title: Oral bioavailability of pivampicillin in foals at different ages.
abstract: The plasma disposition of ampicillin after intravenous administration at a dose rate of 15 mg/kg was studied in six healthy, 1-month-old foals. The oral bioavailability of pivampicillin was determined in the same foals at four ages, ranging from 11 days to 4 months. Pivampicillin was administered orally at a dose rate of 19.9 mg/kg, which is equivalent on a molecular basis to 15 mg/kg ampicillin. Ampicillin concentrations in plasma were determined up to 12 hours after administration. After intravenous administration, the mean distribution and elimination half-lives of ampicillin were 0.121 and 0.624 h, respectively. The volume of distribution (Vss) appeared to be 0.334 l/kg. Orally administered pivampicillin was rapidly absorbed in all age groups, producing mean peak plasma concentrations of 3.83 to 5.69 micrograms/ml 1 h after administration. The mean bioavailability of pivampicillin in the different age groups ranged from 39.4 to 52.9%. There was no statistically significant difference in peak plasma concentration or bioavailability between the age groups. It is concluded that pivampicillin at a dose rate of 19.9 mg/kg orally gives satisfactory plasma concentrations in foals of all ages.
authors: Department of General and Large Animal Surgery, Faculty of Veterinary Medicine, Utrecht University.
authors: J M
authors: JM
authors: Ensink
authors: A
authors: A
authors: Barneveld
authors: W R
authors: WR
authors: Klein
authors: A S
authors: AS
authors: van Miert
authors: A G
authors: AG
authors: Vulto
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D005260:Female; D006736:Horses / Q000097:blood / Q000378:metabolism*; D007275:Injections, Intravenous; D008297:Male; D010917:Pivampicillin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D010917:Pivampicillin