Drug–Drug Interactions In Poly-Pharmacy Patients: Updated Evidence

Abstract

Background: Polypharmacy, which refers to taking several drugs at the same time, is becoming an increasingly widespread phenomenon because of aging populations and the increase in multimorbidity. The practice increases the chances of drug-drug interactions (DDIs) that may interfere with the effectiveness of the therapy, trigger adverse drug reactions, and raise hospitalization. DDIs can be caused by the pharmacokinetic mechanisms (absorption, distribution, metabolism, or excretion) and by the pharmacodynamic mechanisms (additive, synergistic, or antagonistic), only the number and type of medications prescribed increase their complexity.

Aim of Work: The purpose of this review is to establish recent evidences concerning the prevalence, pathophysiology, and clinical consequences of DDIs in polypharmacy patients. It also investigates high-risk population, drug classes with most frequent implications, and approaches to the prevention and management of DDIs in clinical practice.

Methods: The search through the literature in PubMed, Google scholar, and MEDLINE was carried out to find articles published between 2016 and 2025. The keywords incorporated were polypharmacy, drug-drug interactions, adverse drug reactions, elderly, multimorbidity, and chronic diseases. Articles were filtered based on relevancy and duplicates, case reports, non-full-text articles, and irrelevant articles were filtered out. The review takes into consideration studies that include observational studies, clinical trials, systematic reviews, and meta-analyses that tackle the epidemiology, mechanisms, and treatment of DDIs in polypharmacy.

Results: The results indicate that DDIs are very common among patients taking a combination of drugs, more so among older individuals and in chronic illnesses. Common medicines implicated by this would include cardiovascular medicines, anticoagulants, psychotropics, and non-steroidal anti-inflammatory drugs. Both the pharmacodynamics and pharmacokinetic interplay in enhancing adverse events, therapeutic failure, and hospitalization. Computational and clinical decision-support tools that are being developed can be useful in predicting and managing DDIs.

Conclusion: DDIs continue to pose a significant issue in polypharmacy patients particularly in patients at high risk. The prompt identification, drug evaluation, patient tracking, and predictive mechanisms are necessary in minimizing the negative outcome. A combination of clinical pharmacology and technology can streamline patient safety in managing polypharmacy through a multidisciplinary approach.