Copyright © The Author(s) 2024. This article is distributed under a Creative Commons Attribution 4.0 International License 1 RESEARCH ARTICLE Open Access Potential drug-drug interactions in elderly patients in a renal ward: a single-center retrospective study in Pakistan Acta Pharmaciae Indonesia: Acta Pharm Indo E-ISSN 2621-4520 Ahmad et al (2024) Vol 12(2): 15510 https://doi.org/10.20884/1.api.2024.12.2.15510 ABSTRACT Background: The increasing prevalence of kidney disease among elderly populations has led to a rise in potential drug-drug interactions (pDDIs), particularly due to widespread polypharmacy use in this demographic. Objective: This study aims to retrospectively analyze pDDIs and identify their prevalence and associated factors among elderly patients in a renal ward. Methods: This retrospective observational study was conducted at Saidu Group of Teaching Hospital in Swat, Pakistan, from January to December 2022. Data were obtained from the Patients Records Office using a conventional paper-based record system. A sample of 43 elderly patients (age ≥60 years) was selected through consecutive sampling. Drug interactions were assessed using freely available online tools: Drugs.com and Medscape Drug Checker, selected for their user-friendly accessibility and suitability in resource-limited settings. Results: Among the 43 elderly subjects with balanced gender distribution, the mean age was 66.53 ± 7.68 years. Comorbidities were present in 74.4% of patients, and each patient was prescribed an average of 4.58 medications. According to Medscape, 62.79% of patients experienced one or more potential drug interactions, while Drugs.com identified interactions in 67.44% of cases. Notably, 15% of these interactions were classified as high-risk by both tools. Logistic regression analysis indicated a significantly higher risk of potential drug interactions with increasing numbers of prescribed medications (OR = 4.515, p = 0.033). Conclusion: This study identified a high prevalence of pDDIs among elderly patients with kidney disease in Pakistan. The majority had comorbidities necessitating multiple medications, thereby increasing the risk of adverse drug reactions (ADRs). Mitigating these risks requires accurate prescribing practices, reliable electronic surveillance systems, and clinical pharmacist support. Keywords: drug-drug interactions, elderly patients, kidney disease, polypharmacy Nouman Ahmad 1 , Andika Yusuf Ramadhan 2 , Asif Mahmood 3 , Shah Faisal 4* ¹Master Program in Biomedical Sciences, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia 2 Clinical Pharmacology Specialist Study Program, Faculty of Medicine, Universitas Indonesia, Jakarta 10430, Indonesia 3 Doctoral Program of Pharmaceutical Sciences, Department of Pharmacy, University of Malakand, Chakdara, Pakistan 4 CECOS University of IT and Emerging Sciences, Hayatabad 25100, Peshawar, Pakistan *Corresponding author: CECOS University of IT and Emerging Sciences, Hayatabad 25100, Peshawar, Pakistan. Email: Shahfaisalpharmacist@gmail.com Introduction The global elderly population is rapidly expanding, with projections indicating an increase from 10% in 2022 to 16% in 2050 for individuals aged 65 years or older [1]. This demographic shift coincides with a growing prevalence of multimorbidity, defined as the concurrent presence of multiple chronic conditions. In Germany, for example, 24% of individuals above 75 years have five or more coexisting diseases [2]. Beyond advanced age (>60 years), other factors such as urbanization, non-communicable diseases, increased body mass index, and tuberculosis contribute to comorbidity burden [3]. This presents the challenge of patients concurrently using multiple medications, leading to potential drug interactions. The occurrence of potential drug-drug interactions (pDDIs) is strongly correlated with individuals aged 60 and above,