Biology Reference
In-Depth Information
Chapter 17
Pharmacokinetics of the Tramadol Injective
Formulations in Alpacas (
Vicugna pacos
)
M. Giorgi, G. Saccomanni, S. Del Carlo, G. Mengozzi, and V. Andreoni
Abstract The objective of the present study was to test the intravenous (IV) and
intramuscular (IM) administration of tramadol to alpacas (
Vicugna pacos
). The
study was a two-group, single-dose, two-treatment, two-period, randomized, open,
balanced, cross-over design. After both administrations of tramadol to alpacas
(2.5 mg/kg b.w.), plasma concentrations of tramadol and its main metabolites
(M1, M2, and M5) were determined using an HPLC method. Moderate side effects
were shown after IV administration. The IM bioavailability of the drug (81.5%) was
within the generally accepted values for a positive bioequivalence decision
(80-125%). The plasma concentrations of M1 and M5 were low, and the amounts
of M2 produced were similar after both routes of administration. In conclusion,
tramadol was rapidly and almost completely absorbed after IM administration, and
its systemic availability was equivalent to IV injection. Hence, IM injection of
tramadol is a useful and good alternative to IV injection in alpacas.
Keywords Tramadol Alpaca Intravenous Intramuscular Pharmacokinetics
17.1
Introduction
Tramadol is a centrally acting analgesic drug that has been used clinically for the last
two decades to treat pain in humans. Recently, tramadol was reported to be
metabolized into inactive metabolites faster in dogs (KuKanich and Papich
2004
;
M. Giorgi (
*
) G. Mengozzi
Dipartimento Clinica Veterinaria, University of Pisa, Pisa, Italy
e-mail:
mgiorgi@vet.unipi.it
G. Saccomanni S. Del Carlo
Dipartimento Scienze Farmaceutiche, University of Pisa, Pisa, Italy
V. Andreoni
Dipartimento Anestesia, University College Dublin, Dublin, Ireland
