P2-29-6 - Polypharmacy in Elderly Cancer Patients

Abstract

Background: Elderly patients often take multiple drugs for the comorbid conditions. The polypharmacy is shown to be associated with increased risk of adverse drug events in anti-cancer chemotherapy. We retrospectively investigated the relationship between age and polypharmacy.Methods: The medical records of patients who received anti-cancer chemotherapy in Fukuoka University Hospital between January 2007 and June 2013 were reviewed for age, the number of comorbid diseases and related medicines, type of cancer, and chemotherapy regimen. The potential drug-drug interactions were analyzed by using pharmaceutical references. This study was approved by an institutional review board of Fukuoka University Hospital.Results: Four hundred and fifty patients were enrolled in this study. Median age was 63 years (range;15-96). Patients were divided in 5 groups according to the age; group A of patients aged ≤44 years (n = 43), group B of aged 45-54 years (n = 52), group C of aged 55-64 years (n = 154), group D of aged 65-74 years (n = 109), and group E of aged ≥75 years (n = 92). There were 124 patients of lymphoma, 51 of lung cancer, 50 of breast cancer, 38 of colorectal cancer, 31 of gastric cancer, 21 of esophageal cancer, and 87 of other malignancies. The mean numbers of comorbid diseases in group A, B, C, D and E were 0.6, 0.9, 1.5, 2.0 and 3.0, respectively, and the mean numbers of medications were 2.7, 3.5, 4.2, 5.7 and 7.8, respectively. The potential interaction between medicines for comorbid diseases and anti-cancer agents was observed in 58 patients (12.8%); 5 in group A, 5 in group B, 14 in group C, 14 in group D and 20 in group E.Conclusions: The number of medications for comorbid diseases increased according to the age. Since these agents might potentially interact with anti-cancer agents, a careful assessment of drug interaction is necessary in elderly patients when they receive anti-cancer chemotherapy.