title: Pharmacokinetics of ceftriaxone after intravenous, intramuscular and subcutaneous administration to domestic cats.
abstract: The pharmacokinetic properties of ceftriaxone, a third-generation cephalosporin, were investigated in five cats after single intravenous, intramuscular and subcutaneous administration at a dosage of 25 mg/kg. Ceftriaxone MICs for some gram-negative and positive strains isolated from clinical cases were determined. Efficacy predictor (t > MIC) was calculated. Serum ceftriaxone disposition was best fitted by a bicompartmental and a monocompartmental open models with first-order elimination after intravenous and intramuscular and subcutaneous dosing, respectively. After intravenous administration, distribution was fast (t1/2d 0.14 +/- 0.02 h) and moderate as reflected by the volume of distribution (V(d(ss))) of 0.57 +/- 0.22 L/kg. Furthermore, elimination was rapid with a plasma clearance of 0.37 +/- 0.13 L/h.kg and a t1/2 of 1.73 +/- 0.23 h. Peak serum concentration (Cmax), tmax and bioavailability for the intramuscular administration were 54.40 +/- 12.92 microg/mL, 0.33 +/- 0.07 h and 85.72 +/- 14.74%, respectively; and for the subcutaneous route the same parameters were 42.35 +/- 17.62 microg/mL, 1.27 +/- 0.95 h and 118.28 +/- 39.17%. Ceftriaxone MIC for gram-negative bacteria ranged from 0.0039 to >8 microg/mL and for gram-positive bacteria from 0.5 to 4 microg/mL. t > MIC was in the range 83.31-91.66% (10-12 h) of the recommended dosing interval (12 h) for Escherichia coli (MIC90 = 0.2 microg/mL).
authors.affiliation: Cátedra de Farmacología, Facultad de Ciencias Veterinarias, Universidad de Buenos Aires, Buenos Aires, Argentina. albarell@fvet.uba.ar
authors.forename: G A
authors.initials: GA
authors.lastname: Albarellos
authors.forename: V E
authors.initials: VE
authors.lastname: Kreil
authors.forename: M F
authors.initials: MF
authors.lastname: Landoni
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002415:Cats / Q000378:metabolism*; D002443:Ceftriaxone / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D007273:Injections, Intramuscular / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D007279:Injections, Subcutaneous / Q000662:veterinary; D008297:Male; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D002443:Ceftriaxone