An internal review by the Horseracing Integrity & Welfare Unit revealed that not all participating laboratories applied the same limit of detection in analyzing samples for the presence of metformin. HIWU has since met with all six laboratories to establish updated, uniform detection limits for the drug.
Metformin is used for the treatment of humans with type 2 diabetes. It can be used to treat insulin resistance associated with equine metabolic syndrome in horses. The Federal Drug Administration has approved metformin use in humans, but it is not officially approved for use in animals.
Drugs and medications people use can increase the possibility of contamination of equine drug testing.
The HIWU website lists five positives for metformin under its pending violations since the implementation of the Horseracing Integrity and Safety Authority’s Anti-Doping and Medication Control Program.
HIWU said it conducted the review, conducted in collaboration with the laboratories, as part of its ongoing process to update ADMIC Program rules based on feedback from horsemen.
To preserve fairness in the adjudication of all reported positive test results, HIWU has lifted the provisional suspensions and will be withdrawing the Equine Anti-Doping Charge letters from trainers Guadalupe Munoz Elizondo and Javier Morzan due to their horses testing positive for Metformin at levels in blood that would not have been reported as adverse analytical findings under the updated limit of detection.
All laboratories contracted with HIWU to test samples in the United States are accredited by the Racing Medication & Testing Consortium. The HISA Equine Analytical Laboratory Accreditation standards are currently in development, and HIWU expects the transition to continue through 2024.
Presently, there are efforts to harmonize testing sensitivity across the laboratories through an external quality assurance program that includes single- and double-blind quality assurance samples and a passed sample exchange program. Additionally, substances will continue to be reviewed on a case-by-case basis to ensure that all laboratories contracted by HIWU report uniform results for the same substances present at the same levels in different samples.
The review of and the update to Metformin’s limit of detection in blood represents progress from previous state-based regulatory structures in which laboratories historically operated independently of each other, resulting in substances being controlled differently depending on the laboratory conducting the testing. HISA’s national structure enables HIWU to oversee testing across much of the country and facilitate uniform enforcement of the ADMC rules. HIWU is committed to harmonizing its laboratories and continues to work with them to reach this goal.
This press release has been edited for content and style by BloodHorse Staff.
