Cefazolin pharmacokinetics in cats under surgical conditions.
Objectives The aim of this study was to determine the plasma pharmacokinetic profile, tissue concentrations and urine elimination of cefazolin in cats under surgical conditions after a single intravenous dose of 20 mg/kg. Methods Intravenous cefazolin (20 mg/kg) was administered to nine young mixed-breed cats 30 mins before they underwent surgical procedures (ovariectomy or orchiectomy). After antibiotic administration, samples from blood, some tissues and urine were taken. Cefazolin concentrations were determined in all biological matrices and pharmacokinetic parameters were estimated. Results Initial plasma concentrations were high (Cp(0), 134.80 ± 40.54 µg/ml), with fast and moderately wide distribution (distribution half-life [t½(d)] 0.16 ± 0.15 h; volume of distribution at steady state [V(d[ss])] 0.29 ± 0.10 l/kg) and rapid elimination (body clearance [ClB], 0.21 ± 0.06 l/h/kg; elimination half-life [t½], 1.18 ± 0.27 h; mean residence time 1.42 ± 0.36 h). Thirty to 60 mins after intravenous administration, cefazolin tissue concentrations ranged from 9.24 µg/ml (subcutaneous tissue) to 26.44 µg/ml (ovary). The tissue/plasma concentration ratio ranged from 0.18 (muscle) to 0.58 (ovary). Cefazolin urine concentrations were high with 84.2% of the administered dose being eliminated in the first 6 h postadministration. Conclusions and relevance Cefazolin plasma concentrations remained above a minimum inhibitory concentration of ⩽2 µg/ml up to 4 h in all the studied cats. This suggests that a single intravenous dose of 20 mg/kg cefazolin would be adequate for perioperative prophylactic use in cats.
1 Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, Buenos Aires, Argentina.
Gabriela A
GA
Albarellos
1 Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, Buenos Aires, Argentina.
Laura
L
Montoya
1 Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, Buenos Aires, Argentina.
Sabrina M
SM
Passini
1 Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, Buenos Aires, Argentina.
Martín P
MP
Lupi
1 Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Chorroarín 280, Buenos Aires, Argentina.
Paula M
PM
Lorenzini
2 Cátedra de Farmacología. Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Buenos Aires, Argentina.
María F
MF
Landoni
D000818:Animals; D002415:Cats / Q000097:blood / Q000378:metabolism* / Q000601:surgery*; D002437:Cefazolin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D006207:Half-Life; D007262:Infusions, Intravenous; D008297:Male; D009919:Orchiectomy / Q000662:veterinary*; D010052:Ovariectomy / Q000662:veterinary*; D014018:Tissue Distribution
D002437:Cefazolin