著者

尾﨑 正和 幸田 恭治 堀 健志 山下 裕司 古川 裕之

出版者

一般社団法人日本医療薬学会

雑誌

医療薬学 (ISSN:1346342X)

巻号頁・発行日

vol.43, no.4, pp.223-229, 2017-04-10 (Released:2018-04-10)

参考文献数

9

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Acetaminophen is approved up to 4,000 mg per day as an analgesic agent in Japan and displays analgesic effects depending on dosage. On the other hand, acetaminophen has some interactional effects. The mechanism of the interaction between acetaminophen and warfarin has not been elucidated, and no interactional cases have been reported in Japan either. However, two cases of marked PT-INR elongation were recognized by two inpatients in our hospital, Japanese males in their 50s and 60s who were treated with concurrent chemoradiotherapy using 70 Gy radiotherapy delivered as 2 Gy daily and triweekly 100 mg/m2 cisplatin, that had been prescribed both drugs. Each PT-INR lapsed into loss of control; the maximum for one was more than 20 which was unmeasurable and for the other, 9.48, given vitamin K2 (VK2) immediately was antagonistic to warfarin. Concomitant drugs of warfarin were promptly checked again to see if it was related to the plasma protein binding ratio and hepatic cytochrome P450 inhibition reaction. Furthermore, each liver function test was also normal. As a result of consideration on these two, the dosage of acetaminophen has possible implications. It could be caused by the active metabolite of acetaminophen, NAPQI (N-acetyl-para-benzoquinone imine), as reported by basic research of VK cycle inhibitory action; however, the mechanism is not completely clear yet so future research is required to clarify this point. In any case, it is necessary to regularly measure PT-INR through the combination of warfarin and acetaminophen.

著者

税所 篤行 高砂 美和子 若林 和貴 秋山 真里 幸田 恭治 髙崎 彰久 松永 和人 石田 博 北原 隆志

出版者

公益社団法人 日本薬学会

雑誌

YAKUGAKU ZASSHI (ISSN:00316903)

巻号頁・発行日

vol.141, no.7, pp.971-978, 2021-07-01 (Released:2021-07-01)

参考文献数

14

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To reduce the number of falls caused by hypnotic agents, the standardization of insomnia treatment was carried out at Yamaguchi University Hospital from April 2019. There were concerns that medical costs would increase due to the selected medicines―suvorexant and eszopiclone―being more expensive than conventional benzodiazepines. In this study, the standardization of insomnia treatment was evaluated by pharmacoeconomics. The costs of the hypnotic agents was considered, as was the cost of examination/treatment following falls. Effectiveness was evaluated as the incidence of falls within 24 hours of taking hypnotic agents. This analysis took the public healthcare payer's perspective. Propensity score matching based on patient background, showed that, per hospitalization the medicine costs of the recommended group increased by 1,020 yen, however, the examination/treatment costs following falls decreased by 487 yen when compared with the non-recommended group. Overall, the recommended group incurred costs of 533 yen more per hospitalization for patients prescribed hypnotic agents compared to the non-recommended group, but the incidence of falls for the recommended group was significantly lower than that in the non-recommended group (1.9% vs. 6.3%; p<0.01). These results suggest that in order to prevent the incidence of falls by 1 case, it is necessary to increase costs by 12,086 yen which is the subthreshold cost for switching to the recommended medicine as standardization. The selection of recommended medicines may be a cost-effectiveness option compared with non-recommended medicines.