Ivermectin and nitroxynil co-Administration in sheep: effect of body condition on their kinectic disposition

Abstract

Ivermectin (IVM) is an endectocide compound from the avermectin family. Nitroxynil (NTX) is a trematodicidal compound. Combination of different drug molecules is a modern and challenging approach in parasite control. The aim of the present work was to study the plasma disposition of both IVM and NTX after subcutaneous (SC) co-administration to sheep with different body conditions. Two groups (n= 8) of sheep with statistical different body weight (fat and thin) were treated with Nitromectin (IVM 200 μg/kg and NTX 10 mg/kg) by the SC route. Blood samples were collected up to 60 days post-treatment and plasma concentrations of IVM and NTX were determined by HPLC. IVM and NTX were well absorbed after its co-administration. Higher IVM plasma concentrations were measured in “thin” sheep compared to the “fat” group. However, NTX plasma concentrations in the thin were lower than these measured in fat group. A large volume of distribution (IVM) and high plasma protein binding (NTX) help to explain the observed pharmacokinetic differences for these drugs in animals with different body condition.