Jame Irvin recently tasted defeat at the hands of Anderson Silva July 19th and subsequently tested positive for Methadone and Oxymorphone, both banned substances. He has 20 days to respond before disciplinary action is handed down.

Methadone is a substance that is usually given to heroin addicts, isn't considered as addictive (although there is a debate on that with a longer half-life and recovery period) and has recently become popular as a pain killer substitute for morphine and oxycodone.

Oxymorphone is another milder form of morphine and is used to treat pain symptoms. Although milder, Oxymorphone can still be habit forming.

Irvin's drug test was taken after the match and he is the only fighter on the card to test positive so far. In addition to Irvin, Anderson Silva, Tim Credeur, Cale Yarbrough, Hermes Franca, Frankie Edgar, Cain Velasquez, Brandon Vera, CB Dollaway, Nate Loughran and Shannon Gugerty were all tested for drugs of abuse and steroids.