Abstract for:Modeling the Pharmacodynamics of Doping Drugs and Analysis of False Negative Tests

In this study, a model for the pathways of nandrolone, an anabolic steroid, in body is constructed. Firstly, we generate the dynamics of nandrolone and its metabolites in the body. Secondly, we design different scenarios to see how nandrolone users can cheat in performance enhancing drug (PED) tests. PED tests for nandrolone check for the presence of 19-NA. Thus, in cheating the tests, PED users typically use inhibitors of 19-NA such as Finasteride, a drug primarily used to cure male balding and prostate growth. Actually, Finasteride does not have a direct effect on 19-NA; its main effect in the body is the inhibition of enzymes that turn nandrolone into its metabolite 19-NA. Accordingly, we include structures for Finasteride and reductase enzymes in the model. Injection Site, Finasteride in Blood, NA in Blood, NE in Blood and Reductase Enzymes are the key variables that we are interested in. The model structure is tested by essential structure validity tests. We also show that the model is consistent with the data in the literature. We test different ways of cheating the PED tests using scenario analyses with Finasteride. We also present some suggestions for World Anti-Doping Agency.