Multi-Injection Pharmacokinetics of Meloxicam in Kemp’s Ridley (Lepidochelys kempii) and Green (Chelonia mydas) Sea Turtles after Subcutaneous Administration

SIMPLE SUMMARY: Drug dosing in sea turtles is often extrapolated from other reptiles, mammals, and humans. A more accurate way to determine the appropriate dose of a particular drug is by performing pharmacokinetic studies in that species. Meloxicam is an anti-inflammatory and pain management drug commonly used in humans and a wide range of animals including sea turtles. The authors recently published a study on single-injection meloxicam pharmacokinetics in sea turtles. The current study is a continuation of the single-injection study with objectives to determine the appropriate frequency of meloxicam administration in Kemp’s ridley and green sea turtles. Further, we evaluated whether the drug accumulated in the blood after multiple injections and if it caused any side effects. The results show that Kemp’s ridley sea turtles should receive a dose of 1 mg/kg subcutaneously every 12 h, whereas in green turtles, this same dose should be used at a frequency of every 48 h. No adverse side effects or statistically or clinically significant changes to blood work parameters were noted. This study provides important information to enhance pain management in endangered sea turtles undergoing rehabilitation. ABSTRACT: The objective of this study was to determine the pharmacokinetics and safety of multiple injections of meloxicam (MLX) administered subcutaneously (SQ) in Kemp’s ridley (Lepidochelys kempii) and green (Chelonia mydas) sea turtles. Based on results from a previously published single-injection study, a multiple-injection regimen was derived for the Kemp’s ridleys, which consisted of administering MLX at a dose of 1 mg/kg SQ every 12 h for 5 days, and for green turtles at a dose of 1 mg/kg SQ every 48 h for three treatments. Six turtles of each species were used for the study, and blood samples were taken at multiple time intervals. The terminal half-life after the last dose for the Kemp’s ridley sea turtles was calculated at 7.18 h, and for the green sea turtles at 23.71 h. Throughout the multiple injections, MLX concentrations remained above 0.57 µg/mL, a concentration targeted in humans for the analgesic and anti-inflammatory effects. No negative side effects or changes to blood parameters evaluated were observed during the study in either species. The results of this study suggest MLX should be administered SQ to Kemp’s ridley sea turtles at a dosage of 1 mg/kg every 12 h and in green sea turtles at a dose of 1 mg/kg every 48 h. The novelty of this work is that it is a multiple-injection study. Multiple injections were administered and produced concentrations that were considered therapeutic in humans, and the turtles did not have any adverse side effects. Furthermore, there were large differences in the pharmacokinetic values between green and Kemp’s ridley sea turtles.