title: Oral bioavailability of sulphamethoxydiazine, sulphathiazole and sulphamoxole in dwarf goats.
abstract: To get a better insight into the oral bioavailability of sulphonamides in ruminants, sulphamethoxydiazine (pKa 7.0), sulphathiazole (pKa 7.2), and sulphamoxole (pKa 7.4) were administered to dwarf goats (n = 5). The drugs were given at 2-week intervals by the intravenous or intraruminal route at a dose of 100 mg per kg body weight. After IV injection, the mean half-life (t1/2 beta in h +/- SEM) was 0.80 +/- 0.10 h, 2.35 +/- 0.38 h, and 3.36 +/- 1.25 h, for sulphathiazole, sulphamoxole, and sulphamethoxydiazine, respectively and the mean distribution volume (Vd beta) was 0.23 +/- 0.05 l/kg, 0.23 +/- 0.04 l/kg, and 0.33 +/- 0.02 l/kg. After intraruminal administration, the mean bioavailability varied from 86.0 +/- 11.8% for sulphamethoxydiazine to 46.6 +/- 4.3% for sulphamoxole, and 52.6 +/- 7.2% for sulphathiazole. The elimination half-life was significantly prolonged, probably due to a low rate of drug absorption from the gastrointestinal tract. In contrast to chloramphenicol, the sulphonamides studied were stable when incubated in rumen fluid at 39 degrees C.
authors.affiliation: Department of Veterinary Basic Sciences, Utrecht University, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Weijkamp
authors.forename: S M
authors.initials: SM
authors.lastname: Faghihi
authors.forename: S M
authors.initials: SM
authors.lastname: Nijmeijer
authors.forename: R F
authors.initials: RF
authors.lastname: Witkamp
authors.forename: A S
authors.initials: AS
authors.lastname: van Miert
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D004334:Drug Administration Schedule; D005260:Female; D006041:Goats / Q000378:metabolism*; D006207:Half-Life; D007275:Injections, Intravenous / Q000662:veterinary; D007408:Intestinal Absorption; D007441:Intubation, Gastrointestinal / Q000662:veterinary; D008297:Male; D008657:Metabolic Clearance Rate; D012417:Rumen; D013417:Sulfameter / Q000008:administration & dosage / Q000493:pharmacokinetics*; D013423:Sulfamoxole / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D013432:Sulfathiazoles; D013417:Sulfameter; D013423:Sulfamoxole; D000077589:Sulfathiazole