Plasma concentration of micafungin in patients with hematologic malignancies

In 20 patients with hematologic malignancies, we measured the plasma concentration of micafungin (MCFG) by high-performance liquid chromatography after drip infusion of MCFG, at 150 mg/day over a 1-h period, and we analyzed the results in relation to the patients’ laboratory parameters of liver and kidney function. Measurement of the plasma concentration was performed at the end of the initial administration of MCFG, 5 to 6 h after the start of the initial administration, immediately before the second dosing, immediately before the fourth dosing, and at the end of the fourth dosing. The plasma concentration of MCFG was correlated with the doses of MCFG per kilogram body weight (P = 0.0008–0.0036). The peak after the initial administration was 2.6 times higher than the trough value after the initial administration. The steady-state trough value was 1.2 times higher than the trough value after the initial administration. There was no correlation between the liver/kidney function parameters and the plasma concentration of MCFG. These results suggest that there was a good correlation between the plasma concentration of MCFG and the dose of MCFG per kilogram body weight, and that MCFG can be administered safely to patients with liver or kidney dysfunction without adjusting the dose.