title: Pharmacokinetics of difloxacin and its concentration in body fluids and endometrial tissues of mares after repeated intragastric administration.
abstract: Pharmacokinetics of difloxacin and its distribution within the body fluids and endometrium of 6 mares were studied after intragastric (IG) administration of 5 individual doses. Difloxacin concentrations were serially measured in serum, urine, peritoneal fluid, synovial fluid, cerebrospinal fluid, and endometrium over 120 h. Bacterial susceptibility to difloxacin was determined for 174 equine pathogens over a 7-month period. Maximum serum concentration (Cmax) was 2.25 +/- 0.70 microg/mL at 3.12 +/- 2.63 h and Cmax after the 5th dose was 2.41 +/- 0.86 microg/mL at 97.86 +/- 1.45 h. The mean elimination half-life (t(1/2)) was 8.75 +/- 2.77 h and area under the serum concentration versus time curve (AUC) was 25.13 +/- 8.79 microg h/mL. Highest mean synovial fluid concentration was 1.26 +/- 0.49 microg/mL at 100 h. Highest mean peritoneal fluid concentration was 1.50 +/- 0.56 microg/mL at 98 h. Highest mean endometrial concentration was 0.78 +/- 0.48 microg/g at 97.5 h. Mean cerebrospinal fluid concentration was 0.87 +/- 0.52 microg/mL at 99 h. Highest mean urine concentration was 92.05 +/- 30.35 microg/mL at 104 h. All isolates of Salmonella spp. and Pasteurella spp. were susceptible. In general, gram-negative organisms were more susceptible than gram-positives. Difloxacin appears to be safe, adequately absorbed, and well distributed to body fluids and endometrial tissues of mares and may be useful in the treatment of susceptible bacterial infections in adult horses.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610-0136, USA.
authors.forename: Aric R
authors.initials: AR
authors.lastname: Adams
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Haines
authors.forename: Murray P
authors.initials: MP
authors.lastname: Brown
authors.forename: Ronald
authors.initials: R
authors.lastname: Gronwall
authors.forename: Kelly
authors.initials: K
authors.lastname: Merritt
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001202:Ascitic Fluid / Q000737:chemistry / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects; D001826:Body Fluids / Q000737:chemistry / Q000378:metabolism*; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004717:Endometrium / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D024841:Fluoroquinolones / Q000493:pharmacokinetics*; D006207:Half-Life; D006736:Horses / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D013582:Synovial Fluid / Q000737:chemistry / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D002939:Ciprofloxacin; C047225:difloxacin