Levores Mechanism of Action

Pharmacotherapeutic Group: quinolone antibacterials, fluoroquinolones. ATC Code: J01MA12.
Pharmacology: Pharmacodynamics: Levofloxacin is a synthetic antibacterial agent of the fluoroquinolone class and is the S (-) enantiomer of the racemic active substance ofloxacin.
Mechanism of action: As a fluoroquinolone antibacterial agent, levofloxacin acts on the DNA-DNA-gyrase complex and topoisomerase IV.
PK/PD relationship: The degree of the bactericidal activity of levofloxacin depends on the ratio of the maximum concentration in serum (Cmax) or the area under the curve (AUC) and the minimal inhibitory concentration (MIC).
Mechanism of resistance: Resistance to levofloxacin is acquired through a stepwise process by target site mutations in both type II topoisomerases, DNA gyrase and topoisomerase IV. Other resistance mechanisms such as permeation barriers (common in Pseudomonas aeruginosa) and efflux mechanisms may also affect susceptibility to levofloxacin. Cross-resistance between levofloxacin and other fluoroquinolones is observed. Due to the mechanism of action, there is generally no cross-resistance between levofloxacin and other classes of antibacterial agents.
Pharmacokinetics: Levofloxacin is rapidly and almost completely absorbed after oral use with peak plasma concentrations achieved within 1 hour of a dose. It is distributed into body tissues including the bronchial mucosa and lungs, but penetration into CSF is relatively poor. Levofloxacin is about 30 to 40% bound to plasma proteins. It is only metabolised to a small degree to inactive metabolites. The elimination half-life of Levofloxacin is 6 to 8 hours, although this may be prolonged in patients with renal impairment. Levofloxacin is excreted largely unchanged, primarily in the urine. It is not removed by haemodialysis or peritoneal dialysis.