JAC Advance Access originally published online on June 27, 2005
Journal of Antimicrobial Chemotherapy 2005 56(2):360-364; doi:10.1093/jac/dki205
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Clearance of moxifloxacin during continuous haemofiltration (CVVHF) in vitro
1 Department of Anaesthesiology, University of Regensburg, Regensburg, Germany; 2 Department of Pharmacology, University of Regensburg, Regensburg, Germany
Received 7 December 2004; returned 22 February 2005; revised 22 April 2005; accepted 24 May 2005
* Correspondence address. Departments of Anaesthesiology and Pharmacology, Regensburg University Medical Centre, University of Regensburg, D-93042 Regensburg, Germany. Tel: +49-941-944-7801; Fax: +49-941-944-7802; E-mail: karl-peter.ittner{at}klinik.uni-regensburg.de
Background/aims: The clearance of moxifloxacin is reported to be unaltered in the presence of renal insufficiency. There is little information about the clearance of intravenous moxifloxacin in renal replacement therapies during intensive care. The aim of this study was to determine the clearance of moxifloxacin during continuous veno-venous haemofiltration (CVVHF) in vitro.
Methods: The elimination of moxifloxacin (reservoir with 600 mL of washed human erythrocytes, 100 mL of NaHCO3 and various amounts of Ringer solution and human albumin to give a total volume of 1000 mL, pH 7.35 ± 0.5; haematocrit 41 ± 2) during CVVHF in vitro with two filter conditions (during priming, after priming), three protein concentrations (human albumin: 0 g/L, 20 g/L, 40 g/L) and two filtration velocities [(i) standard condition: blood flow at 100 mL/min and turnover of 2 L/h; (ii) blood flow at 50 mL/min and turnover of 1 L/h] were investigated.
Results: A new filter needs 20 min of priming before moxifloxacin reaches a steady relative filtration rate. The sieving coefficient with 0 g/L albumin was 1.07, with 20 g/L 0.90 and with 40 g/L 0.80. Under standard filtration conditions (i) the renal clearance was between 26.7 and 35.7 mL/min, and under the altered conditions (ii) it was 15.2 mL/min.
Conclusion: During CVVHF in vitro we found filtration clearances of moxifloxacin of the same order as its renal clearance in healthy subjects. The high sieving coefficient, nearly independent of blood protein concentration, would suggest that moxifloxacin is filtered almost as freely as creatinine. These results do not indicate a need for dose adjustment under appropriate haemofiltration conditions and normal hepatic function.
Keywords: antibiotics , dosage recommendations , renal failure , renal replacement therapy , artificial membranes