Lindecrona R H, Friis C, Aarestrup F M
Department of Pharmacology and Pathobiology, Royal Veterinary and Agricultural University, Copenhagen, Denmark.
Res Vet Sci. 2000 Jun;68(3):261-4. doi: 10.1053/rvsc.2000.0374.
The pharmacodynamic effect of amoxicillin and danofloxacin against two strains of Salmonella typhimurium was examined in an in-vitro pharmacodynamic model. For amoxicillin, peak concentrations of 1, 2 and 4 microg ml(-1)and half-lives (t12) of 3 and 15 hours were evaluated. For danofloxacin peak concentrations of 0.25, 0.50 and 1. 50 microg ml(-1)and half-lives of 7 and 15 hours were examined. For amoxicillin both the peak concentration and the half-life influenced the pharmacodynamic effect (P < 0.001). Maximal pharmacodynamic effect was observed when the antibiotic concentration was greater than minimum inhibitory concentration for 79 per cent or more of the dosing interval. The MICS of the isolates increased when the amoxicillin concentrations were close to the MIC during the first hours of exposure. For danofloxacin the pharmacodynamic effect was dependent on the peak concentration only (P < 0.001). Increases in MIC were found in two cases with the less susceptible strain, where peak concentration/ MIC ratios were equal to or less than 4.
在体外药效学模型中检测了阿莫西林和达氟沙星对两株鼠伤寒沙门氏菌的药效学作用。对于阿莫西林，评估了1、2和4微克/毫升的峰值浓度以及3小时和15小时的半衰期（t12）。对于达氟沙星，检测了0.25、0.50和1.50微克/毫升的峰值浓度以及7小时和15小时的半衰期。对于阿莫西林，峰值浓度和半衰期均影响药效学作用（P<0.001）。当抗生素浓度在给药间隔的79%或更长时间内大于最低抑菌浓度时，观察到最大药效学作用。在暴露的最初几个小时内，当阿莫西林浓度接近最低抑菌浓度时，分离株的最低抑菌浓度增加。对于达氟沙星，药效学作用仅取决于峰值浓度（P<0.001）。在两例对较不敏感菌株的研究中发现最低抑菌浓度增加，其中峰值浓度/最低抑菌浓度比值等于或小于4。
