Effect of Some Anthelmintics on the Pharmacokinetic Aspects of Certain Antibacterials in Goats

Abstract

The present study was carried out to determine the serwn and urine concentrations of florfenicol and danotloxacin and their kinetic parameters following a single intravenous and intramuscular administration in healthy, non-pregnant, non-lactatirig does. This determination was perfonned using microbiological assay method. Moreover, the present work aimed to investigate the effects of premedication with three commonly used anthelmintics (ivermectin, albendazole and rafoxanide) on serum concentrations and kinetic parameters of both antibacterials after a single intramuscular dose. In addition to the bioassay method, a high­ performance liquid chromatography was used to determine serum concentrations of florfenicol. In this respect, the differences between the two methods were reported. Creatinine clearance, florfenicol and danofloxacin clearance and their ratio, protein binding percent and the bioavailabilities following intramuscular injection were also investigated. Moreover, the effect of the tested antibacterials (after multiple doses) on some serum enzymes, creatinine, urea as well as their concentrations in urine were also studied.

The present work was carried out on five clinically healthy, non­ pregnant (non-lactating) does. Their weight ranged between 21-32 kg. Ten experiments have been carried out on the same animals with a period of one-month intervals to insure complete withdrawal of the resident drugs. The obtained results showed the following:

1 - Florfenicol

Following intravenous injection of florfenicol at a dose of 20 mg kg"1 b.wt., the time-concentration curves were best described by a two-compartment open model. The highest serum concentrations were detected 5-minutes post-it\iection then decreased thereafter. No florfenicol could be detected 6 and 12 -hour post-injection for bioassay and HPLC respectively. However, florfenicol could be detected in urine up to 24- hour post-injection. The drug was rapidly distributed in the body fluids and tissues evidenced by short distribution half-life (!o.soc) 10.256 ± 0.938 and 16.26 ± 0.796- minute for bioassay and HPLC, respectively. The elimination half-life (to.513), was longer (156.48 ± 8.676 min.) in HPLC than in case of bioassay (56.237 ± 3.102 min.) as the drug was persisted for a long time.