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Comparison of cefepime pharmacokinetics in neonatal foals and adult dogs


Sarah Y. Gardner Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA. E-mail:


The pharmacokinetics of cefepime, a new fourth generation cephalosporin with enhanced antibacterial activity, was examined in neonatal foals and adult dogs. Cefepime was administered intravenously (i.v.) at a dose of 14 mg/kg to five neonatal foals and six adult dogs. Blood samples were collected in both groups of animals and plasma cefepime concentrations measured by reverse-phase high-performance liquid chromatography (HPLC). Cefepime concentrations in both groups of animals were described by a two-compartment pharmacokinetic model with elimination half-lives of 1.65 and 1.09 h for the foal and dog, respectively. We tested whether or not pharmacokinetic parameters for cefepime could be scaled across species using principles of allometry. The parameters of elimination half-life (t½β), apparent volume of distribution (VDarea), and systemic clearance (CL) were scaled linearly to body weight on a double logarithmic plot with allometric exponents for body weight of 0.26, 1.08 and 0.72, respectively. This study further determined doses for cefepime, a potentially useful antibiotic for neonatal foals and dogs, from the pharmacokinetic values. An i.v. dose of cefepime estimated from this study for treating sensitive bacteria was 11 mg/kg every 8 h for neonatal foals and 40 mg/kg every 6 h for dogs.