title: Some pharmacokinetic parameters of the trypanocidal drug homidium bromide in Friesian and Boran steers using an enzyme-linked immunosorbent assay (ELISA).
abstract: Pharmacokinetic studies on the trypanocidal drug homidium bromide using a competitive enzyme immunoassay (detection limit 0.1 ng/mL) are reported for non-infected Friesian and Boran steers following treatment with homidium bromide at a dose of 1.0 mg/kg b.w. Following intravenous (i.v.) treatment of Friesian steers (n = 5), the mean serum drug concentrations were 31.9 +/- 2.1 and 3.9 +/- 0.4 ng/mL at 1 and 24 h, respectively. The decline in serum drug concentration was tri-exponential with half-lives of 0.064 +/- 0.037 h for t1/2 alpha, 7.17 +/- 1.87 h for t1/2 beta and 106.3 +/- 6.6 h for t1/2 gamma for distribution and elimination phases 1 and 2, respectively. Drug was detectable in serum for 17 days following treatment. The mean residence time (MRT) was 63.4 +/- 7.5 h. Following intramuscular (i.m.) treatment of Friesian steers (n = 5), the drug concentration at 1 h after treatment was 72.5 +/- 2.2 ng/mL. This declined to 9.8 +/- 1.8 ng/mL at 24 h. Low concentrations of between 0.1 and 0.3 ng/mL remained in circulation for up to 90 days post-treatment. Following intramuscular treatment of Boran steers (n = 5), the mean serum drug concentration at 1 h after treatment was 112.1 +/- 40.3 ng/mL. By 24 h after treatment, the concentration had fallen to 13.0 +/- 3.3 ng/mL. Thereafter, the serum drug concentration-versus-time profile and the pharmacokinetic parameters obtained following non-compartmental analysis were similar to those obtained following intramuscular treatment of Friesian steers.
authors.affiliation: Kenya Trypanosomiasis Research Institute (KETRI), Kikuyu, Kenya.
authors.forename: G A
authors.initials: GA
authors.lastname: Murilla
authors.forename: P H
authors.initials: PH
authors.lastname: Holmes
authors.forename: A S
authors.initials: AS
authors.lastname: Peregrine
authors.forename: M C
authors.initials: MC
authors.lastname: Eisler
authors.forename: J M
authors.initials: JM
authors.lastname: Ndung'u
mesh_terms: D000818:Animals; D019540:Area Under Curve; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D004996:Ethidium / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006207:Half-Life; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D008297:Male; D014344:Trypanocidal Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D014344:Trypanocidal Agents; D004996:Ethidium