Testing for trazodone, an antidepressant, in hair collected from horses.
Abstract: Trazodone, a medicine registered for human, is a serotonin agonist-antagonist. At low dose, the drug is sedative due to its antagonist properties. At high dose, it is an agonist with anxiolytic and antidepressant actions. Trazodone can be administered to the horse to reduce anxiety. However, according to the anti-doping rules for horses, the presence of trazodone in blood or urine is considered as a violation which will produce a suspension of both the athlete and the horse as the drug is listed banned on the International Federation of Horseracing Authorities prohibited substances list. As a hair test can provide more evidence or supplementary information to an adverse analytical finding or to document drug exposure, our forensic laboratory received 2 specimens with a request for trazodone identification. After mane collection, trazodone was analysed by a new LC-MS/MS method involving pH 9.5 borate buffer overnight incubation of 20 mg of specimen in presence of clozapine-D4 used as internal standard, followed by solvents extraction. Linearity was verified from 1 to 100 pg/mg (R2 = 0.9967). Limit of detection of the method was 0.1 pg/mg. Trazodone was measured at 0.4 pg/mg in the mane of a horse suspended after an anti-doping violation. In a case of hidden administration, trazodone was identified at 9 and 24 pg/mg in 2 consecutive mane hair segments. Although no controlled study allows interpretation, particularly about the frequency of exposure and the dose that entered in the body, this is the first evidence that trazodone can be incorporated in the mane of horses.
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Publication Date: 2025-03-15 PubMed ID: 40088067DOI: 10.1093/jat/bkaf025Google Scholar: Lookup
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Summary
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This research paper presents a new method for detecting trazodone, an antidepressant and anxiety-reducing drug sometimes improperly administered to horses, in the animals’ hair. The new detection method utilizes LC-MS/MS analysis and offers improved sensitivity and accuracy, allowing for better enforcement of anti-doping regulations in horseracing.
Concept and Methodology
- The researchers focused on the detection of trazodone, a human antidepressant that’s sometimes improperly given to horses to manage anxiety. This is contravening the anti-doping guidelines set by the International Federation of Horseracing Authorities, which ban the use of trazodone.
- The method of testing involved taking horse hair (mane) samples and analyzing them using a new LC-MS/MS method. Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) is a technique widely used in laboratories for detecting specific substances in biological samples.
- The testing process began with an overnight incubation of the hair sample in a pH 9.5 borate buffer solution, in the presence of clozapine-D4 as an internal standard. This was followed by solvent extraction, allowing isolation and analysis of any trazodone present.
Results and Findings
- The new method demonstrated linearity ranging from 1 to 100 pg/mg (with R2 = 0.9967), denoting a very strong linear relationship between the tested and observed concentrations of trazodone – indicating high precision.
- The detection limit was found to be 0.1 pg/mg. This low value indicates that the method is highly sensitive and can detect minute amounts of trazodone in hair samples.
- Using this method, trazodone was detected in the mane of a horse that had been suspended after breaching anti-doping regulations, as well as in two consecutive mane hair segments possibly indicating hidden administration of the drug.
Significance and Implications
- This research is significant because it provides a new, more sensitive and precise method to detect trazodone, helping to ensure adherence to anti-doping policies in horseracing. This enhances the sport’s integrity and protects the wellbeing of the horses.
- These findings, particularly the successful detection of trazodone in hair, suggest potential for further research into this method and its broader application for other prohibited substances, maintaining fair competition in equestrian sports, and monitoring for horse welfare.
Cite This Article
APA
Kintz P, Baudry M, Gheddar L.
(2025).
Testing for trazodone, an antidepressant, in hair collected from horses.
J Anal Toxicol, bkaf025.
https://doi.org/10.1093/jat/bkaf025 Publication
Researcher Affiliations
- X-Pertise Consulting, 42 rue principale, F-67206 Mittelhausbergen, France.
- Institut de médecine légale, 11 rue Humann, F-67000 Strasbourg, France.
- Institut de médecine légale, 11 rue Humann, F-67000 Strasbourg, France.
- Institut de médecine légale, 11 rue Humann, F-67000 Strasbourg, France.
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