Polypharmacy and Potentially Inappropriate Medication Use among Elderly Patients with Cancer in a Tertiary Care Hospital

Abstract

Polypharmacy (PP) in elderly cancer patients undergoing chemotherapy may lead to an increased odds of potentially inappropriate medications (PIMs), increasing the risk of adverse events such as confusion, falls, and delayed treatment. Therefore, evaluating medication use and analyzing associated factors is essential to avoid inappropriate medications, raise awareness, and improve medication safety for elderly cancer patients. Objective: This study aimed to determine the prevalence of PP and PIMs among elderly cancer patients at the chemotherapy unit of Srinagarind Hospital, using the 2023 AGS Beers Criteria and 2023 START/STOPP Criteria version 3. We also identify factors associated with PIMs in this patient population for improving medication safety. Method: A retrospective cross-sectional study was conducted in elderly cancer patients (Age ≥ 65 years old) at the chemotherapy unit of Srinagarind Hospital between January 1, 2023, and December 31, 2023 (12 months). Results: A total of 390 elderly cancer patients were evaluated, with a male predominance (58.0%) and a median age of 69 years (IQR:67-73). The overall prevalence of PP was 91.0% (n=355), sub-classified into PP (5-9 medications) at 65.4% and excessive polypharmacy (≥10 medications) at 25.6%. The overall prevalence of PIMs was 71.0%. When assessed separately, PIMs were identified by the 2023 Beers criteria in 65.9% of patients and by the 2023 START/STOPP Criteria in 53.8% of patients. Commonly identified PIMs included benzodiazepines and prokinetic agents. In univariate analysis, the number of medications (p<0.001) and the number of comorbidities (p<0.001) were significantly associated with PIMs. Multivariate analysis revealed that diabetes mellitus (AOR=1.78, 95%CI:1.05-3.03, p=0.032), excessive polypharmacy (AOR=9.27, 95%CI:3.78-22.73, p<0.001), and a lung cancer diagnosis (AOR=8.58, 95%CI:1.09-67.59, p=0.041) were significant factors for PIMs. Conclusion: Most elderly cancer patients were treated with polypharmacy. The combined use of 2023 Beers Criteria and 2023 START/STOPP Criteria provides a more comprehensive detection of PIMs compared to using either criteria alone. The START/STOPP criteria provide superior efficacy in patient-specific clinical assessment. The number of prescribed medications and the number of comorbidities were factors associated with the occurrence of PIMs.