Effects of pulse high-volume hemofiltration on serum concentration of moxifloxacin in patients with continuous renal replacement therapy

AIM: To study the changes of the serum moxifloxacin concentration in the patients with continuous renal replacement therapy when applied for pulse high-volume hemofiltration (PHVHF). METHODS: The patients applied for PHVHF were intravenously given moxifloxacin at the dose of 400 mg in 60 min. Blood samples were collected from the arterial (input) and venous (output) lines of the extracorporeal circuit immediately at different time points after the beginning of infusion, and replacement fluid was taken at the corresponding time points. The serum concentration of moxifloxacin was measured by high-performance liquid chromatography (HPLC). The pharmacokinetics parameters were determined using DAS 2.1.1 software.RESULTS: Two-compartment model was used to achieve the best concentration-time relation of moxifloxacin. The levels of blood urea nitrogen (BUN), serum creatinine (SCr) and serum K⁺ were obviously decreased after application of PHVHF (P<0.05). The peak serum concentration (C_max) of moxifloxacin was (4.843±1.854) mg/L. The half-life (T_1/2) was (4.822±2.126) h and the peak time (T_max) was (1.31±0.59) h. The total volume of distribution (V_d) was (82.63±24.69) L. The total clearance (CL_tot) was (14.36±8.43) L/h. All the ratios of area under the concentration-time curve (AUC) to 90% minimal inhibitory concentration (MIC₉₀) were more than 100 when the values of MIC₉₀ were 0.25 mg/L, 0.12 mg/L and 0.03 mg/L. All the values of C_max/MIC₉₀ were more than 10 when the values of MIC₉₀ were 0.25 mg/L, 0.12 mg/L and 0.03 mg/L.CONCLUSION: Application of PHVHF obviously improves the renal functions and eliminates a part of moxifloxacin in the serum. However, the serum concentration of moxifloxacin remains at the effective level for controlling the pathogenic bacteria.