mCPP is formed from trazodone by CYP3A4 and is metabolized via hydroxylation by CYP2D6 (to a "para"-hydroxylated metabolite). It may contribute to the pharmacological actions of trazodone. mCPP levels are only 10% of those of trazodone during therapy with trazodone, but is nonetheless present at concentrations known to produce psychic and physical effects in humans when mCPP has been administered alone. In any case, the actions of trazodone, such as its serotonin antagonism, might partially overwhelm those of mCPP. As a consequence of the production of mCPP as a metabolite, patients administered trazodone may test positive on EMIT II urine tests for the presence of MDMA ("ecstasy").