Pharmacokinetics of meloxicam in pigeons after single intravenous, oral, and intramuscular administration

This study aimed to determine the pharmacokinetics of meloxicam in pigeons. Twentyfour 7-wk-old meat pigeons (Columba livia) were randomly divided into 3 groups (PO, IM, and IV) and given a single dose of 1 mg/kg body weight of meloxicam. Plasma samples were taken at predetermined times, which were then analyzed using a validated high-performance liquid chromatography (HPLC) method and subjected to noncompartmental analysis using Phoenix software. Results indicated that meloxicam was absorbed effectively and quickly after PO and IM dosing. Peak concentrations (0.83 +/- 0.21 and 1.59 +/- 0.49 mu g/mL) were achieved at 2 and 0.26 h, respectively, with mean absorption times of 2.56 +/- 1.50 and 1.47 +/- 0.89 h. Bioavailability was high at 86.31 +/- 43.45% and 81.57 +/- 52.58%, respectively, and the area under the concentration-time curve (AUC(0-infinity)) was 5.33 > 2.68 and 5.03 +/- 3.26 h.mg/mL. After IV administration, the elimination was faster with a total body clearance (CL) of 188.75 +/- 83.23 mL/h/kg, an elimination half-life (t(1/2 lambda z)) of 1.76 +/- 0.56 h, and a volume of distribution at steady-state (VSS) of 427.50 +/- 188.43 mL/kg. Considering the lack of a precise analgesic threshold of meloxicam in pigeons and the notable differences in its analgesic threshold among various animal species, formulating a dosing regimen in pigeons presented a significant challenge. Based on the previous analgesic threshold (3.5 mu g/mL) in parrots, a higher dose (e.g., 2 mg/kg) or shorter dosing interval (e.g., every 6 h) is recommended for treating pain in pigeons. Nonetheless, further pharmacodynamic research is required to verify these recommendations.

Automated summary

This study aimed to determine the pharmacokinetics of meloxicam in pigeons. The results showed that meloxicam was effectively and quickly absorbed after oral and intramuscular administration, with high bioavailability. After intravenous administration, the elimination was faster. Formulating a dosing regimen for pigeons presented a significant challenge due to the lack of a precise analgesic threshold and notable differences in analgesic thresholds among various animal species. Higher doses or shorter dosing intervals are recommended for treating pain in pigeons, but further research is required to verify these recommendations.