The athlete claims to have taken a medicine prescribed for his wife by accident.
Onana currently plays for the Dutch team Ajax.

The Anti-Doping Database has registered eight cases involving Furosemide. Brazil has the most cases with three registered in the database.
We have also registered 370 cases involving Furosemide. Most cases in Wrestling (58), Bodybuilding (44) and Boxing (34).
In the Anti-Doping Database we have registered 314 cases involving doping in soccer. Italy has the most cases with 31. Nandrolone is the most commonly used substance with 43 followed by Cocaine (32).