Pharmacokinetics of oral meloxicam in ruminant and preruminant calves

• Published in: Journal of veterinary pharmacology and therapeutics Vol. 35; no. 4; pp. 373 - 381
• Main Authors: MOSHER, R. A, COETZEE, J. F, CULL, C. A, GEHRING, R, KuKANICH, B
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-08-2012
• Subjects: Absorption; Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal - blood; Anti-Inflammatory Agents, Non-Steroidal - pharmacokinetics; Area Under Curve; bioavailability; calves; Cattle; Digestion - physiology; gastrointestinal system; Half-Life; Male; meloxicam; milk replacer; pharmacokinetics; Thiazines - blood; Thiazines - pharmacokinetics; Thiazoles - blood; Thiazoles - pharmacokinetics; Weaning
• ISSN: 0140-7783; 1365-2885
• DOI: 10.1111/j.1365-2885.2011.01331.x

Mosher, R. A., Coetzee, J. F., Cull, C. A., Gehring, R., KuKanich, B. Pharmacokinetics of oral meloxicam in ruminant and preruminant calves. J. vet. Pharmacol. Therap. 35, 373–381. The pharmacokinetics of oral meloxicam has been studied in ruminant, but not preruminant calves. Oral meloxicam was administered at 0.5 mg/kg to six ruminant calves via gavage (RG); to six preruminant calves via gavage (PRG); and to six preruminant calves via suckling in milk replacer (PRF). Plasma drug concentrations, determined over 120‐h postadministration, were analyzed by compartmental and noncompartmental methods. The rate of drug absorption was faster (P < 0.01) in PRF (0.237 ± 0.0478/h) than RG calves (0.0815 ± 0.0188/h), while absorption in PRG calves (0.153 ± 0.128/h) was not different from other groups. Cmax was lower (P = 0.03) in PRF (1.27 ± 0.430 μg/mL) than in PRG calves (2.20 ± 0.467 μg/mL), while Cmax of RG calves (1.95 ± 0.955 μg/mL) was not different from other groups. V/F was higher in PRF calves (365 ± 57 mL/kg) than either PRG (177 ± 63 mL/kg, P < 0.01) or RG (232 ± 83 mL/kg, P = 0.01) calves. These observations were likely due to differences in bioavailability, physiological maturity, and timing of the drug delivery into different compartments of the ruminant gastrointestinal tract. Results suggest that an adjustment in meloxicam dose may be necessary when administered with milk replacer.