JAC Advance Access originally published online on September 16, 2004
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Journal of Antimicrobial Chemotherapy 2004 54(4):836-839; doi:10.1093/jac/dkh412
JAC vol.54 no.4 © The British Society for Antimicrobial Chemotherapy 2004; all rights reserved
Tissue and serum levofloxacin concentrations in diabetic foot infection patients
1 Institute of Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, D-69120 Heidelberg; 2 Pharmacy Department, University of Heidelberg, Im Neuenheimer Feld 670, D-69120 Heidelberg; 3 Division of Endocrinology and Metabolism, Department of Medicine, University of Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg; 4 Outpatient Practice, P/24, D-68161 Mannheim; 5 Outpatient Department for Diabetics, Klinikum am Steinenberg Reutlingen, Steinenbergstr. 31, D-72764 Reutlingen; 6 Institute of Hygiene, University of Ulm, Steinhoevelstr. 9, D-89075 Ulm, Germany
* Corresponding author. Tel: +49-6221-56-37827; Fax: +49-6221-56-5627; Email: klaus_oberdorfer{at}med.uni-heidelberg.de
Objectives: Levofloxacin has a high bioavailability and a broad antibacterial spectrum which covers the common pathogens found in acute and chronic diabetic foot infections. The purpose of our study was to determine the serum and tissue concentrations of levofloxacin when administered orally in patients with infected diabetic foot ulcers and to compare these values with microbiological findings.
Patients and methods: Ten outpatients with diabetes and ulcerations of the lower extremity were included. All patients received oral levofloxacin therapy at a dose of 500 mg once daily. Wound tissue and serum samples were collected and levofloxacin concentrations determined by HPLC with fluorescence detection. Additionally, microbiological cultures were performed from swabs and debrided wound tissue, both before and after treatment. MICs of levofloxacin for all bacterial isolates were determined using the Etest.
Results: Following oral treatment with levofloxacin for an average of 10±3.8 days, all patients received debridement at the affected limbs. The levofloxacin concentrations in necrotic wound tissue were between 2.33–23.23 mg/kg and between 0.12–6.41 mg/L in serum. Tissue-to-serum ratios of levofloxacin concentrations for each patient were >1.0. The MIC values for all 17 initially isolated bacteria were 
2 mg/L. In half of our patients, fluoroquinolones were one of the few oral monotherapy options where the spectrum covered all initially isolated pathogens.
Conclusion: Our data showed good tissue penetration of levofloxacin in diabetic foot ulcers. In combination with adequate surgical debridement, levofloxacin seems well suited to the treatment of skin structure infections of diabetics caused by susceptible organisms.
Keywords: quinolones , pharmacokinetics , soft tissue infections , diabetic foot infections , MRSA