2016 年 42 巻 5 号 p. 328-335
The serum concentration of vancomycin (VCM) must be maintained above a minimum level to be therapeutically effective. However, it is difficult to achieve the optimum serum concentrations in patients undergoing continuous hemodiafiltration (CHDF) because of the change in the pharmacokinetics of administered drugs. To address this problem, we used the Sawchuk-Zaske method to examine the dosage required to achieve optimal VCM levels in patients undergoing CHDF. Blood samples were taken in the drug-elimination phase (5-6 h after administration, which is earlier than usual) to estimate the pharmacokinetics of VCM. The subjects were 11 patients who were administered VCM while undergoing CHDF in the intensive care unit between February 2010 and February 2015. Blood samples were collected at three different times: the first just before the administration of VCM, the second 2 h after VCM administration, and the third 5-6 h (group A) or 16-17 h (group B) after VCM administration. The VCM clearance was 35.6 ± 6.0 and 38.4 ± 4.9 mL/min in group A and B. The distribution volumes were 0.80 ± 0.12 and 0.93 ± 0.23 L/kg in groups A and B, respectively. No significant differences groups were found. Consequently, even if the final blood sample is taken relatively soon after drug administration (5-6 h), the estimated pharmacokinetic parameters can be used to adjust VCM dosage to achieve optimum serum concentrations. Because it is important to adjust the VCM dosage as quickly as possible, these findings should prove useful in clinical practice.