経口抗がん薬服用患者に対する薬剤師外来における残薬確認の有用性

抄録

A pharmacist outpatient service for patients receiving monotherapy with oral anticancer drugs aims to improve safety and medication continuation through pre-examination interviews. We assess medication adherence and monitor chemotherapy-induced adverse events by referring to patientsʼ complaints of symptoms and their medical diaries. In addition, “unused prescribed medicines” can also be a useful information resource. However, unused medicines are becoming a large-scale problem in Japan, thus leading to lower therapeutic effects and higher healthcare costs. In this study, we interviewed 270 patients (cumulative total: 1,385, monthly average: 153.9) from January 1 to October 31, 2017. Adjusted numbers of unused anticancer drugs were 96 and those of unused medicines for supportive care were 420, including moisturizing creams and steroidal ointments (23.1％), antidiarrheal drugs (18.1％), and antiemetic drugs (8.1％). We calculated the reduction in healthcare costs as JPY 5,045,585.5 (monthly average: JPY 560,621) for all unused medicines and as JPY 4,699,791.6 (monthly average: JPY 522,199) for only unused anticancer drugs. Anticancer drugs went unused because of chemotherapy-induced adverse events (grade 1: 37.3％, grade 2: 60.8％, grade 3: 2.0％) and failure to take them as prescribed. However, the chemotherapy discontinuation rate caused by adverse events was only 6.8％ through our continuous interventions. Chemotherapy with oral anticancer drugs needed to be discontinued appropriately in cases of developing grade≧2 adverse events; therefore, unused medicines exist. This pharmacist outpatient service can also lead to major reductions in healthcare costs through management of unused medicines.