IGARASHI Yuki

写真a

Affiliation

Faculty of Pharmacy, Department of Pharmacy Division of Pharmacodynamics (Shiba-Kyoritsu)

Position

Research Associate/Assistant Professor/Instructor

E-mail Address

E-mail address

Page Top ▲

Profile Summary 【 Display / hide 】

  • 　

Page Top ▲

Career 【 Display / hide 】

  • 2023.04
    -
    2025.03

    Yokohama General Hospital, Pharmacy department, pharmacist

  • 2025.04
    -
    Present

    Keio University Faculty of Pharmacy, Division of Pharmacodynamics, Assistant Professor

Page Top ▲

Academic Background 【 Display / hide 】

  • 2012.04
    -
    2019.03

    Keio University, Faculty of Pharmacy, Pharmaceutical department

    University, Graduated

  • 2019.04
    -
    2023.03

    Keio university graduate school

    Graduate School, Graduated, Doctoral course

Page Top ▲

Academic Degrees 【 Display / hide 】

  • Ph.D. in Pharmaceutical Science, Keio university graduate school, Coursework, 2023.03

Page Top ▲

Licenses and Qualifications 【 Display / hide 】

  • Pharmacist License, 2019.05

Page Top ▲
 

Papers 【 Display / hide 】

  • Development and external validation of a population pharmacokinetic model and optimal Vancomycin dosing regimen for overweight and obese patients

    Komatsu T., Tomizawa A., Samura M., Suzuki A., Ishigo T., Fujii S., Ibe Y., Yoshida H., Tanaka H., Fujihara H., Yamaguchi F., Ebihara F., Maruyama T., Yagi Y., Hamada Y., Nagumo F., Takuma A., Chiba H., Nishi Y., Igarashi Y., Enoki Y., Otori K., Matsumoto K.

    Journal of Infection and Chemotherapy 31 ( 12 )  2025.12

    ISSN  1341321X

    　View Summary

    Introduction: This study aimed to develop and evaluate a population pharmacokinetic model and optimal dosing regimen for vancomycin in overweight and obese adults. Methods: A population pharmacokinetic model using a two-compartment system was constructed using a nonlinear mixed-effects approach, incorporating 527 data points from 184 participants. External validation of the model was carried out using an additional 55 data points from 21 participants; these were not used in the construction of the model. Monte Carlo simulations were used to determine the dosage that achieved the steady state area under the curve value falling between 400 μg h/mL and 600 μg h/mL. Results: In the final model, vancomycin clearance was found to be a significant predictor of blood vancomycin levels, alongside creatinine clearance (CCr), blood urea nitrogen levels, and incidence of heart failure. CCr was calculated with adjusted body weight (AdjBW). AdjBW was selected as a predictor of the volume of distribution in the central and peripheral compartments. External validation showed that the highest proportion of cases had deviations of less than 15 % between measured and predicted values in the final model developed in this study. This indicates that our model outperforms previously developed models (five for obese patients and four for non-obese patients). Conclusions: Our model shows that determining effective vancomycin doses for overweight and obese patients depend on estimated CCr rates, AdjBW, BUN levels, and incidence of heart failure.

  • Evaluating the necessity of two-point sampling for vancomycin area under the curve in follow-up therapeutic drug monitoring

    Suzuki A., Fujihara H., Yamaguchi F., Yoshida H., Tanaka H., Yagi Y., Maruyama T., Hamada Y., Ishigo T., Fujii S., Nagumo F., Samura M., Chiba H., Ebihara F., Takuma A., Komatsu T., Tomizawa A., Nishi Y., Igarashi Y., Enoki Y., Matsumoto K.

