title: Comparative plasma and milk dispositions, faecal excretion and efficacy of per os ivermectin and pour-on eprinomectin in horses.
abstract: The horse milk gains increasing interest as a food product for sensitive consumers, such as children with food allergies or elderly people. We investigated the plasma and milk disposition, faecal excretion and efficacy of per os ivermectin (IVM) and pour-on eprinomectin (EPM) in horses. Ten mares were divided into two groups. The equine paste formulation of IVM and bovine pour-on formulation of EPM were administered orally and topically at dosage of 0.2 and 0.5 mg/kg bodyweight. Blood, milk and faecal samples were analysed using high-performance liquid chromatography. The plasma concentration and persistence of IVM were significantly greater and longer compared with those of EPM. Surprisingly, EPM displayed a much higher disposition rate into milk (AUCmilk/plasma: 0.48) than IVM (AUCmilk/plasma: 0.19). IVM exhibited significantly higher faecal excretion (AUCfaeces: 7148.54 ng·d/g) but shorter faecal persistence (MRTfaeces: 1.17 days) compared with EPM (AUCfaeces: 42.43 ng·d/g and MRTfaeces: 3.29 days). Faecal strongyle egg counts (EPG) were performed before and at weekly intervals after treatment. IVM reduced the EPG by 96-100% for up to 8 weeks, whereas the reduction in the EPM group varied from 78 to 99%. In conclusion, due to the relatively low excretion in milk, EPM and IVM may be used safely in lactating mares if their milk is used for human consumption. Nevertheless, much lower plasma and faecal availabilities of EPM could result in subtherapeutic concentrations, which may increase the risk of drug resistance in nematodes after pour-on EPM administration compared with per os IVM.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Balikesir University, Balikesir, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Gokbulut
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Uludag University, Bursa, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Ozuicli
authors.affiliation: Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Balikesir University, Balikesir, Turkey.
authors.forename: D
authors.initials: D
authors.lastname: Aksit
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Balikesir University, Balikesir, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Aksoz
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Balikesir University, Balikesir, Turkey.
authors.forename: O
authors.initials: O
authors.lastname: Korkut
authors.affiliation: General Directory of Agricultural Farms (TIGEM), Karacabey Agricultural Farm, Bursa, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Yalcinkaya
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Uludag University, Bursa, Turkey. vcirak@yahoo.com.
authors.forename: V Y
authors.initials: VY
authors.lastname: Cirak
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000818:Animals; D000871:Anthelmintics / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000627:therapeutic use; D000977:Antiparasitic Agents / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000627:therapeutic use; D019540:Area Under Curve; D005243:Feces / Q000737:chemistry; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy / Q000469:parasitology*; D006736:Horses / Q000097:blood*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics* / Q000627:therapeutic use; D008892:Milk / Q000737:chemistry*; D013319:Strongyle Infections, Equine / Q000188:drug therapy*
chemical_list: D000871:Anthelmintics; D000977:Antiparasitic Agents; D007559:Ivermectin; C101434:eprinomectin