PHARMACOKINETICS OF MELOXICAM IN TURTLES (TRACHEMYS SCRIPTA SCRIPTA SPP) AFTER SINGLE ORAL, INTRACOELOMIC AND INTRAMUSCULAR ADMINISTRATIONS

OBJECTIVE To obtain pharmacokinetic information after single intramuscular, intracoelomic and oral administration of meloxicam in turtles (Trachemys scripta scripta spp). METHODS Eighteen turtles equally divided in three groups were treated with a single dose of meloxicam (0.2 mg kg 1) given via intramuscular, intracoelomic and oral administration, respectively. Blood samples were collected at predetermined time points (before administration and at 0.5, 2, 4, 8, 12, 24, 48, 72, 96 and 120 h post administration) from the subcarapacial vein, and plasma meloxicam concentrations were determined by HPLC (Chinnadurai et al., 2014). Pharmacokinetic parameters were calculated from the resultant concentration-time curves. RESULTS In all subjects in all treated groups, meloxicam appeared in the bloodstream at the first time point (30 min). It was detectable up to 24 h post treatment in all subjects after intracoelomic treatment and in 5 out of 6 turtles following intramuscular and oral administration. Forty-eight hours post-administration, meloxicam was still detectable in 4 out of 6, 3 out of 6 and 1 out of 6 turtles after intracoelomic, intramuscular and oral administration, respectively. At the sampling time on the thirdday (72 h), the drug was only detectable in 1 subject treated via the intracoelomic route. Following intramuscular administration, the Cmax was reached at 1.17 0.45 (mean SD) hours indicating a faster absorption of meloxicam with respect to oral treatment (Tmax 5.23 3.80 h, P = 0.004) and the intracoelomic route (Tmax 2.82 1.39 h), although this last difference was not statistically significant. The intramuscular group accounted for the highest plasma peak of meloxicam (1590.03 1845.32 ng ml 1), the intracoelomic group for the largest AUC (12621.04 6203.79 h*ng ml 1). The oral group had the smallest drug plasma concentrations, meloxicam concentrations were always below 100 ng ml 1, indicating a poor absorption through this administration route. CONCLUSIONS From the data obtained, oral administration of meloxicam seems unsuitable for turtles (Trachemys scripta scripta spp), due to the very low drug concentrations in the blood. Conversely, the intramuscular and intracoelomic routes lead to higher blood concentrations of the drug. Further studies are warranted to establish the effective plasma concentration of meloxicam in turtles, and, consequently, the most suitable route of administration and the dosage regimen.