Assessment of polypharmacy, potentially inappropriate medications, and drug-drug interactions in older patients with cancer

Introduction: This study aimed to determine polypharmacy, potentially inappropriate medications, and potential drug-drug interactions in elderly patients hospitalized in the oncology services of a university hospital in Turkey. Methods: This retrospective cross-sectional study was conducted between September 2021 and September 2022 on cancer patients over 65 years old hospitalized at Suleyman Demirel University Medical Faculty Hospital in Isparta, Turkey. Potentially inappropriate medications were defined according to the 2023 Beers Criteria of the American Geriatrics Society. Potential drug-drug interactions were determined with Medscape (R) drug interaction checker. Results: The median (min-max) of drugs used by the patients was 6 (2-15). Most of the patients (74.3%) had polypharmacy. Approximately half of the patients (51.4%) had potentially inappropriate medications. The most commonly used potentially inappropriate medications were diuretics (22.1%), metoclopramide (11.4%), antidepressant drugs (7.9%), and opioids (6.4%). The presence of comorbidities, mental, behavioral, and neurodevelopmental disorders, circulatory system diseases, and respiratory system diseases were found to be statistically significantly higher in the group with potentially inappropriate medication than in the group without potentially inappropriate medication (p < 0.05). In total, 98 patients (70%) had at least one potential drug-drug interaction. Potential drug-drug interactions were minor in 33.3%, major in 57.5%, serious in 7.74%, and contraindicated in 0.22% Conclusion: According to our study, polypharmacy, potentially inappropriate medications, and potential drug-drug interactions were high in elderly cancer patients. It is important to determine potential drug-drug interactions and potentially inappropriate medications in cancer patients by a multidisciplinary team, including the clinical pharmacist, to prevent possible negative consequences.