Pharmacokinetics of sodium cephapirin in lactating dairy cows
Prades, M.; Brown, M.P.; Gronwall, R.; Miles, N.S.
American Journal of Veterinary Research 49(11): 1888-1890
1988
ISSN/ISBN: 0002-9645 PMID: 3247911 Document Number: 317229
Sodium cephapirin was administered (10 mg/kg of body weight i/m) at 8-hour intervals in 4 consecutive doses to each of 6 lactating dairy cows. Blood, normal milk, mastitic milk, urine, and endometrial tissue samples were collected serially. Mean peak cephapirin concentrations in serum were 13.3 micro g/ml 10 minutes after the 1st injection and were 15.8 micro g/ml 20 minutes after the 4th injection (post 24.33). The overall elimination rate constant value was 0.66/h and plasma clearance was 760 ml/h/kg. Mean peak cephapirin concentration in normal milk was 0.11 micro g/ml at PIH 2 and mean peak cephapirin concentration in mastitic milk was 0.18 micro g/ml at PIH 4. Cephapirin was not detected in the endometrium. The highest concentration of cephapirin in urine was 452 micro g/ml, 2 hours after the 4th dose (PIH 26).