title: Concentration of enrofloxacin and its metabolite ciprofloxacin in canine matrices of the locomotor system.
abstract: Due to its pharmacodynamic and pharmacokinetic properties, the use of enrofloxacin may be indicated in canine osteomyelitis, but there is insufficient data on its distribution within the musculoskeletal tissues. The dogs used in this study were 31 regular veterinary orthopaedic patients. Four hours after their oral or subcutaneous treatment with 10 mg/kg enrofloxacin (Baytril; Bayer, Leverkusen, Germany) once daily for 1 or 3 days, the concentration of enrofloxacin and its main metabolite ciprofloxacin was quantified in plasma, bone, musculature and other matrices of the locomotor system by high pressure liquid chromatography with fluorescence-detection after homogenization and solid phase extraction of the samples. By oral or subcutaneous administration of enrofloxacin once daily for 3 days, higher concentrations of the active constituents in the samples were achieved than by single treatment. Nevertheless, even after single injection, minimal inhibitory enrofloxacin concentrations of up to 0.5 microg ml or microg/g sample against most pathogens of osteomyelitis were exceeded. In the musculature, on average, higher concentrations of active constituents were detected than in less perfused matrices (bones and synovial membranes) at sampling time. The enrofloxacin diffusion into inflamed bone was higher compared with mechanically damaged bone, whereas for ciprofloxacin it was lower. In conclusion, a dosage of 10 mg/kg enrofloxacin is sufficient to exceed the minimal inhibitory concentrations in osteomyelitic bone against most pathogens that are sensitive in vitro, but clinical efficacy remains to be evaluated.
authors.affiliation: Institute of Pharmacology, Toxicology, and Pharmacy, Hannover, Germany. andreas.ehinger@tiho-hannover.de
authors.forename: A M
authors.initials: AM
authors.lastname: Ehinger
authors.forename: A
authors.initials: A
authors.lastname: Meyer-Lindenberg
authors.forename: M
authors.initials: M
authors.lastname: Vick
authors.forename: I
authors.initials: I
authors.lastname: Nolte
authors.forename: M
authors.initials: M
authors.lastname: Kietzmann
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001842:Bone and Bones / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D004285:Dogs / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones; D007279:Injections, Subcutaneous / Q000662:veterinary; D008297:Male; D009132:Muscles / Q000378:metabolism*; D015363:Quinolones / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D002939:Ciprofloxacin