AUTHOR=Li Hui , He Xiaoshuang , Lu Qiuya , Wang Ling , Jiang Jieling , Gao Wenhui , Wang Lining , Hu Jiong , Fang Jie , Bian Xiaolan 

TITLE=Unexpected renal influence on isavuconazole trough concentrations: two case reports and literature review

JOURNAL=Frontiers in Medicine

VOLUME=Volume 12 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1625697

DOI=10.3389/fmed.2025.1625697

ISSN=2296-858X

ABSTRACT=Isavuconazole (ISA) is a first-line treatment for invasive aspergillosis, with routine therapeutic drug monitoring (TDM) typically deemed unnecessary. Although the drug label and prior studies suggest renal function does not affect ISA pharmacokinetics, our findings in two high-risk patients challenge this perspective, showing an inverse correlation between ISA trough concentrations and estimated glomerular filtration rate (eGFR). Trough concentrations exceeding the reported toxicity threshold were associated with adverse drug reactions (ADRs). Given the limited sample size, large-scale retrospective and prospective studies are urgently needed to confirm the impact of renal function on ISA and to develop individualized TDM strategies that optimize efficacy and minimize toxicity.