LevofloxacinIn VitroActivity: Results from an International Comparative Study with Ofloxacin and Ciprofloxacin

Abstract

Levofloxacin, the S-(-)-isomer of ofloxacin, was compared to ofloxacin and ciprofloxacin against > 6000 recent clinical isolates of Gram-positive and Gram-negative bacteria from six different countries. This international multicenter study demonstrated a high level of antibacterial activity of levofloxacin against all the members of Enterobacteriaceae [minimum inhibitory concentration (MIC)50s, < or = 0.03 to 0.12 mg/L] except Providencia rettgeri (MIC50, 2 mg/L), and Providencia stuartii (MIC50, 1 mg/L). Oxacillin-susceptible staphylococci (MIC50s, 0.12 to 0.25 mg/L), enterococci (MIC50s, 0.5 to 2 mg/L), and streptococci (MIC50s, 0.5 mg/L) were also susceptible to levofloxacin, but most isolates of oxacillin-resistant staphylococci had MICs of > or = 4 mg/L. Levofloxacin was also active against non-enteric Gram-negative bacilli, including Acinetobacter species (MIC50s, < or = 0.03 to 1 mg/L), Pseudomonas species (MIC50s, 0.5 to 1 mg/L) and Xanthomonas maltophilia (MIC50, 0.5 mg/L). Overall, levofloxacin inhibited 50% and 90% of all the tested strains at the concentrations of 0.12 and 4 mg/L, respectively. The activity of levofloxacin was generally two-fold greater than ofloxacin and equal to or slightly less potent than ciprofloxacin.

Comparative in vitro Activity of Levofloxacin and Ciprofloxacin against Bacterial Isolates from Neutropenic Patients

“…Levofloxacin has previously been shown to have a broad range of in vitro activity against many aerobic gram-negative and gram-positive bacteria [6][7][8]. The results of the present study confirm in part this finding.…”

“…Levofloxacin is one of the newer fluoroquinolones reported to have a broad spectrum of activity, with excellent activity against both gram-positive and gram-negative bacteria [6][7][8].…”

Ciprofloxacin: review on developments in synthetic, analytical, and medicinal aspects

“…In another investigation, Antonio et al found that ciprofloxacin was more efficacious than some other fluoroquinolones such as ofloxacin and pefloxacin in preventing infections due to Gram-negative bacteria in a specific population of neutropenic patients 20 . Further, Yamane et al reported that the activity of levofloxacin against Gram-positive bacteria was either equal to or less than that of ciprofloxacin 21 . In another study, topical ciprofloxacin/dexamethasone therapy was found to be superior to oral amoxicillin/clavulanic acid in acute otitis media with otorrhea 22 .…”

Development of hemiacetal esterified levofloxacin to prevent chelation with metal-containing drugs

“…Levofloxacin, the levo – isomer of ofloxacin (OFLX) – displays wide antibacterial activity with most strains of bacterial pathogens responsible for respiratory, urinary tract, gastrointestinal and abdominal infections, including Gram‐negative, Gram‐positive and atypical bacterial pathogens. Compared to earlier antibiotics of the new quinolone antimicrobial family such as ciprofloxacin, LVFX strongly inhibits the growth of Gram‐positive bacteria better than that of Gram‐negative bacteria, especially for P. aeruginosa . It is well known that co‐administration of LVFX with aluminium hydroxide (a metal containing drug formulation) reduces the blood concentration of LVFX by about 50% due to formation of an insoluble chelate.…”