The comparative serum disposition kinetics of subcutaneous administration of doramectin, ivermectin and moxidectin in the Australian Merino sheep

Abstract

This study evaluates the comparative serum disposition kinetics of injectable formulations of doramectin (DRM), ivermectin (IVM) and moxidectin (MXD) in Australian Merino sheep. Thirty-six, 2-year-old sheep were allocated by weight into six groups of six animals. Animals in each group received 200 microg/kg of DRM, MXD, IVM or a combination of two of these drugs by subcutaneous (s.c.) injection. Blood was collected at designated intervals (between 1 h and 40 days after treatment) and the serum analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The results indicated that MXD administration produced a significantly higher maximum serum concentration and a more rapid absorption as compared with DRM and IVM. MXD and DRM had a significantly larger area under the concentration vs. time curve (AUC) than IVM, suggesting a more persistent effect for the former two products in sheep. The AUC for DRM was significantly higher when administered alone as compared with that observed when given in combination with MXD or IVM, suggesting preferential elimination of DRM compared with IVM and MXD from concurrent s.c. administration.

Ivermectin in Senegalese Peulh Sheep: Influence of Sex on Plasma Disposition

“…The observed peak plasma concentration (C max ) observed in sheep in this study is lower than that reported after subcutaneous administration of 0.2 mg/kg by Barber and colleagues (2003); it is higher than that obtained by Cerkvenik and colleagues (2002). The AUC, which refers to the extent of absorption, is equivalent to that reported previously in sheep (Cerkvenik et al, 2002;Barber et al, 2003). The AUC values observed suggest that the pharmacokinetics of ivermectin in sheep is independent of breed.…”

“…Many pharmacokinetic studies following different routes of administration of ivermectin in sheep have been performed (Atta and Abo-Shihada, 2000;Cerkvenik et al, 2002;Echeverria et al, 2002;Barber et al, 2003;Molento et al, 2004). However, there remains a lack information about this endectocide in African breeds.…”

Bioavailability of a commercial formulation of ivermectin after subcutaneous administration to sheep

“…In healthy sheep administered 200 µg of ivermectin/kg, SC, the value of C max calculated by other authors [8][9][10][11]15,17,26 ranges from 12 to 35 ng/mL. Results of the study reported here (mean ± SD, 19.55 ± 5.03 ng/mL) are similar to results in another study 15 but are lower than most of the values calculated by other authors.…”

A comparative kinetic study of doramectin and moxidectin in zebu Gobra cattle (Bos indicus)

“…The C max values for doramectin (36.3 ng ml −1 ) and moxidectin (37.5 ng ml −1 ) were equivalent to those reported by Lanusse et al (1997) in cattle (37.5 and 39.4 ng ml −1 , respectively). These values are higher than those reported for sheep (Atta and AboShihada 2000;Barber et al 2003) and goats (Escudero et al 1999). The t max and MRT values for both drugs are also equivalent to those reported for cattle (Lanusse et al 1997).…”