title: Serum disposition of exogenous progesterone after intramuscular administration in bitches.
abstract: Progesterone was administered IM to 6 adult anestrous bitches at a dosage of 2 mg/kg of body weight. Serum progesterone concentrations were measured prior to progesterone administration and for 72 hours thereafter. The serum progesterone concentration time data were analyzed by use of a pharmacokinetics modeling computer program. The mean (+/- SD) peak serum progesterone concentration (34.3 +/- 7.8 ng/ml) was reached at 1.8 +/- 0.2 hours after progesterone administration. The mean serum progesterone concentration was 6.9 +/- 1.4 ng/ml at 24 hours and 2.0 +/- 0.4 ng/ml at 48 hours after progesterone administration. By 72 hours after administration, mean serum progesterone concentration was 0.9 +/- 0.2 ng/ml, which was comparable to serum progesterone concentrations prior to injection. The mean half-life of the absorption phase was 0.5 hours (range, 0.3 to 0.7 hours). The mean half-life of elimination was 12.1 hours (range, 9.5 to 13.8 hours). By analysis of the data, it was established that a dosage of 3 mg/kg, when the hormone was given IM to dogs once a day, would maintain serum progesterone concentration greater than 10 ng/ml.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907.
authors.forename: J C
authors.initials: JC
authors.lastname: Scott-Moncrieff
authors.forename: R W
authors.initials: RW
authors.lastname: Nelson
authors.forename: R L
authors.initials: RL
authors.lastname: Bill
authors.forename: C L
authors.initials: CL
authors.lastname: Matlock
authors.forename: G D
authors.initials: GD
authors.lastname: Bottoms
mesh_terms: D000818:Animals; D001682:Biological Availability; D004285:Dogs / Q000097:blood*; D005260:Female; D006207:Half-Life; D007273:Injections, Intramuscular / Q000662:veterinary; D011374:Progesterone / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D011863:Radioimmunoassay; D012715:Sesame Oil / Q000008:administration & dosage; D013997:Time Factors
chemical_list: D011374:Progesterone; D012715:Sesame Oil