Question 4
Do you have any data comparing PK/PD properties of levofloxacin with other fluoroquinolones and the influence on bacterial killing?
The PK concentrations obtained by levofloxacin are among the highest of the fluoroquinolones, with the 500 mg once daily dose associated with high free AUC and grater free Cmax values than moxifloxacin and ciprofloxacin (Table 1) (5).
A recent study investigating rates and extent of bacterial killing of S. pneumoniae strains with moxifloxacin and levofloxacin demonstrated that moxifloxacin and levofloxacin achieved similar rates and extent of bacterial kill for the wild type, efflux pump type and parC mutant S. pneumoniae (6).
Table 1. Clinical dose and PK parameters of oral quinolones
Drug | Daily dosea (mg) |
AUCb (μg h/ml) |
Cmaxb,c (μ/ml) |
Protein bindingb (%) |
Free AUCd (μg h/ml) |
Free Cmaxd (μg/ml) |
||||||||
Moxifloxacin | 400 x 1 | 51.5 | 4.08 (7 days) | 50 | 25.8 | 2.04 | ||||||||
Ciprofloxacin | 200 x 3 | 13.8 | NA | 30 | 9.7 | NA | ||||||||
Levofloxacin | 500 x 1 | 47.5 | 5.72 (7 days) | 31 | 32.8 | 3.95 | ||||||||
Abbreviations: AUC = area under the plasma concentration-time curve, Cmax = maximum serum drug concentration, NA = not available. |
![]() |
![]() |
![]() |