Doping in equestrian sports: Meta-analysis to validate International Residue Limits for the tropane alkaloids atropine and scopolamine

摘要

The tropane alkaloids atropine and scopolamine are considered as substances relevant for doping in horses. Thus, they shall not be detectable in horses during competition. Both substances can enter the horse either due to intentional, illegitimate application or they can be accidentally ingested via Datura spp. contaminated feed. To facilitate the discrimination between these two causes for the presence of atropine or scopolamine in competition horses, the International Federation of Horseracing Authorities established International Residue Limits (IRLs) of 60 ng/ml urine respectively. These IRLs have not yet been independently validated. In this study, we performed a structured meta-analysis to scientifically validate these IRLs. Defined search and inclusion criteria were used to identify relevant studies, from which the usable data was extracted. The collected data was subsequently used to check which of the available methods for the determination of screening limits could be utilized, which was the case for one of the four usually applied methods. Using this method based on the available data, we concluded that the IRL for atropine has been set appropriately. In contrast, we could not confirm the IRL of scopolamine as scientifically valid.