Pharmacokinetics and Drug Residue in Eggs After Multiple-Day Oral Dosing of Amoxicillin-Clavulanic Acid in Domestic Chickens.

This study examined the pharmacokinetics of orally administered amoxicillin and clavulanic acid tablets (Clavamox, 125 mg/kg PO q12h for 9 doses) in domestic hens and examined both amoxicillin and clavulanic acid concentrations in eggs. Therapeutic plasma concentrations (0.5 µg/mL) of amoxicillin were not reached at any time point, and no amoxicillin was detected in plasma after 2 hours. Pharmacokinetic parameters could not be calculated. The clavulanic acid half-life was 1.1 hours and it was detected up to 8 hours after dosing. No amoxicillin was detected in eggs 4 days postdosing, nor was clavulanic acid detected in any eggs during the same time period. On the basis of these results, orally dosing hens with amoxicillin and clavulanic acid tablets at 125 mg/kg PO q12h does not reach therapeutic plasma concentrations. Additional studies are needed to examine different doses and formulations of medication to determine better dosing and withdrawal recommendations for domestic chickens.

Pharmacokinetics and Egg Residues of Meloxicam After Multiple Day Oral Dosing in Domestic Chickens.

With increased ownership of backyard poultry, veterinarians must treat these birds appropriately and take into consideration drug withdrawal times for eggs meant for consumption. Few studies have examined the pharmacokinetics or egg residues for medications commonly used in avian medicine. This study determined the pharmacokinetics of meloxicam in domestic chickens (n = 8) after oral dosing at 1 mg/kg q12h for a total of 9 doses (5 days). Additionally, the presence of meloxicam residues in eggs was determined. The terminal half-life, maximum concentration, and time to maximum concentration were 3.02 ± 1.15 hours, 7.14 ± 1.54 µg/mL, and 1.6 ± 0.52 hours, respectively. No drug was detected in yolks and whites after 8 days and 3 days, respectively. On the basis of these results, a 2-week withdrawal time should be adequate to avoid drug residues in eggs meant for consumption.