title: Effects of age on the pharmacokinetics of single dose sulfamethazine after intravenous administration in cattle.
abstract: Sulphonamides are still being used widely, influenced by the low cost and the efficacy against many common bacterial infections, since they present a broad spectrum of activity. The aim of this study was to determine the effect of age on the pharmacokinetic/pharmacodynamics (PK/PD) integration of intravenous sulfamethazine (60 mg/kgbw) in cattle, and the possible therapeutic outcomes. Six healthy female calves, at the age of one, three, seven and fifteen weeks were used. Normality analysis was assessed with the Shapiro-Wilk test. Non-parametric tests for paired data were used. Plasma concentrations were quantified using HPLC/uv. Differences were found between one-three-weeks-old calves and seven-fifteen-weeks-old calves, in pharmacokinetic parameters (clearance, area under the concentration-time curve and elimination half-life) and in the PK/PD integration. The ratios obtained in PK/PD integration (T>MIC, WAUC) confirm that it is necessary to apply twice the dose of sulfamethazine in > or = 7 weeks-old cattle to reach a satisfactory dosage regimen (MIC > or = 32 microg/mL).
authors.affiliation: Departamento de Farmacología, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Esperanza, Santa Fe, Argentina.
authors.forename: Eduardo E
authors.initials: EE
authors.lastname: Baroni
authors.forename: Diego C
authors.initials: DC
authors.lastname: Díaz
authors.forename: Eduardo
authors.initials: E
authors.lastname: Picco
authors.forename: Samanta
authors.initials: S
authors.lastname: Waxman
authors.forename: Casilda
authors.initials: C
authors.lastname: Rodríguez
authors.forename: Manuel I
authors.initials: MI
authors.lastname: San Andrés
authors.forename: Juan C
authors.initials: JC
authors.lastname: Boggio
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous; D008826:Microbial Sensitivity Tests; D013418:Sulfamethazine / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000900:Anti-Bacterial Agents; D013418:Sulfamethazine