Abstract

Ceftazidime is a beta-lactam that is used in the treatment of bacterial infections in humans and companion animals, such as dogs and cats. It is prescribed to treat gram-negative infections, especially those caused by Pseudomonas aeruginosa. This study aimed to compare the pharmacokinetics of ceftazidime using a microbiological assay to evaluate the adequacy of the proposed dosage regimens for susceptible gram-negative bacteria. For this purpose, five healthy mongrel male dogs, with a mean age of four years and an average weight of 19.1 kg, were administered a single intravenous bolus dose of ceftazidime (20 mg/kg). Plasma concentrations were measured using a microbiological assay, and dosage regimens were established by integrating pharmacokinetics data with pharmacodynamics parameters. The results showed that ceftazidime was rapidly distributed to the peripheral tissues (0.189 L/kg), with a half-life of 1.15 hours and a clearance rate of 0.166 L/hr./kg. The results obtained from the pharmacokinetics-pharmacodynamic integration suggested 20 mg/kg q8 hours of ceftazidime for susceptible gram-negative bacteria with a Minimum Inhibitory Concentration of ≤ 8 µg/ml, and 20 mg/kg q12 hours of ceftazidime for susceptible gram-negative bacteria with a Minimum Inhibitory Concentration of ≤ 4 µg/ml. In conclusion, a mild correlation was observed between the dogs’ weight and the ceftazidime half-life, which led to an adjustment of the proposed dosage regimen to 20 mg/kg q8 hours. Open Access: This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/. © The Author(s) 2024