Veterinary Medicines and Competition Animals: The Question of Medication Versus Doping Control

Abstract

In racing and other equine sports, it is possible to increase artificially both the physical capability and the presence of a competitive instinct, using drugs, such as anabolic steroids and agents stimulating the central nervous system. The word doping describes this illegitimate use of drugs and the primary motivation of an equine anti-doping policy is to prevent the use of these substances. However, an anti-doping policy must not impede the use of legitimate veterinary medications and most regulatory bodies in the world now distinguish the control of illicit substances (doping control) from the control of therapeutic substances (medication control). For doping drugs, the objective is to detect any trace of drug exposure (parent drug or metabolites) using the most powerful analytical methods (generally chromatographic/mass spectrometric techniques). This so-called "zero tolerance rule" is not suitable for medication control, because the high level of sensitivity of current screening methods allows the detection of totally irrelevant plasma or urine concentrations of legitimate drugs for long periods after their administration. Therefore, a new approach for these legitimate compounds, based upon pharmacokinetic/pharmacodynamic (PK/PD) principles, has been developed. It involves estimating the order of magnitude of the irrelevant plasma concentration (IPC) and of the irrelevant urine concentration (IUC) in order to limit the impact of the high sensitivity of analytical techniques used for medication control. The European Horserace Scientific Liaison Committee (EHSLC), which is the European scientific committee in charge of harmonising sample testing and policies for racehorses in Europe, is responsible for estimating the IPCs and IUCs in the framework of a Risk Analysis. A Risk Analysis approach for doping/medication control involves three sequential steps, namely risk assessment, risk management, and risk communication. For medication control, the main task of EHLSC in the risk management procedure is the establishment of harmonised screening limits (HSL). The HSL is a confidential instruction to laboratories from racing authorities to screen in plasma or urine for the presence of drugs commonly used in equine medication. The HSL is derived from the IPC (for plasma) or from the IUC (for urine), established during the risk assessment step. The EHSLC decided to keep HSL confidential and to inform stakeholders of the duration of the detection time (DT) of the main medications when screening is performed with the HSL. A DT is the time at which the urinary (or plasma) concentration of a drug, in all horses involved in a trial conducted according to the EHSLC guidance rules, is shown to be lower than the HSL when controls are performed using routine screening methods. These DTs, as issued by the EHSLC (and adopted by the Fédération Equestre Internationale or FEI) provide guidance to veterinarians enabling them to determine a withdrawal time (WT) for a given horse under treatment. A WT should always be longer than a DT...

Pharmacokinetics, metabolism and excretion of celecoxib, a selective cyclooxygenase‐2 inhibitor, in horses

“…Rules for controlling medication of animals in competitions are established based on the possibility to increase artificially both the physical capability and the presence of a competitive instinct, using drugs. However, an antidoping policy must not impede the use of legitimate therapeutic medications and most regulatory bodies in the world now distinguish the control of illicit substances (doping control) from the control of therapeutic substances (medication control; Toutain, ). This study indicates that the detection of celecoxib and its carboxy metabolite is key elements for celecoxib doping investigation in horses, due to prolonged elimination profile and considerably high detection concentration in urine and faeces.…”

Descripción del doping en el equino y evaluación en Chile.

“…Además, existe una variabilidad individual entres los caballos en relación a la farmacocinética de las drogas y la disposición de la droga en el plasma y la orina. Esta variabilidad se debe a factores tales como la raza, edad, sexo y peso (Toutain, 2010). Los tiempos de detección publicados proporcionan una información fidedigna y clara, aun así, existen limitantes ya que los estudios farmacocinéticos para evaluar los tiempos de detección de una sustancia han sido realizados en laboratorios bajo condiciones de reposo.…”

“…Según Toutain (2010), en la actualidad la mayoría de los controles se realizan utilizando orina, por otra parte, Wong & Wang (2014) afirman que dentro de los estudios deberían considerar el uso de la sangre ya que el uso de plasma como matriz para el control de la medicación es más eficaz en relación a la farmacocinética del medicamento. Este tipo de muestra es importante, ya que las concentraciones plasmáticas del medicamento sin metabolizarse son más altas.…”

“…El término doping se define principalmente como el uso ilegítimo de drogas que aumenten o disminuyan el rendimiento físico del competidor y hoy las principales políticas anti doping en equinos se basan estrictamente en evitar el uso de estas sustancias. En los deportes donde es sometida la especie equina existe una gran demanda física, por ello en algunas ocasiones existen personas que actúan fuera de las normas deportivas establecidas, promoviendo el uso de drogas para alterar o recomponer el rendimiento físico del equino (Toutain, 2010).…”

The role of veterinarians in equestrian sport: A comparative review of ethical issues surrounding human and equine sports medicine

“…Regulations in racing and other equine sports extend to the administration of therapeutic drugs and to drug-testing (Toutain, 2010), so that the responsibilities of veterinarians are clearly defined, and decisions about what constitutes ethical behaviour are consequently relatively simple to make. However, these responsibilities may be less well defined at low-level competitions.…”