Eprinomectin in dairy goats: dose influence on plasma levels and excretion in milk.
The plasma levels and milk excretion of eprinomectin were determined in goats following topical application at doses of 0.5 mg kg(-1) and 1.0 mg kg(-1). The area under the concentration-time curve (AUC) was 2 times lower for 0.5 mg kg(-1) (8.24 +/- 3.50 ng day(-1) ml(-1)) than for 1.0 mg kg(-1) (15.68 +/- 8.84 ng day(-1) ml(-1)), suggesting that the pharmacokinetics of eprinomectin in goats is dose independent. The bioavailability of eprinomectin in lactating compared with non-lactating goats is low. This is probably due to the physiological status of dairy animals, which present a marked decrease in body fat. Comparison of the eprinomectin concentrations in the milk and plasma demonstrated a parallel disposition of the drug with a milk-to-plasma ratio of 0.10-0.25. The amount of drug recovered in the milk was 0.3-0.5% of the total administered dose. In all cases, the maximum level of residue in milk remained below the maximum acceptable level of 30 ng ml(-1) permitted in lactating cattle.
Dupuy
J
J
INRA-Toulouse, Laboratoire de Pharmacologie-Toxicologie, France.
Chartier
C
C
Sutra
J F
JF
Alvinerie
M
M
D000287:Administration, Topical; D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D003612:Dairying; D004305:Dose-Response Relationship, Drug; D006041:Goats / Q000378:metabolism*; D007559:Ivermectin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics*; D007774:Lactation; D008892:Milk / Q000378:metabolism*
D000871:Anthelmintics; D007559:Ivermectin; C101434:eprinomectin