Isavuconazole-d₄is intended for use as an internal standard for the quantification of isavuconazole by GC- or LC-MS. Isavuconazole is a broad-spectrum triazole antifungal agent.¹It inhibits the growth of clinical isolates ofA. fumigatus,A. terreus,A. flavus, andA. lentulus(MIC₉₀s = 0.39, 0.39, 2, and 0.25 mg/L, respectively) as well asC. albicans,C. krusei, andC. parapsilosis(MIC₅₀s = 0.03, 0.06, and 0.03 mg/L, respectively).^1,2,3,4Isavuconazole also inhibits the growth of several other fungal species, including clinical isolates ofC. neoformansandC. gattii(MIC₉₀s = 0.032 and 0.125 mg/L, respectively).^1,3Formulations containing isavuconazole have been used in the treatment of invasive aspergillosis and mucormycosis.

1.Yamazaki, T., Inagaki, Y., Fujii, T., et al.In vitro activity of isavuconazole against 140 reference fungal strains and 165 clinically isolated yeasts from JapanInt. J. Antimicrob. Agents36(4)324-331(2010) 2.Rudramurthy, S.M., Chakrabarti, A., Geertsen, E., et al.In vitro activity of isavuconazole against 208 Aspergillus flavus isolates in comparison with 7 other antifungal agents: Assessment according to the methodology of the European Committee on Antimicrobial Susceptibility TestingDiagn. Microbiol. Infect. Dis.71(4)370-377(2011) 3.Datta, K., Rhee, P., Byrnes, E., III, et al.Isavuconazole activity against Aspergillus lentulus, Neosartorya udagawae, and Cryptococcus gattii, emerging fungal pathogens with reduced azole susceptibilityJ. Clin. Microbiol.51(9)3090-3093(2013) 4.Astvad, K.M.T., Hare, R.K., and Arendrup, M.C.Evaluation of the in vitro activity of isavuconazole and comparator voriconazole against 2635 contemporary clinical Candida and Aspergillus isolatesClin. Microbiol. Infect.23(11)882-887(2017)