Pharmacokinetic/pharmacodynamic assessments of 10 mg/kg tramadol intramuscular injection in yellow-bellied slider turtles (Trachemys scripta scripta)

Giorgi, M, Salvadori, M, De Vito, V, Owen, H, Demontis, M.P and Varoni, M.V (2015) Pharmacokinetic/pharmacodynamic assessments of 10 mg/kg tramadol intramuscular injection in yellow-bellied slider turtles (Trachemys scripta scripta). Journal of Veterinary Pharmacology and Therapeutics, 38 5: 488-496. doi:10.1111/jvp.12206


Author Giorgi, M
Salvadori, M
De Vito, V
Owen, H
Demontis, M.P
Varoni, M.V
Title Pharmacokinetic/pharmacodynamic assessments of 10 mg/kg tramadol intramuscular injection in yellow-bellied slider turtles (Trachemys scripta scripta)
Journal name Journal of Veterinary Pharmacology and Therapeutics   Check publisher's open access policy
ISSN 1365-2885
0140-7783
Publication date 2015-01-27
Year available 2015
Sub-type Article (original research)
DOI 10.1111/jvp.12206
Open Access Status
Volume 38
Issue 5
Start page 488
End page 496
Total pages 9
Place of publication Oxford, United Kingdom
Publisher Wiley-Blackwell Publishing Ltd
Collection year 2016
Language eng
Formatted abstract
In reptiles, administration of opioid drugs has yielded unexpected results with respect to analgesia. The aims of this study were to assess the pharmacokinetic/pharmacodynamic (PK/PD) properties of tramadol and its active metabolite M1 and to evaluate the effect of the renal portal system on the PK/PD parameters in yellow-bellied slider turtles. Turtles (n = 19) were randomly assigned to four treatment groups, according to a masked, single-dose, four-treatment, unpaired, four-period crossover design. Group A (n = 5) received a single i.m. dose of tramadol (50 mg/mL) at 10 mg/kg in the proximal hindlimb. Group B (n = 5) received the same i.m. dose but in the forelimb. Groups C (n = 5) and D (n = 4) received a single i.m. injection of saline (NaCl 0.9%) of equivalent volume to the volumes of tramadol injected in the hind- and forelimb, respectively. Groups were rotated (1-month washout period) until the completion of the crossover study. Tramadol plasma concentrations were evaluated by a validated HPLC-FL method. An infrared thermal stimulus was applied to the plantar surface of the turtles' hindlimbs to evaluate the thermal withdrawal latency (TWL). The two PK profiles of tramadol differed in the first 2 h following administration, but overlapped in the elimination phases. The metabolite M1 was formed in both the treatment groups, showing similar pharmacokinetic trends, although the amount of M1 was significantly higher (20%) in the hindlimb vs. forelimb group. Turtles given tramadol in the hind- and forelimb showed a significant increase in TWL over the periods of 0.5–48 and 8–48 h, respectively. The calculated % maximal possible response (% MPR) was low (about 24%). The PK/PD correlations between M1 plasma concentrations vs. % MPR appeared to show a counterclockwise hysteresis loop shape.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Veterinary Science Publications
 
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