    Journal of Infection and Chemotherapy 31 ( 11 )  2025.11

    ISSN  1341321X

    　View Summary

    Objective: While both peak and trough (two-point) sampling are recommended to estimate the area under the concentration-time curve (AUC) for vancomycin, one-point sampling may reduce clinical burden. This study aimed to identify patient populations requiring two-point sampling by examining risk factors associated with AUC discrepancies between one- and two-point sampling during follow-up therapeutic drug monitoring (TDM). Method: This multicenter retrospective observational study included adult patients who received vancomycin from September 2020 to December 2023 and underwent two-point sampling at both initial and follow-up TDM. AUC was estimated using the Practical Antimicrobial TDM (PAT) version 4.0, and creatinine clearance (CLcr) was calculated using the Cockcroft-Gault equation. One- and two-point follow-up AUCs were compared using previously entered two-point concentrations from initial TDM. Patients were divided into a discrepancy group (AUC difference ≥10 %) and a non-discrepancy group. Risk factors were identified by univariate and multivariate analysis. Results: AUC values from one- and two-point sampling in 256 cases were highly correlated (r<sup>2</sup> = 0.965, p < 0.001). Seventeen cases (6.6 %) showed discrepancies ≥10 %. Multivariate analysis identified BMI ≥25 kg/m<sup>2</sup> (OR = 6.946, p = 0.001), CLcr <50 mL/min (OR = 5.863, p = 0.002), and ΔCLcr ≥10 mL/min (OR = 4.444, p = 0.012) as significant risk factors. Conclusion: Although one- and two-point AUCs showed strong correlation, discrepancies ≥10 % were more likely in patients with elevated BMI or impaired/unstable renal function. This suggests that two-point sampling may be essential for these patients to ensure accurate dosing of vancomycin during follow-up TDM.

  • Efficacy and Safety of Isavuconazole for Invasive Fungal Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

    Ayano Kawasaki, Ryuya Shintani, Risa Takao, Yuka Nakazawa, Takayuki Mihara, Shintaro Ikegami, Sora Shimada, Yuri Matsumoto, Yuko Okamoto, Yuki Igarashi, Yuki Enoki, Kazuaki Taguchi, Kazuaki Matsumoto

    Medical Mycology (Oxford University Press)  63 ( 10 )  2025.09

    Research paper (scientific journal), Joint Work, Corresponding author, Accepted,  ISSN  13693786

    　View Summary

    Background Isavuconazole (ISA) is a treatment option for invasive fungal infections (IFIs) and is known for a favorable safety profile compared with other antifungal agents. However, comprehensive evidence regarding its efficacy and safety remains limited. Objectives This study aimed to assess the efficacy and safety of ISA compared with other antifungal agents through a systematic review and meta-analysis restricted to randomized controlled trials (RCTs), to provide more reliable estimates of its clinical effects. Methods Following Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines, a comprehensive literature search was conducted using PubMed, the Cochrane Library, Web of Science, and ClinicalTrials.gov to identify RCTs comparing ISA with other antifungal agents. The primary outcomes were clinical response and mortality. Secondary outcomes included the incidence of adverse events, including serious, drug-related, and organ-specific toxicities. A subgroup analysis was conducted focusing on filamentous fungal infections, comparing ISA and voriconazole. Results Three RCTs met the inclusion criteria. No statistically significant differences were observed between ISA and comparator agents in terms of clinical response, mortality, or total and organ-specific adverse events. A trend toward fewer adverse events was noted in the ISA group. In the subgroup analysis, ISA and voriconazole showed similar efficacy and overall safety; however, the incidence of both drug-related adverse events and hepatobiliary disorders was significantly lower in the ISA group. Conclusions ISA demonstrated efficacy comparable to that of other antifungal agents, with a favorable safety profile in patients with IFIs, including filamentous fungal infections. This meta-analysis of RCTs provides high-quality evidence to support antifungal drug selection in clinical practice.

  • Oral β-lactam combinations are effective in vitro against Mycobacterium avium, regardless of clarithromycin susceptibility

    Maiko Yoshikawa, Tomoyasu Nishimura, Kana Misawa, Rina Shimamura, Kenta Suzuki, Shoko Kashimura, Yuki Igarashi, Yuki Enoki , Kazuaki Taguchi, Naoki Hasegawa, Ho Namkoong, Kazuaki Matsumoto

    Microbiology Spectrum    e0201225 2025.09

    Research paper (scientific journal), Joint Work, Accepted

  • External validation of a flowchart related to achieving the target area under the concentration-time curve for vancomycin: A retrospective multicenter study.

