Effectiveness of a Pharmacist Outpatient Service for Patients Receiving Monotherapy with Oral Anticancer Drugs through Management of Unused Prescribed Medicines

Abstract

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 patients 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 grade2 adverse events; therefore, unused medicines exist. This pharmacist outpatient service can also lead to major reductions in healthcare costs through management of unused medicines. Key words oral anticancer drug, pharmacist outpatient service, unused prescribed medicine, reduction in healthcare costs 緒 言 がん薬物療法は，有効な抗がん薬の開発による 生存期間の延長，支持療法の進歩といった医学・ 薬学的背景の変化，患者意識の変化，入院治療費 の包括化，外来化学療法加算など医療を取り巻く 社会環境の変化等を背景に，外来が主流となって いる．そのなかで，経口抗がん薬は注射薬のよう な侵襲性や点滴による時間的拘束がなく，患者の 従来の生活スタイルを維持しながら治療できる利 点がある． 1, 2） しかしその一方で，服用を患者自身 に委ねているため，副作用モニタリングやマネジ メントを適切に行っていかなければ，治療継続が 困難になってしまうおそれがある． 3-5） 近年，経口抗がん薬服用患者に対し，薬剤師が医 師の診察前に患者面談を行い，薬学的見地から積極 的に介入していく薬剤師外来を開設する施設が全国 で増えてきている． 当院では， 2013年 7月にレゴラフェ ニブ服用患者を対象とした「薬剤師・看護師外来」 を立ち上げ，安全性および治療継続性の向上に向け た支援体制を構築した．現在，4 科（消化器外科， 乳腺外科，頭頸部・耳鼻いんこう科，泌尿器科） ，