title: Pharmacokinetics of sodium cephapirin in lactating dairy cows.
abstract: Sodium cephapirin was administered (10 mg/kg of body weight, IM) 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 micrograms/ml 10 minutes after the 1st injection and were 15.8 micrograms/ml 20 minutes after the 4th injection (post[initial]injection hour [PIH] 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 microgram/ml at PIH 2 and mean peak cephapirin concentration in mastitic milk was 0.18 microgram/ml at PIH 4. Cephapirin was not detected in the endometrium. The highest concentration of cephapirin in urine was 452 micrograms/ml, 2 hours after the 4th dose (PIH 26).
authors.affiliation: Department of Surgical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610-0116.
authors.forename: M
authors.initials: M
authors.lastname: Prades
authors.forename: M P
authors.initials: MP
authors.lastname: Brown
authors.forename: R
authors.initials: R
authors.lastname: Gronwall
authors.forename: N S
authors.initials: NS
authors.lastname: Miles
mesh_terms: D000818:Animals; D002417:Cattle / Q000378:metabolism*; D002511:Cephalosporins / Q000493:pharmacokinetics*; D002514:Cephapirin / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000652:urine; D005260:Female; D007273:Injections, Intramuscular / Q000662:veterinary; D007774:Lactation / Q000378:metabolism*; D008414:Mastitis, Bovine / Q000378:metabolism*; D008892:Milk / Q000032:analysis*; D011247:Pregnancy; D014018:Tissue Distribution
chemical_list: D002511:Cephalosporins; D002514:Cephapirin