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Pharmacokinetics of tramadol and its major metabolite after intramuscular administration in piglets
Author(s) -
Vullo C.,
Kim T.W.,
Meligrana M.,
Marini C.,
Giorgi M.
Publication year - 2014
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1111/jvp.12133
Subject(s) - pharmacokinetics , metabolite , tramadol , pharmacodynamics , pharmacology , plasma concentration , active metabolite , medicine , chemistry , anesthesia , analgesic
Tramadol ( T ) is a centrally acting atypical opioid used for treatment of dogs. Piglets might experience pain following castration, tooth clipping and tail docking and experimental procedures. The aim of this study was to assess the pharmacokinetics of T and its active metabolite M 1 in male piglets after a single intramuscular injection. Six healthy male piglets were administered T (5 mg/kg) intramuscularly. Blood was sampled at scheduled time intervals and drug plasma concentrations evaluated by a validated HPLC method. T plasma concentration was quantitatively detectable from 0.083 to 8 h. M1 was quantified over a shorter time period (0.083–6 h) with a T max at 0.821 h. The study demonstrated that piglets produce a larger amount of M 1 compared with dogs, horses and goats. The human minimum effective concentration of M 1 (40 ng/mL) was exceeded for over 3 h in piglets. If it is assumed to also apply to piglets, it could be speculated that the drug efficacy might exert its action over 3 h or longer. This assumption has to be confirmed by further specific pharmacokinetic/pharmacodynamic studies.