Detection, quantification, metabolism, and behavioral effects of selegiline in horses.
Abstract: Selegiline ([R]-[-]N,alpha-dimethyl-N-2- propynylphenethylamine or l-deprenyl), an irreversible inhibitor of monoamine oxidase, is a classic antidyskinetic and antiparkinsonian agent widely used in human medicine both as monotherapy and as an adjunct to levodopa therapy. Selegiline is classified by the Association of Racing Commissioners International (ARCI) as a class 2 agent, and is considered to have high abuse potential in racing horses. A highly sensitive LC/MS/MS quantitative analytical method has been developed for selegiline and its potential metabolites amphetamine and methamphetamine using commercially available deuterated analogs of these compounds as internal standards. After administering 40 mg of selegiline orally to two horses, relatively low (<60 ng/ml) concentrations of parent selegiline, amphetamine, and methamphetamine were recovered in urine samples. However, relatively high urinary concentrations of another selegiline metabolite were found, tentatively identified as N- desmethylselegiline. This metabolite was synthesized and found to be indistinguishable from the new metabolite recovered from horse urine, thereby confirming the chemical identity of the equine metabolite. Additionally, analysis of urine samples from four horses dosed with 50 mg of selegiline confirmed that N-desmethylselegiline is the major urinary metabolite of selegiline in horses. In related behavior studies, p.o. and i.v. administration of 30 mg of selegiline produced no significant changes in either locomotor activities or heart rates.
Publication Date: 2004-05-12 PubMed ID: 15136987
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Clinical Trial
- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research investigates the detection, quantity, metabolism, and behavioral effects of a drug called selegiline in horses. The drug, often used in human medicine for conditions such as Parkinson’s disease, is considered to have high potential for abuse in racing horses.
Methodology
- The research implemented an LC/MS/MS quantitative analytical method for detecting the presence of selegiline and its potential metabolites, amphetamine and methamphetamine, in the horses. This method used commercially available deuterated analogs of the compounds as internal standards for comparison.
- Two horses were administered 40mg of selegiline orally, and their urine was assessed for the presence and concentration of selegiline and its metabolites.
- The study also conducted behavioral studies, administering 30mg of selegiline to the horses orally and intravenously, and then observing any changes in locomotion activities or heart rates.
Findings
- The results showed that after consuming selegiline, the horses’ urine contained relatively low concentrations (<60 ng/ml) of parent selegiline, amphetamine, and methamphetamine.
- However, a high urinary concentration of another selegiline metabolite, tentatively identified as N-desmethylselegiline, was found.
- The researchers synthesized the metabolite N-desmethylselegiline and compared it to the one found in the horses’ urine. The results confirmed that they were the same, revealing that N-desmethylselegiline is the major urinary metabolite of selegiline in horses.
- The behavioral studies showed no significant changes in either locomotion activities or heart rates after selegiline intake.
Implications
- This study provides a critical understanding of how selegiline is metabolized in horses and introduces an effective method to detect its use and abuse in horse racing.
- The ability to detect the metabolite N-desmethylselegiline can serve as a key tool in uncovering misuse of the drug for competitive advantages in racing.
- The lack of noticeable behavioral changes suggests that additional research is needed to accurately identify overdose or misuse symptoms.
Cite This Article
APA
Dirikolu L, Lehner AF, Karpiesiuk W, Hughes C, Woods WE, Boyles J, Harkins JD, Troppmann A, Tobin T.
(2004).
Detection, quantification, metabolism, and behavioral effects of selegiline in horses.
Vet Ther, 4(3), 257-268.
Publication
Researcher Affiliations
- Department of Biomedical Sciences, College of Veterinary Medicine, Nursing and Allied Health, Tuskegee University, Tuskegee, AL 36088, USA.
MeSH Terms
- Administration, Oral
- Animals
- Behavior, Animal / drug effects
- Female
- Horses / metabolism
- Mass Spectrometry / veterinary
- Monoamine Oxidase Inhibitors / administration & dosage
- Monoamine Oxidase Inhibitors / blood
- Monoamine Oxidase Inhibitors / pharmacokinetics
- Monoamine Oxidase Inhibitors / pharmacology
- Monoamine Oxidase Inhibitors / urine
- Selegiline / administration & dosage
- Selegiline / blood
- Selegiline / pharmacokinetics
- Selegiline / pharmacology
- Selegiline / urine
- Substance Abuse Detection / veterinary
Citations
This article has been cited 0 times.Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
