Clinical Impact of Cytochrome P450 2C19 Genotype on the Treatment of Invasive Aspergillosis under Routine Therapeutic Drug Monitoring of Voriconazole in a Korean Population.
BACKGROUND
Genetic polymorphisms of cytochrome P450 enzymes, especially CYP2C19 influence voriconazole pharmacokinetics. However, the impact of CYP2C19 genetic polymorphisms on the therapeutic efficacy and toxicity of voriconazole therapy are not well established.


METHODS
In this prospective observational study, we analyzed all consecutive adult patients with hematologic diseases who were treated for invasive aspergillosis (IA) with voriconazole between January 2011 and June 2012. CYP2C19 genotype and routine therapeutic drug monitoring of voriconazole were performed. The target range for voriconazole trough levels was 1-5.5 mg/L.


RESULTS
A total of 104 consecutive patients were enrolled, including 39 homozygous extensive metabolizers (EMs, 38%), 50 heterozygous extensive metabolizers (HEMs, 48%), and 15 poor metabolizers (PMs, 14%). The initial voriconazole trough levels were 1.8, 2.7, and 3.2 mg/L in EMs, HEMs, and PMs, respectively (P = 0.068). Out-of-range initial trough levels were most frequently observed in EMs (46%) followed by HEMs (26%) and PMs (0%) (P = 0.001). The frequency of initial trough levels < 1 mg/L but not > 5.5 mg/L differed significantly among the 3 groups (P = 0.005). However, treatment response, all-cause and IA-attributable mortality, and the occurrence of voriconazole-related adverse events did not differ significantly among the 3 groups (P = 0.399, P = 0.412, P = 0.317, and P = 0.518, respectively).


CONCLUSIONS
While none of the initial voriconazole trough levels in PMs was outside the target range, subtherapeutic initial trough levels were frequent in EMs. Although there was no significant relationship between CYP2C19 genotype and either the clinical outcomes of IA or toxicity of voriconazole, further large-scale multicenter studies using clinical data from homogeneous populations are required.
Department of Life Sciences, Pohang University of Science and Technology, Pohang, Korea.
Si-Hyun
SH
Kim
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Catholic Blood and Marrow Transplantation Center, The Catholic University of Korea College of Medicine, Seoul, Korea.
Dong-Gun
DG
Lee
Department of Internal Medicine, Daniel Medical Center, Bucheon, Korea.
Jae-Cheol
JC
Kwon
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Hyo-Jin
HJ
Lee
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Sung-Yeon
SY
Cho
Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Chulmin
C
Park
Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Eun-Young
EY
Kwon
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Sun Hee
SH
Park
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Su-Mi
SM
Choi
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Jung-Hyun
JH
Choi
Division of Infectious Diseases, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea. ; Vaccine Bio Research Institute, The Catholic University of Korea College of Medicine, Seoul, Korea.
Jin-Hong
JH
Yoo
CYP2C19; Invasive aspergillosis; Therapeutic drug monitoring; Voriconazole