Pharmacokinetics of meloxicam after intramuscular and oral administration of a single dose to American flamingos (Phoenicopertus ruber).

OBJECTIVE To determine pharmacokinetics after IM and oral administration of a single dose of meloxicam to American flamingos (Phoenicopertus ruber). ANIMALS 14 adult flamingos. PROCEDURES Flamingos were allocated to 2 groups. Each group received a dose of meloxicam (1 mg/kg) by the IM or oral route. After a 4-week washout period, groups received meloxicam via the other route of administration. Plasma meloxicam concentrations were measured with high-performance liquid chromatography. Data for each bird were analyzed. Estimated values of selected pharmacokinetic parameters were compared by use of a linear mixed-effects ANOVA. Pooled concentration-time profiles for each route of administration were analyzed to examine the influence of body weight on pharmacokinetics. RESULTS Mean ± SD maximum plasma concentration was 1.00 ± 0.88 μg/mL after oral administration. This was approximately 15% of the mean maximum plasma concentration of 5.50 ± 2.86 μg/mL after IM administration. Mean time to maximum plasma concentration was 1.33 ± 1.32 hours after oral administration and 0.28 ± 0.17 hours after IM administration. Mean half-life of the terminal phase after oral administration (3.83 ± 2.64 hours) was approximately twice that after IM administration (1.83 ± 1.22 hours). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the extent and rate of meloxicam absorption were less after oral administration than after IM administration. Intramuscular administration resulted in a short period during which mean plasma concentrations met or exceeded reported efficacious analgesic concentrations in other species, whereas oral administration did not. These results suggested that higher doses may be required for oral administration.