The Pharmacokinetics and Pilot Efficacy of Levamisole Administered by Subcutaneous Injection of a Combination Product in Domestic Goats (Capra aegagrus hircus)

Source Publication (e.g., journal title)

Journal of Veterinary Pharmacology and Therapeutics

Authors

Grace Malla, University of Tennessee College of Veterinary MedicineFollow
Joe Smith, University of Tennessee College of Veterinary MedicineFollow
Meggan Graves, University of Tennessee College of Veterinary MedicineFollow
Lisa Ebner, Texas Tech University School of Veterinary MedicineFollow
Ryan Branham, University of Tennessee College of Veterinary MedicineFollow
Jessica Lynch, University of Tennessee College of Veterinary MedicineFollow
Laura Gilliard, University of Tennessee College of Veterinary MedicineFollow
Julia Cutchin, University of Tennessee College of Veterinary MedicineFollow
Madeline Duncan, University of Tennessee College of Veterinary MedicineFollow
Rebecca Rahn, University of Tennessee College of Veterinary MedicneFollow
Michelle Buckley, Texas Tech University School of Veterinary MedicineFollow
Andrew Ursini, University of Tennessee College of Veterinary MedicineFollow
Cassandra Klostermann, University of Tennessee College of Veterinary MedicineFollow
Jessy Shanks, University of Tennessee College of AgricultureFollow
Sherry Cox, University of Tennessee College of Veterinary MedicineFollow

Author ORCID Identifier

Joe Smith

https://orcid.org/0000-0002-4288-2262

Sherry Cox

https://orcid.org/0000-0002-5184-900X

Document Type

Article

Publication Date

Summer 7-21-2025

DOI

https://doi.org/10.1111/jvp.70013

Abstract

Anthelmintic resistance is a major welfare issue in goats, and the efficacy of anthelmintic drugs lies in judicious use. Recently, an injectable combination (levamisole-doramectin) product labeled for cattle became available. This study’s goal was to compare the levamisole pharmacokinetic parameters of this new combination drug to a commercially available oral levamisole formulation in goats. Six adult goats subcutaneously received a 9 mg/kg dose of the combination product. Blood samples were collected at 14 time points over 48 hours. After a 14-day washout period, the same goats were given 12 mg/kg of oral levamisole and sampled following the same time points. Levamisole concentrations were measured via liquid chromatography. A non-compartmental analysis was used to generate pharmacokinetic (PK) parameters for both formulations. After one subcutaneous (SC) injection, the maximum plasma concentration (C_max), time to C_max (T_max), area under the curve (AUC), and elimination half-life (T_1/2) was 468.57 ± 151.12 ng/mL, 2.24 ± 1.58 hours, 3206.42 ± 1189.73 h*ng/mL, and 2.36 ± 2.07 hours, respectively. After a single oral administration, C_max, T_max, AUC, and T_1/2 were 573.21 ± 149.01 ng/mL, 0.5 ± 0.41 hours, 2995.47 ± 2203.93 h*ng/mL, and 3.74 ± 2.19 hours, respectively. Fecal samples taken before and after subcutaneous administration had an average egg count reduction of 61.97% (P = 0.0625). The relative bioavailability of the SC injection was 185%. Considering bioavailability and egg count reduction, the combination product may be considered for parasite management, however, a field trial is needed to determine its efficacy and other pharmacodynamic parameters.

Recommended Citation

Malla, G., J. Smith, M. Graves, et al. 2025. “ The Pharmacokinetics and Pilot Efficacy of Levamisole Administered by Subcutaneous Injection of a Combination Product in Domestic Goats (Capra aegagrus hircus).” Journal of Veterinary Pharmacology and Therapeutics 1–9. https://doi.org/10.1111/jvp.70013.

Submission Type

Post-print