The FIE web site now has the World Anti-Doping Agency (WADA) current list of prohibited substances and methods, along with relevant WADA anti-doping rules and relevant documents. Note that the updated list now includes cannabis and the "party pill" BZP.
The FIE site also includes details for "Therapeutic Use Expemtions" for athletes who are required for medical reasons to use a prohibited substance.
Go to the President's Corner and select the article "FIE Web Site - Current World Anti-Doping Agency Information". The article has instructions and link to the FIE web site.