Clinical Significance of Measuring the Blood Concentration of Itraconazole Oral Solution in the Field of Hematology

Abstract

Itraconazole (ITCZ), a triazole antifungal agent, is highly fat-soluble. It shows favorable transfer to adipose tissue, but digestive tract absorption is unfavorable.1) In particular, there are marked individual differences in the absorption of capsules. In patients with neutropenia, the absorption rate is reported to be approximately 20%.2,3) To stabilize drug absorption, ITCZ oral solution (ITCZ-OS) containing cyclodextrin as a base was developed. Recently, ITCZ-OS has also been applied in clinical practice in addition to conventional capsules in Japan.Many clinical studies have reported the preventive effects of ITCZ on fungal infection. Some studies indicated that prophylactic therapy with ITCZ-OS significantly decreased the incidence of invasive fungal infection. However, others emphasized that there was no significant decrease. Therefore, the preventive effects of ITCZ-OS remain controversial. [3][4][5][6][7][8][9][10]

Chronic invasive sinus and intracerebral aspergillosis controlled by combination therapy with micafungin and a daily dose of 400 mg itraconazole oral solution

“…We adopted this high-dose ITCZ treatment in our patient by administering ITCZ oral solution and measuring the serum concentration of ITCZ and hydroxyl-ITCZ. The administration of the ITCZ oral solution at a dose of 200 mg once daily to patients in hematology yielded a serum concentration of hydroxy-ITCZ that reached 2396.5 ± 1742.7 ng/mL [9]. Our initial ITCZ dose, 200 mg twice daily, was set based on this report.…”