title: Pharmacokinetics of moxidectin in alpacas following administration of an oral or subcutaneous formulation.
abstract: The purpose of this study was to evaluate the pharmacokinetics of moxidectin in alpacas after single subcutaneous injection of a non-aqueous formulation or oral administration of an aqueous drench at 0.2 mg∗kg(-1). Plasma moxidectin concentrations were measured with reverse phase HPLC, and data analyzed using non-compartmental methods. Half-life was longer (p=0.02) after subcutaneous administration than oral (292+/-170 vs 33+/-39 h). The area under the concentration-time curve was greater (p=0.04) following subcutaneous administration (1484.8+/-1049.5 h∗ng∗ml(-1)) than oral (157.6+/-85.9 h∗ng∗ml(-1)). The peak concentration (Cmax) was higher and the after subcutaneous administration, but the difference was not statistically significant (p=0.18). The relative bioavailability of the oral moxidectin to the subcutaneous moxidectin was 11%. The data suggest a higher relative bioavailability following subcutaneous compared to oral administration. Further studies are needed to determine the therapeutic concentrations of moxidectin in alpacas.
authors.affiliation: University of Tennessee College of Veterinary Medicine, 2407 River Dr, Knoxville, TN 37996, USA; Tennessee Equine Hospital, 1508 Thompsons Station Rd, Thompson's Station, TN 37179, USA. Electronic address: ccocquyt@gmail.com.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Cocquyt
authors.affiliation: University of Tennessee College of Veterinary Medicine, 2407 River Dr, Knoxville, TN 37996, USA. Electronic address: svanamst@utk.edu.
authors.forename: Sarel
authors.initials: S
authors.lastname: Van Amstel
authors.affiliation: University of Tennessee College of Veterinary Medicine, 2407 River Dr, Knoxville, TN 37996, USA. Electronic address: scox6@utk.edu.
authors.forename: Sherry
authors.initials: S
authors.lastname: Cox
authors.affiliation: University of Tennessee College of Veterinary Medicine, 2407 River Dr, Knoxville, TN 37996, USA. Electronic address: brohrbac@utk.edu.
authors.forename: Barton
authors.initials: B
authors.lastname: Rohrbach
authors.affiliation: University of Tennessee College of Veterinary Medicine, 2407 River Dr, Knoxville, TN 37996, USA. Electronic address: tmartinj@utk.edu.
authors.forename: Tomás
authors.initials: T
authors.lastname: Martín-Jiménez
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000969:Antinematodal Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D002161:Camelids, New World; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D006188:Haemonchiasis / Q000188:drug therapy / Q000469:parasitology / Q000662:veterinary*; D006189:Haemonchus / Q000187:drug effects*; D006207:Half-Life; D007279:Injections, Subcutaneous / Q000662:veterinary; D018942:Macrolides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008297:Male
chemical_list: D000969:Antinematodal Agents; D018942:Macrolides; C027837:moxidectin
keywords: Alpaca; Anthelmintic; Camelid; Moxidectin; Pharmacokinetics