Inhibitory Quotient
Fluoroquinolones such as Baytril are drugs with concentration-dependent antimicrobial activity, which means that high plasma peak concentrations are more predictive of therapeutic success than time of plasma drug levels above the MIC of the pathogen during the whole treatment interval. The aim of therapy therefore should be to maximize peak plasma and tissue concentrations, which can be achieved when the total daily dose is given in one single application (11).
One indicator of expected antibacterial activity is the Inhibitory Quotient (IQ), which is the ratio between the peak plasma concentration (Cmax) and the MIC of the pathogen. The IQs of different quinolones are shown in the table for Staphylococcus intermedius/ aureus strains isolated from clinical patients and necropsy material.
The data shown in the table demonstrate the favourable antimicrobial activity of Baytril.
References
| (8) |
Pirro F, Edingloh M, Schmeer N: Bactericidal and inhibitory activity of enrofloxacin and other fluoroquinolones in small animal pathogens. Suppl Compend Contin Educ Pract Vet 21 (12): 19-25, 1999. |
| (11) |
Meinen JB, McClure JT, Rosin E: Pharmacokinetics of enrofloxacin in clinically normal dogs and mice and drug pharmacodynamics in neutropenic mice with Escherichia coli and staphylococcal infections. Am J Vet Res 56 (9): 1219-1224, 1995. |
| (12) |
Heinen E: Comparative pharmacokinetics of enrofloxacin and difloxacin, as well as their main metabolites in dogs. Suppl Compend Contin Educ Pract Vet 21 (12): 12-18, 1999. | |
