Pharmacology: Pharmacodynamics: Levofloxacin is the L-isomer of the racemate, ofloxacin, a quinolone antimicrobial agent. The antibacterial activity of ofloxacin resides primarily in the L-isomer. The mechanism of action oflevofloxacin and other fluoroquinolone antimicrobials involves inhibition of bacterial topoisomerase IV and DNA gyrase (both of which are type II topoisomerases), enzymes required for DNA replication, transcription, repair and recombination.
Pharmacokinetics: Absorption: Rapid and complete.
Distribution: Vd 74-112 L.
Protein binding: 24% to 38%.
Metabolism: Minimally hepatic.
Bioavailability: 99%.
Half-life elimination: 6-8 hours.
Excretion: Urine (87% as unchanged drug, <5% as metabolites) and Feces (<4%).
Toxicology: Preclinical Safety Data: Acute toxicity data: Rat i.v. 423 mg/kg (♂), 395 mg/kg (♀) Dog i.v. 200 mg/kg (♀).
Chronic toxicity data: Beagle i.v. 3 mg/kg/day 4 weeks.