underlying clinically relevant DDIs. High-risk drug classes included anticoagulants, antimicrobials, cardiovascular agents, and central nervous system drugs. The findings highlight the need for systematic medication review, clinical decision-support systems, and improved pharmacology education to reduce interaction-related morbidity and mortality.