OBJECTIVE: We aimed to clarify the drug interaction between tacrolimus and voriconazole and investigate the relationship between blood concentrations of tacrolimus and voriconazole in hematopoietic stem cell transplantation (HSCT) patients. MATERIALS AND METHODS: A retrospective study was conducted to investigate the relationship between blood concentration of tacrolimus and that of voriconazole at the Kindai University Nara Hospital. Patients who received HSCT and tacrolimus and were prescribed voriconazole for the prevention or treatment of aspergillosis from April 2010 to July 2018 were identified from the medical records. A total of 13 patients (administration route of tacrolimus: intravenously in 6 patients, orally in 7 patients) were enrolled in the present study. RESULTS: No significant correlation was observed between the blood concentration/dose (C/D) ratio of tacrolimus and the blood concentration of voriconazole (r = 0.38; p = 0.402; y = 102.8x + 928.1). However, a significant correlation was observed between the C/D ratio of tacrolimus and the blood concentration of voriconazole in the intravenous-administration group (r = 0.94; p = 0.0048; y = 421.9x + 810.5). Meanwhile, no significant correlation was observed in the oral-administration group (r = 0.43; p = 0.34; y = 7.9x + 719). CONCLUSION: The C/D ratio of tacrolimus was significantly correlated with the blood concentration of voriconazole when tacrolimus was intravenously administered. There was a difference in the mechanism of drug interaction between tacrolimus and voriconazole depending on the administration routes.
OBJECTIVE: We aimed to clarify the drug interaction between tacrolimus and voriconazole and investigate the relationship between blood concentrations of tacrolimus and voriconazole in hematopoietic stem cell transplantation (HSCT) patients. MATERIALS AND METHODS: A retrospective study was conducted to investigate the relationship between blood concentration of tacrolimus and that of voriconazole at the Kindai University Nara Hospital. Patients who received HSCT and tacrolimus and were prescribed voriconazole for the prevention or treatment of aspergillosis from April 2010 to July 2018 were identified from the medical records. A total of 13 patients (administration route of tacrolimus: intravenously in 6 patients, orally in 7 patients) were enrolled in the present study. RESULTS: No significant correlation was observed between the blood concentration/dose (C/D) ratio of tacrolimus and the blood concentration of voriconazole (r = 0.38; p = 0.402; y = 102.8x + 928.1). However, a significant correlation was observed between the C/D ratio of tacrolimus and the blood concentration of voriconazole in the intravenous-administration group (r = 0.94; p = 0.0048; y = 421.9x + 810.5). Meanwhile, no significant correlation was observed in the oral-administration group (r = 0.43; p = 0.34; y = 7.9x + 719). CONCLUSION: The C/D ratio of tacrolimus was significantly correlated with the blood concentration of voriconazole when tacrolimus was intravenously administered. There was a difference in the mechanism of drug interaction between tacrolimus and voriconazole depending on the administration routes.