title: Pharmacokinetics and bioavailability of spiramycin in pigs.
abstract: The pharmacokinetics of spiramycin in pigs were investigated after intravenous and oral administration. The potential therapeutically effective blood level was established after a single administration and examined in a subsidiary five day study. The rapid intravenous injection of 25 mg spiramycin/kg bodyweight produced marked salivation in all the test animals. The elimination half-life (2.3 +/- 1.2 hours) was relatively short, in accordance with the total body clearance rate (27.3 +/- 10.1 ml/minute/kg). The high volume of distribution (5.2 +/- 2.2 litres/kg) was due to the accumulation of the drug in the body tissues. The maximum plasma concentration (4.1 +/- 1.7 micrograms/ml) after oral administration of 85 to 100 mg spiramycin/kg bodyweight was reached after 3.7 +/- 0.8 hours and the half-life of the elimination phase was 6.0 +/- 2.4 hours. The oral bioavailability was 45.4 +/- 23.4 per cent. Ad libitum feeding of a diet containing 2550 mg spiramycin/kg produced a steady state concentration of 0.96 +/- 0.27 micrograms/ml. This plasma concentration would provide a potentially therapeutically effective blood concentration against Mycoplasma species, Streptococcus species and Staphylococcus species.
authors.affiliation: Division for Animal Nutrition, Institute of Veterinary Physiology, Zurich, Switzerland.
authors.forename: H M
authors.initials: HM
authors.lastname: Sutter
authors.forename: J
authors.initials: J
authors.lastname: Engeli
authors.forename: P
authors.initials: P
authors.lastname: Müller
authors.forename: B
authors.initials: B
authors.lastname: Schneider
authors.forename: J L
authors.initials: JL
authors.lastname: Riond
authors.forename: M
authors.initials: M
authors.lastname: Warner
mesh_terms: D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D001682:Biological Availability; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous / Q000662:veterinary; D008297:Male; D012472:Salivation / Q000187:drug effects; D015572:Spiramycin / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics*; D013552:Swine / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D015572:Spiramycin