Pharmacokinetics of Oxytetracycline in Loggerhead Sea Turtles (Caretta Caretta) After Single Intravenous and Intramuscular Injections

Abstract

The pharmacokinetics of oxytetracycline in 2-yr-old loggerhead sea turtles (Caretta caretta) after single i.v. and i.m. injections were studied for biologic marking and therapeutic applications. Twenty juvenile turtles were divided into two treatment groups. Ten animals received 25 mg/kg of oxytetracycline i.v. and 10 received the same dosage i.m. Plasma oxytetracycline concentrations were analyzed by reverse-phase high-performance liquid chromatography. Data from the i.v. route best fit a three-compartment model, whereas noncompartmental analysis was used to compare data from both the i.v. and i.m routes. For the i.v. route, means for maximum plasma concentration, terminal phase half-life, systemic clearance, and apparent volume of distribution at steady state were 6.6 microg/ml, 66.1 hr, 290.7 ml/hr/kg, and 18.4 L, respectively. For the i.m. route, means for systemic availability, maximum plasma concentration, and elimination half-life were 91.8%, 1.6 microg/ml, and 61.9 hr, respectively. The remarkably high apparent volume of distribution may possibly be associated with a deep compartment of drug disposition such as bone deposition associated with the large skeletal mass of turtles and the fact that these were well-nourished, growing juveniles. Although maximum plasma concentration by i.m. administration was lower than for the i.v. route, the long elimination time indicates that an infrequent dosing interval may be effective for sensitive bacteria.

Validation of annual skeletal marks in green sea turtles Chelonia mydas using tetracycline labeling

“…It further provides support for additional OTC marking, which appears to be a successful technique for sea turtles that are growing, even with one dose, possibly because of the pharmacokinetics of OTC in turtles which results in a long elimination time (Harms et al 2004). Additional OTC marking will help identify anomalous LAGS, provide a larger sample size for validation and allow comparisons among populations.…”

Pharmacokinetics of danofloxacin after single dose intravenous, intramuscular and subcutaneous administration to loggerhead turtles Caretta caretta

“…Wild loggerhead turtles Caretta caretta may require antimicrobial therapy when brought into oceanariums and rehabilitation facilities for treatment and/or prevention of primary and secondary bacterial infections; however, few pharmacokinetic studies have been performed (Stamper et al 1999, Harms et al 2004, Jacobson et al 2005, Manire et al 2005. The pharmacokinetic properties of danofloxacin have been evaluated in several species (rabbits, Fernández-Varón et al 2007;cows, Shem-Tov et al 1998;and horses, Fernán-dez-Varón et al 2006), but not yet in sea turtles.…”

Pharmacokinetics of cefovecin sodium after subcutaneous administration to Hermann's tortoises (Testudo hermanni)

“…Most studies have been performed with marine turtles, [4][5][6][7][8][9][10][11][12] with few focusing on freshwater 13,14 and terrestrial chelonians. [15][16][17] Consequently, to establish antimicrobial treatment protocols, veterinary practitioners often have to rely on anecdotal reports 18 for information instead of proper pharmacokinetics studies.…”