L. Dirikolu et al., Identification of lidocaine and its metabolites in post-adminstration equine urine by ELISA and MS/MS, J VET PHARM, 23(4), 2000, pp. 215-222
Citations number
9
Categorie Soggetti
Veterinary Medicine/Animal Health
Journal title
JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS
Lidocaine is a local anesthetic drug that is widely used in equine medicine
. It has the advantage of giving good local anesthesia and a longer duratio
n of action than procaine. Charles C. Thomas, Springfield, IL). Although ap
proved for use in horses in training by the American Association of Equine
Practitioners (AAEP), lidocaine is also an Association of Racing Commission
ers International (ARCI) Class 2 drug and its detection in forensic samples
can result in significant penalties.
Lidocaine was observed as a monoprotonated ion at m/z 235 by ESI+ MS/MS (el
ectrospray ionization-positive ion mode) analysis. The base peak ion at m/z
86, representing the postulated methylenediethylamino fragment [CH2N(CH2CH
3)(2)](+), was characteristic of lidocaine and 3-hydroxylidocaine in both E
SI+ and EI (electron impact- positive ion mode) mass spectrometry. In addit
ion, we identified an ion at m/z 427 as the principal parent ion of the ion
at m/z 86, consistent with the presence of a protonated analog of 3-hydrox
ylidocaine-glucuronide.
We also sought to establish post-administration ELISA-based 'detection time
s' for lidocaine and lidocaine-related compounds in urine following single
subcutaneous injections of various doses (10, 40, 400 mg). Our findings sug
gest relatively long ELISA based 'detection times' for lidocaine following
higher doses of this drug.