    Tomoyuki Ishigo, Ayako Suzuki, Yuta Ibe, Satoshi Fujii, Masahide Fukudo, Hiroaki Yoshida, Hiroaki Tanaka, Hisato Fujihara, Fumihiro Yamaguchi, Fumiya Ebihara, Takumi Maruyama, Yusuke Yagi, Yukihiro Hamada, Masaru Samura, Fumio Nagumo, Toshiaki Komatsu, Atsushi Tomizawa, Akitoshi Takuma, Hiroaki Chiba, Yoshifumi Nishi, Yuki Igarashi, Yuki Enoki, Kazuaki Matsumoto

    Journal of Infection and Chemotherapy 31 ( 5 )  2025.05

    Accepted,  ISSN  1341321X

    　View Summary

    During therapeutic drug monitoring (TDM) for vancomycin (VCM), the area under the concentration-time curve (AUC) is important for balancing efficacy versus toxicity. In a previous study, we developed a decision tree (DT) model to achieve the target AUC during TDM over the follow-up period (AUCfollow-up). This study aimed to validate the DT model for achieving the target AUCfollow-up. Patients who received VCM for at least 72 h and had an initial TDM within four doses between January 2023 and December 2023 were analyzed. The AUC of the initial TDM was calculated over 2-point (peak/trough) concentrations via Bayesian estimation. The target AUCfollow-up was defined as 400–600 μg h/mL. Among 188 patients (median age [interquartile range], 66 [56, 79] years; 50 % female), the target AUCfollow-up was achieved in 70 % (132/188). When the predicted AUC was 400–600 μg h/mL, 84 % (102/121) achieved the target AUCfollow-up. In a 12 h dosing interval subgroup, 86 % (88/102) achieved the target AUCfollow-up. Conversely, when the predicted AUC was <400 or >600 μg h/mL, the proportion who achieved the target AUCfollow-up dropped to 44 % (30/67). Only 30 % (3/10) of those with creatinine clearance rates of >130 mL/min/1.73 m2 achieved the target. The area under the receiver operating characteristics curve was 0.74, and the R2 value was 0.15. Our findings confirmed the external validity of the DT model and supported its use for optimizing VCM dosing. Overall, the DT model offers a reliable framework for achieving target AUC values during follow-up for TDM, aiding safe and effective treatment.

display all >>

Page Top ▲

Presentations 【 Display / hide 】

  • 炎症性腸疾患・Clostridioides difficile感染症マウスモデルを用いたfidaxomicinの有用性評価

    三原 貴之, 五十嵐 裕貴, 榎木 裕紀, 田口 和明, 松元 一明

    第72回日本化学療法学会東日本支部総会 第74回日本感染症学会東日本地方会学術集会 合同学会 , 

    2025.09
    , 

    Oral presentation (general)

  • 造血器腫瘍患者におけるバンコマイシン薬物動態モデル別の予測性の検討

    坂本靖宜, 重村明香, 井出和男, 渡邉直優, 鈴木智代, 五十嵐裕貴, 榎木裕紀, 加藤英明, 松元一明

    第72回日本化学療法学会東日本支部総会 第74回日本感染症学会東日本地方会学術集会 合同学会 , 

    2025.09
    , 

    Oral presentation (general)

  • 2点採血でバンコマイシンのAUCを算出した症例におけるAKIリスクの層別化

    石郷友之, 鈴木絢子, 藤居賢, 伊部裕太, 吉田博昭, 田中宏明, 海老原文哉, 丸山拓実, 八木祐助, 佐村優, 南雲史雄, 小松敏彰, 冨澤淳, 詫間章俊, 千葉博暁, 五十嵐裕貴, 榎木裕紀, 浜田幸宏, 西圭史, 松元一明

    第72回日本化学療法学会東日本支部総会 第74回日本感染症学会東日本地方会学術集会 合同学会 , 

    2025.09
    , 

    Oral presentation (general)

