RMTC issues critical withdrawal guidance for Controlled Therapeutic Substances

By: Thoroughbred Horsemen's Association

Posted: March 22, 2023

At the request of the Thoroughbred Horsemen’s Association and other industry organizations, the Racing Medication and Testing Consortium on March 20 issued critical withdrawal guidance for horsemen and veterinarians to better ensure compliance with the Horseracing Integrity and Safety Authority’s new schedule of Controlled Therapeutic Substances and protect against positive tests for routine therapeutic medication use in racing and training. The RMTC withdrawal guidance covers 21 controlled therapeutic substances, three non-steroidal anti-inflammatory drugs, four corticosteroids and clenbuterol.

The complete RMTC advisory is available here. (Note: The withdrawal guidance for phenylbutazone as listed in this document has been changed to 72 hours from 96 hours. The document is expected to be updated.)

Under the HISA statute, HISA is required to reconcile the new national program with international standards. While the industry in North America has been regulating medication administration through RMTC-recommended withdrawal time guidance, which employs a safety factor in addition to detection times, the international program utilizes detection times and restricted administration times only and provides no withdrawal guidance. Responding to concerns expressed by horsemen and veterinarians to us that the change to international standards without withdrawal guidance was not in the best interests of racing, the RMTC and its Scientific Advisory Committee agreed and developed the new guidance.

HORSEMEN AND VETERINARIANS SHOULD NOT RELY ON HISA’S PUBLISHED DETECTION TIMES AS THEY DO NOT CONTAIN A SAFETY FACTOR AND THERE IS A RISK OF A POSITIVE TEST. WHILE NOT A GUARANTEE OF REGULATORY COMPLIANCE, WE URGE ADHERENCE TO THE NEW RMTC WITHDRAWAL GUIDANCE TO AVOID A POSITIVE TEST.

The THA has developed a Quick Reference Guild to assist trainers in complying with the new rules. It is available here. The materials also will be distributed via email and will be available on the backstretch and in the THA and Racing Offices at our affiliate racetracks.

The RMTC also released the following information explaining the terms associated with controlled substances and the HIWU drug-testing program.

SCREENING LIMIT: Considered the decision limit used by the laboratories. If initial testing finds a concentration of a  substance in a sample that is below the screening limit, the laboratory will not pursue the possible presence of a prohibited substance. If initial testing finds a concentration of a substance to be above the screening limit, the laboratory will pursue confirmatory analysis to solidify the positive finding.

LIMIT OF DETECTION: The lowest concentration of a substance that can be identified by the laboratory.

RESTRICTED ADMINISTRATION TIME: A specified interval prior to a race during which the administration of a substance(s) is prohibited. Restricted administration times can be enforced by surveillance, review of medical records, and drug testing.

DETECTION TIME: The first time point after administration of a substance that all test horses in an administration study are at a concentration below the limit of detection or defined screening limit in a specific matrix–serum, plasma, urine, or hair. Detection times are not equivalent to withdrawal times.

WITHDRAWAL TIME: A recommendation as to the minimum interval between administration of a single medication–including specific dosage, route of administration, and treatment schedule–and a race or timed workout. Withdrawal time provides a margin of safety added to a detection time to help guide treatment decisions and avoid an adverse finding.