Practical Efficacy of Prior Checks on Athletes' Medication Use for the Prevention of Unintentional Doping.

<i>Background</i>: Athletes are subjected to disciplinary action for even unintentional doping. This study aimed to clarify the effectiveness of prior checks on athletes' drug regimens by medical personnel with knowledge of anti-doping to prevent unintentional doping. <i>Methods</i>: This is a retrospective evaluation of the inquiries to the Anti-Doping Committee by the Japan Table Tennis Association national team athletes and athlete support personnel between 2011 and 2019 regarding whether the drug in question was permitted and whether it contained any prohibited substance. Discrete evaluations were performed for ethical and over-the-counter drugs, in addition to the evaluation of all drugs. Additionally, we evaluated the drugs according to therapeutic category and World Anti-Doping Agency's classification. <i>Results</i>: Overall, 85/1238 (6.9%) ethical drugs, 49/259 (18.9%) over-the-counter drugs and 134/1497 (9.0%) total drugs were considered as not allowed for use. The proportion of over-the-counter drugs judged as not allowed for use was higher than that of ethical drugs (<i>p</i> &lt; 0.001). When tabulating the drugs not allowed for use in the therapeutic category, numerous prohibited substances were identified in adrenal hormone preparations, Kampo products, synthetic narcotics, antitussives, antihemorrhoidals, and bronchodilators among ethical drugs and in cold remedies, gastrointestinal drugs, and antitussives and expectorants among over-the-counter drugs. <i>Conclusions</i>: Of the ethical and over-the-counter drugs that elite athletes wanted to use, approximately 10% were not allowed because of the risk of unintentional doping. These results suggest that conducting prior checks of the athletes' drug regimens by medical personnel with anti-doping knowledge are effective measures to prevent unintentional doping.