Update on ADMC Cases and the Harmonization Among HIWU-Accredited Laboratories of Metformin’s Limit of Detection in Blood


As part of the ongoing process to update the Horseracing Integrity and Safety Authority’s (HISA) Anti-Doping and Medication Control (ADMC) Program rules based on feedback from horsemen, the Horseracing Integrity & Welfare Unit (HIWU) conducted an internal review of the Limit of Detection in blood for Metformin, a Banned Substance, at its six accredited laboratories. Following this review, which was conducted in collaboration with the laboratories, it was determined that not all applied the same Limit of Detection in analyzing samples for the presence of Metformin. HIWU has since met with all six laboratories to establish an updated, uniform Limit of Detection.

To preserve fairness in the adjudication of all reported Adverse Analytical Findings, i.e., 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 Covered 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 that the transition will 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 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 all testing across the country and facilitate uniform enforcement of the ADMC rules. HIWU is committed to the harmonization of its laboratories and continues to work with them to reach this goal.

Alexa Ravit, HIWU Director of Communications & Outreach
(816) 516-9572