title: Cyclosporin immunosuppression of sheep: pharmacokinetics and allograft survival.
abstract: A chronically immunosuppressed sheep model was established using a regimen of cyclosporin A (CsA; 2-3mg/kg twice daily) and ketoconazole (10mg/kg twice daily). Blood CsA concentrations reached a steady-state after 17 days of treatment. The clearance of CsA decreased from a mean (95% CI) of 9.47 (6.2-12.7)ml/min/kg after a single (first) dose (3mg/kg i.v.) to 1.62 (1.38-1.86)ml/min/kg after 18 days of CsA (3mg/kg i.v. twice daily) co-administration with ketoconazole. These data indicated that the combination of CsA and ketoconazole could be used to give stable high concentrations of CsA in the sheep. Using this regimen in the sheep, the long-term survival of skin allografts was monitored as an indicator of effective immunosuppression. CsA in blood was measured daily and CsA dose adjusted to various target concentration ranges. Provided that the trough concentration of blood CsA was maintained between 1500-2500 mg/l, long-term healthy skin allografts were maintained on the sheep without significant adverse effects on haematological or biochemical parameters.
authors.affiliation: Department of Medicine, University of Western Australia and Fremantle Hospital, Freemantle, WA 6160, Australia. arose@cyllene.uwa.edu.au
authors.forename: A H
authors.initials: AH
authors.lastname: Rose
authors.forename: K F
authors.initials: KF
authors.lastname: Ilett
authors.forename: H L
authors.initials: HL
authors.lastname: O'Donoghue
authors.forename: L P
authors.initials: LP
authors.lastname: Hackett
authors.forename: W J
authors.initials: WJ
authors.lastname: Penhale
authors.forename: L S
authors.initials: LS
authors.lastname: Manning
authors.forename: R J
authors.initials: RJ
authors.lastname: Glancy
authors.forename: L K
authors.initials: LK
authors.lastname: Cullen
authors.forename: J H
authors.initials: JH
authors.lastname: Turner
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D016572:Cyclosporine / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D005260:Female; D006085:Graft Survival; D007166:Immunosuppressive Agents / Q000493:pharmacokinetics*; D007654:Ketoconazole / Q000494:pharmacology; D012756:Sheep; D016038:Skin Transplantation / Q000276:immunology*; D014184:Transplantation, Homologous
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine; D007654:Ketoconazole