The case of Maria Luisa Calle Williams, a Colombian track cyclist, revolves around her disqualification from the 2004 Athens Olympics after testing positive for Heptaminol, a substance not explicitly listed on the World Anti-Doping Agency (WADA) Prohibited List but considered prohibited due to its similarity to listed stimulants. Williams admitted to taking Neo-Saldina, a medication containing Isometheptene, prescribed for migraines. The International Olympic Committee (IOC) Disciplinary Commission revoked her bronze medal, prompting Williams to appeal to the Court of Arbitration for Sport (CAS). The central dispute was whether Isometheptene and its metabolite Heptaminol had "a similar chemical structure or pharmacological effects" to prohibited substances. Expert testimony was divided: Prof. Don H. Catlin supported the IOC's stance, while Dr. Martial Saugy contested it, arguing Isometheptene lacked sufficient similarity to listed stimulants.
The CAS panel reopened proceedings to evaluate new evidence, emphasizing that for a substance to be prohibited under the WADA Code, it must meet at least two of three criteria: potential performance enhancement, health risk, or violation of the spirit of sport. The case highlighted the need for anti-doping agencies to clearly specify which listed substance a disputed substance resembles, rather than broadly categorizing it. The panel also ruled that WADA's classification of a substance as "similar" could be challenged, stressing the importance of expert consensus and procedural fairness.
The IOC and WADA argued Isometheptene was pharmacologically similar to prohibited stimulants like amphetamine, but the panel found their evidence insufficient. Dr. Saugy’s testimony, which highlighted Isometheptene’s primary use for migraines and lack of stimulant effects, carried significant weight. The panel noted the absence of clear performance-enhancing evidence and the high dosage required for any theoretical effect. Additionally, it referenced past removals of substances like Pseudoephedrine from the prohibited list due to minimal performance benefits.
Ultimately, the panel concluded the IOC failed to prove Isometheptene was prohibited under the WADA Code, as it did not meet the required criteria. The majority decision underscored the need for precise scientific evidence and transparency in anti-doping regulations. Williams’ appeal was successful, her disqualification was overturned, and her bronze medal was reinstated. The case set a precedent for evaluating substances not explicitly banned but contested for their similarity to prohibited ones, emphasizing the importance of clarity and fairness in anti-doping proceedings.