Immunoassay detection of drugs in racing horses. IX. Detection of detomidine in equine blood and urine by radioimmunoassay
Detomidine is a potent non-narcotic sedative agent which is currently in the process of being approved for veterinary clinical use in the United States. Since no effective screening method in horses is available for detomidine, we have developed an /sup 125/I radioimmunoassay for detomidine in equine blood and urine as part of a panel of tests for illegal drugs in performance horses. Our /sup 125/I radioimmunoassay has an I-50 for detomidine of approximately 2 ng/ml. Our assay shows limited cross-reactivity with the pharmacodynamically similar xylazine, but does not cross-react with acepromazine, epinephrine, haloperidol or promazine. The plasma kinetic data from clinical (greater than or equal to 5 mg/horse) as well as sub-clinical doses indicate first-order elimination in a dose-dependent manner. Within the first 30 minutes after intravenous (IV) administration of 30 mg/horse, plasma levels peak at approximately 20 ng/ml and then decline with an apparent plasma half-life of 25 minutes. Diuresis can occur with administration of clinical doses of detomidine and this effect was accounted for in the analysis of urine samples. Using this method, administration of 30 mg/horse can be readily detected in equine urine for up to 8 hours after IV injection. Additionally, doses as low as 0.5 mg/horse can be detected for short periods of time in blood and urine with use of this assay. Utilization of this assay by research scientists and forensic analysts will allow for the establishment of proper guidelines and controls regarding detomidine administration to performance horses and assurance of compliance with these guidelines.
- Research Organization:
- Univ. of Kentucky, Lexington (USA)
- OSTI ID:
- 6080474
- Journal Information:
- Res. Commun. Chem. Pathol. Pharmacol.; (United States), Vol. 63:2
- Country of Publication:
- United States
- Language:
- English
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ANALGESICS
RADIOIMMUNOASSAY
HORSES
ANTIBODIES
BIOLOGICAL HALF-LIFE
BLOOD
DOSE-RESPONSE RELATIONSHIPS
IMIDAZOLES
IODINE 125
URINE
ANIMALS
AZOLES
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BIOLOGICAL WASTES
BODY FLUIDS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
IMMUNOASSAY
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MATERIALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
TRACER TECHNIQUES
VERTEBRATES
WASTES
550201* - Biochemistry- Tracer Techniques