  • Mycobacterium avium complexに対するβラクタム系抗菌薬2剤併用のin vitroにおける有効性評価

    吉川万衣子, 西村知泰, 三澤可奈, 島村莉奈, 鈴木健太, 五十嵐裕貴, 榎木裕紀, 長谷川直樹, 南宮湖, 松元一明

    第72回日本化学療法学会東日本支部総会 第74回日本感染症学会東日本地方会学術集会 合同学会 , 

    2025.09
    , 

    Oral presentation (general)

  • Hollow Fiber Infection Modelを用いた肺MAC症に対する標準治療の有効性評価

    鈴木健太, 島村莉奈, 吉川万衣子, 宇山杏奈, 林侑孝, 五十嵐裕貴, 榎木裕紀, 西村知泰, 松元一明

    第72回日本化学療法学会東日本支部総会 第74回日本感染症学会東日本地方会学術集会 合同学会, 

    2025.09
    , 

    Oral presentation (general)

display all >>

Page Top ▲

Research Projects of Competitive Funds, etc. 【 Display / hide 】

  • 瞬間的MICとHFIMを用いた感染部位指向型PK/PD評価手法の構築

    2025.04
    -
    2027.03

    Japan Society for the Promotion of Science (JSPS), Grants-in-Aid for Scientific Research, Grant-in-Aid for Research Activity Start-up, Principal investigator

  • MA-T技術を活用した新規消毒剤の開発研究

    2025
    -
    2026.03

    OTC Self-Medication Promotion Foundation, 調査・研究助成, Principal investigator

Page Top ▲

Awards 【 Display / hide 】

  • 第8回フレッシャーズ・カンファランス優秀演題発表賞

    島村莉奈,西村知泰,吉川万衣子,三澤可奈,矢野大和,榎木裕紀,五十嵐裕貴,長谷川直樹,南宮湖,松元一明, 2025.06, 抗菌薬投与が引き起こすMycobacterium abscessusの細胞壁脂質とコロニー形態変化

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • 日本化学療法学会Young Challenger Award（YCA）2025

    五十嵐裕貴, 2025.05, 日本化学療法学会, β-ラクタム薬/β-ラクタマーゼ阻害薬の併用療法におけるin vivo pharmacokinetics/pharmacodynamics評価方法の構築

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • 第34回日本医療薬学会年会Postdoctoral award

    五十嵐裕貴, 2024.11, 日本医療薬学会, β-ラクタム薬/β-ラクタマーゼ阻害薬の併用療法におけるin vivo pharmacokinetics/pharmacodynamics評価方法の構築

    Type of Award： Award from Japanese society, conference, symposium, etc.

  • 2023年度KP会星野尚美記念薬学研究・活動奨励賞 研究論文部門

    五十嵐裕貴, 2024, Development of an optimized and practical pharmacokinetics/pharmacodynamics analysis method for aztreonam/nacubactam against carbapenemase-producing K. pneumoniae

    Type of Award： Other

  • Sato Pharmaceutical Research Encouragement Award

    五十嵐裕貴, 2020, 佐藤製薬株式会社, PK/PD理論に基づくCefditorenの適正使用を目指したマウスにおける薬物動態研究

    Type of Award： Other

display all >>

Page Top ▲
 

Courses Taught 【 Display / hide 】

  • SEMINAR (PHARMACODYNAMICS)

    2025

  • RESEARCH FOR BACHELOR'S THESIS 1

    2025

  • PRE-CLINICAL TRAINING FOR HOSPITAL & COMMUNITY PHARMACY

    2025

  • PHARMACEUTICAL-ENGLISH SEMINAR

    2025

  • ENGLISH EXERCISES FOR PHARMACEUTICAL SCIENCES

    2025

display all >>

Page Top ▲
 

Memberships in Academic Societies 【 Display / hide 】

  • The Japanese Society of Clinical Pharmacology and Therapeutics, 

    2025.01
    -
    Present

  • The Japanese Society of Pharmaceutical Health Care and Sciences, 

    2021.02
    -
    Present

  • Japanese Society of Chemotherapy, 

    2019.11
    -
    Present
Page Top ▲