Bioavailability and pharmacokinetics of oral meloxicam in llamas

A mean peak plasma concentration (CMAX) of 1.314？μg/mL (Range: 0.826 – 1.776？μg/mL) was recorded at 21.4 hours (Range: 12.0 – 24.0 hours) with a half-life (T ？ λz) of 22.7 hours (Range: 18.0 – 30.8 hours) after oral meloxicam administration. In comparison, a half-life (T ？ λz) of 17.4 hours (Range: 16.2 – 20.7 hours) was demonstrated with IV meloxicam administration. The oral bioavailability (F) of meloxicam (dose normalized) was 76% (Range: 48 – 92%). No adverse effects associated with either treatment modality were observed in the llamas.The mean bioavailability (F) of oral meloxicam was 76% indicating a high degree of gastrointestinal absorption. Plasma meloxicam concentrations >0.2？μg/mL were maintained for up to 72？h after oral administration; >0.2？μg/mL is considered to be the concentration of meloxicam required for analgesic effects in other species such as the horse. These data suggest that a single dosage of oral meloxicam at 1？mg/kg could potentially maintain therapeutic concentrations in plasma for up to 3？days in adult llamas.Over the past few decades, North America has seen a rapid increase in the number of South American camelids raised for fiber, show and companionship. Along with the increase in animal numbers has come an increase in interest for veterinary care and appropriate drug therapies for these animals. To date, however, there are no drugs currently approved by the Food and Drug Administration for use in camelids in the United States. Thus, extra-label use of common veterinary therapeutic drugs in camelids is routine in practice, yet there generally remains a lack of pharmacokinetic (PK) data in camelids. Dosages used have been extrapolated from other large animal species, including cattle, horses, and other small ruminant species. Particularly in regards to oral administration and bioavailability of medications, this practice has proven to be inadequate in some of the camelid pharmacokinetic studies published to date [1-5]. In addition, alth