The objective of this study was to obtain an estimate of the pharmacokinetic parameters of moxidectin administered at a dosage of 1 mg/kg orally and topically to healthy adult giraffe (Giraffa camelopardalis). The maximum plasma concentration (CMAX) of moxidectin after oral and topical administration was 69.2 ± 4.6 and 18.6 ± 16.1 ng/ml (P = 0.045), respectively. The areas under the plasma curve (AUC), a measure of total drug exposure, was 532.0 ± 232.3 and 209.1 ± 180.0 day*ng/ml (P = 0.308) for the oral and topical administrations, respectively. These data suggest moxidectin achieves higher peak plasma concentrations following oral administration compared with topical (transdermal) administration using the cattle pour-on formulation. Additionally, the percent coefficient of variation, a measure of variability, was smaller for the oral formulation (CMAX %CV = 7%; AUC %CV = 44%) compared with the topical formulation (CMAX%CV = 86%; AUC %CV = 86%). The smaller variability suggests that oral administration of moxidectin produces more predictable and less variable drug absorption than topical administration in giraffe and is the preferred route of administration.
Key Words: Anthelmintic resistance, Giraffa camelopardalis, giraffe, Haemonchus contortus, moxidectin, pharmacokinetics
Authors: Gary West, D.V.M., Dipl. A.C.Z.M., Elizabeth E. Hammond, D.V.M., Dipl. A.C.Z.M. and Butch KuKanich, D.V.M., Ph.D., Dipl. A.C.V.C.P.
Journal: Journal of Zoo and Wildlife Medicine
PK of oral and topical moxidectin in reticulated giraffe.pdf