Burrows G E, Barto P B, Weeks B R
J Vet Pharmacol Ther. 1986 Jun;9(2):213-22. doi: 10.1111/j.1365-2885.1986.tb00032.x.
The effects of pneumonia on the pharmacokinetics of chloramphenicol, lincomycin, and oxytetracycline were evaluated in two-month-old calves. Pneumonia was induced by injection of Pasteurella haemolytica cultures directly through the thoracic wall into each lung. Six days prior to induction of pneumonia, the antibiotics were administered in a single i.v. dose. The antibiotics were administered again 48 (i.v.), 60 and 72 h (i.m.) following injection of P. haemolytica. The pharmacokinetics of chloramphenicol (25 mg/kg) and lincomycin (10 mg/kg) were not significantly different in calves with pneumonia. The hybrid rate constant beta for oxytetracycline was increased in calves with pneumonia from 0.0034 +/- 0.0003/min to 0.0048 +/- 0.0007/min between 2 h and 8 h. Thus the elimination half-life in serum was shortened from 212.4 +/- 20.3 min to 149.3 +/- 19.5 min. In addition, there was an apparent but not statistically significant decrease in K12 with pneumonia. These findings accentuate the need for observance of 12-h dose intervals with oxytetracycline.
在两个月大的犊牛中评估了肺炎对氯霉素、林可霉素和土霉素药代动力学的影响。通过将溶血巴斯德菌培养物直接经胸壁注射到每侧肺中来诱发肺炎。在诱发肺炎前6天，静脉注射单剂量抗生素。在注射溶血巴斯德菌后48小时（静脉注射）、60小时和72小时（肌肉注射）再次给予抗生素。患有肺炎的犊牛中，氯霉素（25mg/kg）和林可霉素（10mg/kg）的药代动力学无显著差异。患有肺炎的犊牛中土霉素的混合速率常数β在2小时至8小时之间从0.0034±0.0003/分钟增加到0.0048±0.0007/分钟。因此，血清中的消除半衰期从212.4±20.3分钟缩短至149.3±19.5分钟。此外，肺炎时K12有明显但无统计学意义的下降。这些发现强调了土霉素需遵守12小时给药间隔的必要性。
