The pharmacokinetics of diminazene aceturate after intramuscular administration in healthy dogs

• Main Authors: D.M. Miller, G.E. Swan, R.G. Lobetti, L.S. Jacobson
• Format: Article
• Language: English
• Published: AOSIS 2005-06-01
• Series: Journal of the South African Veterinary Association
• Subjects: Babesia Canis; Babesiosis; Berenil; Canine; Diminazene; Liver Sequestration; Pharmacokinetics; Pharmacology
• Online Access: https://jsava.co.za/index.php/jsava/article/view/416

The pharmacokinetics of diminazene aceturate following intramuscular (i.m.) administration at 4.2 mg/kg was evaluated in 8 healthy German Shepherd dogs. Blood samples were collected at 19 intervals over a period of 21 days. Diminazene plasma concentrations were measured using a validated HPLC method with UV detection and a sensitivity of 25 ng/m . The in vitro and in vivo binding of diminazene to blood elements was additionally determined. Diminazene pharmacokinetics showed a large inter-individual variation after i.m. administration. It had a short absorption half-life (K01-HL of 0.11 + 0.18 h), resulting in a Cmax of 1849 + 268.7 ng/mℓ at Tmax of 0.37 h and a mean overall elimination half-life (T1/2ß) of 5.31 + 3.89 h. A terminal half-life of 27.5 + 25.0 h was measured. At 1 h after i.m. injection, 75% of the diminazene in whole blood was in the plasma fraction. The results of this study indicate that diminazene is rapidly distributed and sequestered into the liver, followed by a slower terminal phase during which diminazene is both redistributed to the peripheral tissues and/or renally excreted. It is recommended that diminazene administered i.m. at 4.2 mg/kg should not be repeated within a 21-day period.