Objective To explore the effects of CYP2C19, CYP2C9 and CYP3A5 genotypes on the plasma concentration of voriconazole in children. Methods Collected blood samples from 50 hospitalized children with invasive fungal infections who received intravenous voriconazole from January 2020 to December 2020. High performance liquid chromatography was used to detect the blood trough concentration of voriconazole, and the time-of-flight mass spectrometry detection system was used to detect the genotypes of CYP2C19, CYP2C9 and CYP3A5, and the effects of children’s genotyping on the plasma concentration, efficacy and adverse reactions of voriconazole were analyzed. Results The total effective rate of 50 children with IFI was 84% （42/50 cases） after voriconazole treatment. The incidence of adverse reactions was 20% （10/50 cases）. The measured plasma concentration of voriconazole ranged from 0.56~7.62 μg/ml. Combined with the different mutation types of CYP2C19 gene loci, three metabolic activities were produced: fast, medium and slow, and the test results showed that there were 16 cases of fast metabolism, 27 cases of intermediate metabolism and 7 cases of slow metabolism. There was a significant difference in plasma concentrations among the three groups （F=15.359, P<0.001）, and the drug concentrations in the fast metabolic group were significantly lower than those in the intermediate metabolic and slow metabolic groups. The mutations of CYP2C9 and CYP3A5 had no significant effect on the plasma concentrations of the drugs, which were （F=2.213, P=0.086 and F=0.757, P=0.475）. Conclusion Voriconazole had significant efficacy in the treatment of invasive fungal infections in children, and the adverse reactions were mild. CYP2C19 genotype was significantly related to the rate of drug metabolism and was an important factor affecting blood drug concentration, the detection of drug concentration and genotype of voriconazole was helpful to adjust the effective drug dose clinically and would achieve more scientific and individualized treatment.

Objective To explore the correlation between dose, blood concentration and efficacy of voriconazole in the treatment of invasive fungal infection in children. Methods 68 children treated with voriconazole during January 2019 to December 2019 were collected. The plasma concentration of voriconazole was assayed by high performance liquid chromatography (HPLC). The correlation between blood concentration and clinical efficacy was statistically analyzed. Results Different drug blood concentrations were obtained with different dosages: <4.0 mg/kg (6 cases) with the trough concentration ranged from 0.4 to 3.31 μg/ml (r=0.613, P=0.195). (4.0 - 7.0) mg/kg (44 cases), ranged from 0.35 to 7.02 μg/ml (r=0.325, P=0.018); >7.0 mg/kg (18 cases), ranged from 1.46 to 12.45 μg/ml (r=0.584，P＜0.023). There was a difference between the three groups (F=7.270, P=0.026). The relationship between the drug blood concentration and the therapeutic effect was obvious. In the <1.0 μg/ml group of 14 cases, 10 cases (71.4%) were effective, and 4 cases were ineffective. In the 1.0 - 5.5 μg/ml group of 48 cases, 44 cases (91.7%) were effective, and 4 cases were ineffective. In the >5.5 μg/ml group of 6 cases, 4 cases (66.7%) were effective and 2 cases ineffective. The difference among the three groups was obvious (χ²=5.360, P=0.039). Among the 68 cases, 58 cases (85.3%) were effective, and 10 cases (14.7%) were ineffective. Adverse reactions occurred in 10 cases (14.7%) with mild liver function injury, which did not affect the treatment and recovered with liver protection treatment. Conclusion This study showed that voriconazole was generally safe and effective in the treatment of invasive fungal infections in children. There was a significant dose-blood concentration and efficacy correlation. Further studies on pharmacokinetics and efficacy should be carried out to optimize the individualized treatment.