Wintertime pharmacokinetics of intravenously and orally administered meloxicam in semi-domesticated reindeer (Rangifer tarandus tarandus)

ObjectiveTo investigate the pharmacokinetics of orally and intravenously (IV) administered meloxicam in semi-domesticated reindeer (Rangifer tarandus tarandus).Study designA crossover design with an 11 day washout period.AnimalsA total of eight young male reindeer, aged 1.5–2.5 years and weighing 74.3 ± 6.3 kg, mean ± standard deviation.MethodsThe reindeer were administered meloxicam (0.5 mg kg^–1 IV or orally). Blood samples were repeatedly collected from the jugular vein for up to 72 hours post administration. Plasma samples were analysed for meloxicam concentrations with ultraperformance liquid chromatography combined with triple quadrupole mass spectrometry. Noncompartmental analysis for determination of pharmacokinetic variables was performed.ResultsThe pharmacokinetic values, median (range), were determined. Elimination half-life (t_½) with the IV route (n = 4) was 15.2 (13.2–16.8) hours, the volume of distribution at steady state was 133 (113–151) mL kg^?1 and clearance was 3.98 (2.63–5.29) mL hour^–1 kg^–1. After oral administration (n = 7), the peak plasma concentration (C_max) was detected at 6 hours, t_½ was 19.3 (16.7–20.5) hours, C_max 1.82 (1.17–2.78) μg mL^–1 and bioavailability (n = 3) 49 (46–73)%. No evident adverse effects were detected after either administration route.Conclusions and clinical relevanceA single dose of meloxicam (0.5 mg kg^–1 IV or orally) has the potential to maintain the therapeutic concentration determined in other species for up to 3 days in reindeer plasma.