Supplementary Material for: Drug-drug interactions in hospitalized urological patients: a retrospective cohort study

Introduction: Exposure to potential drug-drug interactions (pDDIs) can be a notable source of avoidable drug-related harm that requires adequate management to prevent medical errors. We aimed to evaluate pDDIs and associated factors in hospitalized urological patients on admission, during hospitalization, and on discharge.
Methods: A retrospective cohort study was conducted at the Clinic of Urology of the University Clinical Centre Kragujevac, Serbia. To detect pDDIs we used Lexicomp, which categorizes pDDIs as follows: X (Avoid combination), D (Consider therapy modification), C (Monitor therapy), B (No action needed) and A (No known interaction). Multiple linear regression analysis was used to identify factors associated with the number of pDDIs.
Results: More than half of the 220 included patients had at least one pDDI on admission and discharge (57.3% and 63.6%, respectively), whereas 95.0% had at least one pDDI during hospitalization. The total number and number of X, D, C, and B categories of pDDIs were the highest during hospitalization and the lowest on admission. Duration of hospitalization, arrhythmias, dementia, renal failure, cancer, surgery during hospitalization, number of prescribed drugs, and various pharmacological drug classes were risk factors for a higher number of pDDIs, while age, ischemic heart disease, hypertension, and development of infection during hospitalization were protective factors in at least one of the stages. The impact of renal colic depended on the stage and category of pDDI.
Conclusion: More than half of the urological patients were exposed to at least one pDDIs at all stages. Medical professionals should regularly screen for pDDIs, particularly in patients with risk factors.

引言：接触潜在的药物-药物相互作用（pDDIs）可能是可避免的药物相关伤害的一个重要来源，这种伤害需要得到充分的管理以防止医疗错误。本研究旨在评估住院泌尿科患者在入院、住院期间和出院时的pDDIs及其相关因素。方法：在塞尔维亚克拉古耶瓦茨大学临床中心泌尿科进行了回顾性队列研究。为检测pDDIs，我们使用了Lexicomp，该系统将pDDIs分为以下类别：X（避免联合使用）、D（考虑治疗调整）、C（监测治疗）、B（无需采取行动）和A（无已知相互作用）。采用多元线性回归分析以识别与pDDIs数量相关的因素。结果：在220名纳入患者中，超过一半的患者在入院和出院时至少有一种pDDIs（分别占57.3%和63.6%），而在住院期间，95.0%的患者至少有一种pDDIs。pDDIs的总数以及X、D、C和B类别的数量在住院期间最高，而在入院时最低。住院时间、心律失常、痴呆、肾功能衰竭、癌症、住院期间的手术、处方药物数量以及各种药理药物类别是pDDIs数量增加的风险因素，而年龄、缺血性心脏病、高血压以及住院期间感染的发展是至少在某个阶段中的保护因素。肾绞痛的影响取决于pDDIs的阶段和类别。结论：超过一半的泌尿科患者在所有阶段都接触到了至少一种pDDIs。医务人员应定期筛查pDDIs，特别是在具有风险因素的患者中。