Background Peripheral arterial disease (PAD) is a common atherosclerotic condition and can lead to cardiovascular complications. Patients suffering from this disease can develop foot infections, and often debridement or amputation procedures due to poor healing of the wounds are required. Ciprofloxacin is a commonly administered antibacterial in patients with PAD.

Purpose To quantify ciprofloxacin concentrations in peripheral tissues of patients suffering from varying degrees of PAD to assess whether disease severity significantly affected therapeutic concentrations of ciprofloxacin reaching the site of infection.

Material and methods Tissue samples were collected from 50 PAD patients admitted for debridement or amputation procedures. The severity of PAD was assessed by a vascular surgeon using ankle brachial pressure indices and spectral waveform analyses. Tissue samples were collected at the end of the debridement or amputation procedure, which normally took 20 min, homogenised and the amount of ciprofloxacin in each analysed using high performance liquid chromatography. The Mann-Whitney test was applied to correlate between the different types of PAD severity and tissue concentrations achieved.

Results 50 patient samples (33 male; 17 female) were analysed. 44 patients were admitted for an amputation and 6 for a debridement procedure. 34 patients were suffering from severe PAD, 3 patients had no or borderline PAD while 12 patients had mild to moderate PAD. Patients having the lowest concentration of ciprofloxacin were those suffering from severe PAD. The mean concentration of ciprofloxacin in the tissue of patients suffering from severe PAD, mild to moderate PAD and none to borderline PAD was 0.11 µg/mL, 0.42 µg/mL and 1.54 µg/mL, respectively. Pairwise comparison results between the different types of PAD severities indicated that there was a significant difference in the concentration of ciprofloxacin reaching the tissue.

Conclusion The severity of PAD is a significant predictor of the concentration of ciprofloxacin in peripheral tissue. Giving higher doses of ciprofloxacin to try and attain greater concentrations in ischaemic tissue might not result in increased tissue ciprofloxacin concentrations in patients with severe states of PAD.

References and/or Acknowledgements Thanks to the staff at the surgical ward, operating theatre and toxicology department.

No conflict of interest.