Machado Jose Kleber Kobol, Feferbaum Rubens, Kobayashi Celia Etsuco, Sanches Cristina, Santos Silvia Regina Cavani Jorge
University of Sao Paulo, Medical School, Sao Paulo, SP, Brazil.
Clinics (Sao Paulo). 2007 Aug;62(4):405-10. doi: 10.1590/s1807-59322007000400006.
[corrected] The objective of the present study was to evaluate the kinetic disposition of vancomycin in preterm infants with emphasis on the apparent volume of distribution, biological half-life, and total body clearance as well as whether their variations cause significant modification of the trough plasma concentration of the drug, depending on the postconceptional age (PCA) and the postnatal age (PNA).
Twenty-five selected patients were distributed into 2 groups which differed significantly in terms of mean PCA (31.2-32.3 weeks in group 1, n = 13; 33.5-34.1 weeks in group 2, n = 12: CI95%, P < .001) and PNA (group 1, 12.0-18.5 days; group 2, 18.0-34.0 days, CI95%, P < .05). The parents were informed and signed a written consent for participation of the infants in the protocol that had been previously approved by the Ethics Committee of the hospital.
Apparent volume of distribution was significantly increased in group 1 compared with patients of group 2 (0.85 vs. 0.56 L/kg, respectively; P = .01,). Additionally multiple linear regression revealed a good linear correlation (r = 0.85) of trough plasma concentration of vancomycin with the apparent volume of distribution and also with the biological half-life in patients of group 1, while a good correlation (r = 0.91) was obtained for the trough plasma concentration with total body clearance in infants of group 2. The influence of these kinetic parameters on the trough concentration of vancomycin in preterm infants seems to vary according to PCA and PNA.
In conclusion, the trough plasma concentration of vancomycin depends on the pharmacokinetics, and multiple linear correlation indicates that it varies according to the postconceptional and postnatal age of preterm infants.
本研究的目的是评估万古霉素在早产儿体内的动力学处置情况，重点关注分布容积、生物半衰期和全身清除率，以及这些参数的变化是否会根据孕龄（PCA）和出生后年龄（PNA）导致药物谷浓度的显著改变。
选取25例患者分为2组，两组在平均PCA（第1组为31.2 - 32.3周，n = 13；第2组为33.5 - 34.1周，n = 12：95%置信区间，P <.001）和PNA（第1组为12.0 - 18.5天；第2组为18.0 - 34.0天，95%置信区间，P <.05）方面存在显著差异。已将研究方案告知家长并获得其书面同意，该方案先前已获医院伦理委员会批准。
与第2组患者相比，第1组的分布容积显著增加（分别为0.85 vs. 0.56 L/kg；P =.01）。此外，多元线性回归显示，第1组患者中万古霉素的谷浓度与分布容积以及生物半衰期呈良好的线性相关性（r = 0.85），而第2组婴儿中谷浓度与全身清除率具有良好的相关性（r = 0.91）。这些动力学参数对早产儿万古霉素谷浓度的影响似乎因PCA和PNA而异。
总之，万古霉素的谷浓度取决于药代动力学，多元线性相关性表明其会根据早产儿的孕龄和出生后年龄而变化。
