[Comparative study of the circulation of semisynthetic cephalosporins in the blood of rabbits].

Circulation of 4 semisynthetic cephalosporins, such as cephaloridin, cephalotin, cephradin and cephacetryl in the blood of rabbits after their intramuscular administration in single doses of 5 or 20 mg/kg was studied. The above antibiotics were satisfactorily absorbed into the blood reaching the maximum level within 15 to 30 minutes. The blood levels of cephalotin were the lowest and the rate of its elimination from the blood was higher than that of the other drugs. A four-fold increase in the doses of cephalosporins was not accompanied by a proportional increase in their levels in the rabbit blood, the time of the antibiotic circulation in the blood being not significantly changed.