The Pharmacokinetics of Ivermectin in Rabbit

Abstract

Objective: To establish the pharmacokinetics of ivermectin in the rabbit model as a basis for future screening of newly developed micro and macrofilaricides. Method: Pharmacokinetic parameters of ivermectin were investigated in 5 rabbits after a single subcutaneous dose (150ug/kg), as a basis for screening micro- and macro-filaricides. Plasma ivermectin levels were measured by a sensitive High Performance Liquid Chromatography (HPLC) with fluorometric detection method. Results: The mean ±SEM pharmacokinetic parameters were as follows: time taken from dosing to maximum concentration (T max ), 1.4 ±0.4 hrs; maximum concentration (C max ), 34.0 ±1.6ng/ml; volume of distribution (V), 4.8 ±1.3L/kg; area under the plasma concentration-time curve (AUC), 475.6 ±5.4ng.hr/ml; plasma clearance (CI), 9.2 ±1.8ml/min and elimination half life (t), 10.4 ±2.3hrs. Conclusion: The elimination phase of ivermectin pharmacokinetics reveals a secondary peak suggestive of an enterohepatic recycling. Key Words: HPLC, Pharmacokinetics, Ivermectin Orient Journal of Medicine Vol.15(3&4) 2003:42-45